/* returns 0 for success, 2 for libpng problem, 4 for out of memory, 11 for
* unexpected pnmtype; note that outfile might be stdout */
int writepng_init(mainprog_info *mainprog_ptr)
{
/* This has been altered
png_structp png_ptr;*/ /* note: temporary variables! */
png_infop info_ptr;
int color_type, interlace_type;
/* could also replace libpng warning-handler (final NULL), but no need: */
/* This was altered
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
writepng_error_handler, NULL); */
if (!png_ptr)
return 4; /* out of memory */
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
png_destroy_write_struct(&png_ptr, NULL);
return 4; /* out of memory */
}
/* setjmp() must be called in every function that calls a PNG-writing
* libpng function, unless an alternate error handler was installed--
* but compatible error handlers must either use longjmp() themselves
* (as in this program) or exit immediately, so here we go: */
if (setjmp(mainprog_ptr->jmpbuf)) {
png_destroy_write_struct(&png_ptr, &info_ptr);
return 2;
}
/* make sure outfile is (re)opened in BINARY mode */
/* This was altered
png_init_io(png_ptr, mainprog_ptr->outfile); */
/* set the compression levels--in general, always want to leave filtering
* turned on (except for palette images) and allow all of the filters,
* which is the default; want 32K zlib window, unless entire image buffer
* is 16K or smaller (unknown here)--also the default; usually want max
* compression (NOT the default); and remaining compression flags should
* be left alone */
png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);
/*
>> this is default for no filtering; Z_FILTERED is default otherwise:
png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY);
>> these are all defaults:
png_set_compression_mem_level(png_ptr, 8);
png_set_compression_window_bits(png_ptr, 15);
png_set_compression_method(png_ptr, 8);
*/
/* set the image parameters appropriately */
if (mainprog_ptr->pnmtype == 5)
color_type = PNG_COLOR_TYPE_GRAY;
else if (mainprog_ptr->pnmtype == 6)
color_type = PNG_COLOR_TYPE_RGB;
else if (mainprog_ptr->pnmtype == 8)
color_type = PNG_COLOR_TYPE_RGB_ALPHA;
else {
png_destroy_write_struct(&png_ptr, &info_ptr);
return 11;
}
interlace_type = mainprog_ptr->interlaced? PNG_INTERLACE_ADAM7 :
PNG_INTERLACE_NONE;
png_set_IHDR(png_ptr, info_ptr, mainprog_ptr->width, mainprog_ptr->height,
mainprog_ptr->sample_depth, color_type, interlace_type,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
if (mainprog_ptr->gamma > 0.0)
png_set_gAMA(png_ptr, info_ptr, mainprog_ptr->gamma);
if (mainprog_ptr->have_bg) { /* we know it's RGBA, not gray+alpha */
png_color_16 background;
background.red = mainprog_ptr->bg_red;
background.green = mainprog_ptr->bg_green;
background.blue = mainprog_ptr->bg_blue;
png_set_bKGD(png_ptr, info_ptr, &background);
}
if (mainprog_ptr->have_time) {
png_time modtime;
png_convert_from_time_t(&modtime, mainprog_ptr->modtime);
png_set_tIME(png_ptr, info_ptr, &modtime);
}
if (mainprog_ptr->have_text) {
png_text text[6];
int num_text = 0;
if (mainprog_ptr->have_text & TEXT_TITLE) {
text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
text[num_text].key = "Title";
text[num_text].text = mainprog_ptr->title;
++num_text;
}
if (mainprog_ptr->have_text & TEXT_AUTHOR) {
text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
text[num_text].key = "Author";
text[num_text].text = mainprog_ptr->author;
++num_text;
}
if (mainprog_ptr->have_text & TEXT_DESC) {
text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
text[num_text].key = "Description";
text[num_text].text = mainprog_ptr->desc;
++num_text;
}
if (mainprog_ptr->have_text & TEXT_COPY) {
text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
text[num_text].key = "Copyright";
text[num_text].text = mainprog_ptr->copyright;
++num_text;
}
if (mainprog_ptr->have_text & TEXT_EMAIL) {
text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
text[num_text].key = "E-mail";
text[num_text].text = mainprog_ptr->email;
++num_text;
}
if (mainprog_ptr->have_text & TEXT_URL) {
text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
text[num_text].key = "URL";
text[num_text].text = mainprog_ptr->url;
++num_text;
}
png_set_text(png_ptr, info_ptr, text, num_text);
}
/* write all chunks up to (but not including) first IDAT */
png_write_info(png_ptr, info_ptr);
/* if we wanted to write any more text info *after* the image data, we
* would set up text struct(s) here and call png_set_text() again, with
* just the new data; png_set_tIME() could also go here, but it would
* have no effect since we already called it above (only one tIME chunk
* allowed) */
/* set up the transformations: for now, just pack low-bit-depth pixels
* into bytes (one, two or four pixels per byte) */
png_set_packing(png_ptr);
/* png_set_shift(png_ptr, &sig_bit); to scale low-bit-depth values */
/* make sure we save our pointers for use in writepng_encode_image() */
mainprog_ptr->png_ptr = png_ptr;
mainprog_ptr->info_ptr = info_ptr;
/* OK, that's all we need to do for now; return happy */
return 0;
}
int I_ScreenShot (const char *fname)
{
int result = -1;
FILE *fp = fopen(fname, "wb");
if (fp)
{
png_struct *png_ptr = png_create_write_struct(
PNG_LIBPNG_VER_STRING, png_error_ptr_NULL, error_fn, warning_fn);
if (png_ptr)
{
png_info *info_ptr = png_create_info_struct(png_ptr);
if (info_ptr)
{
SDL_Surface *scr = SDL_GetVideoSurface();
png_time ptime;
png_set_compression_level(png_ptr, 2);
png_init_io(png_ptr, fp);
png_set_IHDR(
png_ptr, info_ptr, SCREENWIDTH, SCREENHEIGHT, 8,
(V_GetMode() == VID_MODE8)
? PNG_COLOR_TYPE_PALETTE
: PNG_COLOR_TYPE_RGB,
PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT,
PNG_FILTER_TYPE_DEFAULT);
png_convert_from_time_t(&ptime, time(NULL));
png_set_tIME(png_ptr, info_ptr, &ptime);
switch (V_GetMode()) {
#ifdef GL_DOOM
case VID_MODEGL:
result = screenshot_gl(png_ptr, info_ptr);
break;
#endif
case VID_MODE8:
if (write_png_palette(png_ptr, info_ptr, scr) >= 0)
result = screenshot_sdl(png_ptr, info_ptr, scr,
&screenshot_sdl_funcs[SCREENSHOT_SDL_INDEXED]);
break;
case VID_MODE15:
case VID_MODE16:
case VID_MODE32:
result = screenshot_sdl(png_ptr, info_ptr, scr,
&screenshot_sdl_funcs[SCREENSHOT_SDL_HICOLOR]);
break;
default:
break;
}
}
png_destroy_write_struct(&png_ptr, png_infopp_NULL);
}
fclose(fp);
}
return result;
}
