bool MCImageEncodePNG(MCImageIndexedBitmap *p_indexed, IO_handle p_stream, uindex_t &r_bytes_written)
{
bool t_success = true;
MCPNGWriteContext t_context;
t_context.stream = p_stream;
t_context.byte_count = 0;
png_structp t_png_ptr = nil;
png_infop t_info_ptr = nil;
png_color *t_png_palette = nil;
png_byte *t_png_transparency = nil;
png_bytep t_data_ptr = nil;
uindex_t t_stride = 0;
/*init png stuff*/
if (t_success)
{
t_success = nil != (t_png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
(png_voidp)NULL, (png_error_ptr)NULL,
(png_error_ptr)NULL));
}
if (t_success)
t_success = nil != (t_info_ptr = png_create_info_struct(t_png_ptr));
/*in case of png error*/
if (setjmp(png_jmpbuf(t_png_ptr)))
t_success = false;
if (t_success)
png_set_write_fn(t_png_ptr,(png_voidp)&t_context,fakewrite,fakeflush);
if (t_success)
{
png_set_IHDR(t_png_ptr, t_info_ptr, p_indexed->width, p_indexed->height, 8,
PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
png_set_gAMA(t_png_ptr, t_info_ptr, 1/MCgamma);
}
if (t_success)
t_success = MCMemoryNewArray(p_indexed->palette_size, t_png_palette);
/*create palette for 8 bit*/
if (t_success)
{
for (uindex_t i = 0; i < p_indexed->palette_size ; i++)
{
t_png_palette[i].red = p_indexed->palette[i].red >> 8;
t_png_palette[i].green = p_indexed->palette[i].green >> 8;
t_png_palette[i].blue = p_indexed->palette[i].blue >> 8;
}
png_set_PLTE(t_png_ptr, t_info_ptr, t_png_palette, p_indexed->palette_size);
}
if (MCImageIndexedBitmapHasTransparency(p_indexed))
{
if (t_success)
t_success = MCMemoryAllocate(p_indexed->palette_size, t_png_transparency);
if (t_success)
{
memset(t_png_transparency, 0xFF, p_indexed->palette_size);
t_png_transparency[p_indexed->transparent_index] = 0x00;
png_set_tRNS(t_png_ptr, t_info_ptr, t_png_transparency, p_indexed->palette_size, NULL);
}
}
if (t_success)
png_write_info(t_png_ptr, t_info_ptr);
if (t_success)
{
t_data_ptr = (png_bytep)p_indexed->data;
t_stride = p_indexed->stride;
}
if (t_success)
{
for (uindex_t i = 0; i < p_indexed->height; i++)
{
png_write_row(t_png_ptr, t_data_ptr);
t_data_ptr += t_stride;
}
}
if (t_success)
png_write_end(t_png_ptr, t_info_ptr);
if (t_png_ptr != nil)
png_destroy_write_struct(&t_png_ptr, &t_info_ptr);
if (t_png_palette != nil)
MCMemoryDeleteArray(t_png_palette);
if (t_png_transparency != nil)
MCMemoryDeallocate(t_png_transparency);
if (t_success)
r_bytes_written = t_context.byte_count;
return t_success;
}
bool MCImageEncodeGIF(MCImageIndexedBitmap *p_indexed, IO_handle p_stream, uindex_t &r_bytes_written)
{
bool t_success = true;
int32_t t_transparent = -1;
uindex_t t_palette_size;
uindex_t t_depth;
t_depth = GifBitSize(p_indexed->palette_size);
// GIF requires palette size to be 2^depth
t_palette_size = 1 << t_depth;
int t_err = 0;
GifFileType *t_gif = nil;
ColorMapObject *t_colormap = nil;
MCGIFWriteContext t_context;
t_context.stream = p_stream;
t_context.byte_count = 0;
t_success = nil != (t_gif = EGifOpen(&t_context, gif_writeFunc, &t_err));
if (t_success)
t_success = nil != (t_colormap = GifMakeMapObject(t_palette_size, nil));
if (t_success)
{
for (uindex_t i = 0; i < p_indexed->palette_size; i++)
{
t_colormap->Colors[i].Red = p_indexed->palette[i].red;
t_colormap->Colors[i].Green = p_indexed->palette[i].green;
t_colormap->Colors[i].Blue = p_indexed->palette[i].blue;
}
for (uindex_t i = p_indexed->palette_size; i < t_palette_size; i++)
{
t_colormap->Colors[i].Red =
t_colormap->Colors[i].Green =
t_colormap->Colors[i].Blue = 0;
}
if (MCImageIndexedBitmapHasTransparency(p_indexed))
{
t_transparent = p_indexed->transparent_index;
t_colormap->Colors[t_transparent].Red =
t_colormap->Colors[t_transparent].Green =
t_colormap->Colors[t_transparent].Blue = 0xFF;
}
t_success = GIF_OK == EGifPutScreenDesc(t_gif, p_indexed->width, p_indexed->height, t_depth, 0, t_colormap);
}
if (t_success)
{
if (t_transparent != -1)
{
GraphicsControlBlock t_gcb;
MCMemoryClear(&t_gcb, sizeof(t_gcb));
t_gcb.TransparentColor = t_transparent;
GifByteType t_extension[4];
uindex_t t_extension_size;
t_extension_size = EGifGCBToExtension(&t_gcb, t_extension);
// Should always be 4 bytes
MCAssert(t_extension_size == sizeof(t_extension));
t_success = GIF_OK == EGifPutExtension(t_gif, GRAPHICS_EXT_FUNC_CODE, sizeof(t_extension), t_extension);
}
}
if (t_success)
t_success = GIF_OK == EGifPutImageDesc(t_gif, 0, 0, p_indexed->width, p_indexed->height, false, nil);
for (uindex_t y = 0; t_success && y < p_indexed->height; y++)
t_success = GIF_OK == EGifPutLine(t_gif, (uint8_t*)p_indexed->data + y * p_indexed->stride, p_indexed->width);
int t_error_code;
if (GIF_ERROR == EGifCloseFile(t_gif, &t_error_code))
t_success = false;
GifFreeMapObject(t_colormap);
if (t_success)
r_bytes_written = t_context.byte_count;
return t_success;
}
