plcore.c

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//      Central dispatch facility for PLplot.
//      Also contains the PLplot main data structures, external access
//      routines, and initialization calls.
//
//      This stuff used to be in "dispatch.h", "dispatch.c", and "base.c".
//
//
// Copyright (C) 2004  Joao Cardoso
// Copyright (C) 2004, 2005  Rafael Laboissiere
// Copyright (C) 2004, 2006  Andrew Ross
// Copyright (C) 2004  Andrew Roach
// Copyright (C) 2005-2016 Alan W. Irwin
// Copyright (C) 2005  Thomas J. Duck
//
// This file is part of PLplot.
//
// PLplot is free software; you can redistribute it and/or modify
// it under the terms of the GNU Library General Public License as published
// by the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// PLplot is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public License
// along with PLplot; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
//
//

#define DEBUG
#define NEED_PLDEBUG
#include "plcore.h"

#ifdef ENABLE_DYNDRIVERS
  #ifndef LTDL_WIN32
    #include <ltdl.h>
  #else
    #include "ltdl_win32.h"
  #endif
#endif

#if HAVE_DIRENT_H
// The following conditional is a workaround for a bug in the MacOSX system.
// When  the dirent.h file will be fixed upstream by Apple Inc, this should
// go away.
# ifdef NEED_SYS_TYPE_H
#  include <sys/types.h>
# endif
# include <dirent.h>
# define NAMLEN( dirent )    strlen( ( dirent )->d_name )
#else
# if defined ( _MSC_VER )
#  include "dirent_msvc.h"
# else
#  define dirent    direct
#  define NAMLEN( dirent )    ( dirent )->d_namlen
#  if HAVE_SYS_NDIR_H
#   include <sys/ndir.h>
#  endif
#  if HAVE_SYS_DIR_H
#   include <sys/dir.h>
#  endif
#  if HAVE_NDIR_H
#   include <ndir.h>
#  endif
# endif
#endif

// AM: getcwd has a somewhat strange status on Windows, its proper
// name is _getcwd, this is a problem in the case of DLLs, like with
// the Java bindings. The functions _getcwd() and chdir() are
// declared in direct.h for Visual C++. Since chdir() is deprecated
// (but still available) in Visual C++ we redefine chdir to _chdir.
//
#if defined ( _MSC_VER )
#  include <direct.h>
#  define getcwd        _getcwd
#  define chdir         _chdir
#endif

#define BUFFER_SIZE     80
#define BUFFER2_SIZE    300
#define DRVSPEC_SIZE    400

#include <errno.h>

int
text2num( PLCHAR_VECTOR text, char end, PLUNICODE *num );

int
text2fci( PLCHAR_VECTOR text, unsigned char *hexdigit, unsigned char *hexpower );

//--------------------------------------------------------------------------
// Driver Interface
//
// These routines are the low-level interface to the driver -- all calls to
// driver functions must pass through here.  For implementing driver-
// specific functions, the escape function is provided.  The command stream
// gets duplicated to the plot buffer here.
//
// All functions that result in graphics actually being plotted (rather than
// just a change of state) are filtered as necessary before being passed on.
// The default settings do not require any filtering, i.e.  PLplot physical
// coordinates are the same as the device physical coordinates (currently
// this can't be changed anyway), and a global view equal to the entire page
// is used.
//
// The reason one wants to put view-specific filtering here is that if
// enabled, the plot buffer should receive the unfiltered data stream.  This
// allows a specific view to be used from an interactive device (e.g. TCL/TK
// driver) but be restored to the full view at any time merely by
// reprocessing the contents of the plot buffer.
//
// The metafile, on the other hand, *should* be affected by changes in the
// view, since this is a crucial editing capability.  It is recommended that
// the initial metafile be created without a restricted global view, and
// modification of the view done on a per-plot basis as desired during
// subsequent processing.
//
//--------------------------------------------------------------------------

enum { AT_BOP, DRAWING, AT_EOP };

// Initialize device.
// The plot buffer must be called last.

// The following array of chars is used both here and in plsym.c for
// translating the Greek characters from the #g escape sequences into
// the Hershey and Unicode codings
//
const char plP_greek_mnemonic[] = "ABGDEZYHIKLMNCOPRSTUFXQWabgdezyhiklmncoprstufxqw";

void
plP_init( void )
{
    char * save_locale;
    plsc->page_status   = AT_EOP;
    plsc->stream_closed = FALSE;

    save_locale = plsave_set_locale();
    ( *plsc->dispatch_table->pl_init )( (struct PLStream_struct *) plsc );
    plrestore_locale( save_locale );

    if ( plsc->plbuf_write )
        plbuf_init( plsc );
}

// End of page
// The plot buffer must be called first.
// Ignore instruction if already at eop.

void
plP_eop( void )
{
    int skip_driver_eop = 0;

    if ( plsc->page_status == AT_EOP )
        return;

    plsc->page_status = AT_EOP;

    if ( plsc->plbuf_write )
        plbuf_eop( plsc );

// Call user eop handler if present.

    if ( plsc->eop_handler != NULL )
        ( *plsc->eop_handler )( plsc->eop_data, &skip_driver_eop );

    if ( !skip_driver_eop )
    {
        char *save_locale = plsave_set_locale();
        if ( !plsc->stream_closed )
        {
            ( *plsc->dispatch_table->pl_eop )( (struct PLStream_struct *) plsc );
        }
        plrestore_locale( save_locale );
    }
}

// Set up new page.
// The plot buffer must be called last.
// Ignore if already at bop.
// It's not actually necessary to be AT_EOP here, so don't check for it.

void
plP_bop( void )
{
    int skip_driver_bop = 0;

    plP_subpInit();
    if ( plsc->page_status == AT_BOP )
        return;

    plsc->page_status = AT_BOP;
    plsc->nplwin      = 0;

// Call user bop handler if present.

    if ( plsc->bop_handler != NULL )
        ( *plsc->bop_handler )( plsc->bop_data, &skip_driver_bop );

    if ( !skip_driver_bop )
    {
        char *save_locale = plsave_set_locale();
        if ( !plsc->stream_closed )
        {
            ( *plsc->dispatch_table->pl_bop )( (struct PLStream_struct *) plsc );
        }
        plrestore_locale( save_locale );
    }

    if ( plsc->plbuf_write )
        plbuf_bop( plsc );
}

// Tidy up device (flush buffers, close file, etc).

void
plP_tidy( void )
{
    char * save_locale;
    if ( plsc->tidy )
    {
        ( *plsc->tidy )( plsc->tidy_data );
        plsc->tidy      = NULL;
        plsc->tidy_data = NULL;
    }

    save_locale = plsave_set_locale();
    ( *plsc->dispatch_table->pl_tidy )( (struct PLStream_struct *) plsc );
    plrestore_locale( save_locale );

    if ( plsc->plbuf_write )
    {
        plbuf_tidy( plsc );
    }

    plsc->OutFile = NULL;
}

// Change state.

void
plP_state( PLINT op )
{
    char * save_locale;
    if ( plsc->plbuf_write )
        plbuf_state( plsc, op );

    save_locale = plsave_set_locale();
    if ( !plsc->stream_closed )
    {
        ( *plsc->dispatch_table->pl_state )( (struct PLStream_struct *) plsc, op );
    }
    plrestore_locale( save_locale );
}

// Escape function, for driver-specific commands.

void
plP_esc( PLINT op, void *ptr )
{
    char   * save_locale;
    PLINT  clpxmi, clpxma, clpymi, clpyma;
    EscText* args;

    // The plot buffer must be called first
    if ( plsc->plbuf_write )
        plbuf_esc( plsc, op, ptr );

    // Text coordinates must pass through the driver interface filter
    if ( ( op == PLESC_HAS_TEXT && plsc->dev_unicode ) ||
         ( op == PLESC_END_TEXT && plsc->alt_unicode ) )
    {
        // Apply the driver interface filter
        if ( plsc->difilt )
        {
            args = (EscText *) ptr;
            difilt( &( args->x ), &( args->y ), 1, &clpxmi, &clpxma, &clpymi, &clpyma );
        }
    }

    save_locale = plsave_set_locale();
    if ( !plsc->stream_closed )
    {
        ( *plsc->dispatch_table->pl_esc )( (struct PLStream_struct *) plsc, op, ptr );
    }
    plrestore_locale( save_locale );
}

// Set up plot window parameters.
// The plot buffer must be called first
// Some drivers (metafile, Tk) need access to this data

void
plP_swin( PLWindow *plwin )
{
    PLWindow *w;
    PLINT    clpxmi, clpxma, clpymi, clpyma;

// Provide plot buffer with unfiltered window data

    if ( plsc->plbuf_write )
        plbuf_esc( plsc, PLESC_SWIN, (void *) plwin );

    w = &plsc->plwin[plsc->nplwin++ % PL_MAXWINDOWS];

    w->dxmi = plwin->dxmi;
    w->dxma = plwin->dxma;
    w->dymi = plwin->dymi;
    w->dyma = plwin->dyma;

    if ( plsc->difilt )
    {
        xscl[0] = plP_dcpcx( w->dxmi );
        xscl[1] = plP_dcpcx( w->dxma );
        yscl[0] = plP_dcpcy( w->dymi );
        yscl[1] = plP_dcpcy( w->dyma );

        difilt( xscl, yscl, 2, &clpxmi, &clpxma, &clpymi, &clpyma );

        w->dxmi = plP_pcdcx( xscl[0] );
        w->dxma = plP_pcdcx( xscl[1] );
        w->dymi = plP_pcdcy( yscl[0] );
        w->dyma = plP_pcdcy( yscl[1] );
    }

    w->wxmi = plwin->wxmi;
    w->wxma = plwin->wxma;
    w->wymi = plwin->wymi;
    w->wyma = plwin->wyma;

// If the driver wants to process swin commands, call it now
// It must use the filtered data, which it can get from *plsc

    if ( plsc->dev_swin )
    {
        char *save_locale = plsave_set_locale();
        if ( !plsc->stream_closed )
        {
            ( *plsc->dispatch_table->pl_esc )( (struct PLStream_struct *) plsc,
                PLESC_SWIN, NULL );
        }
        plrestore_locale( save_locale );
    }
}

// Calls the device specific wait for user input function.  This
// action depends on the state of the nopause flag and whether
// user input is supported by the driver.

void
plP_wait( void )
{
    // If the nopause is disabled (which means pauses are wanted) and the
    // the device supports waiting for user input
    if ( !plsc->nopause && *plsc->dispatch_table->pl_wait != NULL )
    {
        char *save_locale = plsave_set_locale();
        if ( !plsc->stream_closed )
        {
            ( *plsc->dispatch_table->pl_wait )( (struct PLStream_struct *) plsc );
        }
        plrestore_locale( save_locale );
    }
}

//--------------------------------------------------------------------------
//  Drawing commands.
//--------------------------------------------------------------------------

// Draw line between two points
// The plot buffer must be called first so it gets the unfiltered data

void
plP_line( short *x, short *y )
{
    PLINT i, npts = 2, clpxmi, clpxma, clpymi, clpyma;

    plsc->page_status = DRAWING;

    if ( plsc->plbuf_write )
        plbuf_line( plsc, x[0], y[0], x[1], y[1] );

    if ( plsc->difilt )
    {
        for ( i = 0; i < npts; i++ )
        {
            xscl[i] = x[i];
            yscl[i] = y[i];
        }
        difilt( xscl, yscl, npts, &clpxmi, &clpxma, &clpymi, &clpyma );
        plP_pllclp( xscl, yscl, npts, clpxmi, clpxma, clpymi, clpyma, grline );
    }
    else
    {
        grline( x, y, npts );
    }
}

// Draw polyline
// The plot buffer must be called first

void
plP_polyline( short *x, short *y, PLINT npts )
{
    PLINT i, clpxmi, clpxma, clpymi, clpyma;

    plsc->page_status = DRAWING;

    if ( plsc->plbuf_write )
        plbuf_polyline( plsc, x, y, npts );

    if ( plsc->difilt )
    {
        for ( i = 0; i < npts; i++ )
        {
            xscl[i] = x[i];
            yscl[i] = y[i];
        }
        difilt( xscl, yscl, npts, &clpxmi, &clpxma, &clpymi, &clpyma );
        plP_pllclp( xscl, yscl, npts, clpxmi, clpxma, clpymi, clpyma,
            grpolyline );
    }
    else
    {
        grpolyline( x, y, npts );
    }
}

// Fill polygon
// The plot buffer must be called first
// Here if the desired area fill capability isn't present, we mock up
// something in software

static int foo;

void
plP_fill( short *x, short *y, PLINT npts )
{
    PLINT i, clpxmi, clpxma, clpymi, clpyma;

    plsc->page_status = DRAWING;

    if ( plsc->plbuf_write )
    {
        plsc->dev_npts = npts;
        plsc->dev_x    = x;
        plsc->dev_y    = y;
        plbuf_esc( plsc, PLESC_FILL, NULL );
    }

// Account for driver ability to do fills

    if ( plsc->patt == 0 && !plsc->dev_fill0 )
    {
        if ( !foo )
        {
            plwarn( "Driver does not support hardware solid fills, switching to software fill.\n" );
            foo = 1;
        }
        plsc->patt = 8;
        plpsty( plsc->patt );
    }
    if ( plsc->dev_fill1 )
    {
        plsc->patt = -ABS( plsc->patt );
    }

// Perform fill.  Here we MUST NOT allow the software fill to pass through the
// driver interface filtering twice, else we get the infamous 2*rotation for
// software fills on orientation swaps.
//

    if ( plsc->patt > 0 )
        plfill_soft( x, y, npts );

    else
    {
        if ( plsc->difilt )
        {
            for ( i = 0; i < npts; i++ )
            {
                xscl[i] = x[i];
                yscl[i] = y[i];
            }
            difilt( xscl, yscl, npts, &clpxmi, &clpxma, &clpymi, &clpyma );
            plP_plfclp( xscl, yscl, npts, clpxmi, clpxma, clpymi, clpyma,
                grfill );
        }
        else
        {
            grfill( x, y, npts );
        }
    }
}

// Render a gradient
// The plot buffer must be called first
// N.B. plP_gradient is never called (see plgradient) unless the
// device driver has set plsc->dev_gradient to true.

void
plP_gradient( short *x, short *y, PLINT npts )
{
    PLINT i, clpxmi, clpxma, clpymi, clpyma;

    plsc->page_status = DRAWING;

    if ( plsc->plbuf_write )
    {
        plsc->dev_npts = npts;
        plsc->dev_x    = x;
        plsc->dev_y    = y;
        plbuf_esc( plsc, PLESC_GRADIENT, NULL );
    }

    // Render gradient with driver.
    if ( plsc->difilt )
    {
        for ( i = 0; i < npts; i++ )
        {
            xscl[i] = x[i];
            yscl[i] = y[i];
        }
        difilt( xscl, yscl, npts, &clpxmi, &clpxma, &clpymi, &clpyma );
        plP_plfclp( xscl, yscl, npts, clpxmi, clpxma, clpymi, clpyma,
            grgradient );
    }
    else
    {
        grgradient( x, y, npts );
    }
}

// Account for driver ability to draw text itself
//
// #define DEBUG_TEXT
//

//--------------------------------------------------------------------------
//  int text2num( char *text, char end, PLUNICODE *num)
//       char *text - pointer to the text to be parsed
//       char end   - end character (i.e. ')' or ']' to stop parsing
//       PLUNICODE *num - pointer to an PLUNICODE to store the value
//
//    Function takes a string, which can be either hex or decimal,
//    and converts it into an PLUNICODE, stopping at either a null,
//    or the character pointed to by 'end'. This implementation using
//    the C library strtoul replaces the original brain-dead version
//    and should be more robust to invalid control strings.
//--------------------------------------------------------------------------

int text2num( PLCHAR_VECTOR text, char end, PLUNICODE *num )
{
    char *endptr;
    // This special base logic required to _avoid_ interpretation of
    // numbers with leading zeroes as octal numbers if base = 0.
    int base = 10;
    if ( !strncmp( text, "0x", 2 ) || !strncmp( text, "0X", 2 ) )
        base = 16;

    *num = (PLUNICODE) strtoul( text, &endptr, base );

    if ( end != endptr[0] )
    {
        char msgbuf[BUFFER2_SIZE];
        snprintf( msgbuf, BUFFER2_SIZE, "text2num: for base = %d, strtoul found invalid non-numeric character \"%c\" detected in string \"%s\" when looking for \"%c\" ", base, *endptr, text, end );
        plwarn( msgbuf );
    }

    return (int) ( endptr - text );
}

//--------------------------------------------------------------------------
//  int text2fci( char *text, unsigned char *hexdigit, unsigned char *hexpower)
//       char *text - pointer to the text to be parsed
//       unsigned char *hexdigit - pointer to hex value that is stored.
//       unsigned char *hexpower - pointer to hex power (left shift) that is stored.
//
//    Function takes a pointer to a string, which is looked up in a table
//    to determine the corresponding FCI (font characterization integer)
//    hex digit value and hex power (left shift).  All matched strings
//    start with "<" and end with the two characters "/>".
//    If the lookup succeeds, hexdigit and hexpower are set to the appropriate
//    values in the table, and the function returns the number of characters
//    in text that are consumed by the matching string in the table lookup.
//
//    If the lookup fails, hexdigit is set to 0, hexpower is set to and
//    impossible value, and the function returns 0.
//--------------------------------------------------------------------------

int text2fci( PLCHAR_VECTOR text, unsigned char *hexdigit, unsigned char *hexpower )
{
    typedef struct
    {
        PLCHAR_VECTOR ptext;
        unsigned char hexdigit;
        unsigned char hexpower;
    }
    TextLookupTable;
    // This defines the various font control commands and the corresponding
    // hexdigit and hexpower in the FCI.
    //
#define N_TextLookupTable    10
    const TextLookupTable lookup[N_TextLookupTable] = {
        { "<sans-serif/>", PL_FCI_SANS,    PL_FCI_FAMILY },
        { "<serif/>",      PL_FCI_SERIF,   PL_FCI_FAMILY },
        { "<monospace/>",  PL_FCI_MONO,    PL_FCI_FAMILY },
        { "<script/>",     PL_FCI_SCRIPT,  PL_FCI_FAMILY },
        { "<symbol/>",     PL_FCI_SYMBOL,  PL_FCI_FAMILY },
        { "<upright/>",    PL_FCI_UPRIGHT, PL_FCI_STYLE  },
        { "<italic/>",     PL_FCI_ITALIC,  PL_FCI_STYLE  },
        { "<oblique/>",    PL_FCI_OBLIQUE, PL_FCI_STYLE  },
        { "<medium/>",     PL_FCI_MEDIUM,  PL_FCI_WEIGHT },
        { "<bold/>",       PL_FCI_BOLD,    PL_FCI_WEIGHT }
    };
    int i, length;
    for ( i = 0; i < N_TextLookupTable; i++ )
    {
        length = (int) strlen( lookup[i].ptext );
        if ( !strncmp( text, lookup[i].ptext, (size_t) length ) )
        {
            *hexdigit = lookup[i].hexdigit;
            *hexpower = lookup[i].hexpower;
            return ( length );
        }
    }
    *hexdigit = 0;
    *hexpower = PL_FCI_HEXPOWER_IMPOSSIBLE;
    return ( 0 );
}

static
void alternate_unicode_processing( PLCHAR_VECTOR string, EscText * args )
{
    size_t        i, len;
    char          esc;
    unsigned char hexdigit, hexpower;
    PLUNICODE     fci;
    PLUNICODE     orig_fci;
    PLINT         ig;
    int           skip;
    PLUNICODE     code;
    int           idx = -1;

    // Initialize to an empty string
    args->unicode_array_len = 0;

    len = strlen( string );

    // If the string is empty, return now
    if ( len == 0 )
        return;

    // Get the current escape character
    plgesc( &esc );

    // Obtain FCI (font characterization integer) for start of string.
    plgfci( &fci );
    orig_fci = fci;

    // Signal the begin of text processing to the driver
    args->n_fci = fci;
    plP_esc( PLESC_BEGIN_TEXT, args );

    for ( i = 0; i < len; i++ )
    {
        skip = 0;

        if ( string[i] == esc )
        {
            switch ( string[i + 1] )
            {
            case '(': // hershey code
                i           += 2 + text2num( &string[i + 2], ')', &code );
                idx          = plhershey2unicode( (int) code );
                args->n_char =
                    (PLUNICODE) hershey_to_unicode_lookup_table[idx].Unicode;
                plP_esc( PLESC_TEXT_CHAR, args );

                skip = 1;
                break;

            case '[': // unicode
                i           += 2 + text2num( &string[i + 2], ']', &code );
                args->n_char = code;
                plP_esc( PLESC_TEXT_CHAR, args );
                skip = 1;
                break;

            case '<': // change font
                if ( '0' <= string[i + 2] && string[i + 2] <= '9' )
                {
                    i += 2 + text2num( &string[i + 2], '>', &code );
                    if ( code & PL_FCI_MARK )
                    {
                        // code is a complete FCI (font characterization
                        // integer): change FCI to this value.
                        //
                        fci  = code;
                        skip = 1;

                        args->n_fci       = fci;
                        args->n_ctrl_char = PLTEXT_FONTCHANGE;
                        plP_esc( PLESC_CONTROL_CHAR, args );
                    }
                    else
                    {
                        // code is not complete FCI. Change
                        // FCI with hex power in rightmost hex
                        // digit and hex digit value in second rightmost
                        // hex digit.
                        //
                        hexdigit = ( code >> 4 ) & PL_FCI_HEXDIGIT_MASK;
                        hexpower = code & PL_FCI_HEXPOWER_MASK;
                        plP_hex2fci( hexdigit, hexpower, &fci );
                        skip = 1;

                        args->n_fci       = fci;
                        args->n_ctrl_char = PLTEXT_FONTCHANGE;
                        plP_esc( PLESC_CONTROL_CHAR, args );
                    }
                }
                else
                {
                    i += text2fci( &string[i + 1], &hexdigit, &hexpower );
                    if ( hexpower < 7 )
                    {
                        plP_hex2fci( hexdigit, hexpower, &fci );
                        skip = 1;

                        args->n_fci       = fci;
                        args->n_ctrl_char = PLTEXT_FONTCHANGE;
                        plP_esc( PLESC_CONTROL_CHAR, args );
                    }
                }
                break;

            case 'f': // Deprecated Hershey-style font change
            case 'F': // Deprecated Hershey-style font change
                // We implement an approximate response here so that
                // reasonable results are obtained for unicode fonts,
                // but this method is deprecated and the #<nnn> or
                // #<command string> methods should be used instead
                // to change unicode fonts in mid-string.
                //
                fci = PL_FCI_MARK;
                if ( string[i + 2] == 'n' )
                {
                    // medium, upright, sans-serif
                    plP_hex2fci( PL_FCI_SANS, PL_FCI_FAMILY, &fci );
                }
                else if ( string[i + 2] == 'r' )
                {
                    // medium, upright, serif
                    plP_hex2fci( PL_FCI_SERIF, PL_FCI_FAMILY, &fci );
                }
                else if ( string[i + 2] == 'i' )
                {
                    // medium, italic, serif
                    plP_hex2fci( PL_FCI_ITALIC, PL_FCI_STYLE, &fci );
                    plP_hex2fci( PL_FCI_SERIF, PL_FCI_FAMILY, &fci );
                }
                else if ( string[i + 2] == 's' )
                {
                    // medium, upright, script
                    plP_hex2fci( PL_FCI_SCRIPT, PL_FCI_FAMILY, &fci );
                }
                else
                    fci = PL_FCI_IMPOSSIBLE;

                if ( fci != PL_FCI_IMPOSSIBLE )
                {
                    i   += 2;
                    skip = 1;

                    args->n_fci       = fci;
                    args->n_ctrl_char = PLTEXT_FONTCHANGE;
                    plP_esc( PLESC_CONTROL_CHAR, args );
                }
                break;

            case 'g': // Greek font
            case 'G': // Greek font
                // Get the index in the lookup table
                // 527 = upper case alpha displacement in Hershey Table
                // 627 = lower case alpha displacement in Hershey Table
                //
                ig = plP_strpos( plP_greek_mnemonic, string[i + 2] );
                if ( ig >= 0 )
                {
                    if ( ig >= 24 )
                        ig = ig + 100 - 24;
                    ig = ig + 527;
                    // Follow pldeco in plsym.c which for
                    // lower case epsilon, theta, and phi
                    // substitutes (684, 685, and 686) for
                    // (631, 634, and 647)
                    if ( ig == 631 )
                        ig = 684;
                    else if ( ig == 634 )
                        ig = 685;
                    else if ( ig == 647 )
                        ig = 686;
                    idx  = plhershey2unicode( ig );
                    i   += 2;
                    skip = 1; // skip is set if we have copied something
                              // into the unicode table

                    args->n_char =
                        (PLUNICODE) hershey_to_unicode_lookup_table[idx].Unicode;
                    plP_esc( PLESC_TEXT_CHAR, args );
                }
                else
                {
                    // Use "unknown" unicode character if string[i+2]
                    // is not in the Greek array.
                    i   += 2;
                    skip = 1;    // skip is set if we have copied something
                                 // into the unicode table

                    args->n_char =
                        (PLUNICODE) hershey_to_unicode_lookup_table[idx].Unicode;
                    plP_esc( PLESC_TEXT_CHAR, args );
                }
                break;

            case 'u':
                args->n_ctrl_char = PLTEXT_SUPERSCRIPT;
                plP_esc( PLESC_CONTROL_CHAR, args );
                i   += 1;
                skip = 1;
                break;

            case 'd':
                args->n_ctrl_char = PLTEXT_SUBSCRIPT;
                plP_esc( PLESC_CONTROL_CHAR, args );
                i   += 1;
                skip = 1;
                break;
            case 'b':
                args->n_ctrl_char = PLTEXT_BACKCHAR;
                plP_esc( PLESC_CONTROL_CHAR, args );
                i   += 1;
                skip = 1;
                break;
            case '+':
                args->n_ctrl_char = PLTEXT_OVERLINE;
                plP_esc( PLESC_CONTROL_CHAR, args );
                i   += 1;
                skip = 1;
                break;
            case '-':
                args->n_ctrl_char = PLTEXT_UNDERLINE;
                plP_esc( PLESC_CONTROL_CHAR, args );
                i   += 1;
                skip = 1;
                break;
            }
        }

        if ( skip == 0 )
        {
            PLUNICODE     unichar = 0;
#ifdef HAVE_LIBUNICODE
            PLCHAR_VECTOR ptr = unicode_get_utf8( string + i, &unichar );
#else
            PLCHAR_VECTOR ptr = utf8_to_ucs4( string + i, &unichar );
#endif
            if ( ptr == NULL )
            {
                char buf[BUFFER_SIZE];
                char tmpstring[31];
                strncpy( tmpstring, string, 30 );
                tmpstring[30] = '\0';
                snprintf( buf, BUFFER_SIZE, "UTF-8 string is malformed: %s%s",
                    tmpstring, strlen( string ) > 30 ? "[...]" : "" );
                plabort( buf );
                return;
            }
            i += (int) ( ptr - ( string + i ) - 1 );

            // Search for escesc (an unescaped escape) in the input
            // string and adjust unicode_buffer accordingly).
            //
            if ( string[i] == esc && string[i + 1] == esc )
            {
                i++;
                args->n_char = (PLUNICODE) esc;
            }
            else
            {
                args->n_char = unichar;
            }
            plP_esc( PLESC_TEXT_CHAR, args );
        }
    }

    // Signal the end of text string processing to the driver
    plP_esc( PLESC_END_TEXT, args );
}

static
void encode_unicode( PLCHAR_VECTOR string, EscText *args )
{
    char          esc;
    PLINT         ig;
    PLUNICODE     fci;
    PLUNICODE     orig_fci;
    unsigned char hexdigit, hexpower;
    size_t        i, j, len;
    int           skip;
    PLUNICODE     code;
    int           idx = -1;

    // Initialize to an empty string
    args->unicode_array_len = 0;

    // this length is only used in the loop
    // counter, we will work out the length of
    // the unicode string as we go
    len = strlen( string );

    // If the string is empty, return now
    if ( len == 0 )
        return;

    // Get the current escape character
    plgesc( &esc );

    // At this stage we will do some translations into unicode, like
    // conversion to Greek , and will save other translations such as
    // superscript for the driver to do later on. As we move through
    // the string and do the translations, we will get
    // rid of the esc character sequence, just replacing it with
    // unicode.
    //

    // Obtain FCI (font characterization integer) for start of string.
    plgfci( &fci );
    orig_fci = fci;

    // Walk through the string, and convert some stuff to unicode on the fly
    for ( j = i = 0; i < len; i++ )
    {
        skip = 0;

        if ( string[i] == esc )
        {
            // We have an escape character, so we need to look at the
            // next character to determine what action needs to be taken
            switch ( string[i + 1] )
            {
            case '(': // hershey code
                i  += ( 2 + text2num( &string[i + 2], ')', &code ) );
                idx = plhershey2unicode( (int) code );
                args->unicode_array[j++] =
                    (PLUNICODE) hershey_to_unicode_lookup_table[idx].Unicode;

                // if unicode_buffer[j-1] corresponds to the escape
                // character must unescape it by appending one more.
                // This will probably always be necessary since it is
                // likely unicode_buffer will always have to contain
                // escape characters that are interpreted by the device
                // driver.
                //
                if ( args->unicode_array[j - 1] == (PLUNICODE) esc )
                    args->unicode_array[j++] = (PLUNICODE) esc;
                j--;
                skip = 1;
                break;

            case '[': // unicode
                i += ( 2 + text2num( &string[i + 2], ']', &code ) );
                args->unicode_array[j++] = code;

                // if unicode_buffer[j-1] corresponds to the escape
                // character must unescape it by appending one more.
                // This will probably always be necessary since it is
                // likely unicode_buffer will always have to contain
                // escape characters that are interpreted by the device
                // driver.
                //
                if ( args->unicode_array[j - 1] == (PLUNICODE) esc )
                    args->unicode_array[j++] = (PLUNICODE) esc;
                j--;
                skip = 1;
                break;

            case '<': // change font
                if ( '0' <= string[i + 2] && string[i + 2] <= '9' )
                {
                    i += 2 + text2num( &string[i + 2], '>', &code );
                    if ( code & PL_FCI_MARK )
                    {
                        // code is a complete FCI (font characterization
                        // integer): change FCI to this value.
                        //
                        fci = code;
                        args->unicode_array[j] = fci;
                        skip = 1;
                    }
                    else
                    {
                        // code is not complete FCI. Change
                        // FCI with hex power in rightmost hex
                        // digit and hex digit value in second rightmost
                        // hex digit.
                        //
                        hexdigit = ( code >> 4 ) & PL_FCI_HEXDIGIT_MASK;
                        hexpower = code & PL_FCI_HEXPOWER_MASK;
                        plP_hex2fci( hexdigit, hexpower, &fci );
                        args->unicode_array[j] = fci;
                        skip = 1;
                    }
                }
                else
                {
                    i += text2fci( &string[i + 1], &hexdigit, &hexpower );
                    if ( hexpower < 7 )
                    {
                        plP_hex2fci( hexdigit, hexpower, &fci );
                        args->unicode_array[j] = fci;
                        skip = 1;
                    }
                }
                break;

            case 'f': // Deprecated Hershey-style font change
            case 'F': // Deprecated Hershey-style font change
                // We implement an approximate response here so that
                // reasonable results are obtained for unicode fonts,
                // but this method is deprecated and the #<nnn> or
                // #<command string> methods should be used instead
                // to change unicode fonts in mid-string.
                //
                fci = PL_FCI_MARK;
                if ( string[i + 2] == 'n' )
                {
                    // medium, upright, sans-serif
                    plP_hex2fci( PL_FCI_SANS, PL_FCI_FAMILY, &fci );
                }
                else if ( string[i + 2] == 'r' )
                {
                    // medium, upright, serif
                    plP_hex2fci( PL_FCI_SERIF, PL_FCI_FAMILY, &fci );
                }
                else if ( string[i + 2] == 'i' )
                {
                    // medium, italic, serif
                    plP_hex2fci( PL_FCI_ITALIC, PL_FCI_STYLE, &fci );
                    plP_hex2fci( PL_FCI_SERIF, PL_FCI_FAMILY, &fci );
                }
                else if ( string[i + 2] == 's' )
                {
                    // medium, upright, script
                    plP_hex2fci( PL_FCI_SCRIPT, PL_FCI_FAMILY, &fci );
                }
                else
                    fci = PL_FCI_IMPOSSIBLE;

                if ( fci != PL_FCI_IMPOSSIBLE )
                {
                    i += 2;
                    args->unicode_array[j] = fci;
                    skip = 1;
                }
                break;

            case 'g': // Greek font
            case 'G': // Greek font
                // Get the index in the lookup table
                // 527 = upper case alpha displacement in Hershey Table
                // 627 = lower case alpha displacement in Hershey Table
                //

                ig = plP_strpos( plP_greek_mnemonic, string[i + 2] );
                if ( ig >= 0 )
                {
                    if ( ig >= 24 )
                        ig = ig + 100 - 24;
                    ig = ig + 527;
                    // Follow pldeco in plsym.c which for
                    // lower case epsilon, theta, and phi
                    // substitutes (684, 685, and 686) for
                    // (631, 634, and 647)
                    if ( ig == 631 )
                        ig = 684;
                    else if ( ig == 634 )
                        ig = 685;
                    else if ( ig == 647 )
                        ig = 686;
                    idx = (int) plhershey2unicode( ig );
                    args->unicode_array[j++] =
                        (PLUNICODE) hershey_to_unicode_lookup_table[idx].Unicode;
                    i   += 2;
                    skip = 1; // skip is set if we have copied something
                              // into the unicode table
                }
                else
                {
                    // Use "unknown" unicode character if string[i+2]
                    // is not in the Greek array.
                    args->unicode_array[j++] = (PLUNICODE) 0x00;
                    i   += 2;
                    skip = 1;   // skip is set if we have copied something
                                // into  the unicode table
                }
                j--;
                break;
            }
        }

        if ( skip == 0 )
        {
            PLUNICODE     unichar = 0;
#ifdef HAVE_LIBUNICODE
            PLCHAR_VECTOR ptr = unicode_get_utf8( string + i, &unichar );
#else
            PLCHAR_VECTOR ptr = utf8_to_ucs4( string + i, &unichar );
#endif
            if ( ptr == NULL )
            {
                char buf[BUFFER_SIZE];
                char tmpstring[31];
                strncpy( tmpstring, string, 30 );
                tmpstring[30] = '\0';
                snprintf( buf, BUFFER_SIZE, "UTF-8 string is malformed: %s%s",
                    tmpstring, strlen( string ) > 30 ? "[...]" : "" );
                plabort( buf );
                return;
            }
            args->unicode_array[j] = unichar;
            i += (int) ( ptr - ( string + i ) - 1 );

            // Search for escesc (an unescaped escape) in the input
            // string and adjust unicode_buffer accordingly).
            //
            if ( args->unicode_array[j] == (PLUNICODE) esc
                 && string[i + 1] == esc )
            {
                i++;
                args->unicode_array[++j] = (PLUNICODE) esc;
            }
        }
        j++;
    }

    // Much easier to set the length than
    // work it out later :-)
    args->unicode_array_len = (short unsigned int) j;
}

static PLUNICODE unicode_buffer_static[1024];

void
plP_text( PLINT base, PLFLT just, PLFLT *xform, PLINT x, PLINT y,
          PLINT refx, PLINT refy, PLCHAR_VECTOR string )
{
    size_t len;

    // First, check if the caller passed an empty string.  If it is,
    // then we can return now
    if ( string == NULL )
        return;

    if ( plsc->dev_text ) // Does the device render it's own text ?
    {
        EscText args;

        args.text_type = PL_STRING_TEXT;
        args.base      = base;
        args.just      = just;
        args.xform     = xform;
        args.x         = x;
        args.y         = y;
        args.refx      = refx;
        args.refy      = refy;

        // Always store the string passed by the caller, even for unicode
        // enabled drivers.  The plmeta driver will use this field to store
        // the string data in the metafile.
        args.string = string;

        // Does the device also understand unicode?
        if ( plsc->dev_unicode )
        {
            if ( plsc->alt_unicode )
            {
                // We are using the alternate unicode processing
                alternate_unicode_processing( string, &args );

                // All text processing is done, so we can exit
                return;
            }
            else
            {
                // Setup storage for the unicode array and
                // process the string to generate the unicode
                // representation of it.
                args.unicode_array = unicode_buffer_static;
                encode_unicode( string, &args );

                len = (size_t) args.unicode_array_len;
            }
        }
        else
        {
            //  We are using the char array, NULL out the unicode part
            args.unicode_array     = NULL;
            args.unicode_array_len = 0;

            len = strlen( string );
        }

        // If the string is not empty, ask the driver to display it
        if ( len > 0 )
            plP_esc( PLESC_HAS_TEXT, &args );

#ifndef DEBUG_TEXT
    }
    else
    {
#endif
        plstr( base, xform, refx, refy, string );
    }
}

// convert utf8 string to ucs4 unichar
static PLCHAR_VECTOR
utf8_to_ucs4( PLCHAR_VECTOR ptr, PLUNICODE *unichar )
{
    char tmp;
    int  isFirst = 1;
    int  cnt     = 0;

    do
    {
        // Get next character in string
        tmp = *ptr++;
        if ( isFirst ) // First char in UTF8 sequence
        {
            isFirst = 0;
            // Determine length of sequence
            if ( (unsigned char) ( tmp & 0x80 ) == 0x00 ) // single char
            {
                *unichar = (unsigned int) tmp & 0x7F;
                cnt      = 0;
            }
            else if ( (unsigned char) ( tmp & 0xE0 ) == 0xC0 ) // 2 chars
            {
                *unichar = (unsigned int) tmp & 0x1F;
                cnt      = 1;
            }
            else if ( (unsigned char) ( tmp & 0xF0 ) == 0xE0 ) // 3 chars
            {
                *unichar = (unsigned char) tmp & 0x0F;
                cnt      = 2;
            }
            else if ( (unsigned char) ( tmp & 0xF8 ) == 0xF0 ) // 4 chars
            {
                *unichar = (unsigned char) tmp & 0x07;
                cnt      = 3;
            }
            else if ( (unsigned char) ( tmp & 0xFC ) == 0xF8 ) // 5 chars
            {
                *unichar = (unsigned char) tmp & 0x03;
                cnt      = 4;
            }
            else if ( (unsigned char) ( tmp & 0xFE ) == 0xFC ) // 6 chars
            {
                *unichar = (unsigned char) tmp & 0x01;
                cnt      = 5;
            }
            else  // Malformed
            {
                ptr = NULL;
                cnt = 0;
            }
        }
        else   // Subsequent char in UTF8 sequence
        {
            if ( (unsigned char) ( tmp & 0xC0 ) == 0x80 )
            {
                *unichar = ( *unichar << 6 ) | ( (unsigned int) tmp & 0x3F );
                cnt--;
            }
            else  // Malformed
            {
                ptr = NULL;
                cnt = 0;
            }
        }
    } while ( cnt > 0 );
    return ptr;
}

// convert ucs4 unichar to utf8 string
int
ucs4_to_utf8( PLUNICODE unichar, char *ptr )
{
    unsigned char *tmp;
    int           len;

    tmp = (unsigned char *) ptr;

    if ( ( unichar & 0xffff80 ) == 0 ) // single byte
    {
        *tmp = (unsigned char) unichar;
        tmp++;
        len = 1;
    }
    else if ( ( unichar & 0xfff800 ) == 0 ) // two bytes
    {
        *tmp = (unsigned char) 0xc0 | (unsigned char) ( unichar >> 6 );
        tmp++;
        *tmp = (unsigned char) ( 0x80 | (unsigned char) ( unichar & (PLUINT) 0x3f ) );
        tmp++;
        len = 2;
    }
    else if ( ( unichar & 0xff0000 ) == 0 ) // three bytes
    {
        *tmp = (unsigned char) 0xe0 | (unsigned char) ( unichar >> 12 );
        tmp++;
        *tmp = (unsigned char) ( 0x80 | (unsigned char) ( ( unichar >> 6 ) & 0x3f ) );
        tmp++;
        *tmp = (unsigned char) ( 0x80 | ( (unsigned char) unichar & 0x3f ) );
        tmp++;
        len = 3;
    }
    else if ( ( unichar & 0xe0000 ) == 0 ) // four bytes
    {
        *tmp = (unsigned char) 0xf0 | (unsigned char) ( unichar >> 18 );
        tmp++;
        *tmp = (unsigned char) ( 0x80 | (unsigned char) ( ( unichar >> 12 ) & 0x3f ) );
        tmp++;
        *tmp = (unsigned char) ( 0x80 | (unsigned char) ( ( unichar >> 6 ) & 0x3f ) );
        tmp++;
        *tmp = (unsigned char) ( 0x80 | (unsigned char) ( unichar & 0x3f ) );
        tmp++;
        len = 4;
    }
    else  // Illegal coding
    {
        len = 0;
    }
    *tmp = '\0';

    return len;
}

static void
grline( short *x, short *y, PLINT PL_UNUSED( npts ) )
{
    char *save_locale = plsave_set_locale();
    if ( !plsc->stream_closed )
    {
        ( *plsc->dispatch_table->pl_line )( (struct PLStream_struct *) plsc,
            x[0], y[0], x[1], y[1] );
    }
    plrestore_locale( save_locale );
}

static void
grpolyline( short *x, short *y, PLINT npts )
{
    char *save_locale = plsave_set_locale();
    if ( !plsc->stream_closed )
    {
        ( *plsc->dispatch_table->pl_polyline )( (struct PLStream_struct *) plsc,
            x, y, npts );
    }
    plrestore_locale( save_locale );
}

static void
grfill( short *x, short *y, PLINT npts )
{
    char * save_locale;
    plsc->dev_npts = npts;
    plsc->dev_x    = x;
    plsc->dev_y    = y;

    save_locale = plsave_set_locale();
    if ( !plsc->stream_closed )
    {
        ( *plsc->dispatch_table->pl_esc )( (struct PLStream_struct *) plsc,
            PLESC_FILL, NULL );
    }
    plrestore_locale( save_locale );
}

static void
grgradient( short *x, short *y, PLINT npts )
{
    char * save_locale;
    plsc->dev_npts = npts;
    plsc->dev_x    = x;
    plsc->dev_y    = y;

    save_locale = plsave_set_locale();
    if ( !plsc->stream_closed )
    {
        ( *plsc->dispatch_table->pl_esc )( (struct PLStream_struct *) plsc,
            PLESC_GRADIENT, NULL );
    }
    plrestore_locale( save_locale );
}

//--------------------------------------------------------------------------
// void difilt
//
// Driver interface filter -- passes all coordinates through a variety
// of filters.  These include filters to change :
//
//      - mapping of meta to physical coordinates
//      - plot orientation
//      - window into plot (zooms)
//      - window into device (i.e set margins)
//
// The filters are applied in the order specified above.  Because the
// orientation change comes first, subsequent window specifications affect
// the new coordinates (i.e. after a 90 degree flip, what was x is now y).
// This is the only way that makes sense from a graphical interface
// (e.g. TCL/TK driver).
//
// Where appropriate, the page clip limits are modified.
//--------------------------------------------------------------------------

void
difilt( PLINT *xsc, PLINT *ysc, PLINT npts,
        PLINT *clpxmi, PLINT *clpxma, PLINT *clpymi, PLINT *clpyma )
{
    PLINT i, x, y;

// Map meta coordinates to physical coordinates

    if ( plsc->difilt & PLDI_MAP )
    {
        for ( i = 0; i < npts; i++ )
        {
            xsc[i] = (PLINT) ( plsc->dimxax * xsc[i] + plsc->dimxb );
            ysc[i] = (PLINT) ( plsc->dimyay * ysc[i] + plsc->dimyb );
        }
    }

// Change orientation

    if ( plsc->difilt & PLDI_ORI )
    {
        for ( i = 0; i < npts; i++ )
        {
            x      = (PLINT) ( plsc->dioxax * xsc[i] + plsc->dioxay * ysc[i] + plsc->dioxb );
            y      = (PLINT) ( plsc->dioyax * xsc[i] + plsc->dioyay * ysc[i] + plsc->dioyb );
            xsc[i] = x;
            ysc[i] = y;
        }
    }

// Change window into plot space

    if ( plsc->difilt & PLDI_PLT )
    {
        for ( i = 0; i < npts; i++ )
        {
            xsc[i] = (PLINT) ( plsc->dipxax * xsc[i] + plsc->dipxb );
            ysc[i] = (PLINT) ( plsc->dipyay * ysc[i] + plsc->dipyb );
        }
    }

// Change window into device space and set clip limits
// (this is the only filter that modifies them)

    if ( plsc->difilt & PLDI_DEV )
    {
        for ( i = 0; i < npts; i++ )
        {
            xsc[i] = (PLINT) ( plsc->didxax * xsc[i] + plsc->didxb );
            ysc[i] = (PLINT) ( plsc->didyay * ysc[i] + plsc->didyb );
        }
        *clpxmi = plsc->diclpxmi;
        *clpxma = plsc->diclpxma;
        *clpymi = plsc->diclpymi;
        *clpyma = plsc->diclpyma;
    }
    else
    {
        *clpxmi = plsc->phyxmi;
        *clpxma = plsc->phyxma;
        *clpymi = plsc->phyymi;
        *clpyma = plsc->phyyma;
    }
}


// Function is unused except for commented out image code
// If / when that is fixed, then reinstate this function.
// Needs a prototype and the casting fixed.
//
// void
// sdifilt( short *xscl, short *yscl, PLINT npts,
//          PLINT *clpxmi, PLINT *clpxma, PLINT *clpymi, PLINT *clpyma )
// {
//     int   i;
//     short x, y;

// // Map meta coordinates to physical coordinates

//     if ( plsc->difilt & PLDI_MAP )
//     {
//         for ( i = 0; i < npts; i++ )
//         {
//             xscl[i] = (PLINT) ( plsc->dimxax * xscl[i] + plsc->dimxb );
//             yscl[i] = (PLINT) ( plsc->dimyay * yscl[i] + plsc->dimyb );
//         }
//     }

// // Change orientation

//     if ( plsc->difilt & PLDI_ORI )
//     {
//         for ( i = 0; i < npts; i++ )
//         {
//             x       = (PLINT) ( plsc->dioxax * xscl[i] + plsc->dioxay * yscl[i] + plsc->dioxb );
//             y       = (PLINT) ( plsc->dioyax * xscl[i] + plsc->dioyay * yscl[i] + plsc->dioyb );
//             xscl[i] = x;
//             yscl[i] = y;
//         }
//     }

// // Change window into plot space

//     if ( plsc->difilt & PLDI_PLT )
//     {
//         for ( i = 0; i < npts; i++ )
//         {
//             xscl[i] = (PLINT) ( plsc->dipxax * xscl[i] + plsc->dipxb );
//             yscl[i] = (PLINT) ( plsc->dipyay * yscl[i] + plsc->dipyb );
//         }
//     }

// // Change window into device space and set clip limits
// // (this is the only filter that modifies them)

//     if ( plsc->difilt & PLDI_DEV )
//     {
//         for ( i = 0; i < npts; i++ )
//         {
//             xscl[i] = (PLINT) ( plsc->didxax * xscl[i] + plsc->didxb );
//             yscl[i] = (PLINT) ( plsc->didyay * yscl[i] + plsc->didyb );
//         }
//         *clpxmi = (PLINT) ( plsc->diclpxmi );
//         *clpxma = (PLINT) ( plsc->diclpxma );
//         *clpymi = (PLINT) ( plsc->diclpymi );
//         *clpyma = (PLINT) ( plsc->diclpyma );
//     }
//     else
//     {
//         *clpxmi = plsc->phyxmi;
//         *clpxma = plsc->phyxma;
//         *clpymi = plsc->phyymi;
//         *clpyma = plsc->phyyma;
//     }
// }

//--------------------------------------------------------------------------
// void difilt_clip
//
// This provides the transformed text clipping region for the benefit of
// those drivers that render their own text.
//--------------------------------------------------------------------------

void
difilt_clip( PLINT *x_coords, PLINT *y_coords )
{
    PLINT x1c, x2c, y1c, y2c;

    x1c         = plsc->clpxmi;
    y1c         = plsc->clpymi;
    x2c         = plsc->clpxma;
    y2c         = plsc->clpyma;
    x_coords[0] = x1c;
    x_coords[1] = x1c;
    x_coords[2] = x2c;
    x_coords[3] = x2c;
    y_coords[0] = y1c;
    y_coords[1] = y2c;
    y_coords[2] = y2c;
    y_coords[3] = y1c;
    difilt( x_coords, y_coords, 4, &x1c, &x2c, &y1c, &y2c );
}


//--------------------------------------------------------------------------
// void pldi_ini
//
// Updates driver interface, making sure everything is in order.
// Even if filter is not being used, the defaults need to be set up.
//--------------------------------------------------------------------------

static void
setdef_diplt( void )
{
    plsc->dipxmin = 0.0;
    plsc->dipxmax = 1.0;
    plsc->dipymin = 0.0;
    plsc->dipymax = 1.0;
}

static void
setdef_didev( void )
{
    plsc->mar    = 0.0;
    plsc->aspect = 0.0;
    plsc->jx     = 0.0;
    plsc->jy     = 0.0;
}

static void
setdef_diori( void )
{
    plsc->diorot = 0.;
}

static void
pldi_ini( void )
{
    if ( plsc->level >= 1 )
    {
        if ( plsc->plbuf_write )
            plbuf_di( plsc );
        if ( plsc->difilt & PLDI_MAP )  // Coordinate mapping
            calc_dimap();

        if ( plsc->difilt & PLDI_ORI )  // Orientation
            calc_diori();
        else
            setdef_diori();

        if ( plsc->difilt & PLDI_PLT )  // Plot window
            calc_diplt();
        else
            setdef_diplt();

        if ( plsc->difilt & PLDI_DEV )  // Device window
            calc_didev();
        else
            setdef_didev();
    }
}

//--------------------------------------------------------------------------
// void pldid2pc
//
// Converts input values from relative device coordinates to relative plot
// coordinates.  This function must be called when selecting a plot window
// from a display driver, since the coordinates chosen by the user are
// necessarily device-specific.
//--------------------------------------------------------------------------

void
pldid2pc( PLFLT *xmin, PLFLT *ymin, PLFLT *xmax, PLFLT *ymax )
{
    PLFLT pxmin, pymin, pxmax, pymax;
    PLFLT sxmin, symin, sxmax, symax;
    PLFLT rxmin, rymin, rxmax, rymax;

    if ( plsc->difilt & PLDI_DEV )
    {
        pldebug( "pldid2pc",
            "Relative device coordinates (in): %f, %f, %f, %f\n",
            *xmin, *ymin, *xmax, *ymax );

        pxmin = plP_dcpcx( *xmin );
        pymin = plP_dcpcy( *ymin );
        pxmax = plP_dcpcx( *xmax );
        pymax = plP_dcpcy( *ymax );

        sxmin = ( pxmin - plsc->didxb ) / plsc->didxax;
        symin = ( pymin - plsc->didyb ) / plsc->didyay;
        sxmax = ( pxmax - plsc->didxb ) / plsc->didxax;
        symax = ( pymax - plsc->didyb ) / plsc->didyay;

        rxmin = plP_pcdcx( (PLINT) sxmin );
        rymin = plP_pcdcy( (PLINT) symin );
        rxmax = plP_pcdcx( (PLINT) sxmax );
        rymax = plP_pcdcy( (PLINT) symax );

        *xmin = ( rxmin < 0 ) ? 0 : rxmin;
        *xmax = ( rxmax > 1 ) ? 1 : rxmax;
        *ymin = ( rymin < 0 ) ? 0 : rymin;
        *ymax = ( rymax > 1 ) ? 1 : rymax;

        pldebug( "pldid2pc",
            "Relative plot coordinates (out): %f, %f, %f, %f\n",
            rxmin, rymin, rxmax, rymax );
    }
}

//--------------------------------------------------------------------------
// void pldip2dc
//
// Converts input values from relative plot coordinates to relative
// device coordinates.
//--------------------------------------------------------------------------

void
pldip2dc( PLFLT *xmin, PLFLT *ymin, PLFLT *xmax, PLFLT *ymax )
{
    PLFLT pxmin, pymin, pxmax, pymax;
    PLFLT sxmin, symin, sxmax, symax;
    PLFLT rxmin, rymin, rxmax, rymax;

    if ( plsc->difilt & PLDI_DEV )
    {
        pldebug( "pldip2pc",
            "Relative plot coordinates (in): %f, %f, %f, %f\n",
            *xmin, *ymin, *xmax, *ymax );

        pxmin = plP_dcpcx( *xmin );
        pymin = plP_dcpcy( *ymin );
        pxmax = plP_dcpcx( *xmax );
        pymax = plP_dcpcy( *ymax );

        sxmin = pxmin * plsc->didxax + plsc->didxb;
        symin = pymin * plsc->didyay + plsc->didyb;
        sxmax = pxmax * plsc->didxax + plsc->didxb;
        symax = pymax * plsc->didyay + plsc->didyb;

        rxmin = plP_pcdcx( (PLINT) sxmin );
        rymin = plP_pcdcy( (PLINT) symin );
        rxmax = plP_pcdcx( (PLINT) sxmax );
        rymax = plP_pcdcy( (PLINT) symax );

        *xmin = ( rxmin < 0 ) ? 0 : rxmin;
        *xmax = ( rxmax > 1 ) ? 1 : rxmax;
        *ymin = ( rymin < 0 ) ? 0 : rymin;
        *ymax = ( rymax > 1 ) ? 1 : rymax;

        pldebug( "pldip2pc",
            "Relative device coordinates (out): %f, %f, %f, %f\n",
            rxmin, rymin, rxmax, rymax );
    }
}

//--------------------------------------------------------------------------
// void plsdiplt
//
// Set window into plot space
//--------------------------------------------------------------------------

void
c_plsdiplt( PLFLT xmin, PLFLT ymin, PLFLT xmax, PLFLT ymax )
{
    plsc->dipxmin = ( xmin < xmax ) ? xmin : xmax;
    plsc->dipxmax = ( xmin < xmax ) ? xmax : xmin;
    plsc->dipymin = ( ymin < ymax ) ? ymin : ymax;
    plsc->dipymax = ( ymin < ymax ) ? ymax : ymin;

    if ( xmin == 0. && xmax == 1. && ymin == 0. && ymax == 1. )
    {
        plsc->difilt &= ~PLDI_PLT;
        return;
    }

    plsc->difilt |= PLDI_PLT;
    pldi_ini();
}

//--------------------------------------------------------------------------
// void plsdiplz
//
// Set window into plot space incrementally (zoom)
//--------------------------------------------------------------------------

void
c_plsdiplz( PLFLT xmin, PLFLT ymin, PLFLT xmax, PLFLT ymax )
{
    if ( plsc->difilt & PLDI_PLT )
    {
        xmin = plsc->dipxmin + ( plsc->dipxmax - plsc->dipxmin ) * xmin;
        ymin = plsc->dipymin + ( plsc->dipymax - plsc->dipymin ) * ymin;
        xmax = plsc->dipxmin + ( plsc->dipxmax - plsc->dipxmin ) * xmax;
        ymax = plsc->dipymin + ( plsc->dipymax - plsc->dipymin ) * ymax;
    }

    plsdiplt( xmin, ymin, xmax, ymax );
}

//--------------------------------------------------------------------------
// void calc_diplt
//
// Calculate transformation coefficients to set window into plot space.
//
// Note: if driver has requested to handle these commands itself, we must
// send the appropriate escape command.  If the driver succeeds it will
// cancel the filter operation.  The command is deferred until this point
// to ensure that the driver has been initialized.
//--------------------------------------------------------------------------

static void
calc_diplt( void )
{
    PLINT pxmin, pxmax, pymin, pymax, pxlen, pylen;

    if ( plsc->dev_di )
    {
        char *save_locale = plsave_set_locale();
        if ( !plsc->stream_closed )
        {
            ( *plsc->dispatch_table->pl_esc )( (struct PLStream_struct *) plsc,
                PLESC_DI, NULL );
        }
        plrestore_locale( save_locale );
    }

    if ( !( plsc->difilt & PLDI_PLT ) )
        return;

    pxmin = plP_dcpcx( plsc->dipxmin );
    pxmax = plP_dcpcx( plsc->dipxmax );
    pymin = plP_dcpcy( plsc->dipymin );
    pymax = plP_dcpcy( plsc->dipymax );

    pxlen = pxmax - pxmin;
    pylen = pymax - pymin;
    pxlen = MAX( 1, pxlen );
    pylen = MAX( 1, pylen );

    plsc->dipxax = plsc->phyxlen / (double) pxlen;
    plsc->dipyay = plsc->phyylen / (double) pylen;
    plsc->dipxb  = plsc->phyxmi - plsc->dipxax * pxmin;
    plsc->dipyb  = plsc->phyymi - plsc->dipyay * pymin;
}

//--------------------------------------------------------------------------
// void plgdiplt
//
// Retrieve current window into plot space
//--------------------------------------------------------------------------

void
c_plgdiplt( PLFLT *p_xmin, PLFLT *p_ymin, PLFLT *p_xmax, PLFLT *p_ymax )
{
    *p_xmin = plsc->dipxmin;
    *p_xmax = plsc->dipxmax;
    *p_ymin = plsc->dipymin;
    *p_ymax = plsc->dipymax;
}

//--------------------------------------------------------------------------
// void plsdidev
//
// Set window into device space using margin, aspect ratio, and
// justification.  If you want to just use the previous value for any of
// these, just pass in the magic value PL_NOTSET.
//
// It is unlikely that one should ever need to change the aspect ratio
// but it's in there for completeness.
//--------------------------------------------------------------------------

void
c_plsdidev( PLFLT mar, PLFLT aspect, PLFLT jx, PLFLT jy )
{
    plsetvar( plsc->mar, mar );
    plsetvar( plsc->aspect, aspect );
    plsetvar( plsc->jx, jx );
    plsetvar( plsc->jy, jy );

    if ( mar == 0. && aspect == 0. && jx == 0. && jy == 0. &&
         !( plsc->difilt & PLDI_ORI ) )
    {
        plsc->difilt &= ~PLDI_DEV;
        return;
    }

    plsc->difilt |= PLDI_DEV;
    pldi_ini();
}

//--------------------------------------------------------------------------
// void calc_didev
//
// Calculate transformation coefficients to set window into device space.
// Calculates relative window bounds and calls plsdidxy to finish the job.
//--------------------------------------------------------------------------

static void
calc_didev( void )
{
    PLFLT lx, ly, aspect, aspdev;
    PLFLT xmin, xmax, xlen, ymin, ymax, ylen;
    PLINT pxmin, pxmax, pymin, pymax, pxlen, pylen;

    if ( plsc->dev_di )
    {
        char *save_locale = plsave_set_locale();
        if ( !plsc->stream_closed )
        {
            ( *plsc->dispatch_table->pl_esc )( (struct PLStream_struct *) plsc,
                PLESC_DI, NULL );
        }
        plrestore_locale( save_locale );
    }

    if ( !( plsc->difilt & PLDI_DEV ) )
        return;

// Calculate aspect ratio of physical device

    lx     = plsc->phyxlen / plsc->xpmm;
    ly     = plsc->phyylen / plsc->ypmm;
    aspdev = lx / ly;

    if ( plsc->difilt & PLDI_ORI )
        aspect = plsc->aspori;
    else
        aspect = plsc->aspect;

    if ( aspect <= 0. )
        aspect = plsc->aspdev;

// Failsafe

    plsc->mar = ( plsc->mar > 0.5 ) ? 0.5 : plsc->mar;
    plsc->mar = ( plsc->mar < 0.0 ) ? 0.0 : plsc->mar;
    plsc->jx  = ( plsc->jx > 0.5 ) ?  0.5 : plsc->jx;
    plsc->jx  = ( plsc->jx < -0.5 ) ? -0.5 : plsc->jx;
    plsc->jy  = ( plsc->jy > 0.5 ) ?  0.5 : plsc->jy;
    plsc->jy  = ( plsc->jy < -0.5 ) ? -0.5 : plsc->jy;

// Relative device coordinates that neutralize aspect ratio difference

    xlen = ( aspect < aspdev ) ? ( aspect / aspdev ) : 1.0;
    ylen = ( aspect < aspdev ) ? 1.0 : ( aspdev / aspect );

    xlen *= ( 1.0 - 2. * plsc->mar );
    ylen *= ( 1.0 - 2. * plsc->mar );

    xmin = ( 1. - xlen ) * ( 0.5 + plsc->jx );
    xmax = xmin + xlen;

    ymin = ( 1. - ylen ) * ( 0.5 + plsc->jy );
    ymax = ymin + ylen;

// Calculate transformation coefficients

    pxmin = plP_dcpcx( xmin );
    pxmax = plP_dcpcx( xmax );
    pymin = plP_dcpcy( ymin );
    pymax = plP_dcpcy( ymax );

    pxlen = pxmax - pxmin;
    pylen = pymax - pymin;
    pxlen = MAX( 1, pxlen );
    pylen = MAX( 1, pylen );

    plsc->didxax = pxlen / (double) plsc->phyxlen;
    plsc->didyay = pylen / (double) plsc->phyylen;
    plsc->didxb  = pxmin - plsc->didxax * plsc->phyxmi;
    plsc->didyb  = pymin - plsc->didyay * plsc->phyymi;

// Set clip limits to conform to new page size

    plsc->diclpxmi = (PLINT) ( plsc->didxax * plsc->phyxmi + plsc->didxb );
    plsc->diclpxma = (PLINT) ( plsc->didxax * plsc->phyxma + plsc->didxb );
    plsc->diclpymi = (PLINT) ( plsc->didyay * plsc->phyymi + plsc->didyb );
    plsc->diclpyma = (PLINT) ( plsc->didyay * plsc->phyyma + plsc->didyb );
}

//--------------------------------------------------------------------------
// void plgdidev
//
// Retrieve current window into device space
//--------------------------------------------------------------------------

void
c_plgdidev( PLFLT *p_mar, PLFLT *p_aspect, PLFLT *p_jx, PLFLT *p_jy )
{
    *p_mar    = plsc->mar;
    *p_aspect = plsc->aspect;
    *p_jx     = plsc->jx;
    *p_jy     = plsc->jy;
}

//--------------------------------------------------------------------------
// void plsdiori
//
// Set plot orientation, specifying rotation in units of pi/2.
//--------------------------------------------------------------------------

void
c_plsdiori( PLFLT rot )
{
    plsc->diorot = rot;
    if ( rot == 0. )
    {
        plsc->difilt &= ~PLDI_ORI;
        pldi_ini();
        return;
    }

    plsc->difilt |= PLDI_ORI;
    pldi_ini();
}

//--------------------------------------------------------------------------
// void calc_diori
//
// Calculate transformation coefficients to arbitrarily orient plot.
// Preserve aspect ratios so the output doesn't suck.
//--------------------------------------------------------------------------

static void
calc_diori( void )
{
    PLFLT cost, sint;
    PLFLT x0, y0, lx, ly, aspect;
    PLFLT affine_result[NAFFINE], affine_left[NAFFINE];

    if ( plsc->dev_di )
    {
        char *save_locale = plsave_set_locale();
        if ( !plsc->stream_closed )
        {
            ( *plsc->dispatch_table->pl_esc )( (struct PLStream_struct *) plsc,
                PLESC_DI, NULL );
        }
        plrestore_locale( save_locale );
    }

    if ( !( plsc->difilt & PLDI_ORI ) )
        return;

// Center point of rotation

    x0 = ( plsc->phyxma + plsc->phyxmi ) / 2.;
    y0 = ( plsc->phyyma + plsc->phyymi ) / 2.;

// Rotation

    cost = ABS( cos( plsc->diorot * PI / 2. ) );
    sint = ABS( sin( plsc->diorot * PI / 2. ) );

// Flip aspect ratio as necessary.  Grungy but I don't see a better way

    aspect = plsc->aspect;
    if ( aspect == 0. )
        aspect = plsc->aspdev;

    if ( plsc->freeaspect )
        plsc->aspori = aspect;
    else
        plsc->aspori = ( aspect * cost + sint ) / ( aspect * sint + cost );

    if ( !( plsc->difilt & PLDI_DEV ) )
    {
        plsc->difilt |= PLDI_DEV;
        setdef_didev();
    }
    calc_didev();

    // Compute scale factors for relative device coordinates.  Only
    // the aspect ratio of lx to ly matters.  Note, plsc->phyxlen and
    // plsc->phyylen are in PLplot core library coordinates and don't
    // know anything about device coordinates which are likely to have
    // a quite different aspect ratio.  So to correct between the two
    // coordinate systems must divide plsc->phyxlen/plsc->phyylen by
    // plsc->aspori.

    // N.B. comment out this correction because causes other issues.

    //lx = plsc->phyxlen/plsc->aspori;
    lx = plsc->phyxlen;
    ly = plsc->phyylen;

// Transformation coefficients

    //
    // plsc->dioxax = r11;
    // plsc->dioxay = r21 * ( lx / ly );
    // plsc->dioxb  = ( 1. - r11 ) * x0 - r21 * y0 * ( lx / ly );
    //
    // plsc->dioyax = r12 * ( ly / lx );
    // plsc->dioyay = r22;
    // plsc->dioyb  = ( 1. - r22 ) * y0 - r12 * x0 * ( ly / lx );
    //

    // Calculate affine transformation as product of translate to middle
    // of device, scale to relative device coordinates, rotate, unscale
    // to physical coordinates, untranslate to original zero point.
    plP_affine_translate( affine_result, x0, y0 );
    plP_affine_scale( affine_left, lx, ly );
    plP_affine_multiply( affine_result, affine_left, affine_result );
    plP_affine_rotate( affine_left, plsc->diorot * 90. );
    plP_affine_multiply( affine_result, affine_left, affine_result );
    plP_affine_scale( affine_left, 1. / lx, 1. / ly );
    plP_affine_multiply( affine_result, affine_left, affine_result );
    plP_affine_translate( affine_left, -x0, -y0 );
    plP_affine_multiply( affine_result, affine_left, affine_result );
    plsc->dioxax = affine_result[0];
    plsc->dioxay = affine_result[2];
    plsc->dioxb  = affine_result[4];
    plsc->dioyax = affine_result[1];
    plsc->dioyay = affine_result[3];
    plsc->dioyb  = affine_result[5];
}

//--------------------------------------------------------------------------
// void plgdiori
//
// Get plot orientation
//--------------------------------------------------------------------------

void
c_plgdiori( PLFLT *p_rot )
{
    *p_rot = plsc->diorot;
}

//--------------------------------------------------------------------------
// void plsdimap
//
// Set up transformation from metafile coordinates.  The size of the plot is
// scaled so as to preserve aspect ratio.  This isn't intended to be a
// general-purpose facility just yet (not sure why the user would need it,
// for one).
//--------------------------------------------------------------------------

void
c_plsdimap( PLINT dimxmin, PLINT dimxmax, PLINT dimymin, PLINT dimymax,
            PLFLT dimxpmm, PLFLT dimypmm )
{
    plsetvar( plsc->dimxmin, dimxmin );
    plsetvar( plsc->dimxmax, dimxmax );
    plsetvar( plsc->dimymin, dimymin );
    plsetvar( plsc->dimymax, dimymax );
    plsetvar( plsc->dimxpmm, dimxpmm );
    plsetvar( plsc->dimypmm, dimypmm );

    plsc->difilt |= PLDI_MAP;
    pldi_ini();
}

//--------------------------------------------------------------------------
// void calc_dimap
//
// Set up transformation from metafile coordinates.  The size of the plot is
// scaled so as to preserve aspect ratio.  This isn't intended to be a
// general-purpose facility just yet (not sure why the user would need it,
// for one).
//--------------------------------------------------------------------------

static void
calc_dimap()
{
    PLFLT lx, ly;
    PLINT pxmin, pxmax, pymin, pymax;
    PLFLT dimxlen, dimylen, pxlen, pylen;

    if ( ( plsc->dimxmin == plsc->phyxmi ) && ( plsc->dimxmax == plsc->phyxma ) &&
         ( plsc->dimymin == plsc->phyymi ) && ( plsc->dimymax == plsc->phyyma ) &&
         ( plsc->dimxpmm == plsc->xpmm ) && ( plsc->dimypmm == plsc->ypmm ) )
    {
        plsc->difilt &= ~PLDI_MAP;
        return;
    }

// Set default aspect ratio

    lx = ( plsc->dimxmax - plsc->dimxmin + 1 ) / plsc->dimxpmm;
    ly = ( plsc->dimymax - plsc->dimymin + 1 ) / plsc->dimypmm;

    plsc->aspdev = lx / ly;

// Build transformation to correct physical coordinates

    dimxlen = plsc->dimxmax - plsc->dimxmin;
    dimylen = plsc->dimymax - plsc->dimymin;

    pxmin = plsc->phyxmi;
    pxmax = plsc->phyxma;
    pymin = plsc->phyymi;
    pymax = plsc->phyyma;
    pxlen = pxmax - pxmin;
    pylen = pymax - pymin;

    plsc->dimxax = pxlen / dimxlen;
    plsc->dimyay = pylen / dimylen;
    plsc->dimxb  = pxmin - pxlen * plsc->dimxmin / dimxlen;
    plsc->dimyb  = pymin - pylen * plsc->dimymin / dimylen;
}

//--------------------------------------------------------------------------
// void plflush()
//
// Flushes the output stream.  Use sparingly, if at all.
//--------------------------------------------------------------------------

void
c_plflush( void )
{
    if ( plsc->dev_flush )
    {
        char *save_locale = plsave_set_locale();
        if ( !plsc->stream_closed )
        {
            ( *plsc->dispatch_table->pl_esc )( (struct PLStream_struct *) plsc,
                PLESC_FLUSH, NULL );
        }
        plrestore_locale( save_locale );
    }
    else
    {
        if ( plsc->OutFile != NULL )
            fflush( plsc->OutFile );
    }
}

//--------------------------------------------------------------------------
// Startup routines.
//--------------------------------------------------------------------------

//--------------------------------------------------------------------------
// void pllib_init()
//
// Initialize library.  Called internally by every startup routine.
// Everything you want to always be initialized before plinit() is called
// you should put here.  E.g. dispatch table setup, rcfile read, etc.
//--------------------------------------------------------------------------

void
pllib_init()
{
    if ( lib_initialized )
        return;
    lib_initialized = 1;

#ifdef ENABLE_DYNDRIVERS
// Create libltdl resources
    lt_dlinit();
#endif

// Initialize the dispatch table with the info from the static drivers table
// and the available dynamic drivers.

    plInitDispatchTable();
}

//--------------------------------------------------------------------------
// void plstar(nx, ny)
//
// Initialize PLplot, passing in the windows/page settings.
//--------------------------------------------------------------------------

void
c_plstar( PLINT nx, PLINT ny )
{
    pllib_init();

    if ( plsc->level != 0 )
        plend1();

    plssub( nx, ny );

    c_plinit();
}

//--------------------------------------------------------------------------
// void plstart(devname, nx, ny)
//
// Initialize PLplot, passing the device name and windows/page settings.
//--------------------------------------------------------------------------

void
c_plstart( PLCHAR_VECTOR devname, PLINT nx, PLINT ny )
{
    pllib_init();

    if ( plsc->level != 0 )
        plend1();

    plssub( nx, ny );
    plsdev( devname );

    c_plinit();
}

//--------------------------------------------------------------------------
// void plinit()
//
// Initializes PLplot, using preset or default options.
//--------------------------------------------------------------------------

void
c_plinit( void )
{
    PLFLT lx, ly, xpmm_loc, ypmm_loc, aspect_old, aspect_new;

    pllib_init();

    if ( plsc->level != 0 )
        plend1();

// Set stream number

    plsc->ipls = ipls;

// Set up devices

    pllib_devinit();

// Auxiliary stream setup

    plstrm_init();

// Set title for window to a sensible default if not defined
    if ( plsc->plwindow == NULL )
    {
        if ( plsc->program )
        {
            if ( ( plsc->plwindow = (char *) malloc( (size_t) ( 1 + strlen( plsc->program ) ) * sizeof ( char ) ) ) == NULL )
            {
                plexit( "plinit: Insufficient memory" );
            }
            strcpy( plsc->plwindow, plsc->program );
        }
        else
        {
            if ( ( plsc->plwindow = (char *) malloc( (size_t) 7 * sizeof ( char ) ) ) == NULL )
            {
                plexit( "plinit: Insufficient memory" );
            }
            strcpy( plsc->plwindow, "PLplot" );
        }
    }

// Initialize device & first page

    plP_init();
    plP_bop();
    plsc->level = 1;


// The driver options are freed after driver initialisation,
// since it is assumed that in this function options are
// processed and stored somewhere else. For further driver
// initialisations (e.g. copy stream) there are no driver
// options defined.

    plP_FreeDrvOpts();

// Calculate factor such that the character aspect ratio is preserved
// when the overall aspect ratio is changed, i.e., if portrait mode is
// requested (only honored for subset of drivers) or if the aspect ratio
// is specified in any way, or if a 90 deg rotation occurs with
// -freeaspect.

// Case where plsc->aspect has a value.... (e.g., -a aspect on the
// command line or 2nd parameter of plsdidev specified)
    if ( plsc->aspect > 0. )
    {
        lx               = plsc->phyxlen / plsc->xpmm;
        ly               = plsc->phyylen / plsc->ypmm;
        aspect_old       = lx / ly;
        aspect_new       = plsc->aspect;
        plsc->caspfactor = sqrt( aspect_old / aspect_new );
    }
// Case of 90 deg rotations with -freeaspect (this is also how portrait
// mode is implemented for the drivers that honor -portrait).
    else if ( plsc->freeaspect && ABS( cos( plsc->diorot * PI / 2. ) ) <= 1.e-5 )
    {
        lx               = plsc->phyxlen / plsc->xpmm;
        ly               = plsc->phyylen / plsc->ypmm;
        aspect_old       = lx / ly;
        aspect_new       = ly / lx;
        plsc->caspfactor = sqrt( aspect_old / aspect_new );
    }

    else
        plsc->caspfactor = 1.;

// Load fonts

    plsc->cfont = 1;
    plfntld( initfont );

// Set up subpages

    plP_subpInit();

// Set up number of allowed digits before switching to scientific notation
// The user can always change this

    if ( plsc->xdigmax == 0 )
        plsc->xdigmax = 4;

    if ( plsc->ydigmax == 0 )
        plsc->ydigmax = 4;

    if ( plsc->zdigmax == 0 )
        plsc->zdigmax = 3;

    if ( plsc->timefmt == NULL )
        c_pltimefmt( "%c" );

    // Use default transformation between continuous and broken-down time
    // (and vice versa) if the transformation has not yet been defined
    // for this stream.
    if ( plsc->qsasconfig == NULL )
        c_plconfigtime( 0., 0., 0., 0x0, 0, 0, 0, 0, 0, 0, 0. );

// Switch to graphics mode and set color and arrow style

    plgra();
    plcol0( 1 );

    pllsty( 1 );
    plpsty( 0 );

    // Set up default arrow style;
    plsvect( NULL, NULL, 6, 0 );

// Set clip limits.

    plsc->clpxmi = plsc->phyxmi;
    plsc->clpxma = plsc->phyxma;
    plsc->clpymi = plsc->phyymi;
    plsc->clpyma = plsc->phyyma;

// Page aspect ratio.

    lx           = plsc->phyxlen / plsc->xpmm;
    ly           = plsc->phyylen / plsc->ypmm;
    plsc->aspdev = lx / ly;

// Initialize driver interface

    pldi_ini();

// Apply compensating factor to original xpmm and ypmm so that
// character aspect ratio is preserved when overall aspect ratio
// is changed.  This must appear here in the code because previous
// code in this routine and in routines that it calls must use the original
// values of xpmm and ypmm before the compensating factor is applied.

    plP_gpixmm( &xpmm_loc, &ypmm_loc );
    plP_setpxl( xpmm_loc * plsc->caspfactor, ypmm_loc / plsc->caspfactor );
}

//--------------------------------------------------------------------------
// void plend()
//
// End a plotting session for all open streams.
//--------------------------------------------------------------------------

void
c_plend( void )
{
    PLINT i;

    if ( lib_initialized == 0 )
        return;

    for ( i = PL_NSTREAMS - 1; i >= 0; i-- )
    {
        if ( pls[i] != NULL )
        {
            plsstrm( i );
            c_plend1();
        }
    }
    plfontrel();
#ifdef ENABLE_DYNDRIVERS
// Release the libltdl resources
    lt_dlexit();
// Free up memory allocated to the dispatch tables
    for ( i = 0; i < npldynamicdevices; i++ )
    {
        free_mem( loadable_device_list[i].devnam );
        free_mem( loadable_device_list[i].description );
        free_mem( loadable_device_list[i].drvnam );
        free_mem( loadable_device_list[i].tag );
    }
    free_mem( loadable_device_list );
    for ( i = 0; i < nloadabledrivers; i++ )
    {
        free_mem( loadable_driver_list[i].drvnam );
    }
    free_mem( loadable_driver_list );
    for ( i = nplstaticdevices; i < npldrivers; i++ )
    {
        free_mem( dispatch_table[i]->pl_MenuStr );
        free_mem( dispatch_table[i]->pl_DevName );
        free_mem( dispatch_table[i] );
    }
#endif
    for ( i = 0; i < nplstaticdevices; i++ )
    {
        free_mem( dispatch_table[i] );
    }
    free_mem( dispatch_table );

    lib_initialized = 0;
}

//--------------------------------------------------------------------------
// void plend1()
//
// End a plotting session for the current stream only.  After the stream is
// ended the memory associated with the stream's PLStream data structure is
// freed (for stream > 0), and the stream counter is set to 0 (the default).
//--------------------------------------------------------------------------

void
c_plend1( void )
{
    if ( plsc->level > 0 )
    {
        plP_eop();
        plP_wait();
        plP_tidy();
        plsc->level = 0;
    }
    // Move from plP_tidy because FileName may be set even if level == 0
    if ( plsc->FileName )
        free_mem( plsc->FileName );

// Free all malloc'ed stream memory

    free_mem( plsc->cmap0 );
    free_mem( plsc->cmap1 );
    free_mem( plsc->plwindow );
    free_mem( plsc->geometry );
    free_mem( plsc->dev );
    free_mem( plsc->BaseName );
    free_mem( plsc->plbuf_buffer );

    if ( plsc->program )
        free_mem( plsc->program );
    if ( plsc->server_name )
        free_mem( plsc->server_name );
    if ( plsc->server_host )
        free_mem( plsc->server_host );
    if ( plsc->server_port )
        free_mem( plsc->server_port );
    if ( plsc->user )
        free_mem( plsc->user );
    if ( plsc->plserver )
        free_mem( plsc->plserver );
    if ( plsc->auto_path )
        free_mem( plsc->auto_path );

    if ( plsc->arrow_x )
        free_mem( plsc->arrow_x );
    if ( plsc->arrow_y )
        free_mem( plsc->arrow_y );

    if ( plsc->timefmt )
        free_mem( plsc->timefmt );

    // Close qsastime library for this stream that was opened by
    // plconfigtime call in plinit.

    closeqsas( &( plsc->qsasconfig ) );

    // Free memory used by the plot metafiles
    if ( plsc->mf_infile )
        free_mem( plsc->mf_infile );
    if ( plsc->mf_outfile )
        free_mem( plsc->mf_outfile );

// Free malloc'ed stream if not in initial stream, else clear it out

    if ( ipls > 0 )
    {
        free_mem( plsc );
        pls[ipls] = NULL;
        plsstrm( 0 );
    }
    else
    {
        memset( (char *) pls[ipls], 0, sizeof ( PLStream ) );
    }
}

//--------------------------------------------------------------------------
// void plsstrm
//
// Set stream number.  If the data structure for a new stream is
// unallocated, we allocate it here.
//--------------------------------------------------------------------------

void
c_plsstrm( PLINT strm )
{
    if ( strm < 0 || strm >= PL_NSTREAMS )
    {
        fprintf( stderr,
            "plsstrm: Illegal stream number %d, must be in [0, %d]\n",
            (int) strm, PL_NSTREAMS );
    }
    else
    {
        ipls = strm;
        if ( pls[ipls] == NULL )
        {
            pls[ipls] = (PLStream *) malloc( (size_t) sizeof ( PLStream ) );
            if ( pls[ipls] == NULL )
                plexit( "plsstrm: Out of memory." );

            memset( (char *) pls[ipls], 0, sizeof ( PLStream ) );
        }
        plsc       = pls[ipls];
        plsc->ipls = ipls;
    }
}

//--------------------------------------------------------------------------
// void plgstrm
//
// Get current stream number.
//--------------------------------------------------------------------------

void
c_plgstrm( PLINT *p_strm )
{
    *p_strm = ipls;
}

//--------------------------------------------------------------------------
// void plmkstrm
//
// Creates a new stream and makes it the default.  Differs from using
// plsstrm(), in that a free stream number is found, and returned.
//
// Unfortunately, I /have/ to start at stream 1 and work upward, since
// stream 0 is preallocated.  One of the BIG flaws in the PLplot API is
// that no initial, library-opening call is required.  So stream 0 must be
// preallocated, and there is no simple way of determining whether it is
// already in use or not.
//--------------------------------------------------------------------------

void
c_plmkstrm( PLINT *p_strm )
{
    int i;

    for ( i = 1; i < PL_NSTREAMS; i++ )
    {
        if ( pls[i] == NULL )
            break;
    }

    if ( i == PL_NSTREAMS )
    {
        fprintf( stderr, "plmkstrm: Cannot create new stream\n" );
        *p_strm = -1;
    }
    else
    {
        *p_strm = i;
        plsstrm( i );
    }
    plstrm_init();
}

//--------------------------------------------------------------------------
// void plstrm_init
//
// Does required startup initialization of a stream.  Should be called right
// after creating one (for allocating extra memory, etc).  Users shouldn't
// need to call this directly.
//
// This function can be called multiple times for a given stream, in which
// case only the first call produces any effect.  For streams >= 1, which
// are created dynamically, this is called by the routine that allocates
// the stream.  Stream 0, which is preallocated, is much harder to deal with
// because any of a number of different calls may be the first call to the
// library.  This is handled by just calling plstrm_init() from every
// function that might be called first.  Sucks, but it should work.
//--------------------------------------------------------------------------

void
plstrm_init( void )
{
    if ( !plsc->initialized )
    {
        plsc->initialized = 1;

        if ( plsc->cmap0 == NULL )
            plspal0( "" );

        if ( plsc->cmap1 == NULL )
            plspal1( "", TRUE );

        // Set continuous plots to use the full color map 1 range
        plsc->cmap1_min = 0.0;
        plsc->cmap1_max = 1.0;
    }

    plsc->psdoc = NULL;
}

//--------------------------------------------------------------------------
// pl_cpcolor
//
// Utility to copy one PLColor to another.
//--------------------------------------------------------------------------

void
pl_cpcolor( PLColor *to, PLColor *from )
{
    to->r = from->r;
    to->g = from->g;
    to->b = from->b;
    to->a = from->a;
}

//--------------------------------------------------------------------------
// void plcpstrm
//
// Copies state parameters from the reference stream to the current stream.
// Tell driver interface to map device coordinates unless flags == 1.
//
// This function is used for making save files of selected plots (e.g.
// from the TK driver).  After initializing, you can get a copy of the
// current plot to the specified device by switching to this stream and
// issuing a plcpstrm() and a plreplot(), with calls to plbop() and
// pleop() as appropriate.  The plot buffer must have previously been
// enabled (done automatically by some display drivers, such as X).
//--------------------------------------------------------------------------

void
c_plcpstrm( PLINT iplsr, PLINT flags )
{
    int      i;
    PLStream *plsr;

    plsr = pls[iplsr];
    if ( plsr == NULL )
    {
        fprintf( stderr, "plcpstrm: stream %d not in use\n", (int) iplsr );
        return;
    }

// May be debugging

    plsc->debug = plsr->debug;

// Plot buffer -- need to copy buffer pointer so that plreplot() works
// This also prevents inadvertent writes into the plot buffer
    plsc->plbuf_buffer_grow = plsr->plbuf_buffer_grow;
    plsc->plbuf_buffer_size = plsr->plbuf_buffer_size;
    plsc->plbuf_top         = plsr->plbuf_top;
    plsc->plbuf_readpos     = plsr->plbuf_readpos;
    if ( ( plsc->plbuf_buffer = malloc( plsc->plbuf_buffer_size ) ) == NULL )
        plexit( "plcpstrm: Error allocating plot buffer." );
    memcpy( plsc->plbuf_buffer, plsr->plbuf_buffer, plsr->plbuf_top );

// Driver interface
// Transformation must be recalculated in current driver coordinates

    if ( plsr->difilt & PLDI_PLT )
        plsdiplt( plsr->dipxmin, plsr->dipymin, plsr->dipxmax, plsr->dipymax );

    if ( plsr->difilt & PLDI_DEV )
        plsdidev( plsr->mar, plsr->aspect, plsr->jx, plsr->jy );

    if ( plsr->difilt & PLDI_ORI )
        plsdiori( plsr->diorot );

// Map device coordinates

    if ( !( flags & 0x01 ) )
    {
        pldebug( "plcpstrm", "mapping parameters: %d %d %d %d %f %f\n",
            plsr->phyxmi, plsr->phyxma, plsr->phyymi, plsr->phyyma,
            plsr->xpmm, plsr->ypmm );
        plsdimap( plsr->phyxmi, plsr->phyxma, plsr->phyymi, plsr->phyyma,
            plsr->xpmm, plsr->ypmm );
    }

// current color

    pl_cpcolor( &plsc->curcolor, &plsr->curcolor );

// cmap 0

    plsc->icol0 = plsr->icol0;
    plsc->ncol0 = plsr->ncol0;
    if ( plsc->cmap0 != NULL )
        free( (void *) plsc->cmap0 );

    if ( ( plsc->cmap0 = (PLColor *) calloc( 1, (size_t) plsc->ncol0 * sizeof ( PLColor ) ) ) == NULL )
    {
        plexit( "c_plcpstrm: Insufficient memory" );
    }

    for ( i = 0; i < plsc->ncol0; i++ )
        pl_cpcolor( &plsc->cmap0[i], &plsr->cmap0[i] );

// cmap 1

    plsc->icol1     = plsr->icol1;
    plsc->ncol1     = plsr->ncol1;
    plsc->cmap1_min = plsr->cmap1_min;
    plsc->cmap1_max = plsr->cmap1_max;
    if ( plsc->cmap1 != NULL )
        free( (void *) plsc->cmap1 );

    if ( ( plsc->cmap1 = (PLColor *) calloc( 1, (size_t) plsc->ncol1 * sizeof ( PLColor ) ) ) == NULL )
    {
        plexit( "c_plcpstrm: Insufficient memory" );
    }

    for ( i = 0; i < plsc->ncol1; i++ )
        pl_cpcolor( &plsc->cmap1[i], &plsr->cmap1[i] );

// Initialize if it hasn't been done yet.

    if ( plsc->level == 0 )
        plinit();
}

//--------------------------------------------------------------------------
// pllib_devinit()
//
// Does preliminary setup of device driver.
//
// This function (previously plGetDev) used to be what is now shown as
// plSelectDev below.  However, the situation is a bit more complicated now in
// the dynloadable drivers era.  We now have to:
//
// 1) Make sure the dispatch table is initialized to the union of static
//    drivers and available dynamic drivers (done from pllib_init now).
// 2) Allow the user to select the desired device.
// 3) Initialize the dispatch table entries for the selected device, in the
//    case that it is a dynloadable driver that has not yet been loaded.
//
// Also made non-static, in order to allow some device calls to be made prior
// to calling plinit().  E.g. plframe needs to tell the X driver to create its
// internal data structure during widget construction time (using the escape
// function), but doesn't call plinit() until the plframe is actually mapped.
//--------------------------------------------------------------------------

void
pllib_devinit()
{
    if ( plsc->dev_initialized )
        return;
    plsc->dev_initialized = 1;

    plSelectDev();

    plLoadDriver();

// offset by one since table is zero-based, but input list is not
    plsc->dispatch_table = dispatch_table[plsc->device - 1];
}

int plInBuildTree()
{
    static int inited      = 0;
    static int inBuildTree = 0;

    if ( inited == 0 )
    {
        int  len_currdir, len_builddir;
        char currdir[PLPLOT_MAX_PATH], *pcurrdir = currdir;
        char builddir[PLPLOT_MAX_PATH], *pbuilddir = builddir;


        if ( getcwd( currdir, PLPLOT_MAX_PATH ) == NULL )
        {
            pldebug( "plInBuildTree():", "Not enough buffer space" );
        }
        else
        {
            pldebug( "plInBuildTree(): ", "current directory >%s<\n", currdir );
            pldebug( "plInBuildTree(): ", "build directory >%s<\n", BUILD_DIR );
            // The chdir / getcwd call is to ensure we get the physical
            // path without any symlinks
            // Ignore error in chdir - build tree may not exist
            if ( chdir( BUILD_DIR ) == 0 )
            {
                if ( getcwd( builddir, PLPLOT_MAX_PATH ) == NULL )
                {
                    pldebug( "plInBuildTree():", "Not enough buffer space" );
                }
                else
                {
                    len_currdir  = strlen( currdir );
                    len_builddir = strlen( builddir );
#if defined ( IGNORECASE )
                    pldebug( "plInBuildTree(): ", "comparing ignoring case\n" );
                    // On Windows all parts of the path are case insensitive
                    // so convert to lower case for the comparison.
                    for (; *pcurrdir; ++pcurrdir )
                    {
                        *pcurrdir = tolower( *pcurrdir );
                        if ( *pcurrdir == '\\' )
                        {
                            *pcurrdir = '/';
                        }
                    }
                    for (; *pbuilddir; ++pbuilddir )
                    {
                        *pbuilddir = tolower( *pbuilddir );
                        if ( *pbuilddir == '\\' )
                        {
                            *pbuilddir = '/';
                        }
                    }
                    // builddir does not have trailing path delimiter
                    // so the strncmp comparison checks if currdir is
                    // exactly the builddir or builddir with a string
                    // appended.  So if that test succeeds, then check
                    // further if the currdir is exactly the build_dir
                    // or the appended string starts with the path
                    // delimiter, i.e., whether currdir is the builddir or
                    // a subdirectory of that directory.
                    if ( strncmp( builddir, currdir, len_builddir ) == 0 &&
                         ( len_currdir == len_builddir || currdir[len_builddir] == '\\' || currdir[len_builddir] == '/' ) )
#else
                    pldebug( "plInBuildTree(): ", "comparing respecting case\n" );
                    if ( strncmp( builddir, currdir, len_builddir ) == 0 &&
                         ( len_currdir == len_builddir || currdir[len_builddir] == '/' ) )
#endif
                    {
                        inBuildTree = 1;
                    }
                }
                if ( chdir( currdir ) != 0 )
                    pldebug( "plInBuildTree():", "Unable to chdir to current directory" );
            }
        }
        inited = 1;
    }
    return inBuildTree;
}

#ifdef ENABLE_DYNDRIVERS

PLCHAR_VECTOR
plGetDrvDir()
{
    PLCHAR_VECTOR drvdir;

// Get drivers directory in PLPLOT_DRV_DIR or DRV_DIR,
//  on this order
//

    if ( plInBuildTree() == 1 )
    {
        drvdir = BUILD_DIR "/drivers";
        pldebug( "plGetDrvDir", "Using %s as the driver directory.\n", drvdir );
    }
    else
    {
        pldebug( "plGetDrvDir", "Trying to read env var PLPLOT_DRV_DIR\n" );
        drvdir = getenv( "PLPLOT_DRV_DIR" );

        if ( drvdir == NULL )
        {
            pldebug( "plGetDrvDir",
                "Will use drivers dir: " DRV_DIR "\n" );
            drvdir = DRV_DIR;
        }
    }

    return drvdir;
}

#endif


//--------------------------------------------------------------------------
// void plInitDispatchTable()
//
// ...
//--------------------------------------------------------------------------

static int plDispatchSequencer( const void *p1, const void *p2 )
{
    const PLDispatchTable* t1 = *(const PLDispatchTable * const *) p1;
    const PLDispatchTable* t2 = *(const PLDispatchTable * const *) p2;

//     printf( "sorting: t1.name=%s t1.seq=%d t2.name=%s t2.seq=%d\n",
//             t1->pl_DevName, t1->pl_seq, t2->pl_DevName, t2->pl_seq );

    return t1->pl_seq - t2->pl_seq;
}

static void
plInitDispatchTable()
{
    int n;

#ifdef ENABLE_DYNDRIVERS
    char          buf[BUFFER2_SIZE];
    PLCHAR_VECTOR drvdir;
    char          *devnam, *devdesc, *devtype, *driver, *tag, *seqstr;
    int           seq;
    int           i, j, driver_found, done = 0;
    FILE          *fp_drvdb   = NULL;
    DIR           * dp_drvdir = NULL;
    struct dirent * entry;
    // lt_dlhandle dlhand;

    // Make sure driver counts are zeroed
    npldynamicdevices = 0;
    nloadabledrivers  = 0;

// Open a temporary file in which all the plD_DEVICE_INFO_<driver> strings
// will be stored
    fp_drvdb = pl_create_tempfile( NULL );
    if ( fp_drvdb == NULL )
    {
        plabort( "plInitDispatchTable: Could not open temporary file" );
        return;
    }

// Open the drivers directory
    drvdir    = plGetDrvDir();
    dp_drvdir = opendir( drvdir );
    if ( dp_drvdir == NULL )
    {
        fclose( fp_drvdb );
        plabort( "plInitDispatchTable: Could not open drivers directory" );
        return;
    }

// Loop over each entry in the drivers directory

    pldebug( "plInitDispatchTable", "Scanning dyndrivers dir\n" );
    while ( ( entry = readdir( dp_drvdir ) ) != NULL )
    {
        char   * name = entry->d_name;
        // Suffix .driver_info has a length of 12 letters.
        size_t len = strlen( name ) - 12;

        pldebug( "plInitDispatchTable",
            "Consider file %s\n", name );

// Only consider entries that have the ".driver_info" suffix
        if ( ( len > 0 ) && ( strcmp( name + len, ".driver_info" ) == 0 ) )
        {
            char path[PLPLOT_MAX_PATH];
            FILE * fd;

// Open the driver's info file
            snprintf( path, PLPLOT_MAX_PATH, "%s/%s", drvdir, name );
            fd = fopen( path, "r" );
            if ( fd == NULL )
            {
                closedir( dp_drvdir );
                fclose( fp_drvdb );
                snprintf( buf, BUFFER2_SIZE,
                    "plInitDispatchTable: Could not open driver info file %s\n",
                    name );
                plabort( buf );
                return;
            }

// Each line in the <driver>.driver_info file corresponds to a specific device.
// Write it to the drivers db file and take care of leading newline
// character

            pldebug( "plInitDispatchTable",
                "Opened driver info file %s\n", name );
            while ( fgets( buf, BUFFER2_SIZE, fd ) != NULL )
            {
                fprintf( fp_drvdb, "%s", buf );
                if ( buf [strlen( buf ) - 1] != '\n' )
                    fprintf( fp_drvdb, "\n" );
                npldynamicdevices++;
            }
            fclose( fd );
        }
    }

// Make sure that the temporary file containing the drivers database
// is ready to read and close the directory handle
    fflush( fp_drvdb );
    closedir( dp_drvdir );

#endif

// Allocate space for the dispatch table.
    if ( ( dispatch_table = (PLDispatchTable **)
                            malloc( (size_t) ( nplstaticdevices + npldynamicdevices ) * sizeof ( PLDispatchTable * ) ) ) == NULL )
    {
#ifdef ENABLE_DYNDRIVERS
        fclose( fp_drvdb );
#endif
        plexit( "plInitDispatchTable: Insufficient memory" );
    }

// Initialize the dispatch table entries for the static devices by calling
// the dispatch table initialization function for each static device.  This
// is the same function that would be called at load time for dynamic
// drivers.

    for ( n = 0; n < nplstaticdevices; n++ )
    {
        if ( ( dispatch_table[n] = (PLDispatchTable *) malloc( sizeof ( PLDispatchTable ) ) ) == NULL )
        {
#ifdef ENABLE_DYNDRIVERS
            fclose( fp_drvdb );
#endif
            plexit( "plInitDispatchTable: Insufficient memory" );
        }

        // Initialize to zero to force all function pointers to NULL.  That way optional capabilities
        // (e.g. wait for user input) do not need to be explicitly set to NULL in the driver's
        // initialization function
        memset( dispatch_table[n], 0, sizeof ( PLDispatchTable ) );

        ( *static_device_initializers[n] )( dispatch_table[n] );
    }
    npldrivers = nplstaticdevices;

#ifdef ENABLE_DYNDRIVERS

// Allocate space for the device and driver specs.  We may not use all of
// these driver descriptors, but we obviously won't need more drivers than
// devices...
    if ( ( ( loadable_device_list = malloc( (size_t) npldynamicdevices * sizeof ( PLLoadableDevice ) ) ) == NULL ) ||
         ( ( loadable_driver_list = malloc( (size_t) npldynamicdevices * sizeof ( PLLoadableDriver ) ) ) == NULL ) )
    {
        fclose( fp_drvdb );
        plexit( "plInitDispatchTable: Insufficient memory" );
    }

    rewind( fp_drvdb );

    i    = 0;
    done = !( i < npldynamicdevices );
    while ( !done )
    {
        char *p = fgets( buf, BUFFER2_SIZE, fp_drvdb );

        if ( p == 0 )
        {
            done = 1;
            continue;
        }

        devnam  = strtok( buf, ":" );
        devdesc = strtok( 0, ":" );
        devtype = strtok( 0, ":" );
        driver  = strtok( 0, ":" );
        seqstr  = strtok( 0, ":" );
        tag     = strtok( 0, "\n" );

        if ( devnam == NULL || devdesc == NULL || devtype == NULL || driver == NULL ||
             seqstr == NULL || tag == NULL )
        {
            continue; // Ill-formatted line, most probably not a valid driver information file
        }

        seq = atoi( seqstr );

        n = npldrivers++;

        if ( ( dispatch_table[n] = malloc( sizeof ( PLDispatchTable ) ) ) == NULL )
        {
            fclose( fp_drvdb );
            plexit( "plInitDispatchTable: Insufficient memory" );
        }

        // Initialize to zero to force all function pointers to NULL.  That way optional capabilities
        // (e.g. wait for user input) do not need to be explicitly set to NULL in the driver's
        // initialization function nor do we need to do it in this function.
        memset( dispatch_table[n], 0, sizeof ( PLDispatchTable ) );

        // Fill in the dispatch table entries.
        dispatch_table[n]->pl_MenuStr = plstrdup( devdesc );
        dispatch_table[n]->pl_DevName = plstrdup( devnam );
        dispatch_table[n]->pl_type    = atoi( devtype );
        dispatch_table[n]->pl_seq     = seq;

        // Add a record to the loadable device list
        loadable_device_list[i].devnam      = plstrdup( devnam );
        loadable_device_list[i].description = plstrdup( devdesc );
        loadable_device_list[i].drvnam      = plstrdup( driver );
        loadable_device_list[i].tag         = plstrdup( tag );

        // Now see if this driver has been seen before.  If not, add a driver
        // entry for it.
        driver_found = 0;
        for ( j = 0; j < nloadabledrivers; j++ )
            if ( strcmp( driver, loadable_driver_list[j].drvnam ) == 0 )
            {
                driver_found = 1;
                break;
            }

        if ( !driver_found )
        {
            loadable_driver_list[nloadabledrivers].drvnam = plstrdup( driver );
            loadable_driver_list[nloadabledrivers].dlhand = 0;
            nloadabledrivers++;
        }

        loadable_device_list[i].drvidx = j;

        // Get ready for next loadable device spec
        i++;
    }

// RML: close fp_drvdb
    fclose( fp_drvdb );

#endif

    if ( npldrivers == 0 )
    {
        npldynamicdevices = 0;
        plexit( "No device drivers found - please check the environment variable PLPLOT_DRV_DIR" );
    }

// Finally, we need to sort the list into presentation order, based on the
// sequence number in the dispatch ttable entries.

    qsort( dispatch_table, (size_t) npldrivers, sizeof ( PLDispatchTable* ),
        plDispatchSequencer );
}

//--------------------------------------------------------------------------
// void plSelectDev()
//
// If the user has not already specified the output device, or the
// one specified is either: (a) not available, (b) "?", or (c) NULL, the
// user is prompted for it.
//
// Prompting quits after 10 unsuccessful tries in case the user has
// run the program in the background with insufficient input.
//--------------------------------------------------------------------------

static void
plSelectDev()
{
    int    dev, i, count;
    size_t length;
    char   response[80];
    char   * devname_env;

// If device name is not already specified, try to get it from environment

    if ( plsc->DevName[0] == '\0' )
    {
        devname_env = getenv( "PLPLOT_DEV" );
        if ( devname_env )
        {
            strncpy( plsc->DevName, devname_env, sizeof ( plsc->DevName ) - 1 );
            plsc->DevName[sizeof ( plsc->DevName ) - 1] = '\0';
        }
    }

// Device name already specified.  See if it is valid.

    if ( *( plsc->DevName ) != '\0' && *( plsc->DevName ) != '?' )
    {
        length = strlen( plsc->DevName );
        for ( i = 0; i < npldrivers; i++ )
        {
            if ( ( *plsc->DevName == *dispatch_table[i]->pl_DevName ) &&
                 ( strncmp( plsc->DevName,
                       dispatch_table[i]->pl_DevName, length ) == 0 ) )
                break;
        }
        if ( i < npldrivers )
        {
            plsc->device = i + 1;
            return;
        }
        else
        {
            fprintf( stderr, "Requested device %s not available\n",
                plsc->DevName );
        }
    }

    dev   = 0;
    count = 0;

    if ( npldrivers == 1 )
        dev = 1;

// User hasn't specified it correctly yet, so we prompt

    while ( dev < 1 || dev > npldrivers )
    {
        fprintf( stdout, "\nPlotting Options:\n" );
        for ( i = 0; i < npldrivers; i++ )
        {
            fprintf( stdout, " <%2d> %-10s %s\n", i + 1,
                dispatch_table[i]->pl_DevName,
                dispatch_table[i]->pl_MenuStr );
        }
        if ( ipls == 0 )
            fprintf( stdout, "\nEnter device number or keyword: " );
        else
            fprintf( stdout, "\nEnter device number or keyword (stream %d): ",
                (int) ipls );

        plio_fgets( response, sizeof ( response ), stdin );

        // First check to see if device keyword was entered.
        // Final "\n" in response messes things up, so ignore it.

        length = strlen( response );
        if ( *( response - 1 + length ) == '\n' )
            length--;

        for ( i = 0; i < npldrivers; i++ )
        {
            if ( !strncmp( response, dispatch_table[i]->pl_DevName,
                     (unsigned int) length ) )
                break;
        }
        if ( i < npldrivers )
        {
            dev = i + 1;
        }
        else
        {
            if ( ( dev = atoi( response ) ) < 1 )
            {
                fprintf( stdout, "\nInvalid device: %s", response );
                dev = 0;
            }
        }
        if ( count++ > 10 )
            plexit( "plSelectDev: Too many tries." );
    }
    plsc->device = dev;
    strcpy( plsc->DevName, dispatch_table[dev - 1]->pl_DevName );
}

//--------------------------------------------------------------------------
// void plLoadDriver()
//
// Make sure the selected driver is loaded.  Static drivers are already
// loaded, but if the user selected a dynamically loadable driver, we may
// have to take care of that now.
//--------------------------------------------------------------------------

static void
plLoadDriver( void )
{
#ifdef ENABLE_DYNDRIVERS
    int  i, drvidx;
    char sym[BUFFER_SIZE];
    char *tag;

    int  n = plsc->device - 1;
    PLDispatchTable  *dev    = dispatch_table[n];
    PLLoadableDriver *driver = 0;

// If the dispatch table is already filled in, then either the device was
// linked in statically, or else perhaps it was already loaded.  In either
// case, we have nothing left to do.
    if ( dev->pl_init )
        return;

    pldebug( "plLoadDriver", "Device not loaded!\n" );

// Now search through the list of loadable devices, looking for the record
// that corresponds to the requested device.
    for ( i = 0; i < npldynamicdevices; i++ )
        if ( strcmp( dev->pl_DevName, loadable_device_list[i].devnam ) == 0 )
            break;

// If we couldn't find such a record, then there is some sort of internal
// logic flaw since plSelectDev is supposed to only select a valid device.
//
    if ( i == npldynamicdevices )
    {
        fprintf( stderr, "No such device: %s.\n", dev->pl_DevName );
        plexit( "plLoadDriver detected device logic screwup" );
    }

// Note the device tag, and the driver index. Note that a given driver could
// supply multiple devices, each with a unique tag to distinguish the driver
// entry points for the different supported devices.
    tag    = loadable_device_list[i].tag;
    drvidx = loadable_device_list[i].drvidx;

    pldebug( "plLoadDriver", "tag=%s, drvidx=%d\n", tag, drvidx );

    driver = &loadable_driver_list[drvidx];

// Load the driver if it hasn't been loaded yet.
    if ( !driver->dlhand )
    {
        char drvspec[ DRVSPEC_SIZE ];
#if defined ( LTDL_WIN32 ) || defined ( __CYGWIN__ )
        snprintf( drvspec, DRVSPEC_SIZE, "%s", driver->drvnam );
#else
        snprintf( drvspec, DRVSPEC_SIZE, "%s/%s", plGetDrvDir(), driver->drvnam );
#endif  // LTDL_WIN32

        pldebug( "plLoadDriver", "Trying to load %s on %s\n",
            driver->drvnam, drvspec );

        driver->dlhand = lt_dlopenext( drvspec );

        // A few of our drivers do not depend on other libraries.  So
        // allow them to be completely removed by plend to give clean
        // valgrind results.  However, the (large) remainder of our
        // drivers do depend on other libraries so mark them resident
        // to prevent problems with atexit handlers / library
        // reinitialisation such as those seen with qt and cairo
        // drivers.
        if ( !( strcmp( driver->drvnam, "mem" ) == 0 ||
                strcmp( driver->drvnam, "null" ) == 0 ||
                strcmp( driver->drvnam, "plmeta" ) == 0 ||
                strcmp( driver->drvnam, "ps" ) == 0 ||
                strcmp( driver->drvnam, "svg" ) == 0 ||
                strcmp( driver->drvnam, "xfig" ) == 0 ) )
            lt_dlmakeresident( driver->dlhand );
    }

// If it still isn't loaded, then we're doomed.
    if ( !driver->dlhand )
    {
        pldebug( "plLoadDriver", "lt_dlopenext failed because of "
            "the following reason:\n%s\n", lt_dlerror() );
        fprintf( stderr, "Unable to load driver: %s.\n", driver->drvnam );
        plexit( "Unable to load driver" );
    }

// Now we are ready to ask the driver's device dispatch init function to
// initialize the entries in the dispatch table.

    snprintf( sym, BUFFER_SIZE, "plD_dispatch_init_%s", tag );
    {
        PLDispatchInit dispatch_init = (PLDispatchInit) lt_dlsym( driver->dlhand, sym );
        if ( !dispatch_init )
        {
            fprintf( stderr,
                "Unable to locate dispatch table initialization function for driver: %s.\n",
                driver->drvnam );
            return;
        }

        ( *dispatch_init )( dev );
    }
#endif
}

//--------------------------------------------------------------------------
// void plfontld()
//
// Load specified font set.
//--------------------------------------------------------------------------

void
c_plfontld( PLINT ifont )
{
    if ( ifont != 0 )
        ifont = 1;

    if ( plsc->level > 0 )
        plfntld( ifont );
    else
        initfont = ifont;
}

//--------------------------------------------------------------------------
// void plreplot()
//
// Replays contents of plot buffer to current device/file.
//--------------------------------------------------------------------------

void
c_plreplot( void )
{
    if ( plsc->plbuf_buffer != NULL )
    {
        plRemakePlot( plsc );
    }
    else
    {
        plwarn( "plreplot: plot buffer not available" );
    }
}

//--------------------------------------------------------------------------
// void plgFileDevs()
//
// Returns a list of file-oriented device names and their menu strings,
// for use in a graphical interface.  The caller must allocate enough
// space for (*p_menustr) and (*p_devname) to hold a pointer for each
// device -- 20 or so is plenty.  E.g. char *menustr[20].  The size of
// these arrays should be passed in *p_ndev, which, on exit, holds the
// number of devices actually present.
//--------------------------------------------------------------------------

void
plgFileDevs( const char ***p_menustr, const char ***p_devname, int *p_ndev )
{
    plgdevlst( *p_menustr, *p_devname, p_ndev, 0 );
}

//--------------------------------------------------------------------------
// void plgDevs()
//
// Like plgFileDevs(), but returns names and menu strings for all devices.
//--------------------------------------------------------------------------

void
plgDevs( const char ***p_menustr, const char ***p_devname, int *p_ndev )
{
    plgdevlst( *p_menustr, *p_devname, p_ndev, -1 );
}

static void
plgdevlst( const char **p_menustr, const char **p_devname, int *p_ndev, int type )
{
    int i, j;

    pllib_init();

    for ( i = j = 0; i < npldrivers; i++ )
    {
        if ( type < 0 || dispatch_table[i]->pl_type == type )
        {
            p_menustr[j] = dispatch_table[i]->pl_MenuStr;
            p_devname[j] = dispatch_table[i]->pl_DevName;
            if ( ++j + 1 >= *p_ndev )
            {
                plwarn( "plgdevlst:  too many devices" );
                break;
            }
        }
    }
    p_menustr[j] = NULL;
    p_devname[j] = NULL;
    *p_ndev      = j;
}

//--------------------------------------------------------------------------
//  Various external access routines.
//--------------------------------------------------------------------------

// Get output device parameters.

void
c_plgpage( PLFLT *p_xp, PLFLT *p_yp,
           PLINT *p_xleng, PLINT *p_yleng, PLINT *p_xoff, PLINT *p_yoff )
{
    *p_xp    = plsc->xdpi;
    *p_yp    = plsc->ydpi;
    *p_xleng = plsc->xlength;
    *p_yleng = plsc->ylength;
    *p_xoff  = plsc->xoffset;
    *p_yoff  = plsc->yoffset;
}

// Set output device parameters.  Usually ignored by the driver.

void
c_plspage( PLFLT xp, PLFLT yp, PLINT xleng, PLINT yleng, PLINT xoff, PLINT yoff )
{
    if ( plsc->level > 0 )
        plwarn( "calling plspage() after plinit() may give unpredictable results" );

    if ( xp )
        plsc->xdpi = xp;
    if ( yp )
        plsc->ydpi = yp;

    if ( xleng )
        plsc->xlength = xleng;
    if ( yleng )
        plsc->ylength = yleng;

    if ( xoff )
        plsc->xoffset = xoff;
    if ( yoff )
        plsc->yoffset = yoff;
}

// Set the number of subwindows in x and y

void
c_plssub( PLINT nx, PLINT ny )
{
    if ( nx > 0 )
        plsc->nsubx = nx;
    if ( ny > 0 )
        plsc->nsuby = ny;

// Force a page advance

    if ( plsc->level > 0 )
    {
        plP_subpInit();
//AWI   plP_eop();
//      plP_bop();
    }
    //write the sub pages to the buffer if required
    if ( plsc->plbuf_write )
        plbuf_ssub( plsc );
}

// Set the device (keyword) name

void
c_plsdev( PLCHAR_VECTOR devname )
{
    if ( plsc->level > 0 )
    {
        plwarn( "plsdev: Must be called before plinit." );
        return;
    }
    if ( devname != NULL )
    {
        strncpy( plsc->DevName, devname, sizeof ( plsc->DevName ) - 1 );
        plsc->DevName[sizeof ( plsc->DevName ) - 1] = '\0';
    }
}

// Get the current device (keyword) name
// Note: you MUST have allocated space for this (80 characters is safe)

void
c_plgdev( char *p_dev )
{
    strcpy( p_dev, plsc->DevName );
}

// Set the memory area to be plotted (with the 'mem' driver) as the 'dev'
// member of the stream structure.  Also set the number
// of pixels in the memory passed in in 'plotmem'.
// Plotmem is a block of memory maxy by maxx by 3 bytes long, say:
// 480 x 640 x 3 (Y, X, RGB)
//
// This memory will be freed by the user!
//

void
c_plsmem( PLINT maxx, PLINT maxy, void *plotmem )
{
    plsc->dev           = plotmem;
    plsc->dev_mem_alpha = 0;
    plP_setphy( 0, maxx, 0, maxy );
}

// Same as plsmem, but the buffer is (Y, X, RGBA)

void
c_plsmema( PLINT maxx, PLINT maxy, void *plotmem )
{
    plsc->dev           = plotmem;
    plsc->dev_mem_alpha = 1;
    plP_setphy( 0, maxx, 0, maxy );
}

// Get the current stream pointer

void
plgpls( PLStream **p_pls )
{
    *p_pls = plsc;
}

// Get the (current) run level.
// Valid settings are:
//   0  uninitialized
//   1  initialized
//   2  viewport defined
//   3  world coords defined
//

void
c_plglevel( PLINT *p_level )
{
    *p_level = plsc->level;
}

// Set the function pointer for the keyboard event handler

void
plsKeyEH( void ( *KeyEH )( PLGraphicsIn *, void *, int * ),
          void *KeyEH_data )
{
    plsc->KeyEH      = KeyEH;
    plsc->KeyEH_data = KeyEH_data;
}

// Set the function pointer for the (mouse) button event handler

void
plsButtonEH( void ( *ButtonEH )( PLGraphicsIn *, void *, int * ),
             void *ButtonEH_data )
{
    plsc->ButtonEH      = ButtonEH;
    plsc->ButtonEH_data = ButtonEH_data;
}

// Sets an optional user bop handler.

void
plsbopH( void ( *handler )( void *, int * ), void *handler_data )
{
    plsc->bop_handler = handler;
    plsc->bop_data    = handler_data;
}

// Sets an optional user eop handler.

void
plseopH( void ( *handler )( void *, int * ), void *handler_data )
{
    plsc->eop_handler = handler;
    plsc->eop_data    = handler_data;
}

// Set the variables to be used for storing error info

void
plsError( PLINT *errcode, char *errmsg )
{
    if ( errcode != NULL )
        plsc->errcode = errcode;

    if ( errmsg != NULL )
        plsc->errmsg = errmsg;
}

// Set orientation.  Must be done before calling plinit.

void
c_plsori( PLINT ori )
{
    plsdiori( (PLFLT) ori );
}

//
// Set pen width.  Can be done any time, but before calling plinit is best
// since otherwise it may be volatile (i.e. reset on next page advance).
// If width < 0 or is unchanged by the call, nothing is done.
//

void
c_plwidth( PLFLT width )
{
    if ( width != plsc->width && width >= 0. )
    {
        plsc->width = width;

        if ( plsc->level > 0 )
        {
            if ( !plsc->widthlock )
                plP_state( PLSTATE_WIDTH );
        }
    }
}

// Set the output file pointer

void
plgfile( FILE **p_file )
{
    *p_file = plsc->OutFile;
}

// Get the output file pointer

void
plsfile( FILE *file )
{
    plsc->OutFile = file;
}

// Get the (current) output file name.  Must be preallocated to >=80 bytes
// Beyond that, I truncate it.  You have been warned.

void
c_plgfnam( char *fnam )
{
    if ( fnam == NULL )
    {
        plabort( "filename string must be preallocated to >=80 bytes" );
        return;
    }

    *fnam = '\0';
    if ( plsc->FileName != NULL )
    {
        strncpy( fnam, plsc->FileName, 79 );
        fnam[79] = '\0';
    }
}

// Set the output file name.

void
c_plsfnam( PLCHAR_VECTOR fnam )
{
    plP_sfnam( plsc, fnam );
}

// Set the pointer to the data used in driver initialisation

// N.B. Currently used only by the wxwidgets device driver and
// associated binding.  This function might be used for other device drivers
// later on whether written in c++ or c.  But this function is not part of the
// common API and should not be propagated to any binding other than
// c++.

void
plsdevdata( void *data )
{
    plsc->dev_data = data;
}

// Set the pause (on end-of-page) status

void
c_plspause( PLINT p )
{
    plsc->nopause = !p;
}

// Set the floating point precision (in number of places) in numeric labels.

void
c_plprec( PLINT setp, PLINT prec )
{
    plsc->setpre = setp;
    plsc->precis = prec;
}

// Get the floating point precision (in number of places) in numeric labels.

void
plP_gprec( PLINT *p_setp, PLINT *p_prec )
{
    *p_setp = plsc->setpre;
    *p_prec = plsc->precis;
}

PLCHAR_VECTOR
plP_gtimefmt()
{
    return (PLCHAR_VECTOR) plsc->timefmt;
}

//
// Set the escape character for text strings.
// From C you can pass as a character, from Fortran it needs to be the decimal
// ASCII value.  Only selected characters are allowed to prevent the user from
// shooting himself in the foot (a '\' isn't allowed since it conflicts with
// C's use of backslash as a character escape).
//

void
c_plsesc( char esc )
{
    switch ( esc )
    {
    case '!':                   // ASCII 33
    case '#':                   // ASCII 35
    case '$':                   // ASCII 36
    case '%':                   // ASCII 37
    case '&':                   // ASCII 38
    case '*':                   // ASCII 42
    case '@':                   // ASCII 64
    case '^':                   // ASCII 94
    case '~':                   // ASCII 126
        plsc->esc = esc;
        break;

    default:
        plwarn( "plsesc: Invalid escape character, ignoring." );
    }
}

// Get the escape character for text strings.

void
plgesc( char *p_esc )
{
    if ( plsc->esc == '\0' )
        plsc->esc = '#';

    *p_esc = plsc->esc;
}

// Set the FCI (font characterization integer) for unicode-enabled device
// drivers.
//
void
c_plsfci( PLUNICODE fci )
{
    // Always mark FCI as such.
    plsc->fci = fci | PL_FCI_MARK;
}

// Get the FCI (font characterization integer) for unicode-enabled device
// drivers.
//
void
c_plgfci( PLUNICODE *p_fci )
{
    // Always mark FCI as such.
    *p_fci = plsc->fci | PL_FCI_MARK;
}
// Store hex digit value shifted to the left by hexdigit hexadecimal digits
// into pre-existing FCI.
//
void
plP_hex2fci( unsigned char hexdigit, unsigned char hexpower, PLUNICODE *pfci )
{
    PLUNICODE mask;
    hexpower = hexpower & PL_FCI_HEXPOWER_MASK;
    mask     = ~( ( (PLUNICODE) PL_FCI_HEXDIGIT_MASK ) << ( (PLUNICODE) 4 * hexpower ) );
    *pfci    = *pfci & mask;
    mask     = ( ( (PLUNICODE) ( hexdigit & PL_FCI_HEXDIGIT_MASK ) ) << ( 4 * hexpower ) );
    *pfci    = *pfci | mask;
}

// Retrieve hex digit value from FCI that is masked out and shifted to the
// right by hexpower hexadecimal digits.
void
plP_fci2hex( PLUNICODE fci, unsigned char *phexdigit, unsigned char hexpower )
{
    PLUNICODE mask;
    hexpower   = hexpower & PL_FCI_HEXPOWER_MASK;
    mask       = ( ( (PLUNICODE) PL_FCI_HEXPOWER_MASK ) << ( (PLUNICODE) ( 4 * hexpower ) ) );
    *phexdigit = (unsigned char) ( ( fci & mask ) >>
                                   ( (PLUNICODE) ( 4 * hexpower ) ) );
}

// Get the current library version number
// Note: you MUST have allocated space for this (80 characters is safe)
void
c_plgver( char *p_ver )
{
    strcpy( p_ver, PLPLOT_VERSION );
}

// Set inferior X window

void
plsxwin( PLINT window_id )
{
    plsc->window_id = window_id;
}

//--------------------------------------------------------------------------
//  These set/get information for family files, and may be called prior
//  to plinit to set up the necessary parameters.  Arguments:
//
//      fam     familying flag (boolean)
//      num     member number
//      bmax    maximum member size
//--------------------------------------------------------------------------

// Get family file parameters

void
c_plgfam( PLINT *p_fam, PLINT *p_num, PLINT *p_bmax )
{
    *p_fam  = plsc->family;
    *p_num  = plsc->member;
    *p_bmax = plsc->bytemax;
}

// Set family file parameters

void
c_plsfam( PLINT fam, PLINT num, PLINT bmax )
{
    if ( plsc->level > 0 )
        plwarn( "plsfam: Must be called before plinit." );

    if ( fam >= 0 )
        plsc->family = fam;
    if ( num >= 0 )
        plsc->member = num;
    if ( bmax >= 0 )
        plsc->bytemax = bmax;
}

// Advance to the next family file on the next new page

void
c_plfamadv( void )
{
    plsc->famadv = 1;
}

//--------------------------------------------------------------------------
//  Interface routines for axis labling parameters.
//  See pldtik.c for more info.
//--------------------------------------------------------------------------

// Get x axis labeling parameters

void
c_plgxax( PLINT *p_digmax, PLINT *p_digits )
{
    *p_digmax = plsc->xdigmax;
    *p_digits = plsc->xdigits;
}

// Set x axis labeling parameters

void
c_plsxax( PLINT digmax, PLINT digits )
{
    plsc->xdigmax = digmax;
    plsc->xdigits = digits;
}

// Get y axis labeling parameters

void
c_plgyax( PLINT *p_digmax, PLINT *p_digits )
{
    *p_digmax = plsc->ydigmax;
    *p_digits = plsc->ydigits;
}

// Set y axis labeling parameters

void
c_plsyax( PLINT digmax, PLINT digits )
{
    plsc->ydigmax = digmax;
    plsc->ydigits = digits;
}

// Get z axis labeling parameters

void
c_plgzax( PLINT *p_digmax, PLINT *p_digits )
{
    *p_digmax = plsc->zdigmax;
    *p_digits = plsc->zdigits;
}

// Set z axis labeling parameters

void
c_plszax( PLINT digmax, PLINT digits )
{
    plsc->zdigmax = digmax;
    plsc->zdigits = digits;
}

// Get character default height and current (scaled) height

void
c_plgchr( PLFLT *p_def, PLFLT *p_ht )
{
    *p_def = plsc->chrdef;
    *p_ht  = plsc->chrht;
}

// Get viewport boundaries in normalized device coordinates

void
c_plgvpd( PLFLT *p_xmin, PLFLT *p_xmax, PLFLT *p_ymin, PLFLT *p_ymax )
{
    *p_xmin = plsc->vpdxmi;
    *p_xmax = plsc->vpdxma;
    *p_ymin = plsc->vpdymi;
    *p_ymax = plsc->vpdyma;
}

// Get viewport boundaries in world coordinates

void
c_plgvpw( PLFLT *p_xmin, PLFLT *p_xmax, PLFLT *p_ymin, PLFLT *p_ymax )
{
    *p_xmin = plsc->vpwxmi;
    *p_xmax = plsc->vpwxma;
    *p_ymin = plsc->vpwymi;
    *p_ymax = plsc->vpwyma;
}

// Get the viewport boundaries in world coordinates, expanded slightly
void
plP_xgvpw( PLFLT *p_xmin, PLFLT *p_xmax, PLFLT *p_ymin, PLFLT *p_ymax )
{
    PLFLT dx, dy;

    dx = ( plsc->vpwxma - plsc->vpwxmi ) * 1.0e-5;
    dy = ( plsc->vpwyma - plsc->vpwymi ) * 1.0e-5;

    // The plot window is made slightly larger than requested so that
    // the end limits will be on the graph

    *p_xmin = plsc->vpwxmi - dx;
    *p_xmax = plsc->vpwxma + dx;
    *p_ymin = plsc->vpwymi - dy;
    *p_ymax = plsc->vpwyma + dy;
}

//--------------------------------------------------------------------------
//  These should not be called by the user.
//--------------------------------------------------------------------------

// Get x-y domain in world coordinates for 3d plots

void
plP_gdom( PLFLT *p_xmin, PLFLT *p_xmax, PLFLT *p_ymin, PLFLT *p_ymax )
{
    *p_xmin = plsc->domxmi;
    *p_xmax = plsc->domxma;
    *p_ymin = plsc->domymi;
    *p_ymax = plsc->domyma;
}

// Get vertical (z) scale parameters for 3-d plot

void
plP_grange( PLFLT *p_zscl, PLFLT *p_zmin, PLFLT *p_zmax )
{
    *p_zscl = plsc->zzscl;
    *p_zmin = plsc->ranmi;
    *p_zmax = plsc->ranma;
}

// Get parameters used in 3d plots

void
plP_gw3wc( PLFLT *p_dxx, PLFLT *p_dxy, PLFLT *p_dyx, PLFLT *p_dyy, PLFLT *p_dyz )
{
    *p_dxx = plsc->cxx;
    *p_dxy = plsc->cxy;
    *p_dyx = plsc->cyx;
    *p_dyy = plsc->cyy;
    *p_dyz = plsc->cyz;
}

// Get clip boundaries in physical coordinates

void
plP_gclp( PLINT *p_ixmin, PLINT *p_ixmax, PLINT *p_iymin, PLINT *p_iymax )
{
    *p_ixmin = plsc->clpxmi;
    *p_ixmax = plsc->clpxma;
    *p_iymin = plsc->clpymi;
    *p_iymax = plsc->clpyma;
}

// Set clip boundaries in physical coordinates

void
plP_sclp( PLINT ixmin, PLINT ixmax, PLINT iymin, PLINT iymax )
{
    plsc->clpxmi = ixmin;
    plsc->clpxma = ixmax;
    plsc->clpymi = iymin;
    plsc->clpyma = iymax;
    if ( plsc->plbuf_write )
        plbuf_clip( plsc );
}

// Get physical device limits in physical coordinates

void
plP_gphy( PLINT *p_ixmin, PLINT *p_ixmax, PLINT *p_iymin, PLINT *p_iymax )
{
    *p_ixmin = plsc->phyxmi;
    *p_ixmax = plsc->phyxma;
    *p_iymin = plsc->phyymi;
    *p_iymax = plsc->phyyma;
}

// Get number of subpages on physical device and current subpage

void
plP_gsub( PLINT *p_nx, PLINT *p_ny, PLINT *p_cs )
{
    *p_nx = plsc->nsubx;
    *p_ny = plsc->nsuby;
    *p_cs = plsc->cursub;
}

// Set number of subpages on physical device and current subpage

void
plP_ssub( PLINT nx, PLINT ny, PLINT cs )
{
    plsc->nsubx  = nx;
    plsc->nsuby  = ny;
    plsc->cursub = cs;
}

// Get number of pixels to a millimeter

void
plP_gpixmm( PLFLT *p_x, PLFLT *p_y )
{
    *p_x = plsc->xpmm;
    *p_y = plsc->ypmm;
}

// All the drivers call this to set physical pixels/mm.

void
plP_setpxl( PLFLT xpmm, PLFLT ypmm )
{
    plsc->xpmm = xpmm;
    plsc->ypmm = ypmm;
    plsc->umx  = (PLINT) ( 1000.0 / plsc->xpmm );
    plsc->umy  = (PLINT) ( 1000.0 / plsc->ypmm );
}

// Sets up physical limits of plotting device.

void
plP_setphy( PLINT xmin, PLINT xmax, PLINT ymin, PLINT ymax )
{
    if ( xmin > xmax || ymin > ymax )
        plexit( "plP_setphy: device minima must not exceed maxima" );

    plsc->phyxmi  = xmin;
    plsc->phyxma  = xmax;
    plsc->phyymi  = ymin;
    plsc->phyyma  = ymax;
    plsc->phyxlen = xmax - xmin;
    plsc->phyylen = ymax - ymin;
}

//--------------------------------------------------------------------------
// void c_plscompression()
//
// Set compression.
// Has to be done before plinit.
//--------------------------------------------------------------------------

void
c_plscompression( PLINT compression )
{
    if ( plsc->level <= 0 )
    {
        plsc->dev_compression = compression;
    }
}

//--------------------------------------------------------------------------
// void c_plgcompression()
//
// Get compression
//--------------------------------------------------------------------------

void
c_plgcompression( PLINT *compression )
{
    *compression = plsc->dev_compression;
}


//--------------------------------------------------------------------------
// void plP_getinitdriverlist()
//
// Check to see if a driver/stream has been initialised
// Returns a space separated list of matches streams/drivers
// If more than one stream uses the same device, then the device name
// will be returned for each stream.
// Caller must allocate enough memory for "names" to hold the answer.
//--------------------------------------------------------------------------

void
plP_getinitdriverlist( char *names )
{
    int i;

    for ( i = 0; i < PL_NSTREAMS; ++i )
    {
        if ( pls[i] != NULL )
        {
            if ( i == 0 )
                strcpy( names, pls[i]->DevName );
            else
            {
                strcat( names, " " );
                strcat( names, pls[i]->DevName );
            }
        }
        else
            break;
    }
}


//--------------------------------------------------------------------------
// PLINT plP_checkdriverinit()
//
// Checks from a list of given drivers which ones have been initialised
// and returns the number of devices matching the list, or -1 if in error.
// Effectively returns the number of streams matching the given stream.
//--------------------------------------------------------------------------

PLINT plP_checkdriverinit( char *names )
{
    char  *buff;
    char  *tok = NULL;
    PLINT ret  = 0;                                     // set up return code to 0, the value if no devices match

    buff = (char *) malloc( (size_t) PL_NSTREAMS * 8 ); // Allocate enough memory for 8
                                                        // characters for each possible stream

    if ( buff != NULL )
    {
        memset( buff, 0, PL_NSTREAMS * 8 );     // Make sure we clear it
        plP_getinitdriverlist( buff );          // Get the list of initialised devices

        for ( tok = strtok( buff, " ," );       // Check each device against the "name"
              tok; tok = strtok( 0, " ," ) )    // supplied to the subroutine
        {
            if ( strstr( names, tok ) != NULL ) // Check to see if the device has been initialised
            {
                ret++;                          // Bump the return code if it has
            }
        }
        free( buff );                // Clear up that memory we allocated
    }
    else
        ret = -1; // Error flag

    return ( ret );
}


//--------------------------------------------------------------------------
// plP_image
//
// Author: Alessandro Mirone, Nov 2001
//
// Updated by Hezekiah Carty, Mar 2008.
//   - Added support for pltr callback
//   - Commented out the "dev_fastimg" rendering path
//
//--------------------------------------------------------------------------

void
plP_image( PLFLT *z, PLINT nx, PLINT ny, PLFLT xmin, PLFLT ymin, PLFLT dx, PLFLT dy,
           void ( *pltr )( PLFLT, PLFLT, PLFLT *, PLFLT *, PLPointer ), PLPointer pltr_data )
{
    plsc->page_status = DRAWING;

    plimageslow( z, nx, ny, xmin, ymin, dx, dy, pltr, pltr_data );

    //
    // COMMENTED OUT by Hezekiah Carty, March 2008
    // The current dev_fastimg rendering method does not work as-is with
    // the plimagefr coordinate transform support.
    // This is hopefully temporary, until the dev_fastimg rendering
    // path can be updated to work with the new plimage internals.
    // Until then, all plimage* rendering is done by the plimageslow
    // rendering path.
    //
#if 0   // BEGIN dev_fastimg COMMENT
    PLINT i, npts;
    short *xscl, *yscl;
    int   plbuf_write;

    plsc->page_status = DRAWING;

    if ( plsc->dev_fastimg == 0 )
    {
        plimageslow( x, y, z, nx - 1, ny - 1,
            xmin, ymin, dx, dy, zmin, zmax );
        return;
    }

    if ( plsc->plbuf_write )
    {
        IMG_DT img_dt;

        img_dt.xmin = xmin;
        img_dt.ymin = ymin;
        img_dt.dx   = dx;
        img_dt.dy   = dy;

        plsc->dev_ix    = x;
        plsc->dev_iy    = y;
        plsc->dev_z     = z;
        plsc->dev_nptsX = nx;
        plsc->dev_nptsY = ny;
        plsc->dev_zmin  = zmin;
        plsc->dev_zmax  = zmax;

        plbuf_esc( plsc, PLESC_IMAGE, &img_dt );
    }

    // avoid re-saving plot buffer while in plP_esc()
    plbuf_write       = plsc->plbuf_write;
    plsc->plbuf_write = 0;

    npts = nx * ny;
    if ( plsc->difilt ) // isn't this odd? when replaying the plot buffer, e.g., when resizing the window, difilt() is caled again! the plot buffer should already contain the transformed data--it would save a lot of time! (and allow for differently oriented plots when in multiplot mode)
    {
        PLINT clpxmi, clpxma, clpymi, clpyma;

        if ( ( ( xscl = (short *) malloc( nx * ny * sizeof ( short ) ) ) == NULL ) ||
             ( ( yscl = (short *) malloc( nx * ny * sizeof ( short ) ) ) == NULL ) )
        {
            plexit( "plP_image: Insufficient memory" );
        }

        for ( i = 0; i < npts; i++ )
        {
            xscl[i] = x[i];
            yscl[i] = y[i];
        }
        sdifilt( xscl, yscl, npts, &clpxmi, &clpxma, &clpymi, &clpyma );
        plsc->imclxmin = clpxmi;
        plsc->imclymin = clpymi;
        plsc->imclxmax = clpxma;
        plsc->imclymax = clpyma;
        grimage( xscl, yscl, z, nx, ny );
        free( xscl );
        free( yscl );
    }
    else
    {
        plsc->imclxmin = plsc->phyxmi;
        plsc->imclymin = plsc->phyymi;
        plsc->imclxmax = plsc->phyxma;
        plsc->imclymax = plsc->phyyma;
        grimage( x, y, z, nx, ny );
    }
    plsc->plbuf_write = plbuf_write;
#endif  // END dev_fastimg COMMENT
}

//--------------------------------------------------------------------------
// plstransform
//
// Set a universal coordinate transform function which will be applied to all
// plotted items.
//--------------------------------------------------------------------------
void
c_plstransform( PLTRANSFORM_callback coordinate_transform, PLPointer coordinate_transform_data )
{
    plsc->coordinate_transform      = coordinate_transform;
    plsc->coordinate_transform_data = coordinate_transform_data;
}