PLplot: gd.c Source File

PLplot 5.15.0

gd.c
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1 // PNG, GIF, and JPEG device driver based on libgd
2 //
3 // Copyright (C) 2004 Joao Cardoso
4 // Copyright (C) 2002, 2003, 2004 Andrew Roach
5 //
6 // This file is part of PLplot.
7 //
8 // PLplot is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU Library General Public License as published
10 // by the Free Software Foundation; either version 2 of the License, or
11 // (at your option) any later version.
12 //
13 // PLplot is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU Library General Public License for more details.
17 //
18 // You should have received a copy of the GNU Library General Public License
19 // along with PLplot; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 //
22
23 // GIF SUPPORT
24 //
25 // Following the expiration of Unisys's worldwide patents on lzw compression
26 // GD 2.0.28+ have reinstated support for GIFs, and so support for this
27 // format has been added to the GD family of drivers. GIF's only support
28 // 1, 4 and 8 bit, so no truecolour. Why would you want GIFs though ? PNG is
29 // a far superior format, not only giving you 1,4,8 and 24 bit, but also
30 // better compression and just about all browsers now support them.
31 //
32
33 //
34 // The GD drivers, PNG, GIF, and JPEG, support a number of different options
35 // depending on the version of GD installed.
36 //
37 // If you have installed GD Ver 2.+ you gain support for truecolour (24
38 // bit, 16 millionish) modes as well as different line widths. These
39 // capibilities are part of GD more so than the GD driver, so they aren't
40 // available in any 1.? versions of the driver.
41 //
42 // 24 bit support is, by default, set to "auto" if you have V2.+ of GD.
43 // What this means is the *driver* decides when to use 24 bit or 8 bit
44 // modes for PNG files. The logic is rather simple - if you have less than
45 // 257 colours, it is set to 8 bit mode, if more then it's in 24 bit mode.
46 // This should work fine for most people, most of the time, in most
47 // situations; however, it can be overridden in case it has to via the
48 // "-drvopt" command line switch. The png driver has two related settings:
49 // 8bit and
50 // 24bit
51 //
52 // If either of these command line toggles are set, that mode becomes the
53 // standard used regardless of the number of colours used. It can be envoked
54 // as follows:
55 // x08c -dev png -drvopt 8bit -fam -o 8bitpng
56 // or
57 // x08c -dev png -drvopt 24bit -fam -o 24bitpng
58 //
59 // NOTE:
60 // The 24 bit PNG file is an RGBA file, not RGB - it includes alpha channel
61 // (transparency). Transparency is set to opaque, but the fact it is an
62 // RGBA and not an RGB might cause some problems with some viewers.
63 // Sadly, I can't do anything about it... sorry.
64 //
65 // GIF files can only have 256 colours, so naturally truecolour mode is not
66 // supported for this sub-driver.
67 //
68 // Stuff for GD V1.? as well as V2.+
69 //
70 // optimise
71 //
72 // From version 1.17 of the GD driver, a command line option has been
73 // added to try and optimise the PNG files. If successful, the optimise
74 // command will create 4 bit (16 colour) PNGs instead of 8 bit (256 colour)
75 // ones. This results in slightly smaller files with no loss in any colour
76 // information. The function has no real memory overhead, but does have a
77 // slight speed hit in exchange for the optimisation. For example:
78 // x08c -dev png -drvopt 8bit,optimise -fam -o 8bitpng
79 // forces the png driver to make 8bit pngs, and will then optimise any PNG
80 // images with 16 or less colours into a 4 bit PNG. Note, this DOESN'T WORK
81 // WITH 24bit PNGs yet, and will never work with JPEGs.
82 //
83 //
84 // Also as of version 1.17 of the GD driver, the options for palette
85 // modification previously set with the command line option "-hack" have
86 // now been moved to two options settable from the -drvopt switch.
87 //
88 // def_black15
89 //
90 // -drvopt def_black15 sets index 15, usually white, to black if index 0,
91 // the background colour and usually black, has been set to white from the
92 // command line option -bg
93 //
94 // swp_red15
95 //
96 // -drvopt swp_red15 swaps index 15, usually white, with index 1, which is
97 // usually red. This might be desirable occasionally, but it is principally
98 // included for cases when the background has been set on the command line
99 // to white, and the "def_black15" option has been issued to redefine index
100 // 15 as black. By issuing a command like:
101 // x08c -dev png -bg ffffff -drvopt def_black15,swp_red15
102 // the driver will set the background to white, then redefine index 15 of
103 // cmap0, which is usually white to black, then swap index 2 (red) to 15
104 // (white originally, now black), so at the end of the day, the "default"
105 // plotting colour is now black. Why do all of this ? It is a very quick
106 // way of making a nice web-friendly png without having to redefine the
107 // cmaps within your program.
108 //
109 // smoothlines
110 //
111 // -drvopt smoothlines=1 turns on anti-aliased line and polygong drawing if
112 // you are using a 24bit mode. Unfortunately gd doesn't honour line
113 // width when anti-aliasing, so by default it is off.
114 //
115
116
117 #include "plDevs.h"
118
119 #if defined ( PLD_png ) || defined ( PLD_jpeg ) || defined ( PLD_gif )
120
121 #include "plplotP.h"
122 #include "drivers.h"
123
124 #include <gd.h>
125
126 // Device info
127 //
128 // Don't knoq if all this logic is necessary, but basically we are going to
129 // start with all three sub-drivers present, then work out way down to two
130 // and finally one of each.
131 //
132
133 PLDLLIMPEXP_DRIVER const char* plD_DEVICE_INFO_gd =
134 #if defined ( PLD_png )
135 "png:PNG file:0:gd:39:png\n"
136 #endif
137 #if defined ( PLD_jpeg )
138 "jpeg:JPEG file:0:gd:40:jpeg\n"
139 #endif
140 #if defined ( PLD_gif )
141 "gif:GIF file:0:gd:47:gif\n"
142 #endif
143 ;
144
145 #if GD2_VERS >= 2
146 #ifdef PL_HAVE_FREETYPE
147 #define SMOOTH_LINES_OK
148 #endif
149 #endif
150
151 #ifdef PL_HAVE_FREETYPE
152
153 //
154 // Freetype support has been added to the GD family of drivers using the
155 // plfreetype.c module, and implemented as a driver-specific optional extra
156 // invoked via the -drvopt command line toggle. It uses the
157 // "PLESC_HAS_TEXT" command for rendering within the driver.
158 //
159 // Freetype support is turned on/off at compile time by defining
160 // "PL_HAVE_FREETYPE".
161 //
162 // To give the user some level of control over the fonts that are used,
163 // environmental variables can be set to over-ride the definitions used by
164 // the five default plplot fonts.
165 //
166 // Freetype rendering is used with the command line "-drvopt text".
167 // Anti-aliased fonts can be used by issuing "-drvopt text,smooth"
168 //
169
170 #include "plfreetype.h"
171
172 #endif
173
174 // Prototypes for functions in this file.
175
176 static void fill_polygon( PLStream *pls );
177 static void setcmap( PLStream *pls );
178 static void plD_init_png_Dev( PLStream *pls );
179 static void plD_gd_optimise( PLStream *pls );
180 static void plD_black15_gd( PLStream *pls );
181 static void plD_red15_gd( PLStream *pls );
182 #ifdef PLD_gif
183 static void plD_init_gif_Dev( PLStream *pls );
184 #endif
185
186 #ifdef PL_HAVE_FREETYPE
187
188 static void plD_pixel_gd( PLStream *pls, short x, short y );
189 static PLINT plD_read_pixel_gd( PLStream *pls, short x, short y );
190 static void plD_set_pixel_gd( PLStream *pls, short x, short y, PLINT colour );
191 static void init_freetype_lv1( PLStream *pls );
192 static void init_freetype_lv2( PLStream *pls );
193
194 #endif
195
196 // top level declarations
197
198 static int NCOLOURS = gdMaxColors;
199
200 // In an attempt to fix a problem with the hidden line removal functions
201 // that results in hidden lines *not* being removed from "small" plot
202 // pages (ie, like a normal video screen), a "virtual" page of much
203 // greater size is used to trick the algorithm into working correctly.
204 // If, in future, this gets fixed on its own, then don't define
205 // "use_experimental_hidden_line_hack"
206 //
207
208 #define use_experimental_hidden_line_hack
209
210 // I think the current version of Freetype supports up to a maximum of
211 // 128 grey levels for text smoothing. You can get quite acceptable
212 // results with as few as 4 grey-levels. Uusually only about 5 get used
213 // anyway, but the question is where, in the "grey spectrum" will they be ?
214 // Who knows ? The following define lets you set a maximum limit on the
215 // number of grey-levels used. It is really only here for the 24bit mode
216 // and could be set to 255, but that would slow things down and use more
217 // memory. 64 seems to be a nice compromise, but if you want to change it,
218 // then change it here.
219 //
220
221 #ifndef max_number_of_grey_levels_used_in_text_smoothing
222 #define max_number_of_grey_levels_used_in_text_smoothing 64
223 #endif
224
225 // Not present in versions before 2.0
226
227 #ifndef gdImagePalettePixel
228 #define gdImagePalettePixel( im, x, y ) ( im )->pixels[( y )][( x )]
229 #endif
230
231 #if GD2_VERS >= 2
232 int plToGdAlpha( PLFLT a )
233 {
234 int tmp = (int) ( ( 1.0 - a ) * gdAlphaMax );
235 return tmp;
236 }
237 #endif
238
239 // Struct to hold device-specific info.
240
241 typedef struct
242 {
243 gdImagePtr im_out; // Graphics pointer
244 PLINT pngx;
245 PLINT pngy;
246
247 int colour; // Current Colour
248 int totcol; // Total number of colours
249 int ncol1; // Actual size of ncol1 we got
250
251 PLFLT scale; // scaling factor to "blow up" to
252 // the "virtual" page in removing hidden lines
253
254 int optimise; // Flag used for 4bit pngs
255 int black15; // Flag used for forcing a black colour
256 int red15; // Flag for swapping red and 15
257
258 unsigned char TRY_BLENDED_ANTIALIASING; // Flag to try and set up BLENDED ANTIALIASING
259
260 #if GD2_VERS >= 2
261 int truecolour; // Flag to ALWAYS force 24 bit mode
262 int palette; // Flag to ALWAYS force 8 bit mode
263 unsigned char smooth; // Flag to ask for line smoothing
264 #endif
265 } png_Dev;
266
267 void plD_init_png( PLStream * );
268 void plD_line_png( PLStream *, short, short, short, short );
269 void plD_polyline_png( PLStream *, short *, short *, PLINT );
270 void plD_eop_png( PLStream * );
271 void plD_eop_jpeg( PLStream * );
272 void plD_bop_png( PLStream * );
273 void plD_tidy_png( PLStream * );
274 void plD_state_png( PLStream *, PLINT );
275 void plD_esc_png( PLStream *, PLINT, void * );
276 #ifdef PLD_gif
277 void plD_init_gif( PLStream * );
278 void plD_eop_gif( PLStream * );
279 #endif
280
281 #ifdef PLD_png
282
283 void plD_dispatch_init_png( PLDispatchTable *pdt )
284 {
285 #ifndef ENABLE_DYNDRIVERS
286 pdt->pl_MenuStr = "PNG file";
287 pdt->pl_DevName = "png";
288 #endif
289 pdt->pl_type = plDevType_FileOriented;
290 pdt->pl_seq = 39;
291 pdt->pl_init = (plD_init_fp) plD_init_png;
292 pdt->pl_line = (plD_line_fp) plD_line_png;
293 pdt->pl_polyline = (plD_polyline_fp) plD_polyline_png;
294 pdt->pl_eop = (plD_eop_fp) plD_eop_png;
295 pdt->pl_bop = (plD_bop_fp) plD_bop_png;
296 pdt->pl_tidy = (plD_tidy_fp) plD_tidy_png;
297 pdt->pl_state = (plD_state_fp) plD_state_png;
298 pdt->pl_esc = (plD_esc_fp) plD_esc_png;
299 }
300
301 #endif
302
303 #ifdef PLD_jpeg
304
305 void plD_dispatch_init_jpeg( PLDispatchTable *pdt )
306 {
307 #ifndef ENABLE_DYNDRIVERS
308 pdt->pl_MenuStr = "JPEG File";
309 pdt->pl_DevName = "jpeg";
310 #endif
311 pdt->pl_type = plDevType_FileOriented;
312 pdt->pl_seq = 40;
313 pdt->pl_init = (plD_init_fp) plD_init_png;
314 pdt->pl_line = (plD_line_fp) plD_line_png;
315 pdt->pl_polyline = (plD_polyline_fp) plD_polyline_png;
316 pdt->pl_eop = (plD_eop_fp) plD_eop_jpeg;
317 pdt->pl_bop = (plD_bop_fp) plD_bop_png;
318 pdt->pl_tidy = (plD_tidy_fp) plD_tidy_png;
319 pdt->pl_state = (plD_state_fp) plD_state_png;
320 pdt->pl_esc = (plD_esc_fp) plD_esc_png;
321 }
322 #endif
323
324
325 #ifdef PLD_gif
326
327 void plD_dispatch_init_gif( PLDispatchTable *pdt )
328 {
329 #ifndef ENABLE_DYNDRIVERS
330 pdt->pl_MenuStr = "GIF File";
331 pdt->pl_DevName = "gif";
332 #endif
333 pdt->pl_type = plDevType_FileOriented;
334 pdt->pl_seq = 47;
335 pdt->pl_init = (plD_init_fp) plD_init_gif;
336 pdt->pl_line = (plD_line_fp) plD_line_png;
337 pdt->pl_polyline = (plD_polyline_fp) plD_polyline_png;
338 pdt->pl_eop = (plD_eop_fp) plD_eop_gif;
339 pdt->pl_bop = (plD_bop_fp) plD_bop_png;
340 pdt->pl_tidy = (plD_tidy_fp) plD_tidy_png;
341 pdt->pl_state = (plD_state_fp) plD_state_png;
342 pdt->pl_esc = (plD_esc_fp) plD_esc_png;
343 }
344 #endif
345
346
347 //--------------------------------------------------------------------------
348 // plD_init_png_Dev()
349 //
350 //--------------------------------------------------------------------------
351
352 static void
353 plD_init_png_Dev( PLStream *pls )
354 {
355 png_Dev *dev;
356
357 // Stuff for the driver options, these vars are copied into the driver
358 // structure so that everything is thread safe and reenterant.
359 //
360
361 static int optimise = 0;
362 static int black15 = 0;
363 static int red15 = 0;
364 #if GD2_VERS >= 2
365 static int truecolour = 0;
366 static int palette = 0;
367 static int smooth_line = 0;
368 #endif
369 #ifdef PL_HAVE_FREETYPE
370 static int freetype = 1;
371 static int smooth_text = 1;
372 FT_Data *FT;
373 #endif
374
375 DrvOpt gd_options[] = { { "optimise", DRV_INT, &optimise, "Optimise PNG palette when possible" },
376 { "def_black15", DRV_INT, &black15, "Define idx 15 as black. If the background is \"whiteish\" (from \"-bg\" option), force index 15 (traditionally white) to be \"black\"" },
377 { "swp_red15", DRV_INT, &red15, "Swap index 1 (usually red) and 1 (usually white); always done after \"black15\"; quite useful for quick changes to web pages" },
378 #if GD2_VERS >= 2
379 { "8bit", DRV_INT, &palette, "Palette (8 bit) mode" },
380 { "24bit", DRV_INT, &truecolour, "Truecolor (24 bit) mode" },
381 { "smoothlines", DRV_INT, &smooth_line, "Turn line Anti Aliasing on (1) or off (0)" },
382 #endif
383 #ifdef PL_HAVE_FREETYPE
384 { "text", DRV_INT, &freetype, "Use driver text (FreeType)" },
385 { "smooth", DRV_INT, &smooth_text, "Turn text smoothing on (1) or off (0)" },
386 #endif
387 { NULL, DRV_INT, NULL, NULL } };
388
389
390 // Allocate and initialize device-specific data
391
392 if ( pls->dev != NULL )
393 free( (void *) pls->dev );
394
395 pls->dev = calloc( 1, (size_t) sizeof ( png_Dev ) );
396 if ( pls->dev == NULL )
397 plexit( "plD_init_png_Dev: Out of memory." );
398
399 dev = (png_Dev *) pls->dev;
400
401 dev->colour = 1; // Set a fall back pen colour in case user doesn't
402
403
404 // Check for and set up driver options
405
406 plParseDrvOpts( gd_options );
407
408 dev->black15 = black15;
409 dev->red15 = red15;
410 dev->optimise = optimise;
411
412 #if GD2_VERS >= 2
413
414 dev->palette = palette;
415 dev->truecolour = truecolour;
416
417
418
419 if ( ( dev->truecolour > 0 ) && ( dev->palette > 0 ) )
420 plwarn( "Selecting both \"truecolor\" AND \"palette\" driver options is contradictory, so\nI will just use my best judgment.\n" );
421 else if ( dev->truecolour > 0 )
422 NCOLOURS = 16777216;
423 else if ( ( dev->truecolour == 0 ) && ( dev->palette == 0 ) && ( ( pls->ncol1 + pls->ncol0 ) > NCOLOURS ) )
424 {
425 NCOLOURS = 16777216;
426 }
427
428 if ( ( dev->palette == 0 ) && ( dev->optimise == 0 ) && ( smooth_line == 1 ) )
429 dev->smooth = 1; // Allow smoothing of lines if we have a truecolour device
430
431 #endif
432
433 #ifdef PL_HAVE_FREETYPE
434 if ( freetype )
435 {
436 pls->dev_text = 1; // want to draw text
437 pls->dev_unicode = 1; // want unicode
438
439 // As long as we aren't optimising, we'll try to use better antialaising
440 // We can also only do this if the user wants smoothing, and hasn't
441 // selected a palette mode.
442 //
443
444
445 init_freetype_lv1( pls );
446 FT = (FT_Data *) pls->FT;
447 FT->want_smooth_text = smooth_text > 0 ? 1 : 0;
448 if ( ( dev->optimise == 0 ) && ( dev->palette == 0 ) && ( smooth_text != 0 ) )
449 {
450 FT->BLENDED_ANTIALIASING = 1;
451 dev->truecolour = 1;
452 }
453 }
454
455 #endif
456 }
457
458 //--------------------------------------------------------------------------
459 // plD_init_png()
460 //
461 // Initialize device.
462 //--------------------------------------------------------------------------
463
464 void plD_init_png( PLStream *pls )
465 {
466 png_Dev *dev = NULL;
467
468 pls->termin = 0; // Not an interactive device
469 pls->icol0 = 1;
470 pls->bytecnt = 0;
471 pls->page = 0;
472 pls->dev_fill0 = 1; // Can do solid fills
473
474 if ( !pls->colorset )
475 pls->color = 1; // Is a color device
476
477 // Initialize family file info
478 plFamInit( pls );
479
480 // Prompt for a file name if not already set
481 plOpenFile( pls );
482
483 // Allocate and initialize device-specific data
484 plD_init_png_Dev( pls );
485 dev = (png_Dev *) pls->dev;
486
487 // set dpi and page size defaults if the user has not already set
488 // these with -dpi or -geometry command line options or with
489 // plspage.
490
491 if ( pls->xdpi <= 0. || pls->ydpi <= 0. )
492 {
493 // Use recommended default pixels per inch.
494 plspage( PLPLOT_DEFAULT_PIXELS_PER_INCH, PLPLOT_DEFAULT_PIXELS_PER_INCH, 0, 0, 0, 0 );
495 }
496
497 if ( pls->xlength == 0 || pls->ylength == 0 )
498 {
499 // Use recommended default pixel width and height.
500 plspage( 0., 0., PLPLOT_DEFAULT_WIDTH_PIXELS, PLPLOT_DEFAULT_HEIGHT_PIXELS, 0, 0 );
501 }
502
503 pls->graphx = GRAPHICS_MODE;
504
505 dev->pngx = pls->xlength - 1; // should I use -1 or not???
506 dev->pngy = pls->ylength - 1;
507
508 #ifdef use_experimental_hidden_line_hack
509
510 if ( dev->pngx > dev->pngy ) // Work out the scaling factor for the
511 { // "virtual" (oversized) page
512 dev->scale = (PLFLT) ( PIXELS_X - 1 ) / (PLFLT) dev->pngx;
513 }
514 else
515 {
516 dev->scale = (PLFLT) PIXELS_Y / (PLFLT) dev->pngy;
517 }
518 #else
519
520 dev->scale = 1.;
521
522 #endif
523
524 // Convert DPI to pixels/mm
525 plP_setpxl( dev->scale * pls->xdpi / PLPLOT_MM_PER_INCH, dev->scale * pls->ydpi / PLPLOT_MM_PER_INCH );
526
527 plP_setphy( 0, dev->scale * dev->pngx, 0, dev->scale * dev->pngy );
528
529 #ifdef PL_HAVE_FREETYPE
530 if ( pls->dev_text )
531 {
532 init_freetype_lv2( pls );
533 }
534 #endif
535 }
536
537
538 #ifdef PLD_gif
539
540 //--------------------------------------------------------------------------
541 // plD_init_gif_Dev()
542 //
543 // We need a new initialiser for the GIF version of the GD driver because
544 // the GIF one does not support TRUECOLOUR
545 //--------------------------------------------------------------------------
546
547 static void
548 plD_init_gif_Dev( PLStream *pls )
549 {
550 png_Dev *dev;
551
552 // Stuff for the driver options, these vars are copied into the driver
553 // structure so that everything is thread safe and reenterant.
554 //
555
556 static int black15 = 0;
557 static int red15 = 0;
558 #ifdef PL_HAVE_FREETYPE
559 static int freetype = 1;
560 static int smooth_text = 0;
561 FT_Data *FT;
562 #endif
563
564 DrvOpt gd_options[] = { { "def_black15", DRV_INT, &black15, "Define idx 15 as black. If the background is \"whiteish\" (from \"-bg\" option), force index 15 (traditionally white) to be \"black\"" },
565 { "swp_red15", DRV_INT, &red15, "Swap index 1 (usually red) and 1 (usually white); always done after \"black15\"; quite useful for quick changes to web pages" },
566 #ifdef PL_HAVE_FREETYPE
567 { "text", DRV_INT, &freetype, "Use driver text (FreeType)" },
568 { "smooth", DRV_INT, &smooth_text, "Turn text smoothing on (1) or off (0)" },
569 #endif
570 { NULL, DRV_INT, NULL, NULL } };
571
572
573 // Allocate and initialize device-specific data
574
575 if ( pls->dev != NULL )
576 free( (void *) pls->dev );
577
578 pls->dev = calloc( 1, (size_t) sizeof ( png_Dev ) );
579 if ( pls->dev == NULL )
580 plexit( "plD_init_gif_Dev: Out of memory." );
581
582 dev = (png_Dev *) pls->dev;
583
584 dev->colour = 1; // Set a fall back pen colour in case user doesn't
585
586 // Check for and set up driver options
587
588 plParseDrvOpts( gd_options );
589
590 dev->black15 = black15;
591 dev->red15 = red15;
592
593 dev->optimise = 0; // Optimise does not work for GIFs... should, but it doesn't
594 dev->palette = 1; // Always use palette mode for GIF files
595 dev->truecolour = 0; // Never have truecolour in GIFS
596
597 #ifdef PL_HAVE_FREETYPE
598 if ( freetype )
599 {
600 pls->dev_text = 1; // want to draw text
601 pls->dev_unicode = 1; // want unicode
602
603 init_freetype_lv1( pls );
604 FT = (FT_Data *) pls->FT;
605
606 FT->want_smooth_text = smooth_text > 0 ? 1 : 0;
607 }
608
609 #endif
610 }
611
612 //--------------------------------------------------------------------------
613 // plD_init_gif()
614 //
615 // Initialize device.
616 //--------------------------------------------------------------------------
617
618 void plD_init_gif( PLStream *pls )
619 {
620 png_Dev *dev = NULL;
621
622 pls->termin = 0; // Not an interactive device
623 pls->icol0 = 1;
624 pls->bytecnt = 0;
625 pls->page = 0;
626 pls->dev_fill0 = 1; // Can do solid fills
627
628 if ( !pls->colorset )
629 pls->color = 1; // Is a color device
630
631 // Initialize family file info
632 plFamInit( pls );
633
634 // Prompt for a file name if not already set
635 plOpenFile( pls );
636
637 // Allocate and initialize device-specific data
638 plD_init_gif_Dev( pls );
639 dev = (png_Dev *) pls->dev;
640
641 // set dpi and page size defaults if the user has not already set
642 // these with -dpi or -geometry command line options or with
643 // plspage.
644
645 if ( pls->xdpi <= 0. || pls->ydpi <= 0. )
646 {
647 // Use recommended default pixels per inch.
648 plspage( PLPLOT_DEFAULT_PIXELS_PER_INCH, PLPLOT_DEFAULT_PIXELS_PER_INCH, 0, 0, 0, 0 );
649 }
650
651 if ( pls->xlength == 0 || pls->ylength == 0 )
652 {
653 // Use recommended default pixel width and height.
654 plspage( 0., 0., PLPLOT_DEFAULT_WIDTH_PIXELS, PLPLOT_DEFAULT_HEIGHT_PIXELS, 0, 0 );
655 }
656
657 pls->graphx = GRAPHICS_MODE;
658
659 dev->pngx = pls->xlength - 1; // should I use -1 or not???
660 dev->pngy = pls->ylength - 1;
661
662 #ifdef use_experimental_hidden_line_hack
663
664 if ( dev->pngx > dev->pngy ) // Work out the scaling factor for the
665 { // "virtual" (oversized) page
666 dev->scale = (PLFLT) ( PIXELS_X - 1 ) / (PLFLT) dev->pngx;
667 }
668 else
669 {
670 dev->scale = (PLFLT) PIXELS_Y / (PLFLT) dev->pngy;
671 }
672 #else
673
674 dev->scale = 1.;
675
676 #endif
677
678
679 // Convert DPI to pixels/mm
680 plP_setpxl( dev->scale * pls->xdpi / PLPLOT_MM_PER_INCH, dev->scale * pls->ydpi / PLPLOT_MM_PER_INCH );
681
682 plP_setphy( 0, dev->scale * dev->pngx, 0, dev->scale * dev->pngy );
683
684 #ifdef PL_HAVE_FREETYPE
685 if ( pls->dev_text )
686 {
687 init_freetype_lv2( pls );
688 }
689 #endif
690 }
691
692 #endif
693
694
695 //--------------------------------------------------------------------------
696 // plD_line_png()
697 //
698 // Draw a line in the current color from (x1,y1) to (x2,y2).
699 //--------------------------------------------------------------------------
700
701 void
702 plD_line_png( PLStream *pls, short x1a, short y1a, short x2a, short y2a )
703 {
704 png_Dev *dev = (png_Dev *) pls->dev;
705 int x1 = x1a / dev->scale, y1 = y1a / dev->scale, x2 = x2a / dev->scale, y2 = y2a / dev->scale;
706 y1 = dev->pngy - y1;
707 y2 = dev->pngy - y2;
708
709 #ifdef SMOOTH_LINES_OK
710 if ( dev->smooth == 1 )
711 {
712 gdImageSetAntiAliased( dev->im_out, dev->colour );
713 gdImageLine( dev->im_out, x1, y1, x2, y2, gdAntiAliased );
714 }
715 else
716 {
717 gdImageLine( dev->im_out, x1, y1, x2, y2, dev->colour );
718 }
719 #else
720 gdImageLine( dev->im_out, x1, y1, x2, y2, dev->colour );
721 #endif
722 }
723
724 //--------------------------------------------------------------------------
725 // plD_polyline_png()
726 //
727 // Draw a polyline in the current color.
728 //--------------------------------------------------------------------------
729
730 void
731 plD_polyline_png( PLStream *pls, short *xa, short *ya, PLINT npts )
732 {
733 PLINT i;
734
735 for ( i = 0; i < npts - 1; i++ )
736 plD_line_png( pls, xa[i], ya[i], xa[i + 1], ya[i + 1] );
737 }
738
739
740 //--------------------------------------------------------------------------
741 // fill_polygon()
742 //
743 // Fill polygon described in points pls->dev_x[] and pls->dev_y[].
744 //--------------------------------------------------------------------------
745
746 static void
747 fill_polygon( PLStream *pls )
748 {
749 png_Dev *dev = (png_Dev *) pls->dev;
750
751 int i;
752 gdPoint *points = NULL;
753
754 if ( pls->dev_npts < 1 )
755 return;
756
757 points = malloc( (size_t) pls->dev_npts * sizeof ( gdPoint ) );
758
759 for ( i = 0; i < pls->dev_npts; i++ )
760 {
761 points[i].x = pls->dev_x[i] / dev->scale;
762 points[i].y = dev->pngy - ( pls->dev_y[i] / dev->scale );
763 }
764
765 #ifdef SMOOTH_LINES_OK
766 if ( dev->smooth == 1 )
767 {
768 gdImageSetAntiAliased( dev->im_out, dev->colour );
769 gdImageFilledPolygon( dev->im_out, points, pls->dev_npts, gdAntiAliased );
770 }
771 else
772 {
773 gdImageFilledPolygon( dev->im_out, points, pls->dev_npts, dev->colour );
774 }
775 #else
776 gdImageFilledPolygon( dev->im_out, points, pls->dev_npts, dev->colour );
777 #endif
778
779 free( points );
780 }
781
782 //--------------------------------------------------------------------------
783 // setcmap()
784 //
785 // Sets up color palette.
786 //--------------------------------------------------------------------------
787
788 static void
789 setcmap( PLStream *pls )
790 {
791 int i, ncol1 = pls->ncol1;
792 int ncol0 = pls->ncol0, total_colours;
793 PLColor cmap1col;
794 png_Dev *dev = (png_Dev *) pls->dev;
795 PLFLT tmp_colour_pos;
796
797 //
798 // Yuckky fix to get rid of the previosuly allocated palette from the
799 // GD image
800 //
801
802 if ( dev->im_out != NULL )
803 {
804 for ( i = 0; i < 256; i++ )
805 {
806 gdImageColorDeallocate( dev->im_out, i );
807 }
808 }
809
810 if ( ncol0 > NCOLOURS / 2 ) // Check for ridiculous number of colours
811 { // in ncol0, and appropriately adjust the
812 plwarn( "Too many colours in cmap0." ); // number, issuing a
813 ncol0 = NCOLOURS / 2; // warning if it does
814 pls->ncol0 = ncol0;
815 }
816
817 dev->totcol = 0; // Reset the number of colours counter to zero
818
819 total_colours = ncol0 + ncol1; // Work out how many colours are wanted
820
821 if ( total_colours > NCOLOURS ) // Do some rather modest error
822 { // checking to make sure that
823 total_colours = NCOLOURS; // we are not defining more colours
824 ncol1 = total_colours - ncol0; // than we have room for.
825
826 if ( ncol1 <= 0 )
827 {
828 plexit( "Problem setting colourmap in PNG or JPEG driver." );
829 }
830 }
831
832 dev->ncol1 = ncol1; // The actual size of ncol1, regardless of what was asked.
833 // This is dependent on colour slots available.
834 // It might well be the same as ncol1.
835 //
836
837 // Initialize cmap 0 colors
838
839 if ( ( ncol0 > 0 ) && ( dev->im_out != NULL ) ) // make sure the program actually asked for cmap0 first
840 {
841 for ( i = 0; i < ncol0; i++ )
842 {
843 #if GD2_VERS >= 2
844 gdImageColorAllocateAlpha( dev->im_out,
845 pls->cmap0[i].r, pls->cmap0[i].g, pls->cmap0[i].b,
846 plToGdAlpha( pls->cmap0[i].a ) );
847 #else
848 gdImageColorAllocate( dev->im_out,
849 pls->cmap0[i].r, pls->cmap0[i].g, pls->cmap0[i].b );
850 #endif
851 ++dev->totcol; // count the number of colours we use as we use them
852 }
853 }
854
855 // Initialize any remaining slots for cmap1
856
857
858 if ( ( ncol1 > 0 ) && ( dev->im_out != NULL ) ) // make sure that we want to define cmap1 first
859 {
860 for ( i = 0; i < ncol1; i++ )
861 {
862 if ( ncol1 < pls->ncol1 ) // Check the dynamic range of colours
863 {
864 //
865 // Ok, now if we have less colour slots available than are being
866 // defined by pls->ncol1, then we still want to use the full
867 // dynamic range of cmap1 as best we can, so what we do is work
868 // out an approximation to the index in the full dynamic range
869 // in cases when pls->ncol1 exceeds the number of free colours.
870 //
871
872 tmp_colour_pos = i > 0 ? pls->ncol1 * ( (PLFLT) i / ncol1 ) : 0;
873 plcol_interp( pls, &cmap1col, (int) tmp_colour_pos, pls->ncol1 );
874 }
875 else
876 {
877 plcol_interp( pls, &cmap1col, i, ncol1 );
878 }
879
880
881 #if GD2_VERS >= 2
882 gdImageColorAllocateAlpha( dev->im_out,
883 cmap1col.r, cmap1col.g, cmap1col.b,
884 plToGdAlpha( cmap1col.a ) );
885 #else
886 gdImageColorAllocate( dev->im_out,
887 cmap1col.r, cmap1col.g, cmap1col.b );
888 #endif
889
890 ++dev->totcol; // count the number of colours we use as we go
891 }
892 }
893 }
894
895
896 //--------------------------------------------------------------------------
897 // plD_state_png()
898 //
899 // Handle change in PLStream state (color, pen width, fill attribute, etc).
900 //--------------------------------------------------------------------------
901
902 void
903 plD_state_png( PLStream *pls, PLINT op )
904 {
905 png_Dev *dev = (png_Dev *) pls->dev;
906 PLFLT tmp_colour_pos;
907 #if GD2_VERS >= 2
908 long temp_col;
909 #endif
910
911
912 switch ( op )
913 {
914 #if GD2_VERS >= 2
915 case PLSTATE_WIDTH:
916 gdImageSetThickness( dev->im_out, pls->width );
917 break;
918 #endif
919
920 case PLSTATE_COLOR0:
921 #if GD2_VERS >= 2
922
923 if ( ( pls->icol0 == PL_RGB_COLOR ) || // Should never happen since PL_RGB_COLOR is deprecated, but here for backwards compatibility
924 ( gdImageTrueColor( dev->im_out ) ) ) // We will do this if we are in "TrueColour" mode
925 {
926 if ( ( dev->totcol < NCOLOURS ) || // See if there are slots left, if so we will allocate a new colour
927 ( gdImageTrueColor( dev->im_out ) ) ) // In TrueColour mode we allocate each colour as we come to it
928 {
929 // Next allocate a new colour to a temporary slot since what we do with it will vary depending on if its a palette index or truecolour
930 #if GD2_VERS >= 2
931 temp_col = gdImageColorAllocateAlpha( dev->im_out, pls->curcolor.r,
932 pls->curcolor.g, pls->curcolor.b,
933 plToGdAlpha( pls->curcolor.a ) );
934 #else
935 temp_col = gdImageColorAllocate( dev->im_out, pls->curcolor.r,
936 pls->curcolor.g, pls->curcolor.b );
937 #endif
938
939 if ( gdImageTrueColor( dev->im_out ) )
940 dev->colour = temp_col; // If it's truecolour, then we will directly set dev->colour to our "new" colour
941 else
942 {
943 dev->colour = dev->totcol; // or else, we will just set it to the last colour
944 dev->totcol++; // Bump the total colours for next time round
945 }
946 }
947 }
948 else // just a normal colour allocate, so don't worry about the above stuff, just grab the index
949 {
950 dev->colour = pls->icol0;
951 }
952
953 #else
954 dev->colour = pls->icol0;
955 if ( dev->colour == PL_RGB_COLOR )
956 {
957 if ( dev->totcol < NCOLOURS )
958 {
959 #if GD2_VERS >= 2
960 gdImageColorAllocateAlpha( dev->im_out, pls->curcolor.r,
961 pls->curcolor.g, pls->curcolor.b,
962 plToGdAlpha( pls->curcolor.a ) );
963 #else
964 gdImageColorAllocate( dev->im_out, pls->curcolor.r,
965 pls->curcolor.g, pls->curcolor.b );
966 #endif
967 dev->colour = dev->totcol;
968 }
969 }
970 #endif
971 break;
972
973 case PLSTATE_COLOR1:
974
975 #if GD2_VERS >= 2
976 if ( !gdImageTrueColor( dev->im_out ) )
977 {
978 #endif
979 //
980 // Start by checking to see if we have to compensate for cases where
981 // we don't have the full dynamic range of cmap1 at our disposal
982 //
983 if ( dev->ncol1 < pls->ncol1 )
984 {
985 tmp_colour_pos = dev->ncol1 * ( (PLFLT) pls->icol1 / ( pls->ncol1 > 0 ? pls->ncol1 : 1 ) );
986 dev->colour = pls->ncol0 + (int) tmp_colour_pos;
987 }
988 else
989 dev->colour = pls->ncol0 + pls->icol1;
990 #if GD2_VERS >= 2
991 }
992 else // it is a truecolour image
993 {
994 #if GD2_VERS >= 2
995 dev->colour = gdTrueColorAlpha( pls->curcolor.r, pls->curcolor.g,
996 pls->curcolor.b,
997 plToGdAlpha( pls->curcolor.a ) );
998 #else
999 dev->colour = gdTrueColor( pls->curcolor.r, pls->curcolor.g,
1000 pls->curcolor.b );
1001 #endif
1002 }
1003 #endif
1004 break;
1005
1006
1007 case PLSTATE_CMAP0:
1008 case PLSTATE_CMAP1:
1009
1010 #if GD2_VERS >= 2
1011 if ( ( dev->im_out != NULL ) && !gdImageTrueColor( dev->im_out ) )
1012 {
1013 #endif
1014
1015 //
1016 // Code to redefine the entire palette
1017 //
1018
1019
1020 if ( pls->color )
1021 setcmap( pls );
1022
1023 #if GD2_VERS >= 2
1024 }
1025 #endif
1026
1027 break;
1028 }
1029 }
1030
1031
1032 //--------------------------------------------------------------------------
1033 // plD_esc_png()
1034 //
1035 // Escape function.
1036 //--------------------------------------------------------------------------
1037
1038 void plD_esc_png( PLStream *pls, PLINT op, void *ptr )
1039 {
1040 switch ( op )
1041 {
1042 case PLESC_FILL: // fill
1043 fill_polygon( pls );
1044 break;
1045
1046 #ifdef PL_HAVE_FREETYPE
1047 case PLESC_HAS_TEXT:
1048 plD_render_freetype_text( pls, (EscText *) ptr );
1049 break;
1050 #endif
1051 }
1052 }
1053
1054 //--------------------------------------------------------------------------
1055 // plD_bop_png()
1056 //
1057 // Set up for the next page.
1058 // Advance to next family file if necessary (file output).
1059 //--------------------------------------------------------------------------
1060
1061 void plD_bop_png( PLStream *pls )
1062 {
1063 png_Dev *dev;
1064
1065 plGetFam( pls );
1066 // force new file if pls->family set for all subsequent calls to plGetFam
1067 // n.b. putting this after plGetFam call is important since plinit calls
1068 // bop, and you don't want the familying sequence started until after
1069 // that first call to bop.
1070
1071 // n.b. pls->dev can change because of an indirect call to plD_init_png
1072 // from plGetFam if familying is enabled. Thus, wait to define dev until
1073 // now.
1074
1075 dev = (png_Dev *) pls->dev;
1076
1077 pls->famadv = 1;
1078
1079 pls->page++;
1080
1081 if ( dev->black15 )
1082 plD_black15_gd( pls );
1083 if ( dev->red15 )
1084 plD_red15_gd( pls );
1085
1086 #if GD2_VERS >= 2
1087 if ( ( ( ( ( dev->truecolour > 0 ) && ( dev->palette > 0 ) ) || // In an EXTREMELY convaluted
1088 ( ( dev->truecolour == 0 ) && ( dev->palette == 0 ) ) ) && // manner, all this is just
1089 ( ( pls->ncol1 + pls->ncol0 ) <= 256 ) ) || // asking the question, do we
1090 ( ( ( dev->palette > 0 ) && ( dev->truecolour == 0 ) ) ) ) // want truecolour or not ?
1091 {
1092 #endif
1093
1094 dev->im_out = gdImageCreate( pls->xlength, pls->ylength );
1095
1096 setcmap( pls );
1097
1098 #if GD2_VERS >= 2
1099 }
1100 else
1101 {
1102 dev->im_out = gdImageCreateTrueColor( pls->xlength, pls->ylength );
1103 plP_state( PLSTATE_COLOR0 );
1104
1105 //
1106 // In truecolour mode, the background colour GD makes is ALWAYS black, so to
1107 // "simulate" (stimulate?) a background colour other than black, we will just
1108 // draw a dirty big rectange covering the whole image and colour it in
1109 // whatever colour cmap0[0] happens to be.
1110 //
1111 // Question to C gurus: while it is slightly illogical and ugly, would:
1112 // if ((pls->cmap0[0].r+pls->cmap0[0].g+pls->cmap0[0].b)!=0)
1113 // be more computationally efficient than:
1114 // if ((pls->cmap0[0].r!=0)||(pls->cmap0[0].g!=0)||(pls->cmap0[0].b!=0))
1115 // ???
1116 //
1117
1118 if ( ( pls->cmap0[0].r != 0 ) || ( pls->cmap0[0].g != 0 ) ||
1119 ( pls->cmap0[0].b != 0 ) || ( pls->cmap0[0].a != 0.0 ) )
1120 {
1121 gdImageFilledRectangle( dev->im_out, 0, 0, pls->xlength - 1, pls->ylength - 1,
1122 gdTrueColorAlpha( pls->cmap0[0].r, pls->cmap0[0].g,
1123 pls->cmap0[0].b,
1124 plToGdAlpha( pls->cmap0[0].a ) ) );
1125 }
1126 }
1127
1128
1129 // This ensures the line width is set correctly at the beginning of
1130 // each page
1131
1132 plD_state_png( pls, PLSTATE_WIDTH );
1133
1134 #endif
1135 }
1136
1137 //--------------------------------------------------------------------------
1138 // plD_tidy_png()
1139 //
1140 // Close graphics file or otherwise clean up.
1141 //--------------------------------------------------------------------------
1142
1143 void plD_tidy_png( PLStream *pls )
1144 {
1145 #ifdef PL_HAVE_FREETYPE
1146 if ( pls->dev_text )
1147 {
1148 plD_FreeType_Destroy( pls );
1149 }
1150 #endif
1151
1152 plCloseFile( pls );
1153 free_mem( pls->dev );
1154 }
1155
1156 //--------------------------------------------------------------------------
1157 // plD_black15_gd()
1158 //
1159 // This small function simply redefines index 15 of cmap0, which is
1160 // usually set to white, to black, but only if index 0, which is usually
1161 // black, has been redefined to white (for example, through -bg).
1162 //
1163 //--------------------------------------------------------------------------
1164
1165 void plD_black15_gd( PLStream *pls )
1166 {
1167 if ( pls->ncol0 > 15 )
1168 {
1169 if ( ( pls->cmap0[0].r > 227 ) && ( pls->cmap0[0].g > 227 ) && ( pls->cmap0[0].b > 227 ) )
1170 {
1171 pls->cmap0[15].r = 0;
1172 pls->cmap0[15].g = 0;
1173 pls->cmap0[15].b = 0;
1174 }
1175 }
1176 }
1177
1178
1179 //--------------------------------------------------------------------------
1180 // plD_red15_gd()
1181 //
1182 //
1183 // This function swaps index 1, often the default plotting colour, with
1184 // index 15, the last defined colour.
1185 //
1186 // Colour 15 is usually white, and 1 is usually red, so swapping the two
1187 // might be desirable occasionally, but it is principally here for cases
1188 // when the background has been set on the command line to white, and the
1189 // "def_black15" option has been issued to redefine index 15 as black. By
1190 // issuing a command like
1191 //
1192 // ... -bg ffffff -drvopt def_black15,swp_red15
1193 //
1194 // the driver will set the background to white, then redefine index 15 of
1195 // cmap0, which is usually white to black, then swap index 2 (red) to 15
1196 // (white originally, now black), so at the end of the day, the "default"
1197 // plotting colour is now black. Why do all of this ? It is a very quick
1198 // way of making a nice web-friendly png without having to redefine the
1199 // cmaps within your program.
1200 //
1201 // If you don't like it, don't use it !
1202 //
1203 //--------------------------------------------------------------------------
1204
1205 void plD_red15_gd( PLStream *pls )
1206 {
1207 char r = pls->cmap0[1].r;
1208 char g = pls->cmap0[1].g;
1209 char b = pls->cmap0[1].b;
1210
1211 if ( pls->ncol0 > 15 )
1212 {
1213 pls->cmap0[1].r = pls->cmap0[15].r;
1214 pls->cmap0[1].g = pls->cmap0[15].r;
1215 pls->cmap0[1].b = pls->cmap0[15].r;
1216
1217 pls->cmap0[15].r = r;
1218 pls->cmap0[15].g = g;
1219 pls->cmap0[15].b = b;
1220 }
1221 }
1222
1223
1224 //--------------------------------------------------------------------------
1225 // plD_gd_optimise()
1226 //
1227 //
1228 // This function pretty much does exactly what it says - it optimises the
1229 // PNG file. It does this by checking to see if all the allocated colours
1230 // were actually used. If they were not, then it deallocates them. This
1231 // function often results in the PNG file being saved as a 4 bit (16
1232 // colour) PNG rather than an 8 bit (256 colour) PNG. The file size
1233 // difference is not huge, not as great as for GIFs for example (I think
1234 // most of the saving comes from removing redundant entries from the
1235 // palette entry in the header); however some modest size savings occur.
1236 //
1237 // The function isn't always successful - the optimiser will always
1238 // deallocate unused colours as it finds them, but GD will only deallocate
1239 // them "for real" until 16 colours are used up, and then stop since it
1240 // doesn't make a difference if you have 17 colours or 255 colours. The
1241 // result of this is you may end up with an image using say, 130 colours,
1242 // but you will have 240 colour entries, some of which aren't used, and
1243 // aren't blanked out.
1244 //
1245 // Another side-effect of this function is the relative position of the
1246 // colour indices MAY shift as colours are deallocated. I really don't
1247 // think this should worry anyone, but if it does, don't optimise the
1248 // image !
1249 //
1250 //--------------------------------------------------------------------------
1251
1252 void plD_gd_optimise( PLStream *pls )
1253 {
1254 png_Dev *dev = (png_Dev *) pls->dev;
1255 int i, j;
1256 char *bbuf;
1257
1258 bbuf = calloc( 256, (size_t) 1 ); // Allocate a buffer to "check off" colours as they are used
1259 if ( bbuf == NULL )
1260 plexit( "plD_gd_optimise: Out of memory." );
1261
1262 for ( i = 0; i < ( pls->xlength - 1 ); i++ ) // Walk through the image pixel by pixel
1263 { // checking to see what colour it is
1264 for ( j = 0; j < ( pls->ylength - 1 ); j++ ) // and adding it to the list of used colours
1265 {
1266 bbuf[gdImagePalettePixel( dev->im_out, i, j )] = 1;
1267 }
1268 }
1269
1270 for ( i = 0; i < 256; i++ ) // next walk over the colours and deallocate
1271 { // unused ones
1272 if ( bbuf[i] == 0 )
1273 gdImageColorDeallocate( dev->im_out, i );
1274 }
1275
1276 free( bbuf );
1277 }
1278
1279
1280 #ifdef PLD_png
1281
1282 //--------------------------------------------------------------------------
1283 // plD_eop_png()
1284 //
1285 // End of page.
1286 //--------------------------------------------------------------------------
1287
1288 void plD_eop_png( PLStream *pls )
1289 {
1290 png_Dev *dev = (png_Dev *) pls->dev;
1291 int im_size = 0;
1292 int png_compression;
1293 void *im_ptr = NULL;
1294 size_t nwrite;
1295
1296 if ( pls->family || pls->page == 1 )
1297 {
1298 if ( dev->optimise )
1299 {
1300 #if GD2_VERS >= 2
1301 if ( ( ( ( ( dev->truecolour > 0 ) && ( dev->palette > 0 ) ) || // In an EXTREMELY convaluted
1302 ( ( dev->truecolour == 0 ) && ( dev->palette == 0 ) ) ) && // manner, all this is just
1303 ( ( pls->ncol1 + pls->ncol0 ) <= 256 ) ) || // asking the question, do we
1304 ( ( ( dev->palette > 0 ) && ( dev->truecolour == 0 ) ) ) ) // want truecolour or not ?
1305 {
1306 #endif
1307 plD_gd_optimise( pls );
1308
1309 #if GD2_VERS >= 2
1310 }
1311 #endif
1312 }
1313
1314
1315 // image is written to output file by the driver
1316 // since if the gd.dll is linked to a different c
1317 // lib a crash occurs - this fix works also in Linux
1318 // gdImagePng(dev->im_out, pls->OutFile);
1319 #if GD2_VERS >= 2
1320
1321 //Set the compression/quality level for PNG files.
1322 // pls->dev_compression values of 1-9 translate to the zlib compression values 1-9
1323 // pls->dev_compression values 10 <= compression <= 99 are divided by 10 to get the zlib
1324 // compression value. Values <=0 or greater than 99 are set to 90 which
1325 // translates to a zlib compression value of 9, the highest quality
1326 // of compression or smallest file size or largest computer time required
1327 // to achieve the compression. Smaller zlib compression values correspond
1328 // to lower qualities of compression (larger file size), but lower
1329 // computer times as well.
1330
1331 png_compression = ( ( pls->dev_compression <= 0 ) || ( pls->dev_compression > 99 ) ) ? 90 : pls->dev_compression;
1332 png_compression = ( png_compression > 9 ) ? ( png_compression / 10 ) : png_compression;
1333 im_ptr = gdImagePngPtrEx( dev->im_out, &im_size, png_compression );
1334 #else
1335 im_ptr = gdImagePngPtr( dev->im_out, &im_size );
1336 #endif
1337 if ( im_ptr )
1338 {
1339 nwrite = fwrite( im_ptr, sizeof ( char ), im_size, pls->OutFile );
1340 if ( nwrite != im_size )
1341 plabort( "gd driver: Error writing png file" );
1342 gdFree( im_ptr );
1343 }
1344
1345 gdImageDestroy( dev->im_out );
1346 dev->im_out = NULL;
1347 }
1348 }
1349
1350 #endif
1351
1352 #ifdef PL_HAVE_FREETYPE
1353
1354 //--------------------------------------------------------------------------
1355 // void plD_pixel_gd (PLStream *pls, short x, short y)
1356 //
1357 // callback function, of type "plD_pixel_fp", which specifies how a single
1358 // pixel is set in the current colour.
1359 //--------------------------------------------------------------------------
1360
1361 void plD_pixel_gd( PLStream *pls, short x, short y )
1362 {
1363 png_Dev *dev = (png_Dev *) pls->dev;
1364
1365 gdImageSetPixel( dev->im_out, x, y, dev->colour );
1366 }
1367
1368 //--------------------------------------------------------------------------
1369 // void plD_set_pixel_gd (PLStream *pls, short x, short y)
1370 //
1371 // callback function, of type "plD_pixel_fp", which specifies how a single
1372 // pixel is set directly to hardware, using the colour provided
1373 //--------------------------------------------------------------------------
1374
1375 void plD_set_pixel_gd( PLStream *pls, short x, short y, PLINT colour )
1376 {
1377 png_Dev *dev = (png_Dev *) pls->dev;
1378 int R, G, B;
1379 int Colour;
1380
1381 G = GetGValue( colour );
1382 R = GetRValue( colour );
1383 B = GetBValue( colour );
1384
1385 Colour = gdImageColorResolve( dev->im_out, R, G, B );
1386 gdImageSetPixel( dev->im_out, x, y, Colour );
1387 }
1388
1389 //--------------------------------------------------------------------------
1390 // PLINT plD_read_pixel_gd (PLStream *pls, short x, short y)
1391 //
1392 // callback function, of type "plD_read_pixel_gd", which specifies how a
1393 // single pixel's RGB is read (in the destination context), then
1394 // returns an RGB encoded int with the info for blending.
1395 //--------------------------------------------------------------------------
1396
1397 PLINT plD_read_pixel_gd( PLStream *pls, short x, short y )
1398 {
1399 png_Dev *dev = (png_Dev *) pls->dev;
1400 PLINT colour;
1401 unsigned char R, G, B;
1402
1403 colour = gdImageGetTrueColorPixel( dev->im_out, x, y );
1404
1405 R = gdTrueColorGetRed( colour );
1406 G = gdTrueColorGetGreen( colour );
1407 B = gdTrueColorGetBlue( colour );
1408
1409 colour = RGB( R, G, B );
1410 return ( colour );
1411 }
1412
1413
1414 //--------------------------------------------------------------------------
1415 // void init_freetype_lv1 (PLStream *pls)
1416 //
1417 // "level 1" initialisation of the freetype library.
1418 // "Level 1" initialisation calls plD_FreeType_init(pls) which allocates
1419 // memory to the pls->FT structure, then sets up the pixel callback
1420 // function.
1421 //--------------------------------------------------------------------------
1422
1423 static void init_freetype_lv1( PLStream *pls )
1424 {
1425 FT_Data *FT;
1426
1427 plD_FreeType_init( pls );
1428
1429 FT = (FT_Data *) pls->FT;
1430 FT->pixel = (plD_pixel_fp) plD_pixel_gd;
1431 FT->read_pixel = (plD_read_pixel_fp) plD_read_pixel_gd;
1432 FT->set_pixel = (plD_set_pixel_fp) plD_set_pixel_gd;
1433 }
1434
1435 //--------------------------------------------------------------------------
1436 // void init_freetype_lv2 (PLStream *pls)
1437 //
1438 // "Level 2" initialisation of the freetype library.
1439 // "Level 2" fills in a few setting that aren't public until after the
1440 // graphics sub-syetm has been initialised.
1441 // The "level 2" initialisation fills in a few things that are defined
1442 // later in the initialisation process for the GD driver.
1443 //
1444 // FT->scale is a scaling factor to convert co-ordinates. This is used by
1445 // the GD and other drivers to scale back a larger virtual page and this
1446 // eliminate the "hidden line removal bug". Set it to 1 if your device
1447 // doesn't have scaling.
1448 //
1449 // Some coordinate systems have zero on the bottom, others have zero on
1450 // the top. Freetype does it one way, and most everything else does it the
1451 // other. To make sure everything is working ok, we have to "flip" the
1452 // coordinates, and to do this we need to know how big in the Y dimension
1453 // the page is, and whether we have to invert the page or leave it alone.
1454 //
1455 // FT->ymax specifies the size of the page FT->invert_y=1 tells us to
1456 // invert the y-coordinates, FT->invert_y=0 will not invert the
1457 // coordinates.
1458 //--------------------------------------------------------------------------
1459
1460 static void init_freetype_lv2( PLStream *pls )
1461 {
1462 png_Dev *dev = (png_Dev *) pls->dev;
1463 FT_Data *FT = (FT_Data *) pls->FT;
1464
1465 FT->scale = dev->scale;
1466 FT->ymax = dev->pngy;
1467 FT->invert_y = 1;
1468 FT->smooth_text = 0;
1469
1470 if ( ( FT->want_smooth_text == 1 ) && ( FT->BLENDED_ANTIALIASING == 0 ) ) // do we want to at least *try* for smoothing ?
1471 {
1472 FT->ncol0_org = pls->ncol0; // save a copy of the original size of ncol0
1473 FT->ncol0_xtra = NCOLOURS - ( pls->ncol1 + pls->ncol0 ); // work out how many free slots we have
1474 FT->ncol0_width = FT->ncol0_xtra / ( pls->ncol0 - 1 ); // find out how many different shades of anti-aliasing we can do
1475 if ( FT->ncol0_width > 4 ) // are there enough colour slots free for text smoothing ?
1476 {
1477 if ( FT->ncol0_width > max_number_of_grey_levels_used_in_text_smoothing )
1478 FT->ncol0_width = max_number_of_grey_levels_used_in_text_smoothing; // set a maximum number of shades
1479 plscmap0n( FT->ncol0_org + ( FT->ncol0_width * pls->ncol0 ) ); // redefine the size of cmap0
1480 // the level manipulations are to turn off the plP_state(PLSTATE_CMAP0)
1481 // call in plscmap0 which (a) leads to segfaults since the GD image is
1482 // not defined at this point and (b) would be inefficient in any case since
1483 // setcmap is always called later (see plD_bop_png) to update the driver
1484 // color palette to be consistent with cmap0.
1485 {
1486 PLINT level_save;
1487 level_save = pls->level;
1488 pls->level = 0;
1489 pl_set_extended_cmap0( pls, FT->ncol0_width, FT->ncol0_org ); // call the function to add the extra cmap0 entries and calculate stuff
1490 pls->level = level_save;
1491 }
1492 FT->smooth_text = 1; // Yippee ! We had success setting up the extended cmap0
1493 }
1494 else
1495 plwarn( "Insufficient colour slots available in CMAP0 to do text smoothing." );
1496 }
1497 else if ( ( FT->want_smooth_text == 1 ) && ( FT->BLENDED_ANTIALIASING == 1 ) ) // If we have a truecolour device, we wont even bother trying to change the palette
1498 {
1499 FT->smooth_text = 1;
1500 }
1501 }
1502
1503 #endif
1504
1505
1506 #ifdef PLD_jpeg
1507
1508 //--------------------------------------------------------------------------
1509 // plD_eop_jpeg()
1510 //
1511 // End of page.
1512 //--------------------------------------------------------------------------
1513
1514 void plD_eop_jpeg( PLStream *pls )
1515 {
1516 png_Dev *dev = (png_Dev *) pls->dev;
1517 int im_size = 0;
1518 void *im_ptr = NULL;
1519 size_t nwrite;
1520 int jpeg_compression;
1521
1522 if ( pls->family || pls->page == 1 )
1523 {
1524 // Set the compression/quality level for JPEG files
1525 // The higher the value, the bigger/better the image is
1526 //
1527 if ( ( pls->dev_compression <= 0 ) || ( pls->dev_compression > 99 ) )
1528 jpeg_compression = 90;
1529 else
1530 jpeg_compression = pls->dev_compression;
1531
1532 // image is written to output file by the driver
1533 // since if the gd.dll is linked to a different c
1534 // lib a crash occurs - this fix works also in Linux
1535 // gdImageJpeg(dev->im_out, pls->OutFile, jpeg_compression);
1536 im_ptr = gdImageJpegPtr( dev->im_out, &im_size, jpeg_compression );
1537 if ( im_ptr )
1538 {
1539 nwrite = fwrite( im_ptr, sizeof ( char ), im_size, pls->OutFile );
1540 if ( nwrite != im_size )
1541 plabort( "gd driver: Error writing png file" );
1542 gdFree( im_ptr );
1543 }
1544
1545 gdImageDestroy( dev->im_out );
1546 dev->im_out = NULL;
1547 }
1548 }
1549
1550 #endif
1551
1552 #ifdef PLD_gif
1553
1554 //--------------------------------------------------------------------------
1555 // plD_eop_gif()
1556 //
1557 // End of page.
1558 //--------------------------------------------------------------------------
1559
1560 void plD_eop_gif( PLStream *pls )
1561 {
1562 png_Dev *dev = (png_Dev *) pls->dev;
1563 int im_size = 0;
1564 void *im_ptr = NULL;
1565 size_t nwrite;
1566
1567 if ( pls->family || pls->page == 1 )
1568 {
1569 // image is written to output file by the driver
1570 // since if the gd.dll is linked to a different c
1571 // lib a crash occurs - this fix works also in Linux
1572 // gdImageGif(dev->im_out, pls->OutFile);
1573 im_ptr = gdImageGifPtr( dev->im_out, &im_size );
1574 if ( im_ptr )
1575 {
1576 nwrite = fwrite( im_ptr, sizeof ( char ), im_size, pls->OutFile );
1577 if ( nwrite != im_size )
1578 plabort( "gd driver: Error writing png file" );
1579 gdFree( im_ptr );
1580 }
1581
1582 gdImageDestroy( dev->im_out );
1583 dev->im_out = NULL;
1584 }
1585 }
1586
1587 #endif
1588
1589
1590 //#endif
1591
1592
1593 #else
1594 int
1595 pldummy_png()
1596 {
1597 return 0;
1598 }
1599
1600 #endif // PNG
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