671242f350d172e106580348e24bab66b0d7e6a5vboxsync/*---------------------------------------------------------------------------
671242f350d172e106580348e24bab66b0d7e6a5vboxsync rpng - simple PNG display program rpng-x.c
671242f350d172e106580348e24bab66b0d7e6a5vboxsync This program decodes and displays PNG images, with gamma correction and
671242f350d172e106580348e24bab66b0d7e6a5vboxsync optionally with a user-specified background color (in case the image has
671242f350d172e106580348e24bab66b0d7e6a5vboxsync transparency). It is very nearly the most basic PNG viewer possible.
671242f350d172e106580348e24bab66b0d7e6a5vboxsync This version is for the X Window System (tested by author under Unix and
671242f350d172e106580348e24bab66b0d7e6a5vboxsync by Martin Zinser under OpenVMS; may work under OS/2 with some tweaking).
671242f350d172e106580348e24bab66b0d7e6a5vboxsync - 8-bit support
671242f350d172e106580348e24bab66b0d7e6a5vboxsync - use %.1023s to simplify truncation of title-bar string?
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ---------------------------------------------------------------------------
671242f350d172e106580348e24bab66b0d7e6a5vboxsync - 1.01: initial public release
671242f350d172e106580348e24bab66b0d7e6a5vboxsync - 1.02: modified to allow abbreviated options; fixed long/ulong mis-
671242f350d172e106580348e24bab66b0d7e6a5vboxsync match; switched to png_jmpbuf() macro
671242f350d172e106580348e24bab66b0d7e6a5vboxsync - 1.10: added support for non-default visuals; fixed X pixel-conversion
671242f350d172e106580348e24bab66b0d7e6a5vboxsync - 1.11: added extra set of parentheses to png_jmpbuf() macro; fixed
671242f350d172e106580348e24bab66b0d7e6a5vboxsync command-line parsing bug
671242f350d172e106580348e24bab66b0d7e6a5vboxsync - 1.12: fixed small X memory leak (thanks to Francois Petitjean)
671242f350d172e106580348e24bab66b0d7e6a5vboxsync - 1.13: fixed XFreeGC() crash bug
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ---------------------------------------------------------------------------
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Copyright (c) 1998-2001 Greg Roelofs. All rights reserved.
671242f350d172e106580348e24bab66b0d7e6a5vboxsync This software is provided "as is," without warranty of any kind,
671242f350d172e106580348e24bab66b0d7e6a5vboxsync express or implied. In no event shall the author or contributors
671242f350d172e106580348e24bab66b0d7e6a5vboxsync be held liable for any damages arising in any way from the use of
671242f350d172e106580348e24bab66b0d7e6a5vboxsync this software.
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Permission is granted to anyone to use this software for any purpose,
671242f350d172e106580348e24bab66b0d7e6a5vboxsync including commercial applications, and to alter it and redistribute
671242f350d172e106580348e24bab66b0d7e6a5vboxsync it freely, subject to the following restrictions:
671242f350d172e106580348e24bab66b0d7e6a5vboxsync 1. Redistributions of source code must retain the above copyright
671242f350d172e106580348e24bab66b0d7e6a5vboxsync notice, disclaimer, and this list of conditions.
671242f350d172e106580348e24bab66b0d7e6a5vboxsync 2. Redistributions in binary form must reproduce the above copyright
671242f350d172e106580348e24bab66b0d7e6a5vboxsync notice, disclaimer, and this list of conditions in the documenta-
671242f350d172e106580348e24bab66b0d7e6a5vboxsync tion and/or other materials provided with the distribution.
671242f350d172e106580348e24bab66b0d7e6a5vboxsync 3. All advertising materials mentioning features or use of this
671242f350d172e106580348e24bab66b0d7e6a5vboxsync software must display the following acknowledgment:
671242f350d172e106580348e24bab66b0d7e6a5vboxsync This product includes software developed by Greg Roelofs
671242f350d172e106580348e24bab66b0d7e6a5vboxsync and contributors for the book, "PNG: The Definitive Guide,"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync published by O'Reilly and Associates.
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ---------------------------------------------------------------------------*/
671242f350d172e106580348e24bab66b0d7e6a5vboxsync/* #define DEBUG : this enables the Trace() macros */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync#include "readpng.h" /* typedefs, common macros, readpng prototypes */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync/* could just include png.h, but this macro is the only thing we need
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * (name and typedefs changed to local versions); note that side effects
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * only happen with alpha (which could easily be avoided with
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * "ush acopy = (alpha);") */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync#define alpha_composite(composite, fg, alpha, bg) { \
671242f350d172e106580348e24bab66b0d7e6a5vboxsync/* local prototypes */
671242f350d172e106580348e24bab66b0d7e6a5vboxsyncstatic int rpng_x_create_window(void);
671242f350d172e106580348e24bab66b0d7e6a5vboxsyncstatic int rpng_x_display_image(void);
671242f350d172e106580348e24bab66b0d7e6a5vboxsyncstatic void rpng_x_cleanup(void);
671242f350d172e106580348e24bab66b0d7e6a5vboxsyncstatic char titlebar[1024], *window_name = titlebar;
671242f350d172e106580348e24bab66b0d7e6a5vboxsyncstatic ulg image_width, image_height, image_rowbytes;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync/* X-specific variables */
671242f350d172e106580348e24bab66b0d7e6a5vboxsynculg numcolors=0, pixels[256];
671242f350d172e106580348e24bab66b0d7e6a5vboxsyncush reds[256], greens[256], blues[256];
671242f350d172e106580348e24bab66b0d7e6a5vboxsync double default_display_exponent; /* whole display system */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* First set the default value for our display-system exponent, i.e.,
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * the product of the CRT exponent and the exponent corresponding to
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * the frame-buffer's lookup table (LUT), if any. This is not an
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * ones), but it should cover 99% of the current possibilities. */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync#if defined(NeXT)
671242f350d172e106580348e24bab66b0d7e6a5vboxsync if (some_next_function_that_returns_gamma(&next_gamma))
671242f350d172e106580348e24bab66b0d7e6a5vboxsync LUT_exponent = 1.0 / next_gamma;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* there doesn't seem to be any documented function to get the
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * "gamma" value, so we do it the hard way */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync infile = fopen("/etc/config/system.glGammaVal", "r");
671242f350d172e106580348e24bab66b0d7e6a5vboxsync if (some_mac_function_that_returns_gamma(&mac_gamma))
671242f350d172e106580348e24bab66b0d7e6a5vboxsync LUT_exponent = mac_gamma / 2.61;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync default_display_exponent = LUT_exponent * CRT_exponent;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* If the user has set the SCREEN_GAMMA environment variable as suggested
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * (somewhat imprecisely) in the libpng documentation, use that; otherwise
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * use the default value we just calculated. Either way, the user may
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * override this via a command-line option. */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* Now parse the command line for options and the PNG filename. */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync if (argv[1]) /* shouldn't be any more args after filename */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync fprintf(stderr, PROGNAME ": can't open PNG file [%s]\n", filename);
671242f350d172e106580348e24bab66b0d7e6a5vboxsync if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ": [%s] is not a PNG file: incorrect signature\n",
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ": [%s] has bad IHDR (libpng longjmp)\n",
671242f350d172e106580348e24bab66b0d7e6a5vboxsync fprintf(stderr, PROGNAME ": insufficient memory\n");
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ": unknown readpng_init() error\n");
671242f350d172e106580348e24bab66b0d7e6a5vboxsync fprintf(stderr, PROGNAME ": can't open X display [%s]\n",
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* usage screen */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync fprintf(stderr, "\n%s %s: %s\n", PROGNAME, VERSION, appname);
671242f350d172e106580348e24bab66b0d7e6a5vboxsync "Usage: %s [-display xdpy] [-gamma exp] [-bgcolor bg] file.png\n"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync " xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync " exp \ttransfer-function exponent (``gamma'') of the display\n"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync "\t\t system in floating-point format (e.g., ``%.1f''); equal\n"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync "\t\t to the product of the lookup-table exponent (varies)\n"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync "\t\t and the CRT exponent (usually 2.2); must be positive\n"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync " bg \tdesired background color in 7-character hex RGB format\n"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync "\t\t (e.g., ``#ff7700'' for orange: same as HTML colors);\n"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync "\t\t used with transparent images\n"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync "is displayed) to quit.\n"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* set the title-bar string, but make sure buffer doesn't overflow */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync sprintf(titlebar, "%s: ...%s", appname, filename+(alen+flen+6-1023));
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* if the user didn't specify a background color on the command line,
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * check for one in the PNG file--if not, the initialized values of 0
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * (black) will be used */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync unsigned r, g, b; /* this approach quiets compiler warnings */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync } else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ": libpng error while checking for background color\n");
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* do the basic X initialization stuff, make the window and fill it
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * with the background color */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* decode the image, all at once */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync image_data = readpng_get_image(display_exponent, &image_channels,
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* done with PNG file, so clean up to minimize memory usage (but do NOT
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * nuke image_data!) */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync fprintf(stderr, PROGNAME ": unable to decode PNG image\n");
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* display image (composite with background if requested) */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Trace((stderr, "calling rpng_x_display_image()\n"))
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Trace((stderr, "done with rpng_x_display_image()\n"))
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* wait for the user to tell us when to quit */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync "Done. Press Q, Esc or mouse button 1 (within image window) to quit.\n");
671242f350d172e106580348e24bab66b0d7e6a5vboxsync while (!(e.type == ButtonPress && e.xbutton.button == Button1) &&
671242f350d172e106580348e24bab66b0d7e6a5vboxsync !(e.type == KeyPress && /* v--- or 1 for shifted keys */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ((k = XLookupKeysym(&e.xkey, 0)) == XK_q || k == XK_Escape) ));
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* OK, we're done: clean up all image and X resources and go away */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync XTextProperty windowName, *pWindowName = &windowName;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync/* GRR: add 8-bit support */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync if (/* depth != 8 && */ depth != 16 && depth != 24 && depth != 32) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync "screen depth %d not supported (only 16-, 24- or 32-bit TrueColor)\n",
671242f350d172e106580348e24bab66b0d7e6a5vboxsync (depth == 8)? PseudoColor : TrueColor, &visual_info);
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Trace((stderr, "default depth is %d: checking other visuals\n",
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* 24-bit first */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync VisualScreenMask | VisualDepthMask, &visual_info, &visuals_matched);
671242f350d172e106580348e24bab66b0d7e6a5vboxsync/* GRR: add 15-, 16- and 32-bit TrueColor visuals (also DirectColor?) */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync fprintf(stderr, "default screen depth %d not supported, and no"
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Trace((stderr, "XGetVisualInfo() returned %d 24-bit visuals\n",
671242f350d172e106580348e24bab66b0d7e6a5vboxsync colormap_size = visual_list[0].colormap_size;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync visual_class = visual->class;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync visualID = XVisualIDFromVisual(visual);
671242f350d172e106580348e24bab66b0d7e6a5vboxsync XMatchVisualInfo(display, screen, depth, TrueColor, &visual_info);
671242f350d172e106580348e24bab66b0d7e6a5vboxsync/* GRR: add/check 8-bit support */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync colormap = XCreateColormap(display, root, visual, AllocNone);
671242f350d172e106580348e24bab66b0d7e6a5vboxsync RShift = 15 - rpng_x_msb(RMask); /* these are right-shifts */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync RShift = rpng_x_msb(RMask) - 7; /* these are left-shifts */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync RShift = 7 - rpng_x_msb(RMask); /* these are right-shifts, too */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync if (depth >= 15 && (RShift < 0 || GShift < 0 || BShift < 0)) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync fprintf(stderr, "rpng internal logic error: negative X shift(s)!\n");
671242f350d172e106580348e24bab66b0d7e6a5vboxsync/*---------------------------------------------------------------------------
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Finally, create the window.
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ---------------------------------------------------------------------------*/
671242f350d172e106580348e24bab66b0d7e6a5vboxsync attr.event_mask = ExposureMask | KeyPressMask | ButtonPressMask;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync attrmask |= CWColormap | CWBackPixel | CWBorderPixel;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync window = XCreateWindow(display, root, 0, 0, image_width, image_height, 0,
671242f350d172e106580348e24bab66b0d7e6a5vboxsync if (!XStringListToTextProperty(&window_name, 1, pWindowName))
671242f350d172e106580348e24bab66b0d7e6a5vboxsync if (!XStringListToTextProperty(&icon_name, 1, pIconName))
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* OK if either hints allocation fails; XSetWMProperties() allows NULLs */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* window will not be resizable */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync size_hints->min_width = size_hints->max_width = (int)image_width;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync size_hints->min_height = size_hints->max_height = (int)image_height;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* wm_hints->icon_pixmap = icon_pixmap; */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync wm_hints->flags = StateHint | InputHint /* | IconPixmapHint */ ;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync XSetWMProperties(display, window, pWindowName, pIconName, NULL, 0,
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* various properties and hints no longer needed; free memory */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync/*---------------------------------------------------------------------------
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Fill window with the specified background color.
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ---------------------------------------------------------------------------*/
671242f350d172e106580348e24bab66b0d7e6a5vboxsync bg_pixel = ((((ulg)bg_red << 8) >> RShift) & RMask) |
671242f350d172e106580348e24bab66b0d7e6a5vboxsync } else /* depth == 8 */ {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* GRR: add 8-bit support */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync XFillRectangle(display, window, gc, 0, 0, image_width, image_height);
671242f350d172e106580348e24bab66b0d7e6a5vboxsync/*---------------------------------------------------------------------------
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Wait for first Expose event to do any drawing, then flush.
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ---------------------------------------------------------------------------*/
671242f350d172e106580348e24bab66b0d7e6a5vboxsync/*---------------------------------------------------------------------------
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Allocate memory for the X- and display-specific version of the image.
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ---------------------------------------------------------------------------*/
671242f350d172e106580348e24bab66b0d7e6a5vboxsync } else /* depth == 8 */ {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync fprintf(stderr, PROGNAME ": unable to allocate image memory\n");
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ximage = XCreateImage(display, visual, depth, ZPixmap, 0,
671242f350d172e106580348e24bab66b0d7e6a5vboxsync fprintf(stderr, PROGNAME ": XCreateImage() failed\n");
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* to avoid testing the byte order every pixel (or doubling the size of
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * the drawing routine with a giant if-test), we arbitrarily set the byte
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * order to MSBFirst and let Xlib worry about inverting things on little-
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * endian machines (like Linux/x86, old VAXen, etc.)--this is not the most
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * efficient approach (the giant if-test would be better), but in the
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * interest of clarity, we take the easy way out... */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync} /* end function rpng_x_create_window() */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync uch r, g, b, a;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync/* int bpp = ximage->bits_per_pixel; */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Trace((stderr, "beginning display loop (image_channels == %d)\n",
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Trace((stderr, " (width = %ld, rowbytes = %ld, ximage_rowbytes = %d)\n",
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Trace((stderr, " (bpp = %d)\n", ximage->bits_per_pixel))
671242f350d172e106580348e24bab66b0d7e6a5vboxsync Trace((stderr, " (byte_order = %s)\n", ximage->byte_order == MSBFirst?
671242f350d172e106580348e24bab66b0d7e6a5vboxsync "MSBFirst" : (ximage->byte_order == LSBFirst? "LSBFirst" : "unknown")))
671242f350d172e106580348e24bab66b0d7e6a5vboxsync for (lastrow = row = 0; row < image_height; ++row) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync for (i = image_width; i > 0; --i) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* recall that we set ximage->byte_order = MSBFirst above */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* GRR BUG: this assumes bpp == 32, but may be 24: */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync red = (RShift < 0)? red << (-RShift) : red >> RShift;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync green = (GShift < 0)? green << (-GShift) : green >> GShift;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync blue = (BShift < 0)? blue << (-BShift) : blue >> BShift;
671242f350d172e106580348e24bab66b0d7e6a5vboxsync pixel = (red & RMask) | (green & GMask) | (blue & BMask);
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* recall that we set ximage->byte_order = MSBFirst above */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync } else /* if (image_channels == 4) */ {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync for (i = image_width; i > 0; --i) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync if (a == 255) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync } else if (a == 0) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* this macro (from png.h) composites the foreground
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * and background values and puts the result into the
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * first argument */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* recall that we set ximage->byte_order = MSBFirst above */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* display after every 16 lines */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
671242f350d172e106580348e24bab66b0d7e6a5vboxsync for (lastrow = row = 0; row < image_height; ++row) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync for (i = image_width; i > 0; --i) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* recall that we set ximage->byte_order = MSBFirst above */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync } else /* if (image_channels == 4) */ {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync for (i = image_width; i > 0; --i) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync if (a == 255) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync } else if (a == 0) {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* this macro (from png.h) composites the foreground
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * and background values and puts the result back into
671242f350d172e106580348e24bab66b0d7e6a5vboxsync * the first argument (== fg byte here: safe) */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* recall that we set ximage->byte_order = MSBFirst above */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* display after every 16 lines */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
671242f350d172e106580348e24bab66b0d7e6a5vboxsync } else /* depth == 8 */ {
671242f350d172e106580348e24bab66b0d7e6a5vboxsync /* GRR: add 8-bit support */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
671242f350d172e106580348e24bab66b0d7e6a5vboxsync free(ximage->data); /* we allocated it, so we free it */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync ximage->data = (char *)NULL; /* instead of XDestroyImage() */
671242f350d172e106580348e24bab66b0d7e6a5vboxsync for (i = 31; i >= 0; --i) {