elevationsnow
Joined: 10 Sep 2005
Posts: 22
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 Posted: Fri Oct 14, 2005 12:08 pm Post subject: Faster PNG loader |
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is there any faster png loader than:
| Code: | void user_warning_fn(png_structp png_ptr, png_const_charp warning_msg)
{
// ignore PNG warnings
}
void loadImage(const char* filename,int xx,int yy)
{
u32* vram32;
u16* vram16;
int bufferwidth;
int pixelformat;
int unknown;
png_structp png_ptr;
png_infop info_ptr;
unsigned int sig_read = 0;
png_uint_32 width, height;
int bit_depth, color_type, interlace_type, x, y;
u32* line;
FILE *fp;
if ((fp = fopen(filename, "rb")) == NULL) return;
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (png_ptr == NULL) {
fclose(fp);
return;
}
png_set_error_fn(png_ptr, (png_voidp) NULL, (png_error_ptr) NULL, user_warning_fn);
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL) {
fclose(fp);
png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL);
return;
}
png_init_io(png_ptr, fp);
png_set_sig_bytes(png_ptr, sig_read);
png_read_info(png_ptr, info_ptr);
png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, int_p_NULL, int_p_NULL);
png_set_strip_16(png_ptr);
png_set_packing(png_ptr);
if (color_type == PNG_COLOR_TYPE_PALETTE) png_set_palette_to_rgb(png_ptr);
if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) png_set_gray_1_2_4_to_8(png_ptr);
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr);
png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
line = (u32*) malloc(width * 4);
if (!line) {
fclose(fp);
png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL);
return;
}
sceDisplayWaitVblankStart(); // if framebuf was set with PSP_DISPLAY_SETBUF_NEXTFRAME, wait until it is changed
sceDisplayGetFrameBuf((void**)&vram32, &bufferwidth, &pixelformat, &unknown);
vram16 = (u16*) vram32;
for (y = 0; y < height; y++) {
png_read_row(png_ptr, (u8*) line, png_bytep_NULL);
for (x = 0; x < width; x++) {
u32 color32 = line[x];
u16 color16;
int r = color32 & 0xff;
int g = (color32 >> 8) & 0xff;
int b = (color32 >> 16) & 0xff;
switch (pixelformat) {
case PSP_DISPLAY_PIXEL_FORMAT_565:
color16 = (r >> 3) | ((g >> 2) << 5) | ((b >> 3) << 11);
PlotPixel(x+xx,y+yy,r,g,b);
break;
case PSP_DISPLAY_PIXEL_FORMAT_5551:
color16 = (r >> 3) | ((g >> 3) << 5) | ((b >> 3) << 10);
PlotPixel(x+xx,y+yy,r,g,b);
break;
case PSP_DISPLAY_PIXEL_FORMAT_4444:
color16 = (r >> 4) | ((g >> 4) << 4) | ((b >> 4) << 8);
PlotPixel(x+xx,y+yy,r,g,b);
break;
case PSP_DISPLAY_PIXEL_FORMAT_8888:
color32 = r | (g << 8) | (b << 16);
PlotPixel(x+xx,y+yy,r,g,b);
break;
}
}
}
free(line);
png_read_end(png_ptr, info_ptr);
png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
fclose(fp);
}
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