/* Transcribe one scanline from the GIF to the picogui bitmap */
void dither_transcribe_line(hwrdither d, GifFileType *f,
int transparent_flag, int transparent_color) {
pgcolor c;
u8 pixel;
GifColorType *color;
int x;
for (x=0;x<f->Image.Width;x++) {
DGifGetPixel(f, &pixel);
color = f->SColorMap->Colors + (pixel % f->SColorMap->ColorCount);
if (transparent_flag) {
c = mkcolora(pixel==transparent_color ? 0 : 127,color->Red,color->Green,color->Blue);
}
else {
c = mkcolor(color->Red,color->Green,color->Blue);
}
vid->dither_store(d,c,PG_LGOP_NONE);
}
}
/* Transcribe one scanline from the GIF to the picogui bitmap */
void transcribe_line(hwrbitmap b, GifFileType *f, int y,
int transparent_flag, int transparent_color) {
pgcolor c;
u8 pixel;
GifColorType *color;
int x;
for (x=0;x<f->Image.Width;x++) {
DGifGetPixel(f, &pixel);
color = f->SColorMap->Colors + (pixel % f->SColorMap->ColorCount);
if (transparent_flag) {
c = mkcolora(pixel==transparent_color ? 0 : 127,color->Red,color->Green,color->Blue);
}
else {
c = mkcolor(color->Red,color->Green,color->Blue);
}
vid->pixel(b,x,y,VID(color_pgtohwr)(c),PG_LGOP_NONE);
}
}
g_error png_load(hwrbitmap *hbmp, const u8 *data, u32 datalen) {
png_structp png_ptr;
png_infop info_ptr;
struct datablock d;
png_bytep *row_pointers;
png_uint_32 width, height;
int bit_depth,colortype,interlace;
int x,y;
u8 r,g,b,a;
pgcolor c;
png_bytep p;
g_error e;
png_colorp palette;
int num_palette;
png_colorp pp;
png_bytep trans;
int num_trans = 0;
#ifdef CONFIG_DITHER
hwrdither dither;
#endif
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr)
return mkerror(PG_ERRT_IO, 68); /* Error initializing libpng */
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
return mkerror(PG_ERRT_IO, 68); /* Error initializing libpng */
}
/* Set libpng error handler */
if (setjmp(png_jmpbuf(png_ptr))) {
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
return mkerror(PG_ERRT_IO, 71); /* Error reading PNG */
}
/* Set libpng read handler */
d.data = data;
d.length = datalen;
png_set_read_fn(png_ptr, &d, (png_rw_ptr) &png_user_read_data);
/* Read the png into memory */
png_read_png(png_ptr, info_ptr,
PNG_TRANSFORM_STRIP_16 |
PNG_TRANSFORM_PACKING,
NULL);
row_pointers = png_get_rows(png_ptr, info_ptr);
png_get_IHDR(png_ptr, info_ptr, &width, &height,
&bit_depth, &colortype, &interlace, NULL, NULL);
if (colortype == PNG_COLOR_TYPE_PALETTE) {
png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette);
png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, NULL);
}
if (interlace != PNG_INTERLACE_NONE)
fprintf(stderr, "png loader: OOPS... interlaced image, will b0rk\n");
/* Allocate the picogui bitmap
*
* Important note: normally we create bitmaps at the display's
* color depth, but if we have an alpha channel
* we need room for ARGB colors.
*/
if (colortype == PNG_COLOR_TYPE_GRAY_ALPHA ||
colortype == PNG_COLOR_TYPE_RGB_ALPHA ||
num_trans)
e = vid->bitmap_new(hbmp,width,height,32);
else
e = vid->bitmap_new(hbmp,width,height,vid->bpp);
if (iserror(e))
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
errorcheck;
#ifdef CONFIG_DITHER
/* Start dithering */
e = vid->dither_start(&dither, *hbmp, 0,0,0,width,height);
errorcheck;
#endif
/* Transcribe it into a picogui bitmap.
* This method is slow, but ensures compatibility
*/
for (y=0;y<height;y++) {
p = row_pointers[y];
for (x=0;x<width;x++) {
switch (colortype) {
case PNG_COLOR_TYPE_GRAY:
g = *(p++);
c = mkcolor(g,g,g);
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
g = *(p++);
a = *(p++);
c = mkcolora(a>>1,g,g,g);
break;
case PNG_COLOR_TYPE_PALETTE:
pp = &palette[ (*p) % num_palette ];
if (*p < num_trans)
c = mkcolora(trans[*p]>>1, pp->red, pp->green, pp->blue);
else if (num_trans)
c = mkcolora(0x7f, pp->red, pp->green, pp->blue);
else
c = mkcolor(pp->red, pp->green, pp->blue);
p++;
break;
case PNG_COLOR_TYPE_RGB:
r = *(p++);
g = *(p++);
b = *(p++);
c = mkcolor(r,g,b);
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
r = *(p++);
g = *(p++);
b = *(p++);
a = *(p++);
c = mkcolora(a>>1,r,g,b);
break;
}
#ifdef CONFIG_DITHER
vid->dither_store(dither, c, PG_LGOP_NONE);
#else
vid->pixel(*hbmp,x,y,VID(color_pgtohwr)(c),PG_LGOP_NONE);
#endif
}
}
