/** @brief Sets the index of the palette entry to be used as transparent color
for the image specified. Does nothing on high color images.
This method sets the index of the palette entry to be used as single transparent
color for the image specified. This works on palletised images only and does
nothing for high color images.
Although it is possible for palletised images to have more than one transparent
color, this method sets the palette entry specified as the single transparent
color for the image. All other colors will be set to be non-transparent by this
method.
As with FreeImage_SetTransparencyTable(), this method also sets the image's
transparency property to TRUE (as it is set and obtained by
FreeImage_SetTransparent() and FreeImage_IsTransparent() respectively) for
palletised images.
@param dib Input image, whose transparent color is to be set.
@param index The index of the palette entry to be set as transparent color.
*/
void DLL_CALLCONV
FreeImage_SetTransparentIndex(FIBITMAP *dib, int index) {
if (dib) {
int count = FreeImage_GetColorsUsed(dib);
if (count) {
BYTE *new_tt = (BYTE *)malloc(count * sizeof(BYTE));
memset(new_tt, 0xFF, count);
if ((index >= 0) && (index < count)) {
new_tt[index] = 0x00;
}
FreeImage_SetTransparencyTable(dib, new_tt, count);
free(new_tt);
}
}
}
static FIBITMAP * DLL_CALLCONV
Load(FreeImageIO *io, fi_handle handle, int page, int flags, void *data) {
png_structp png_ptr = NULL;
png_infop info_ptr;
png_uint_32 width, height;
png_colorp png_palette = NULL;
int color_type, palette_entries = 0;
int bit_depth, pixel_depth; // pixel_depth = bit_depth * channels
FIBITMAP *dib = NULL;
RGBQUAD *palette = NULL; // pointer to dib palette
png_bytepp row_pointers = NULL;
int i;
fi_ioStructure fio;
fio.s_handle = handle;
fio.s_io = io;
if (handle) {
BOOL header_only = (flags & FIF_LOAD_NOPIXELS) == FIF_LOAD_NOPIXELS;
try {
// check to see if the file is in fact a PNG file
BYTE png_check[PNG_BYTES_TO_CHECK];
io->read_proc(png_check, PNG_BYTES_TO_CHECK, 1, handle);
if (png_sig_cmp(png_check, (png_size_t)0, PNG_BYTES_TO_CHECK) != 0) {
return NULL; // Bad signature
}
// create the chunk manage structure
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, error_handler, warning_handler);
if (!png_ptr) {
return NULL;
}
// create the info structure
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
return NULL;
}
// init the IO
png_set_read_fn(png_ptr, &fio, _ReadProc);
if (setjmp(png_jmpbuf(png_ptr))) {
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return NULL;
}
// because we have already read the signature...
png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK);
// read the IHDR chunk
png_read_info(png_ptr, info_ptr);
png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, NULL, NULL, NULL);
pixel_depth = png_get_bit_depth(png_ptr, info_ptr) * png_get_channels(png_ptr, info_ptr);
// get image data type (assume standard image type)
FREE_IMAGE_TYPE image_type = FIT_BITMAP;
if (bit_depth == 16) {
if ((pixel_depth == 16) && (color_type == PNG_COLOR_TYPE_GRAY)) {
image_type = FIT_UINT16;
}
else if ((pixel_depth == 48) && (color_type == PNG_COLOR_TYPE_RGB)) {
image_type = FIT_RGB16;
}
else if ((pixel_depth == 64) && (color_type == PNG_COLOR_TYPE_RGB_ALPHA)) {
image_type = FIT_RGBA16;
} else {
// tell libpng to strip 16 bit/color files down to 8 bits/color
png_set_strip_16(png_ptr);
bit_depth = 8;
}
}
#ifndef FREEIMAGE_BIGENDIAN
if((image_type == FIT_UINT16) || (image_type == FIT_RGB16) || (image_type == FIT_RGBA16)) {
// turn on 16 bit byte swapping
png_set_swap(png_ptr);
}
#endif
// set some additional flags
switch(color_type) {
case PNG_COLOR_TYPE_RGB:
case PNG_COLOR_TYPE_RGB_ALPHA:
#if FREEIMAGE_COLORORDER == FREEIMAGE_COLORORDER_BGR
// flip the RGB pixels to BGR (or RGBA to BGRA)
if(image_type == FIT_BITMAP) {
png_set_bgr(png_ptr);
}
#endif
break;
case PNG_COLOR_TYPE_PALETTE:
// expand palette images to the full 8 bits from 2 bits/pixel
if (pixel_depth == 2) {
png_set_packing(png_ptr);
pixel_depth = 8;
}
break;
case PNG_COLOR_TYPE_GRAY:
// expand grayscale images to the full 8 bits from 2 bits/pixel
// but *do not* expand fully transparent palette entries to a full alpha channel
if (pixel_depth == 2) {
png_set_expand_gray_1_2_4_to_8(png_ptr);
pixel_depth = 8;
}
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
// expand 8-bit greyscale + 8-bit alpha to 32-bit
png_set_gray_to_rgb(png_ptr);
#if FREEIMAGE_COLORORDER == FREEIMAGE_COLORORDER_BGR
// flip the RGBA pixels to BGRA
png_set_bgr(png_ptr);
#endif
pixel_depth = 32;
break;
default:
throw FI_MSG_ERROR_UNSUPPORTED_FORMAT;
}
// unlike the example in the libpng documentation, we have *no* idea where
// this file may have come from--so if it doesn't have a file gamma, don't
// do any correction ("do no harm")
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_gAMA)) {
double gamma = 0;
double screen_gamma = 2.2;
if (png_get_gAMA(png_ptr, info_ptr, &gamma) && ( flags & PNG_IGNOREGAMMA ) != PNG_IGNOREGAMMA) {
png_set_gamma(png_ptr, screen_gamma, gamma);
}
}
// all transformations have been registered; now update info_ptr data
png_read_update_info(png_ptr, info_ptr);
// color type may have changed, due to our transformations
color_type = png_get_color_type(png_ptr,info_ptr);
// create a DIB and write the bitmap header
// set up the DIB palette, if needed
switch (color_type) {
case PNG_COLOR_TYPE_RGB:
png_set_invert_alpha(png_ptr);
if(image_type == FIT_BITMAP) {
dib = FreeImage_AllocateHeader(header_only, width, height, 24, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);
} else {
dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, pixel_depth);
}
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
if(image_type == FIT_BITMAP) {
dib = FreeImage_AllocateHeader(header_only, width, height, 32, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);
} else {
dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, pixel_depth);
}
break;
case PNG_COLOR_TYPE_PALETTE:
dib = FreeImage_AllocateHeader(header_only, width, height, pixel_depth);
png_get_PLTE(png_ptr,info_ptr, &png_palette, &palette_entries);
palette_entries = MIN((unsigned)palette_entries, FreeImage_GetColorsUsed(dib));
palette = FreeImage_GetPalette(dib);
// store the palette
for (i = 0; i < palette_entries; i++) {
palette[i].rgbRed = png_palette[i].red;
palette[i].rgbGreen = png_palette[i].green;
palette[i].rgbBlue = png_palette[i].blue;
}
break;
case PNG_COLOR_TYPE_GRAY:
dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, pixel_depth);
if(pixel_depth <= 8) {
palette = FreeImage_GetPalette(dib);
palette_entries = 1 << pixel_depth;
for (i = 0; i < palette_entries; i++) {
palette[i].rgbRed =
palette[i].rgbGreen =
palette[i].rgbBlue = (BYTE)((i * 255) / (palette_entries - 1));
}
}
break;
default:
throw FI_MSG_ERROR_UNSUPPORTED_FORMAT;
}
// store the transparency table
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
// array of alpha (transparency) entries for palette
png_bytep trans_alpha = NULL;
// number of transparent entries
int num_trans = 0;
// graylevel or color sample values of the single transparent color for non-paletted images
png_color_16p trans_color = NULL;
png_get_tRNS(png_ptr, info_ptr, &trans_alpha, &num_trans, &trans_color);
if((color_type == PNG_COLOR_TYPE_GRAY) && trans_color) {
// single transparent color
if (trans_color->gray < palette_entries) {
BYTE table[256];
memset(table, 0xFF, palette_entries);
table[trans_color->gray] = 0;
FreeImage_SetTransparencyTable(dib, table, palette_entries);
}
} else if((color_type == PNG_COLOR_TYPE_PALETTE) && trans_alpha) {
// transparency table
FreeImage_SetTransparencyTable(dib, (BYTE *)trans_alpha, num_trans);
}
}
// store the background color
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD)) {
// Get the background color to draw transparent and alpha images over.
// Note that even if the PNG file supplies a background, you are not required to
// use it - you should use the (solid) application background if it has one.
png_color_16p image_background = NULL;
RGBQUAD rgbBkColor;
if (png_get_bKGD(png_ptr, info_ptr, &image_background)) {
rgbBkColor.rgbRed = (BYTE)image_background->red;
rgbBkColor.rgbGreen = (BYTE)image_background->green;
rgbBkColor.rgbBlue = (BYTE)image_background->blue;
rgbBkColor.rgbReserved = 0;
FreeImage_SetBackgroundColor(dib, &rgbBkColor);
}
}
// get physical resolution
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_pHYs)) {
png_uint_32 res_x, res_y;
// we'll overload this var and use 0 to mean no phys data,
// since if it's not in meters we can't use it anyway
int res_unit_type = PNG_RESOLUTION_UNKNOWN;
png_get_pHYs(png_ptr,info_ptr, &res_x, &res_y, &res_unit_type);
if (res_unit_type == PNG_RESOLUTION_METER) {
FreeImage_SetDotsPerMeterX(dib, res_x);
FreeImage_SetDotsPerMeterY(dib, res_y);
}
}
// get possible ICC profile
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_iCCP)) {
png_charp profile_name = NULL;
png_bytep profile_data = NULL;
png_uint_32 profile_length = 0;
int compression_type;
png_get_iCCP(png_ptr, info_ptr, &profile_name, &compression_type, &profile_data, &profile_length);
// copy ICC profile data (must be done after FreeImage_AllocateHeader)
FreeImage_CreateICCProfile(dib, profile_data, profile_length);
}
// --- header only mode => clean-up and return
if (header_only) {
// get possible metadata (it can be located both before and after the image data)
ReadMetadata(png_ptr, info_ptr, dib);
if (png_ptr) {
// clean up after the read, and free any memory allocated - REQUIRED
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
}
return dib;
}
// set the individual row_pointers to point at the correct offsets
row_pointers = (png_bytepp)malloc(height * sizeof(png_bytep));
if (!row_pointers) {
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
FreeImage_Unload(dib);
return NULL;
}
// read in the bitmap bits via the pointer table
// allow loading of PNG with minor errors (such as images with several IDAT chunks)
for (png_uint_32 k = 0; k < height; k++) {
row_pointers[height - 1 - k] = FreeImage_GetScanLine(dib, k);
}
png_set_benign_errors(png_ptr, 1);
png_read_image(png_ptr, row_pointers);
// check if the bitmap contains transparency, if so enable it in the header
if (FreeImage_GetBPP(dib) == 32) {
if (FreeImage_GetColorType(dib) == FIC_RGBALPHA) {
FreeImage_SetTransparent(dib, TRUE);
} else {
FreeImage_SetTransparent(dib, FALSE);
}
}
// cleanup
if (row_pointers) {
free(row_pointers);
row_pointers = NULL;
}
// read the rest of the file, getting any additional chunks in info_ptr
png_read_end(png_ptr, info_ptr);
// get possible metadata (it can be located both before and after the image data)
ReadMetadata(png_ptr, info_ptr, dib);
if (png_ptr) {
// clean up after the read, and free any memory allocated - REQUIRED
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
}
return dib;
} catch (const char *text) {
if (png_ptr) {
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
}
if (row_pointers) {
free(row_pointers);
}
if (dib) {
FreeImage_Unload(dib);
}
FreeImage_OutputMessageProc(s_format_id, text);
return NULL;
}
}
return NULL;
}
void fipImage::setTransparencyTable(BYTE *table, int count) {
FreeImage_SetTransparencyTable(_dib, table, count);
_bHasChanged = TRUE;
}
static FIBITMAP * DLL_CALLCONV
Load(FreeImageIO *io, fi_handle handle, int page, int flags, void *data) {
if( data == NULL ) {
return NULL;
}
GIFinfo *info = (GIFinfo *)data;
if( page == -1 ) {
page = 0;
}
if( page < 0 || page >= (int)info->image_descriptor_offsets.size() ) {
return NULL;
}
FIBITMAP *dib = NULL;
try {
bool have_transparent = false, no_local_palette = false, interlaced = false;
int disposal_method = GIF_DISPOSAL_LEAVE, delay_time = 0, transparent_color = 0;
WORD left, top, width, height;
BYTE packed, b;
WORD w;
//playback pages to generate what the user would see for this frame
if( (flags & GIF_PLAYBACK) == GIF_PLAYBACK ) {
//Logical Screen Descriptor
io->seek_proc(handle, 6, SEEK_SET);
WORD logicalwidth, logicalheight;
io->read_proc(&logicalwidth, 2, 1, handle);
io->read_proc(&logicalheight, 2, 1, handle);
#ifdef FREEIMAGE_BIGENDIAN
SwapShort(&logicalwidth);
SwapShort(&logicalheight);
#endif
//set the background color with 0 alpha
RGBQUAD background;
if( info->global_color_table_offset != 0 && info->background_color < info->global_color_table_size ) {
io->seek_proc(handle, info->global_color_table_offset + (info->background_color * 3), SEEK_SET);
io->read_proc(&background.rgbRed, 1, 1, handle);
io->read_proc(&background.rgbGreen, 1, 1, handle);
io->read_proc(&background.rgbBlue, 1, 1, handle);
} else {
background.rgbRed = 0;
background.rgbGreen = 0;
background.rgbBlue = 0;
}
background.rgbReserved = 0;
//allocate entire logical area
dib = FreeImage_Allocate(logicalwidth, logicalheight, 32);
if( dib == NULL ) {
throw "DIB allocated failed";
}
//fill with background color to start
int x, y;
RGBQUAD *scanline;
for( y = 0; y < logicalheight; y++ ) {
scanline = (RGBQUAD *)FreeImage_GetScanLine(dib, y);
for( x = 0; x < logicalwidth; x++ ) {
*scanline++ = background;
}
}
//cache some info about each of the pages so we can avoid decoding as many of them as possible
std::vector<PageInfo> pageinfo;
int start = page, end = page;
while( start >= 0 ) {
//Graphic Control Extension
io->seek_proc(handle, info->graphic_control_extension_offsets[start] + 1, SEEK_SET);
io->read_proc(&packed, 1, 1, handle);
have_transparent = (packed & GIF_PACKED_GCE_HAVETRANS) ? true : false;
disposal_method = (packed & GIF_PACKED_GCE_DISPOSAL) >> 2;
//Image Descriptor
io->seek_proc(handle, info->image_descriptor_offsets[page], SEEK_SET);
io->read_proc(&left, 2, 1, handle);
io->read_proc(&top, 2, 1, handle);
io->read_proc(&width, 2, 1, handle);
io->read_proc(&height, 2, 1, handle);
#ifdef FREEIMAGE_BIGENDIAN
SwapShort(&left);
SwapShort(&top);
SwapShort(&width);
SwapShort(&height);
#endif
pageinfo.push_back(PageInfo(disposal_method, left, top, width, height));
if( start != end ) {
if( left == 0 && top == 0 && width == logicalwidth && height == logicalheight ) {
if( disposal_method == GIF_DISPOSAL_BACKGROUND ) {
pageinfo.pop_back();
start++;
break;
} else if( disposal_method != GIF_DISPOSAL_PREVIOUS ) {
if( !have_transparent ) {
break;
}
}
}
}
start--;
}
if( start < 0 ) {
start = 0;
}
//draw each page into the logical area
for( page = start; page <= end; page++ ) {
PageInfo &info = pageinfo[end - page];
//things we can skip having to decode
if( page != end ) {
if( info.disposal_method == GIF_DISPOSAL_PREVIOUS ) {
continue;
}
if( info.disposal_method == GIF_DISPOSAL_BACKGROUND ) {
for( y = 0; y < info.height; y++ ) {
scanline = (RGBQUAD *)FreeImage_GetScanLine(dib, logicalheight - (y + info.top) - 1) + info.left;
for( x = 0; x < info.width; x++ ) {
*scanline++ = background;
}
}
}
}
//decode page
FIBITMAP *pagedib = Load(io, handle, page, GIF_LOAD256, data);
if( pagedib != NULL ) {
RGBQUAD *pal = FreeImage_GetPalette(pagedib);
have_transparent = false;
if( FreeImage_IsTransparent(pagedib) ) {
int count = FreeImage_GetTransparencyCount(pagedib);
BYTE *table = FreeImage_GetTransparencyTable(pagedib);
for( int i = 0; i < count; i++ ) {
if( table[i] == 0 ) {
have_transparent = true;
transparent_color = i;
break;
}
}
}
//copy page data into logical buffer, with full alpha opaqueness
for( y = 0; y < info.height; y++ ) {
scanline = (RGBQUAD *)FreeImage_GetScanLine(dib, logicalheight - (y + info.top) - 1) + info.left;
BYTE *pageline = FreeImage_GetScanLine(pagedib, info.height - y - 1);
for( x = 0; x < info.width; x++ ) {
if( !have_transparent || *pageline != transparent_color ) {
*scanline = pal[*pageline];
scanline->rgbReserved = 255;
}
scanline++;
pageline++;
}
}
FreeImage_Unload(pagedib);
}
}
return dib;
}
//get the actual frame image data for a single frame
//Image Descriptor
io->seek_proc(handle, info->image_descriptor_offsets[page], SEEK_SET);
io->read_proc(&left, 2, 1, handle);
io->read_proc(&top, 2, 1, handle);
io->read_proc(&width, 2, 1, handle);
io->read_proc(&height, 2, 1, handle);
#ifdef FREEIMAGE_BIGENDIAN
SwapShort(&left);
SwapShort(&top);
SwapShort(&width);
SwapShort(&height);
#endif
io->read_proc(&packed, 1, 1, handle);
interlaced = (packed & GIF_PACKED_ID_INTERLACED) ? true : false;
no_local_palette = (packed & GIF_PACKED_ID_HAVELCT) ? false : true;
int bpp = 8;
if( (flags & GIF_LOAD256) == 0 ) {
if( !no_local_palette ) {
int size = 2 << (packed & GIF_PACKED_ID_LCTSIZE);
if( size <= 2 ) bpp = 1;
else if( size <= 16 ) bpp = 4;
} else if( info->global_color_table_offset != 0 ) {
if( info->global_color_table_size <= 2 ) bpp = 1;
else if( info->global_color_table_size <= 16 ) bpp = 4;
}
}
dib = FreeImage_Allocate(width, height, bpp);
if( dib == NULL ) {
throw "DIB allocated failed";
}
FreeImage_SetMetadataEx(FIMD_ANIMATION, dib, "FrameLeft", ANIMTAG_FRAMELEFT, FIDT_SHORT, 1, 2, &left);
FreeImage_SetMetadataEx(FIMD_ANIMATION, dib, "FrameTop", ANIMTAG_FRAMETOP, FIDT_SHORT, 1, 2, &top);
b = no_local_palette ? 1 : 0;
FreeImage_SetMetadataEx(FIMD_ANIMATION, dib, "NoLocalPalette", ANIMTAG_NOLOCALPALETTE, FIDT_BYTE, 1, 1, &b);
b = interlaced ? 1 : 0;
FreeImage_SetMetadataEx(FIMD_ANIMATION, dib, "Interlaced", ANIMTAG_INTERLACED, FIDT_BYTE, 1, 1, &b);
//Palette
RGBQUAD *pal = FreeImage_GetPalette(dib);
if( !no_local_palette ) {
int size = 2 << (packed & GIF_PACKED_ID_LCTSIZE);
int i = 0;
while( i < size ) {
io->read_proc(&pal[i].rgbRed, 1, 1, handle);
io->read_proc(&pal[i].rgbGreen, 1, 1, handle);
io->read_proc(&pal[i].rgbBlue, 1, 1, handle);
i++;
}
} else if( info->global_color_table_offset != 0 ) {
long pos = io->tell_proc(handle);
io->seek_proc(handle, info->global_color_table_offset, SEEK_SET);
int i = 0;
while( i < info->global_color_table_size ) {
io->read_proc(&pal[i].rgbRed, 1, 1, handle);
io->read_proc(&pal[i].rgbGreen, 1, 1, handle);
io->read_proc(&pal[i].rgbBlue, 1, 1, handle);
i++;
}
io->seek_proc(handle, pos, SEEK_SET);
} else {
//its legal to have no palette, but we're going to generate *something*
for( int i = 0; i < 256; i++ ) {
pal[i].rgbRed = i;
pal[i].rgbGreen = i;
pal[i].rgbBlue = i;
}
}
//LZW Minimum Code Size
io->read_proc(&b, 1, 1, handle);
StringTable stringtable;
stringtable.Initialize(b);
//Image Data Sub-blocks
int x = 0, xpos = 0, y = 0, shift = 8 - bpp, mask = (1 << bpp) - 1, interlacepass = 0;
BYTE *scanline = FreeImage_GetScanLine(dib, height - 1);
BYTE buf[1024];
io->read_proc(&b, 1, 1, handle);
while( b ) {
io->read_proc(stringtable.FillInputBuffer(b), b, 1, handle);
int size = sizeof(buf);
while( stringtable.Decompress(buf, &size) ) {
for( int i = 0; i < size; i++ ) {
scanline[xpos] |= (buf[i] & mask) << shift;
if( shift > 0 ) {
shift -= bpp;
} else {
xpos++;
shift = 8 - bpp;
}
if( ++x >= width ) {
if( interlaced ) {
y += g_GifInterlaceIncrement[interlacepass];
if( y >= height && interlacepass < GIF_INTERLACE_PASSES ) {
y = g_GifInterlaceOffset[++interlacepass];
}
} else {
y++;
}
if( y >= height ) {
stringtable.Done();
break;
}
x = xpos = 0;
shift = 8 - bpp;
scanline = FreeImage_GetScanLine(dib, height - y - 1);
}
}
size = sizeof(buf);
}
io->read_proc(&b, 1, 1, handle);
}
if( page == 0 ) {
size_t idx;
//Logical Screen Descriptor
io->seek_proc(handle, 6, SEEK_SET);
WORD logicalwidth, logicalheight;
io->read_proc(&logicalwidth, 2, 1, handle);
io->read_proc(&logicalheight, 2, 1, handle);
#ifdef FREEIMAGE_BIGENDIAN
SwapShort(&logicalwidth);
SwapShort(&logicalheight);
#endif
FreeImage_SetMetadataEx(FIMD_ANIMATION, dib, "LogicalWidth", ANIMTAG_LOGICALWIDTH, FIDT_SHORT, 1, 2, &logicalwidth);
FreeImage_SetMetadataEx(FIMD_ANIMATION, dib, "LogicalHeight", ANIMTAG_LOGICALHEIGHT, FIDT_SHORT, 1, 2, &logicalheight);
//Global Color Table
if( info->global_color_table_offset != 0 ) {
RGBQUAD globalpalette[256];
io->seek_proc(handle, info->global_color_table_offset, SEEK_SET);
int i = 0;
while( i < info->global_color_table_size ) {
io->read_proc(&globalpalette[i].rgbRed, 1, 1, handle);
io->read_proc(&globalpalette[i].rgbGreen, 1, 1, handle);
io->read_proc(&globalpalette[i].rgbBlue, 1, 1, handle);
globalpalette[i].rgbReserved = 0;
i++;
}
FreeImage_SetMetadataEx(FIMD_ANIMATION, dib, "GlobalPalette", ANIMTAG_GLOBALPALETTE, FIDT_PALETTE, info->global_color_table_size, info->global_color_table_size * 4, globalpalette);
//background color
if( info->background_color < info->global_color_table_size ) {
FreeImage_SetBackgroundColor(dib, &globalpalette[info->background_color]);
}
}
//Application Extension
LONG loop = 1; //If no AE with a loop count is found, the default must be 1
for( idx = 0; idx < info->application_extension_offsets.size(); idx++ ) {
io->seek_proc(handle, info->application_extension_offsets[idx], SEEK_SET);
io->read_proc(&b, 1, 1, handle);
if( b == 11 ) { //All AEs start with an 11 byte sub-block to determine what type of AE it is
char buf[11];
io->read_proc(buf, 11, 1, handle);
if( !memcmp(buf, "NETSCAPE2.0", 11) || !memcmp(buf, "ANIMEXTS1.0", 11) ) { //Not everybody recognizes ANIMEXTS1.0 but it is valid
io->read_proc(&b, 1, 1, handle);
if( b == 3 ) { //we're supposed to have a 3 byte sub-block now
io->read_proc(&b, 1, 1, handle); //this should be 0x01 but isn't really important
io->read_proc(&w, 2, 1, handle);
#ifdef FREEIMAGE_BIGENDIAN
SwapShort(&w);
#endif
loop = w;
if( loop > 0 ) loop++;
break;
}
}
}
}
FreeImage_SetMetadataEx(FIMD_ANIMATION, dib, "Loop", ANIMTAG_LOOP, FIDT_LONG, 1, 4, &loop);
//Comment Extension
for( idx = 0; idx < info->comment_extension_offsets.size(); idx++ ) {
io->seek_proc(handle, info->comment_extension_offsets[idx], SEEK_SET);
std::string comment;
char buf[255];
io->read_proc(&b, 1, 1, handle);
while( b ) {
io->read_proc(buf, b, 1, handle);
comment.append(buf, b);
io->read_proc(&b, 1, 1, handle);
}
comment.append(1, '\0');
sprintf(buf, "Comment%d", idx);
FreeImage_SetMetadataEx(FIMD_COMMENTS, dib, buf, 1, FIDT_ASCII, comment.size(), comment.size(), comment.c_str());
}
}
//Graphic Control Extension
if( info->graphic_control_extension_offsets[page] != 0 ) {
io->seek_proc(handle, info->graphic_control_extension_offsets[page] + 1, SEEK_SET);
io->read_proc(&packed, 1, 1, handle);
io->read_proc(&w, 2, 1, handle);
#ifdef FREEIMAGE_BIGENDIAN
SwapShort(&w);
#endif
io->read_proc(&b, 1, 1, handle);
have_transparent = (packed & GIF_PACKED_GCE_HAVETRANS) ? true : false;
disposal_method = (packed & GIF_PACKED_GCE_DISPOSAL) >> 2;
delay_time = w * 10; //convert cs to ms
transparent_color = b;
if( have_transparent ) {
int size = 1 << bpp;
if( transparent_color <= size ) {
BYTE table[256];
memset(table, 0xFF, size);
table[transparent_color] = 0;
FreeImage_SetTransparencyTable(dib, table, size);
}
}
}
static FIBITMAP * DLL_CALLCONV
Load(FreeImageIO *io, fi_handle handle, int page, int flags, void *data) {
png_structp png_ptr = NULL;
png_infop info_ptr = NULL;
png_uint_32 width, height;
int color_type;
int bit_depth;
int pixel_depth = 0; // pixel_depth = bit_depth * channels
FIBITMAP *dib = NULL;
png_bytepp row_pointers = NULL;
fi_ioStructure fio;
fio.s_handle = handle;
fio.s_io = io;
if (handle) {
BOOL header_only = (flags & FIF_LOAD_NOPIXELS) == FIF_LOAD_NOPIXELS;
try {
// check to see if the file is in fact a PNG file
BYTE png_check[PNG_BYTES_TO_CHECK];
io->read_proc(png_check, PNG_BYTES_TO_CHECK, 1, handle);
if (png_sig_cmp(png_check, (png_size_t)0, PNG_BYTES_TO_CHECK) != 0) {
return NULL; // Bad signature
}
// create the chunk manage structure
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, error_handler, warning_handler);
if (!png_ptr) {
return NULL;
}
// create the info structure
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
return NULL;
}
// init the IO
png_set_read_fn(png_ptr, &fio, _ReadProc);
if (setjmp(png_jmpbuf(png_ptr))) {
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return NULL;
}
// because we have already read the signature...
png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK);
// read the IHDR chunk
png_read_info(png_ptr, info_ptr);
png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, NULL, NULL, NULL);
// configure the decoder
FREE_IMAGE_TYPE image_type = FIT_BITMAP;
if(!ConfigureDecoder(png_ptr, info_ptr, flags, &image_type)) {
throw FI_MSG_ERROR_UNSUPPORTED_FORMAT;
}
// update image info
color_type = png_get_color_type(png_ptr, info_ptr);
bit_depth = png_get_bit_depth(png_ptr, info_ptr);
pixel_depth = bit_depth * png_get_channels(png_ptr, info_ptr);
// create a dib and write the bitmap header
// set up the dib palette, if needed
switch (color_type) {
case PNG_COLOR_TYPE_RGB:
case PNG_COLOR_TYPE_RGB_ALPHA:
dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, pixel_depth, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);
break;
case PNG_COLOR_TYPE_PALETTE:
dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, pixel_depth, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);
if(dib) {
png_colorp png_palette = NULL;
int palette_entries = 0;
png_get_PLTE(png_ptr,info_ptr, &png_palette, &palette_entries);
palette_entries = MIN((unsigned)palette_entries, FreeImage_GetColorsUsed(dib));
// store the palette
RGBQUAD *palette = FreeImage_GetPalette(dib);
for(int i = 0; i < palette_entries; i++) {
palette[i].rgbRed = png_palette[i].red;
palette[i].rgbGreen = png_palette[i].green;
palette[i].rgbBlue = png_palette[i].blue;
}
}
break;
case PNG_COLOR_TYPE_GRAY:
dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, pixel_depth, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);
if(dib && (pixel_depth <= 8)) {
RGBQUAD *palette = FreeImage_GetPalette(dib);
const int palette_entries = 1 << pixel_depth;
for(int i = 0; i < palette_entries; i++) {
palette[i].rgbRed =
palette[i].rgbGreen =
palette[i].rgbBlue = (BYTE)((i * 255) / (palette_entries - 1));
}
}
break;
default:
throw FI_MSG_ERROR_UNSUPPORTED_FORMAT;
}
if(!dib) {
throw FI_MSG_ERROR_DIB_MEMORY;
}
// store the transparency table
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
// array of alpha (transparency) entries for palette
png_bytep trans_alpha = NULL;
// number of transparent entries
int num_trans = 0;
// graylevel or color sample values of the single transparent color for non-paletted images
png_color_16p trans_color = NULL;
png_get_tRNS(png_ptr, info_ptr, &trans_alpha, &num_trans, &trans_color);
if((color_type == PNG_COLOR_TYPE_GRAY) && trans_color) {
// single transparent color
if (trans_color->gray < 256) {
BYTE table[256];
memset(table, 0xFF, 256);
table[trans_color->gray] = 0;
FreeImage_SetTransparencyTable(dib, table, 256);
}
// check for a full transparency table, too
else if ((trans_alpha) && (pixel_depth <= 8)) {
FreeImage_SetTransparencyTable(dib, (BYTE *)trans_alpha, num_trans);
}
} else if((color_type == PNG_COLOR_TYPE_PALETTE) && trans_alpha) {
// transparency table
FreeImage_SetTransparencyTable(dib, (BYTE *)trans_alpha, num_trans);
}
}
// store the background color (only supported for FIT_BITMAP types)
if ((image_type == FIT_BITMAP) && png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD)) {
// Get the background color to draw transparent and alpha images over.
// Note that even if the PNG file supplies a background, you are not required to
// use it - you should use the (solid) application background if it has one.
png_color_16p image_background = NULL;
RGBQUAD rgbBkColor;
if (png_get_bKGD(png_ptr, info_ptr, &image_background)) {
rgbBkColor.rgbRed = (BYTE)image_background->red;
rgbBkColor.rgbGreen = (BYTE)image_background->green;
rgbBkColor.rgbBlue = (BYTE)image_background->blue;
rgbBkColor.rgbReserved = 0;
FreeImage_SetBackgroundColor(dib, &rgbBkColor);
}
}
// get physical resolution
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_pHYs)) {
png_uint_32 res_x, res_y;
// we'll overload this var and use 0 to mean no phys data,
// since if it's not in meters we can't use it anyway
int res_unit_type = PNG_RESOLUTION_UNKNOWN;
png_get_pHYs(png_ptr,info_ptr, &res_x, &res_y, &res_unit_type);
if (res_unit_type == PNG_RESOLUTION_METER) {
FreeImage_SetDotsPerMeterX(dib, res_x);
FreeImage_SetDotsPerMeterY(dib, res_y);
}
}
// get possible ICC profile
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_iCCP)) {
png_charp profile_name = NULL;
png_bytep profile_data = NULL;
png_uint_32 profile_length = 0;
int compression_type;
png_get_iCCP(png_ptr, info_ptr, &profile_name, &compression_type, &profile_data, &profile_length);
// copy ICC profile data (must be done after FreeImage_AllocateHeader)
FreeImage_CreateICCProfile(dib, profile_data, profile_length);
}
// --- header only mode => clean-up and return
if (header_only) {
// get possible metadata (it can be located both before and after the image data)
ReadMetadata(png_ptr, info_ptr, dib);
if (png_ptr) {
// clean up after the read, and free any memory allocated - REQUIRED
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
}
return dib;
}
// set the individual row_pointers to point at the correct offsets
row_pointers = (png_bytepp)malloc(height * sizeof(png_bytep));
if (!row_pointers) {
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
FreeImage_Unload(dib);
return NULL;
}
// read in the bitmap bits via the pointer table
// allow loading of PNG with minor errors (such as images with several IDAT chunks)
for (png_uint_32 k = 0; k < height; k++) {
row_pointers[height - 1 - k] = FreeImage_GetScanLine(dib, k);
}
png_set_benign_errors(png_ptr, 1);
png_read_image(png_ptr, row_pointers);
// check if the bitmap contains transparency, if so enable it in the header
if (FreeImage_GetBPP(dib) == 32) {
if (FreeImage_GetColorType(dib) == FIC_RGBALPHA) {
FreeImage_SetTransparent(dib, TRUE);
} else {
FreeImage_SetTransparent(dib, FALSE);
}
}
// cleanup
if (row_pointers) {
free(row_pointers);
row_pointers = NULL;
}
// read the rest of the file, getting any additional chunks in info_ptr
png_read_end(png_ptr, info_ptr);
// get possible metadata (it can be located both before and after the image data)
ReadMetadata(png_ptr, info_ptr, dib);
if (png_ptr) {
// clean up after the read, and free any memory allocated - REQUIRED
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
}
return dib;
} catch (const char *text) {
if (png_ptr) {
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
}
if (row_pointers) {
free(row_pointers);
}
if (dib) {
FreeImage_Unload(dib);
}
FreeImage_OutputMessageProc(s_format_id, text);
return NULL;
}
}
return NULL;
}