rpng-x.c@ 33335

Last change on this file since 33335 was 6395, checked in by vboxsync, 17 years ago
export libpng and zlib so Windows and OS/2 build cleanly.
Property svn:eol-style set to `native`
File size: 28.3 KB

Line
1	/*---------------------------------------------------------------------------
2
3	rpng - simple PNG display program rpng-x.c
4
5	This program decodes and displays PNG images, with gamma correction and
6	optionally with a user-specified background color (in case the image has
7	transparency). It is very nearly the most basic PNG viewer possible.
8	This version is for the X Window System (tested by author under Unix and
9	by Martin Zinser under OpenVMS; may work under OS/2 with some tweaking).
10
11	to do:
12	- 8-bit support
13	- use %.1023s to simplify truncation of title-bar string?
14
15	---------------------------------------------------------------------------
16
17	Changelog:
18	- 1.01: initial public release
19	- 1.02: modified to allow abbreviated options; fixed long/ulong mis-
20	match; switched to png_jmpbuf() macro
21	- 1.10: added support for non-default visuals; fixed X pixel-conversion
22	- 1.11: added extra set of parentheses to png_jmpbuf() macro; fixed
23	command-line parsing bug
24	- 1.12: fixed small X memory leak (thanks to Francois Petitjean)
25	- 1.13: fixed XFreeGC() crash bug
26
27	---------------------------------------------------------------------------
28
29	Copyright (c) 1998-2001 Greg Roelofs. All rights reserved.
30
31	This software is provided "as is," without warranty of any kind,
32	express or implied. In no event shall the author or contributors
33	be held liable for any damages arising in any way from the use of
34	this software.
35
36	Permission is granted to anyone to use this software for any purpose,
37	including commercial applications, and to alter it and redistribute
38	it freely, subject to the following restrictions:
39
40	1. Redistributions of source code must retain the above copyright
41	notice, disclaimer, and this list of conditions.
42	2. Redistributions in binary form must reproduce the above copyright
43	notice, disclaimer, and this list of conditions in the documenta-
44	tion and/or other materials provided with the distribution.
45	3. All advertising materials mentioning features or use of this
46	software must display the following acknowledgment:
47
48	This product includes software developed by Greg Roelofs
49	and contributors for the book, "PNG: The Definitive Guide,"
50	published by O'Reilly and Associates.
51
52	---------------------------------------------------------------------------*/
53
54	#define PROGNAME "rpng-x"
55	#define LONGNAME "Simple PNG Viewer for X"
56	#define VERSION "1.13 of 16 August 2001"
57
58	#include <stdio.h>
59	#include <stdlib.h>
60	#include <string.h>
61	#include <time.h>
62	#include <X11/Xlib.h>
63	#include <X11/Xutil.h>
64	#include <X11/Xos.h>
65	#include <X11/keysym.h>
66
67	/* #define DEBUG : this enables the Trace() macros */
68
69	#include "readpng.h" /* typedefs, common macros, readpng prototypes */
70
71
72	/* could just include png.h, but this macro is the only thing we need
73	* (name and typedefs changed to local versions); note that side effects
74	* only happen with alpha (which could easily be avoided with
75	* "ush acopy = (alpha);") */
76
77	#define alpha_composite(composite, fg, alpha, bg) { \
78	ush temp = ((ush)(fg)*(ush)(alpha) + \
79	(ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128); \
80	(composite) = (uch)((temp + (temp >> 8)) >> 8); \
81	}
82
83
84	/* local prototypes */
85	static int rpng_x_create_window(void);
86	static int rpng_x_display_image(void);
87	static void rpng_x_cleanup(void);
88	static int rpng_x_msb(ulg u32val);
89
90
91	static char titlebar[1024], *window_name = titlebar;
92	static char *appname = LONGNAME;
93	static char *icon_name = PROGNAME;
94	static char *filename;
95	static FILE *infile;
96
97	static char *bgstr;
98	static uch bg_red=0, bg_green=0, bg_blue=0;
99
100	static double display_exponent;
101
102	static ulg image_width, image_height, image_rowbytes;
103	static int image_channels;
104	static uch *image_data;
105
106	/* X-specific variables */
107	static char *displayname;
108	static XImage *ximage;
109	static Display *display;
110	static int depth;
111	static Visual *visual;
112	static XVisualInfo *visual_list;
113	static int RShift, GShift, BShift;
114	static ulg RMask, GMask, BMask;
115	static Window window;
116	static GC gc;
117	static Colormap colormap;
118
119	static int have_nondefault_visual = FALSE;
120	static int have_colormap = FALSE;
121	static int have_window = FALSE;
122	static int have_gc = FALSE;
123	/*
124	ulg numcolors=0, pixels[256];
125	ush reds[256], greens[256], blues[256];
126	*/
127
128
129
130
131	int main(int argc, char **argv)
132	{
133	#ifdef sgi
134	char tmpline[80];
135	#endif
136	char *p;
137	int rc, alen, flen;
138	int error = 0;
139	int have_bg = FALSE;
140	double LUT_exponent; /* just the lookup table */
141	double CRT_exponent = 2.2; /* just the monitor */
142	double default_display_exponent; /* whole display system */
143	XEvent e;
144	KeySym k;
145
146
147	displayname = (char *)NULL;
148	filename = (char *)NULL;
149
150
151	/* First set the default value for our display-system exponent, i.e.,
152	* the product of the CRT exponent and the exponent corresponding to
153	* the frame-buffer's lookup table (LUT), if any. This is not an
154	* exhaustive list of LUT values (e.g., OpenStep has a lot of weird
155	* ones), but it should cover 99% of the current possibilities. */
156
157	#if defined(NeXT)
158	LUT_exponent = 1.0 / 2.2;
159	/*
160	if (some_next_function_that_returns_gamma(&next_gamma))
161	LUT_exponent = 1.0 / next_gamma;
162	*/
163	#elif defined(sgi)
164	LUT_exponent = 1.0 / 1.7;
165	/* there doesn't seem to be any documented function to get the
166	* "gamma" value, so we do it the hard way */
167	infile = fopen("/etc/config/system.glGammaVal", "r");
168	if (infile) {
169	double sgi_gamma;
170
171	fgets(tmpline, 80, infile);
172	fclose(infile);
173	sgi_gamma = atof(tmpline);
174	if (sgi_gamma > 0.0)
175	LUT_exponent = 1.0 / sgi_gamma;
176	}
177	#elif defined(Macintosh)
178	LUT_exponent = 1.8 / 2.61;
179	/*
180	if (some_mac_function_that_returns_gamma(&mac_gamma))
181	LUT_exponent = mac_gamma / 2.61;
182	*/
183	#else
184	LUT_exponent = 1.0; /* assume no LUT: most PCs */
185	#endif
186
187	/* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
188	default_display_exponent = LUT_exponent * CRT_exponent;
189
190
191	/* If the user has set the SCREEN_GAMMA environment variable as suggested
192	* (somewhat imprecisely) in the libpng documentation, use that; otherwise
193	* use the default value we just calculated. Either way, the user may
194	* override this via a command-line option. */
195
196	if ((p = getenv("SCREEN_GAMMA")) != NULL)
197	display_exponent = atof(p);
198	else
199	display_exponent = default_display_exponent;
200
201
202	/* Now parse the command line for options and the PNG filename. */
203
204	while (*++argv && !error) {
205	if (!strncmp(*argv, "-display", 2)) {
206	if (!*++argv)
207	++error;
208	else
209	displayname = *argv;
210	} else if (!strncmp(*argv, "-gamma", 2)) {
211	if (!*++argv)
212	++error;
213	else {
214	display_exponent = atof(*argv);
215	if (display_exponent <= 0.0)
216	++error;
217	}
218	} else if (!strncmp(*argv, "-bgcolor", 2)) {
219	if (!*++argv)
220	++error;
221	else {
222	bgstr = *argv;
223	if (strlen(bgstr) != 7 \|\| bgstr[0] != '#')
224	++error;
225	else
226	have_bg = TRUE;
227	}
228	} else {
229	if (**argv != '-') {
230	filename = *argv;
231	if (argv[1]) /* shouldn't be any more args after filename */
232	++error;
233	} else
234	++error; /* not expecting any other options */
235	}
236	}
237
238	if (!filename) {
239	++error;
240	} else if (!(infile = fopen(filename, "rb"))) {
241	fprintf(stderr, PROGNAME ": can't open PNG file [%s]\n", filename);
242	++error;
243	} else {
244	if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
245	switch (rc) {
246	case 1:
247	fprintf(stderr, PROGNAME
248	": [%s] is not a PNG file: incorrect signature\n",
249	filename);
250	break;
251	case 2:
252	fprintf(stderr, PROGNAME
253	": [%s] has bad IHDR (libpng longjmp)\n",
254	filename);
255	break;
256	case 4:
257	fprintf(stderr, PROGNAME ": insufficient memory\n");
258	break;
259	default:
260	fprintf(stderr, PROGNAME
261	": unknown readpng_init() error\n");
262	break;
263	}
264	++error;
265	} else {
266	display = XOpenDisplay(displayname);
267	if (!display) {
268	readpng_cleanup(TRUE);
269	fprintf(stderr, PROGNAME ": can't open X display [%s]\n",
270	displayname? displayname : "default");
271	++error;
272	}
273	}
274	if (error)
275	fclose(infile);
276	}
277
278
279	/* usage screen */
280
281	if (error) {
282	fprintf(stderr, "\n%s %s: %s\n", PROGNAME, VERSION, appname);
283	readpng_version_info();
284	fprintf(stderr, "\n"
285	"Usage: %s [-display xdpy] [-gamma exp] [-bgcolor bg] file.png\n"
286	" xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
287	" exp \ttransfer-function exponent (``gamma'') of the display\n"
288	"\t\t system in floating-point format (e.g., ``%.1f''); equal\n"
289	"\t\t to the product of the lookup-table exponent (varies)\n"
290	"\t\t and the CRT exponent (usually 2.2); must be positive\n"
291	" bg \tdesired background color in 7-character hex RGB format\n"
292	"\t\t (e.g., ``#ff7700'' for orange: same as HTML colors);\n"
293	"\t\t used with transparent images\n"
294	"\nPress Q, Esc or mouse button 1 (within image window, after image\n"
295	"is displayed) to quit.\n"
296	"\n", PROGNAME, default_display_exponent);
297	exit(1);
298	}
299
300
301	/* set the title-bar string, but make sure buffer doesn't overflow */
302
303	alen = strlen(appname);
304	flen = strlen(filename);
305	if (alen + flen + 3 > 1023)
306	sprintf(titlebar, "%s: ...%s", appname, filename+(alen+flen+6-1023));
307	else
308	sprintf(titlebar, "%s: %s", appname, filename);
309
310
311	/* if the user didn't specify a background color on the command line,
312	* check for one in the PNG file--if not, the initialized values of 0
313	* (black) will be used */
314
315	if (have_bg) {
316	unsigned r, g, b; /* this approach quiets compiler warnings */
317
318	sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
319	bg_red = (uch)r;
320	bg_green = (uch)g;
321	bg_blue = (uch)b;
322	} else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
323	readpng_cleanup(TRUE);
324	fprintf(stderr, PROGNAME
325	": libpng error while checking for background color\n");
326	exit(2);
327	}
328
329
330	/* do the basic X initialization stuff, make the window and fill it
331	* with the background color */
332
333	if (rpng_x_create_window())
334	exit(2);
335
336
337	/* decode the image, all at once */
338
339	Trace((stderr, "calling readpng_get_image()\n"))
340	image_data = readpng_get_image(display_exponent, &image_channels,
341	&image_rowbytes);
342	Trace((stderr, "done with readpng_get_image()\n"))
343
344
345	/* done with PNG file, so clean up to minimize memory usage (but do NOT
346	* nuke image_data!) */
347
348	readpng_cleanup(FALSE);
349	fclose(infile);
350
351	if (!image_data) {
352	fprintf(stderr, PROGNAME ": unable to decode PNG image\n");
353	exit(3);
354	}
355
356
357	/* display image (composite with background if requested) */
358
359	Trace((stderr, "calling rpng_x_display_image()\n"))
360	if (rpng_x_display_image()) {
361	free(image_data);
362	exit(4);
363	}
364	Trace((stderr, "done with rpng_x_display_image()\n"))
365
366
367	/* wait for the user to tell us when to quit */
368
369	printf(
370	"Done. Press Q, Esc or mouse button 1 (within image window) to quit.\n");
371	fflush(stdout);
372
373	do
374	XNextEvent(display, &e);
375	while (!(e.type == ButtonPress && e.xbutton.button == Button1) &&
376	!(e.type == KeyPress && /* v--- or 1 for shifted keys */
377	((k = XLookupKeysym(&e.xkey, 0)) == XK_q \|\| k == XK_Escape) ));
378
379
380	/* OK, we're done: clean up all image and X resources and go away */
381
382	rpng_x_cleanup();
383
384	return 0;
385	}
386
387
388
389
390
391	static int rpng_x_create_window(void)
392	{
393	uch *xdata;
394	int need_colormap = FALSE;
395	int screen, pad;
396	ulg bg_pixel = 0L;
397	ulg attrmask;
398	Window root;
399	XEvent e;
400	XGCValues gcvalues;
401	XSetWindowAttributes attr;
402	XSizeHints *size_hints;
403	XTextProperty windowName, *pWindowName = &windowName;
404	XTextProperty iconName, *pIconName = &iconName;
405	XVisualInfo visual_info;
406	XWMHints *wm_hints;
407
408
409	screen = DefaultScreen(display);
410	depth = DisplayPlanes(display, screen);
411	root = RootWindow(display, screen);
412
413	#ifdef DEBUG
414	XSynchronize(display, True);
415	#endif
416
417	#if 0
418	/* GRR: add 8-bit support */
419	if (/* depth != 8 && */ depth != 16 && depth != 24 && depth != 32) {
420	fprintf(stderr,
421	"screen depth %d not supported (only 16-, 24- or 32-bit TrueColor)\n",
422	depth);
423	return 2;
424	}
425
426	XMatchVisualInfo(display, screen, depth,
427	(depth == 8)? PseudoColor : TrueColor, &visual_info);
428	visual = visual_info.visual;
429	#else
430	if (depth != 16 && depth != 24 && depth != 32) {
431	int visuals_matched = 0;
432
433	Trace((stderr, "default depth is %d: checking other visuals\n",
434	depth))
435
436	/* 24-bit first */
437	visual_info.screen = screen;
438	visual_info.depth = 24;
439	visual_list = XGetVisualInfo(display,
440	VisualScreenMask \| VisualDepthMask, &visual_info, &visuals_matched);
441	if (visuals_matched == 0) {
442	/* GRR: add 15-, 16- and 32-bit TrueColor visuals (also DirectColor?) */
443	fprintf(stderr, "default screen depth %d not supported, and no"
444	" 24-bit visuals found\n", depth);
445	return 2;
446	}
447	Trace((stderr, "XGetVisualInfo() returned %d 24-bit visuals\n",
448	visuals_matched))
449	visual = visual_list[0].visual;
450	depth = visual_list[0].depth;
451	/*
452	colormap_size = visual_list[0].colormap_size;
453	visual_class = visual->class;
454	visualID = XVisualIDFromVisual(visual);
455	*/
456	have_nondefault_visual = TRUE;
457	need_colormap = TRUE;
458	} else {
459	XMatchVisualInfo(display, screen, depth, TrueColor, &visual_info);
460	visual = visual_info.visual;
461	}
462	#endif
463
464	RMask = visual->red_mask;
465	GMask = visual->green_mask;
466	BMask = visual->blue_mask;
467
468	/* GRR: add/check 8-bit support */
469	if (depth == 8 \|\| need_colormap) {
470	colormap = XCreateColormap(display, root, visual, AllocNone);
471	if (!colormap) {
472	fprintf(stderr, "XCreateColormap() failed\n");
473	return 2;
474	}
475	have_colormap = TRUE;
476	}
477	if (depth == 15 \|\| depth == 16) {
478	RShift = 15 - rpng_x_msb(RMask); /* these are right-shifts */
479	GShift = 15 - rpng_x_msb(GMask);
480	BShift = 15 - rpng_x_msb(BMask);
481	} else if (depth > 16) {
482	#define NO_24BIT_MASKS
483	#ifdef NO_24BIT_MASKS
484	RShift = rpng_x_msb(RMask) - 7; /* these are left-shifts */
485	GShift = rpng_x_msb(GMask) - 7;
486	BShift = rpng_x_msb(BMask) - 7;
487	#else
488	RShift = 7 - rpng_x_msb(RMask); /* these are right-shifts, too */
489	GShift = 7 - rpng_x_msb(GMask);
490	BShift = 7 - rpng_x_msb(BMask);
491	#endif
492	}
493	if (depth >= 15 && (RShift < 0 \|\| GShift < 0 \|\| BShift < 0)) {
494	fprintf(stderr, "rpng internal logic error: negative X shift(s)!\n");
495	return 2;
496	}
497
498	/*---------------------------------------------------------------------------
499	Finally, create the window.
500	---------------------------------------------------------------------------*/
501
502	attr.backing_store = Always;
503	attr.event_mask = ExposureMask \| KeyPressMask \| ButtonPressMask;
504	attrmask = CWBackingStore \| CWEventMask;
505	if (have_nondefault_visual) {
506	attr.colormap = colormap;
507	attr.background_pixel = 0;
508	attr.border_pixel = 1;
509	attrmask \|= CWColormap \| CWBackPixel \| CWBorderPixel;
510	}
511
512	window = XCreateWindow(display, root, 0, 0, image_width, image_height, 0,
513	depth, InputOutput, visual, attrmask, &attr);
514
515	if (window == None) {
516	fprintf(stderr, "XCreateWindow() failed\n");
517	return 2;
518	} else
519	have_window = TRUE;
520
521	if (depth == 8)
522	XSetWindowColormap(display, window, colormap);
523
524	if (!XStringListToTextProperty(&window_name, 1, pWindowName))
525	pWindowName = NULL;
526	if (!XStringListToTextProperty(&icon_name, 1, pIconName))
527	pIconName = NULL;
528
529	/* OK if either hints allocation fails; XSetWMProperties() allows NULLs */
530
531	if ((size_hints = XAllocSizeHints()) != NULL) {
532	/* window will not be resizable */
533	size_hints->flags = PMinSize \| PMaxSize;
534	size_hints->min_width = size_hints->max_width = (int)image_width;
535	size_hints->min_height = size_hints->max_height = (int)image_height;
536	}
537
538	if ((wm_hints = XAllocWMHints()) != NULL) {
539	wm_hints->initial_state = NormalState;
540	wm_hints->input = True;
541	/* wm_hints->icon_pixmap = icon_pixmap; */
542	wm_hints->flags = StateHint \| InputHint /* \| IconPixmapHint */ ;
543	}
544
545	XSetWMProperties(display, window, pWindowName, pIconName, NULL, 0,
546	size_hints, wm_hints, NULL);
547
548	/* various properties and hints no longer needed; free memory */
549	if (pWindowName)
550	XFree(pWindowName->value);
551	if (pIconName)
552	XFree(pIconName->value);
553	if (size_hints)
554	XFree(size_hints);
555	if (wm_hints)
556	XFree(wm_hints);
557
558	XMapWindow(display, window);
559
560	gc = XCreateGC(display, window, 0, &gcvalues);
561	have_gc = TRUE;
562
563	/*---------------------------------------------------------------------------
564	Fill window with the specified background color.
565	---------------------------------------------------------------------------*/
566
567	if (depth == 24 \|\| depth == 32) {
568	bg_pixel = ((ulg)bg_red << RShift) \|
569	((ulg)bg_green << GShift) \|
570	((ulg)bg_blue << BShift);
571	} else if (depth == 16) {
572	bg_pixel = ((((ulg)bg_red << 8) >> RShift) & RMask) \|
573	((((ulg)bg_green << 8) >> GShift) & GMask) \|
574	((((ulg)bg_blue << 8) >> BShift) & BMask);
575	} else /* depth == 8 */ {
576
577	/* GRR: add 8-bit support */
578
579	}
580
581	XSetForeground(display, gc, bg_pixel);
582	XFillRectangle(display, window, gc, 0, 0, image_width, image_height);
583
584	/*---------------------------------------------------------------------------
585	Wait for first Expose event to do any drawing, then flush.
586	---------------------------------------------------------------------------*/
587
588	do
589	XNextEvent(display, &e);
590	while (e.type != Expose \|\| e.xexpose.count);
591
592	XFlush(display);
593
594	/*---------------------------------------------------------------------------
595	Allocate memory for the X- and display-specific version of the image.
596	---------------------------------------------------------------------------*/
597
598	if (depth == 24 \|\| depth == 32) {
599	xdata = (uch )malloc(4image_width*image_height);
600	pad = 32;
601	} else if (depth == 16) {
602	xdata = (uch )malloc(2image_width*image_height);
603	pad = 16;
604	} else /* depth == 8 */ {
605	xdata = (uch )malloc(image_widthimage_height);
606	pad = 8;
607	}
608
609	if (!xdata) {
610	fprintf(stderr, PROGNAME ": unable to allocate image memory\n");
611	return 4;
612	}
613
614	ximage = XCreateImage(display, visual, depth, ZPixmap, 0,
615	(char *)xdata, image_width, image_height, pad, 0);
616
617	if (!ximage) {
618	fprintf(stderr, PROGNAME ": XCreateImage() failed\n");
619	free(xdata);
620	return 3;
621	}
622
623	/* to avoid testing the byte order every pixel (or doubling the size of
624	* the drawing routine with a giant if-test), we arbitrarily set the byte
625	* order to MSBFirst and let Xlib worry about inverting things on little-
626	* endian machines (like Linux/x86, old VAXen, etc.)--this is not the most
627	* efficient approach (the giant if-test would be better), but in the
628	* interest of clarity, we take the easy way out... */
629
630	ximage->byte_order = MSBFirst;
631
632	return 0;
633
634	} /* end function rpng_x_create_window() */
635
636
637
638
639
640	static int rpng_x_display_image(void)
641	{
642	uch *src;
643	char *dest;
644	uch r, g, b, a;
645	ulg i, row, lastrow = 0;
646	ulg pixel;
647	int ximage_rowbytes = ximage->bytes_per_line;
648	/* int bpp = ximage->bits_per_pixel; */
649
650
651	Trace((stderr, "beginning display loop (image_channels == %d)\n",
652	image_channels))
653	Trace((stderr, " (width = %ld, rowbytes = %ld, ximage_rowbytes = %d)\n",
654	image_width, image_rowbytes, ximage_rowbytes))
655	Trace((stderr, " (bpp = %d)\n", ximage->bits_per_pixel))
656	Trace((stderr, " (byte_order = %s)\n", ximage->byte_order == MSBFirst?
657	"MSBFirst" : (ximage->byte_order == LSBFirst? "LSBFirst" : "unknown")))
658
659	if (depth == 24 \|\| depth == 32) {
660	ulg red, green, blue;
661
662	for (lastrow = row = 0; row < image_height; ++row) {
663	src = image_data + row*image_rowbytes;
664	dest = ximage->data + row*ximage_rowbytes;
665	if (image_channels == 3) {
666	for (i = image_width; i > 0; --i) {
667	red = *src++;
668	green = *src++;
669	blue = *src++;
670	#ifdef NO_24BIT_MASKS
671	pixel = (red << RShift) \|
672	(green << GShift) \|
673	(blue << BShift);
674	/* recall that we set ximage->byte_order = MSBFirst above */
675	/* GRR BUG: this assumes bpp == 32, but may be 24: */
676	*dest++ = (char)((pixel >> 24) & 0xff);
677	*dest++ = (char)((pixel >> 16) & 0xff);
678	*dest++ = (char)((pixel >> 8) & 0xff);
679	*dest++ = (char)( pixel & 0xff);
680	#else
681	red = (RShift < 0)? red << (-RShift) : red >> RShift;
682	green = (GShift < 0)? green << (-GShift) : green >> GShift;
683	blue = (BShift < 0)? blue << (-BShift) : blue >> BShift;
684	pixel = (red & RMask) \| (green & GMask) \| (blue & BMask);
685	/* recall that we set ximage->byte_order = MSBFirst above */
686	*dest++ = (char)((pixel >> 24) & 0xff);
687	*dest++ = (char)((pixel >> 16) & 0xff);
688	*dest++ = (char)((pixel >> 8) & 0xff);
689	*dest++ = (char)( pixel & 0xff);
690	#endif
691	}
692	} else /* if (image_channels == 4) */ {
693	for (i = image_width; i > 0; --i) {
694	r = *src++;
695	g = *src++;
696	b = *src++;
697	a = *src++;
698	if (a == 255) {
699	red = r;
700	green = g;
701	blue = b;
702	} else if (a == 0) {
703	red = bg_red;
704	green = bg_green;
705	blue = bg_blue;
706	} else {
707	/* this macro (from png.h) composites the foreground
708	* and background values and puts the result into the
709	* first argument */
710	alpha_composite(red, r, a, bg_red);
711	alpha_composite(green, g, a, bg_green);
712	alpha_composite(blue, b, a, bg_blue);
713	}
714	pixel = (red << RShift) \|
715	(green << GShift) \|
716	(blue << BShift);
717	/* recall that we set ximage->byte_order = MSBFirst above */
718	*dest++ = (char)((pixel >> 24) & 0xff);
719	*dest++ = (char)((pixel >> 16) & 0xff);
720	*dest++ = (char)((pixel >> 8) & 0xff);
721	*dest++ = (char)( pixel & 0xff);
722	}
723	}
724	/* display after every 16 lines */
725	if (((row+1) & 0xf) == 0) {
726	XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
727	(int)lastrow, image_width, 16);
728	XFlush(display);
729	lastrow = row + 1;
730	}
731	}
732
733	} else if (depth == 16) {
734	ush red, green, blue;
735
736	for (lastrow = row = 0; row < image_height; ++row) {
737	src = image_data + row*image_rowbytes;
738	dest = ximage->data + row*ximage_rowbytes;
739	if (image_channels == 3) {
740	for (i = image_width; i > 0; --i) {
741	red = ((ush)(*src) << 8);
742	++src;
743	green = ((ush)(*src) << 8);
744	++src;
745	blue = ((ush)(*src) << 8);
746	++src;
747	pixel = ((red >> RShift) & RMask) \|
748	((green >> GShift) & GMask) \|
749	((blue >> BShift) & BMask);
750	/* recall that we set ximage->byte_order = MSBFirst above */
751	*dest++ = (char)((pixel >> 8) & 0xff);
752	*dest++ = (char)( pixel & 0xff);
753	}
754	} else /* if (image_channels == 4) */ {
755	for (i = image_width; i > 0; --i) {
756	r = *src++;
757	g = *src++;
758	b = *src++;
759	a = *src++;
760	if (a == 255) {
761	red = ((ush)r << 8);
762	green = ((ush)g << 8);
763	blue = ((ush)b << 8);
764	} else if (a == 0) {
765	red = ((ush)bg_red << 8);
766	green = ((ush)bg_green << 8);
767	blue = ((ush)bg_blue << 8);
768	} else {
769	/* this macro (from png.h) composites the foreground
770	* and background values and puts the result back into
771	* the first argument (== fg byte here: safe) */
772	alpha_composite(r, r, a, bg_red);
773	alpha_composite(g, g, a, bg_green);
774	alpha_composite(b, b, a, bg_blue);
775	red = ((ush)r << 8);
776	green = ((ush)g << 8);
777	blue = ((ush)b << 8);
778	}
779	pixel = ((red >> RShift) & RMask) \|
780	((green >> GShift) & GMask) \|
781	((blue >> BShift) & BMask);
782	/* recall that we set ximage->byte_order = MSBFirst above */
783	*dest++ = (char)((pixel >> 8) & 0xff);
784	*dest++ = (char)( pixel & 0xff);
785	}
786	}
787	/* display after every 16 lines */
788	if (((row+1) & 0xf) == 0) {
789	XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
790	(int)lastrow, image_width, 16);
791	XFlush(display);
792	lastrow = row + 1;
793	}
794	}
795
796	} else /* depth == 8 */ {
797
798	/* GRR: add 8-bit support */
799
800	}
801
802	Trace((stderr, "calling final XPutImage()\n"))
803	if (lastrow < image_height) {
804	XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
805	(int)lastrow, image_width, image_height-lastrow);
806	XFlush(display);
807	}
808
809	return 0;
810	}
811
812
813
814
815	static void rpng_x_cleanup(void)
816	{
817	if (image_data) {
818	free(image_data);
819	image_data = NULL;
820	}
821
822	if (ximage) {
823	if (ximage->data) {
824	free(ximage->data); /* we allocated it, so we free it */
825	ximage->data = (char )NULL; / instead of XDestroyImage() */
826	}
827	XDestroyImage(ximage);
828	ximage = NULL;
829	}
830
831	if (have_gc)
832	XFreeGC(display, gc);
833
834	if (have_window)
835	XDestroyWindow(display, window);
836
837	if (have_colormap)
838	XFreeColormap(display, colormap);
839
840	if (have_nondefault_visual)
841	XFree(visual_list);
842	}
843
844
845
846
847
848	static int rpng_x_msb(ulg u32val)
849	{
850	int i;
851
852	for (i = 31; i >= 0; --i) {
853	if (u32val & 0x80000000L)
854	break;
855	u32val <<= 1;
856	}
857	return i;
858	}

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source: vbox/trunk/src/libs/libpng-1.2.8/contrib/gregbook/rpng-x.c@ 33335

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