/*
* File: ximapng.cpp
* Purpose: Platform Independent PNG Image Class Loader and Writer
* 07/Aug/2001 Davide Pizzolato - www.xdp.it
* CxImage version 7.0.0 31/Dec/2010
*/
#include "ximapng.h"
#if CXIMAGE_SUPPORT_PNG
#include "ximaiter.h"
////////////////////////////////////////////////////////////////////////////////
void CxImagePNG::ima_png_error(png_struct *png_ptr, char *message)
{
strcpy(info.szLastError,message);
#if PNG_LIBPNG_VER > 10399
longjmp(png_jmpbuf(png_ptr), 1);
#else
longjmp(png_ptr->jmpbuf, 1);
#endif
}
////////////////////////////////////////////////////////////////////////////////
#if CXIMAGE_SUPPORT_DECODE
////////////////////////////////////////////////////////////////////////////////
void CxImagePNG::expand2to4bpp(uint8_t* prow)
{
uint8_t *psrc,*pdst;
uint8_t pos,idx;
for(int32_t x=head.biWidth-1;x>=0;x--){
psrc = prow + ((2*x)>>3);
pdst = prow + ((4*x)>>3);
pos = (uint8_t)(2*(3-x%4));
idx = (uint8_t)((*psrc & (0x03<<pos))>>pos);
pos = (uint8_t)(4*(1-x%2));
*pdst &= ~(0x0F<<pos);
*pdst |= (idx & 0x0F)<<pos;
}
}
////////////////////////////////////////////////////////////////////////////////
bool CxImagePNG::Decode(CxFile *hFile)
{
png_struct *png_ptr;
png_info *info_ptr;
uint8_t *row_pointers=NULL;
CImageIterator iter(this);
cx_try
{
/* Create and initialize the png_struct with the desired error handler
* functions. If you want to use the default stderr and longjump method,
* you can supply NULL for the last three parameters. We also supply the
* the compiler header file version, so that we know if the application
* was compiled with a compatible version of the library. REQUIRED */
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,(void *)NULL,NULL,NULL);
if (png_ptr == NULL) cx_throw("Failed to create PNG structure");
/* Allocate/initialize the memory for image information. REQUIRED. */
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL) {
png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
cx_throw("Failed to initialize PNG info structure");
}
/* Set error handling if you are using the setjmp/longjmp method (this is
* the normal method of doing things with libpng). REQUIRED unless you
* set up your own error handlers in the png_create_read_struct() earlier. */
#if PNG_LIBPNG_VER > 10399
if (setjmp(png_jmpbuf(png_ptr))) {
#else
if (setjmp(png_ptr->jmpbuf)) {
#endif
/* Free all of the memory associated with the png_ptr and info_ptr */
delete [] row_pointers;
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
cx_throw("");
}
// use custom I/O functions
png_set_read_fn(png_ptr, hFile, /*(png_rw_ptr)*/user_read_data);
png_set_error_fn(png_ptr,info.szLastError,/*(png_error_ptr)*/user_error_fn,NULL);
/* read the file information */
png_read_info(png_ptr, info_ptr);
png_uint_32 _width,_height;
int _bit_depth,_color_type,_interlace_type,_compression_type,_filter_type;
#if PNG_LIBPNG_VER > 10399
png_get_IHDR(png_ptr,info_ptr,&_width,&_height,&_bit_depth,&_color_type,
&_interlace_type,&_compression_type,&_filter_type);
#else
_width=info_ptr->width;
_height=info_ptr->height;
_bit_depth=info_ptr->bit_depth;
_color_type=info_ptr->color_type;
_interlace_type=info_ptr->interlace_type;
//_compression_type=info_ptr->compression_type;
//_filter_type=info_ptr->filter_type;
#endif
if (info.nEscape == -1){
head.biWidth = _width;
head.biHeight= _height;
info.dwType = CXIMAGE_FORMAT_PNG;
#if PNG_LIBPNG_VER > 10399
longjmp(png_jmpbuf(png_ptr), 1);
#else
longjmp(png_ptr->jmpbuf, 1);
#endif
}
/* calculate new number of channels */
int32_t channels=0;
switch(_color_type){
case PNG_COLOR_TYPE_GRAY:
case PNG_COLOR_TYPE_PALETTE:
channels = 1;
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
channels = 2;
break;
case PNG_COLOR_TYPE_RGB:
channels = 3;
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
channels = 4;
break;
default:
strcpy(info.szLastError,"unknown PNG color type");
#if PNG_LIBPNG_VER > 10399
longjmp(png_jmpbuf(png_ptr), 1);
#else
longjmp(png_ptr->jmpbuf, 1);
#endif
}
//find the right pixel depth used for cximage
#if PNG_LIBPNG_VER > 10399
int pixel_depth = _bit_depth * png_get_channels(png_ptr,info_ptr);
#else
int pixel_depth = info_ptr->pixel_depth;
#endif
if (channels == 1 && pixel_depth>8) pixel_depth=8;
if (channels == 2) pixel_depth=8;
if (channels >= 3) pixel_depth=24;
if (!Create(_width, _height, pixel_depth, CXIMAGE_FORMAT_PNG)){
#if PNG_LIBPNG_VER > 10399
longjmp(png_jmpbuf(png_ptr), 1);
#else
longjmp(png_ptr->jmpbuf, 1);
#endif
}
/* get metrics */
png_uint_32 _x_pixels_per_unit,_y_pixels_per_unit;
int _phys_unit_type;
#if PNG_LIBPNG_VER > 10399
png_get_pHYs(png_ptr,info_ptr,&_x_pixels_per_unit,&_y_pixels_per_unit,&_phys_unit_type);
#else
_x_pixels_per_unit=info_ptr->x_pixels_per_unit;
_y_pixels_per_unit=info_ptr->y_pixels_per_unit;
_phys_unit_type=info_ptr->phys_unit_type;
#endif
switch (_phys_unit_type)
{
case PNG_RESOLUTION_UNKNOWN:
SetXDPI(_x_pixels_per_unit);
SetYDPI(_y_pixels_per_unit);
break;
case PNG_RESOLUTION_METER:
SetXDPI((long)floor(_x_pixels_per_unit * 254.0 / 10000.0 + 0.5));
SetYDPI((long)floor(_y_pixels_per_unit * 254.0 / 10000.0 + 0.5));
break;
}
int _num_palette;
png_colorp _palette;
#if PNG_LIBPNG_VER > 10399
png_get_PLTE(png_ptr,info_ptr,&_palette,&_num_palette);
#else
_num_palette=info_ptr->num_palette;
_palette=info_ptr->palette;
#endif
if (_num_palette>0){
SetPalette((rgb_color*)_palette,_num_palette);
SetClrImportant(_num_palette);
} else if (_bit_depth ==2) { //<DP> needed for 2 bpp grayscale PNGs
SetPaletteColor(0,0,0,0);
SetPaletteColor(1,85,85,85);
SetPaletteColor(2,170,170,170);
SetPaletteColor(3,255,255,255);
} else SetGrayPalette(); //<DP> needed for grayscale PNGs
int nshift = max(0,(_bit_depth>>3)-1)<<3;
png_bytep _trans_alpha;
int _num_trans;
png_color_16p _trans_color;
#if PNG_LIBPNG_VER > 10399
png_get_tRNS(png_ptr,info_ptr,&_trans_alpha,&_num_trans,&_trans_color);
#else
_num_trans=info_ptr->num_trans;
#endif
if (_num_trans!=0){ //palette transparency
if (_num_trans==1){
if (_color_type == PNG_COLOR_TYPE_PALETTE){
info.nBkgndIndex = _trans_color->index;
} else{
info.nBkgndIndex = _trans_color->gray>>nshift;
}
}
if (_num_trans>1){
RGBQUAD* pal=GetPalette();
if (pal){
uint32_t ip;
if(_trans_alpha != 0) {
for (ip=0;ip<min(head.biClrUsed,(unsigned long)_num_trans);ip++)
pal[ip].rgbReserved=_trans_alpha[ip];
}
for (ip=_num_trans;ip<head.biClrUsed;ip++){
pal[ip].rgbReserved=255;
}
info.bAlphaPaletteEnabled=true;
}
}
}
if (channels == 3){ //check RGB binary transparency
/* seems unnecessary to call again, but the conditional must be important so... */
if (png_get_tRNS(png_ptr,info_ptr,&_trans_alpha,&_num_trans,&_trans_color)){
info.nBkgndColor.rgbRed = (uint8_t)(_trans_color->red>>nshift);
info.nBkgndColor.rgbGreen = (uint8_t)(_trans_color->green>>nshift);
info.nBkgndColor.rgbBlue = (uint8_t)(_trans_color->blue>>nshift);
info.nBkgndColor.rgbReserved = 0;
info.nBkgndIndex = 0;
}
}
int32_t alpha_present = (channels - 1) % 2;
if (alpha_present){
#if CXIMAGE_SUPPORT_ALPHA // <vho>
AlphaCreate();
#else
png_set_strip_alpha(png_ptr);
#endif //CXIMAGE_SUPPORT_ALPHA
}
// <vho> - flip the RGB pixels to BGR (or RGBA to BGRA)
if (_color_type & PNG_COLOR_MASK_COLOR){
png_set_bgr(png_ptr);
}
// <vho> - handle cancel
if (info.nEscape)
#if PNG_LIBPNG_VER > 10399
longjmp(png_jmpbuf(png_ptr), 1);
#else
longjmp(png_ptr->jmpbuf, 1);
#endif
// row_bytes is the width x number of channels x (bit-depth / 8)
#if PNG_LIBPNG_VER > 10399
row_pointers = new uint8_t[png_get_rowbytes(png_ptr,info_ptr) + 8];
#else
row_pointers = new uint8_t[info_ptr->rowbytes + 8];
#endif
// turn on interlace handling
int32_t number_passes = png_set_interlace_handling(png_ptr);
if (number_passes>1){
SetCodecOption( (ENCODE_INTERLACE) | GetCodecOption(CXIMAGE_FORMAT_PNG));
} else {
SetCodecOption(~(ENCODE_INTERLACE) & GetCodecOption(CXIMAGE_FORMAT_PNG));
}
int chan_offset = _bit_depth >> 3;
#if PNG_LIBPNG_VER > 10399
int pixel_offset = (_bit_depth * png_get_channels(png_ptr,info_ptr)) >> 3;
#else
int pixel_offset = info_ptr->pixel_depth >> 3;
#endif
for (int32_t pass=0; pass < number_passes; pass++) {
iter.Upset();
int32_t y=0;
do {
// <vho> - handle cancel
if (info.nEscape)
#if PNG_LIBPNG_VER > 10399
longjmp(png_jmpbuf(png_ptr), 1);
#else
longjmp(png_ptr->jmpbuf, 1);
#endif
#if CXIMAGE_SUPPORT_ALPHA // <vho>
if (AlphaIsValid()) {
//compute the correct position of the line
int32_t ax,ay;
ay = head.biHeight-1-y;
uint8_t* prow= iter.GetRow(ay);
//recover data from previous scan
if (_interlace_type && pass>0 && pass!=7){
for(ax=0;ax<head.biWidth;ax++){
int32_t px = ax * pixel_offset;
if (channels == 2){
row_pointers[px] = prow[ax];
row_pointers[px+chan_offset]=AlphaGet(ax,ay);
} else {
int32_t qx = ax * 3;
row_pointers[px] =prow[qx];
row_pointers[px+chan_offset] =prow[qx+1];
row_pointers[px+chan_offset*2]=prow[qx+2];
row_pointers[px+chan_offset*3]=AlphaGet(ax,ay);
}
}
}
//read next row
png_read_row(png_ptr, row_pointers, NULL);
//RGBA -> RGB + A
for(ax=0;ax<head.biWidth;ax++){
int32_t px = ax * pixel_offset;
if (channels == 2){
prow[ax] = row_pointers[px];
AlphaSet(ax,ay,row_pointers[px+chan_offset]);
} else {
int32_t qx = ax * 3;
prow[qx] =row_pointers[px];
prow[qx+1]=row_pointers[px+chan_offset];
prow[qx+2]=row_pointers[px+chan_offset*2];
AlphaSet(ax,ay,row_pointers[px+chan_offset*3]);
}
}
} else
#endif // CXIMAGE_SUPPORT_ALPHA // vho
{
//recover data from previous scan
if (_interlace_type && pass>0){
#if PNG_LIBPNG_VER > 10399
iter.GetRow(row_pointers, png_get_rowbytes(png_ptr,info_ptr));
#else
iter.GetRow(row_pointers, info_ptr->rowbytes);
#endif
//re-expand buffer for images with bit depth > 8
if (_bit_depth > 8){
for(int32_t ax=(head.biWidth*channels-1);ax>=0;ax--)
row_pointers[ax*chan_offset] = row_pointers[ax];
}
}
//read next row
png_read_row(png_ptr, row_pointers, NULL);
//shrink 16 bit depth images down to 8 bits
if (_bit_depth > 8){
for(int32_t ax=0;ax<(head.biWidth*channels);ax++)
row_pointers[ax] = row_pointers[ax*chan_offset];
}
//copy the pixels
#if PNG_LIBPNG_VER > 10399
iter.SetRow(row_pointers, png_get_rowbytes(png_ptr,info_ptr));
#else
iter.SetRow(row_pointers, info_ptr->rowbytes);
#endif
//<DP> expand 2 bpp images only in the last pass
if (_bit_depth==2 && pass==(number_passes-1))
expand2to4bpp(iter.GetRow());
//go on
iter.PrevRow();
}
y++;
} while(y<head.biHeight);
}
delete [] row_pointers;
row_pointers = NULL;
/* read the rest of the file, getting any additional chunks in info_ptr - REQUIRED */
png_read_end(png_ptr, info_ptr);
/* clean up after the read, and free any memory allocated - REQUIRED */
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
} cx_catch {
if (strcmp(message,"")) strncpy(info.szLastError,message,255);
if (info.nEscape == -1 && info.dwType == CXIMAGE_FORMAT_PNG) return true;
return false;
}
/* that's it */
return true;
}
////////////////////////////////////////////////////////////////////////////////
#endif //CXIMAGE_SUPPORT_DECODE
////////////////////////////////////////////////////////////////////////////////
#if CXIMAGE_SUPPORT_ENCODE
////////////////////////////////////////////////////////////////////////////////
bool CxImagePNG::Encode(CxFile *hFile)
{
if (EncodeSafeCheck(hFile)) return false;
CImageIterator iter(this);
uint8_t trans[256]; //for transparency (don't move)
png_struct *png_ptr;
png_info *info_ptr;
cx_try
{
/* Create and initialize the png_struct with the desired error handler
* functions. If you want to use the default stderr and longjump method,
* you can supply NULL for the last three parameters. We also check that
* the library version is compatible with the one used at compile time,
* in case we are using dynamically linked libraries. REQUIRED.
*/
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,(void *)NULL,NULL,NULL);
if (png_ptr == NULL) cx_throw("Failed to create PNG structure");
/* Allocate/initialize the image information data. REQUIRED */
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL){
png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
cx_throw("Failed to initialize PNG info structure");
}
/* Set error handling. REQUIRED if you aren't supplying your own
* error hadnling functions in the png_create_write_struct() call.
*/
if (setjmp(png_ptr->jmpbuf)){
/* If we get here, we had a problem reading the file */
if (info_ptr->palette) free(info_ptr->palette);
png_destroy_write_struct(&png_ptr, (png_infopp)&info_ptr);
cx_throw("Error saving PNG file");
}
/* set up the output control */
//png_init_io(png_ptr, hFile);
// use custom I/O functions
png_set_write_fn(png_ptr,hFile,/*(png_rw_ptr)*/user_write_data,/*(png_flush_ptr)*/user_flush_data);
/* set the file information here */
info_ptr->width = GetWidth();
info_ptr->height = GetHeight();
info_ptr->pixel_depth = (uint8_t)GetBpp();
info_ptr->channels = (GetBpp()>8) ? (uint8_t)3: (uint8_t)1;
info_ptr->bit_depth = (uint8_t)(GetBpp()/info_ptr->channels);
info_ptr->compression_type = info_ptr->filter_type = 0;
info_ptr->valid = 0;
// set interlace type
DWORD codec_opt = GetCodecOption(CXIMAGE_FORMAT_PNG);
if (codec_opt & CxImagePNG::ENCODE_INTERLACE)
info_ptr->interlace_type = PNG_INTERLACE_ADAM7;
else
info_ptr->interlace_type = PNG_INTERLACE_NONE;
/* set compression level */
int32_t compress_level;
switch (codec_opt & CxImagePNG::ENCODE_COMPRESSION_MASK)
{
case ENCODE_NO_COMPRESSION:
compress_level = Z_NO_COMPRESSION;
break;
case ENCODE_BEST_SPEED:
compress_level = Z_BEST_SPEED;
break;
case ENCODE_BEST_COMPRESSION:
compress_level = Z_BEST_COMPRESSION;
break;
default:
compress_level = Z_DEFAULT_COMPRESSION;
break;
}
png_set_compression_level(png_ptr, compress_level);
bool bGrayScale = IsGrayScale();
if (GetNumColors()){
if (bGrayScale){
info_ptr->color_type = PNG_COLOR_TYPE_GRAY;
} else {
info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
}
} else {
info_ptr->color_type = PNG_COLOR_TYPE_RGB;
}
#if CXIMAGE_SUPPORT_ALPHA
if (AlphaIsValid()){
info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
info_ptr->channels++;
info_ptr->bit_depth = 8;
info_ptr->pixel_depth += 8;
}
#endif
/* set background */
png_color_16 image_background={ 0, 255, 255, 255, 0 };
RGBQUAD tc = GetTransColor();
if (info.nBkgndIndex>=0) {
image_background.blue = tc.rgbBlue;
image_background.green = tc.rgbGreen;
image_background.red = tc.rgbRed;
}
png_set_bKGD(png_ptr, info_ptr, &image_background);
/* set metrics */
png_set_pHYs(png_ptr, info_ptr, head.biXPelsPerMeter, head.biYPelsPerMeter, PNG_RESOLUTION_METER);
png_set_IHDR(png_ptr, info_ptr, info_ptr->width, info_ptr->height, info_ptr->bit_depth,
info_ptr->color_type, info_ptr->interlace_type,
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
//<DP> simple transparency
if (info.nBkgndIndex >= 0){
info_ptr->num_trans = 1;
info_ptr->valid |= PNG_INFO_tRNS;
info_ptr->trans_alpha = trans;
info_ptr->trans_color.index = (uint8_t)info.nBkgndIndex;
info_ptr->trans_color.red = tc.rgbRed;
info_ptr->trans_color.green = tc.rgbGreen;
info_ptr->trans_color.blue = tc.rgbBlue;
info_ptr->trans_color.gray = info_ptr->trans_color.index;
// the transparency indexes start from 0 for non grayscale palette
if (!bGrayScale && head.biClrUsed && info.nBkgndIndex)
SwapIndex(0,(uint8_t)info.nBkgndIndex);
}
/* set the palette if there is one */
if (GetPalette()){
if (!bGrayScale){
info_ptr->valid |= PNG_INFO_PLTE;
}
int32_t nc = GetClrImportant();
if (nc==0) nc = GetNumColors();
if (info.bAlphaPaletteEnabled){
for(uint16_t ip=0; ip<nc;ip++)
trans[ip]=GetPaletteColor((uint8_t)ip).rgbReserved;
info_ptr->num_trans = (uint16_t)nc;
info_ptr->valid |= PNG_INFO_tRNS;
info_ptr->trans_alpha = trans;
}
// copy the palette colors
info_ptr->palette = new png_color[nc];
info_ptr->num_palette = (png_uint_16) nc;
for (int32_t i=0; i<nc; i++)
GetPaletteColor(i, &info_ptr->palette[i].red, &info_ptr->palette[i].green, &info_ptr->palette[i].blue);
}
#if CXIMAGE_SUPPORT_ALPHA // <vho>
//Merge the transparent color with the alpha channel
if (AlphaIsValid() && head.biBitCount==24 && info.nBkgndIndex>=0){
for(int32_t y=0; y < head.biHeight; y++){
for(int32_t x=0; x < head.biWidth ; x++){
RGBQUAD c=GetPixelColor(x,y,false);
if (*(int32_t*)&c==*(int32_t*)&tc)
AlphaSet(x,y,0);
} } }
#endif // CXIMAGE_SUPPORT_ALPHA // <vho>
int32_t row_size = max(info.dwEffWidth, info_ptr->width*info_ptr->channels*(info_ptr->bit_depth/8));
info_ptr->rowbytes = row_size;
uint8_t *row_pointers = new uint8_t[row_size];
/* write the file information */
png_write_info(png_ptr, info_ptr);
//interlace handling
int32_t num_pass = png_set_interlace_handling(png_ptr);
for (int32_t pass = 0; pass < num_pass; pass++){
//write image
iter.Upset();
int32_t ay=head.biHeight-1;
RGBQUAD c;
do {
#if CXIMAGE_SUPPORT_ALPHA // <vho>
if (AlphaIsValid()){
for (int32_t ax=head.biWidth-1; ax>=0;ax--){
c = BlindGetPixelColor(ax,ay);
int32_t px = ax * info_ptr->channels;
if (!bGrayScale){
row_pointers[px++]=c.rgbRed;
row_pointers[px++]=c.rgbGreen;
}
row_pointers[px++]=c.rgbBlue;
row_pointers[px] = AlphaGet(ax,ay);
}
png_write_row(png_ptr, row_pointers);
ay--;
}
else
#endif //CXIMAGE_SUPPORT_ALPHA // <vho>
{
iter.GetRow(row_pointers, row_size);
if (info_ptr->color_type == PNG_COLOR_TYPE_RGB) //HACK BY OP
RGBtoBGR(row_pointers, row_size);
png_write_row(png_ptr, row_pointers);
}
} while(iter.PrevRow());
}
delete [] row_pointers;
row_pointers = NULL;
//if necessary, restore the original palette
if (!bGrayScale && head.biClrUsed && info.nBkgndIndex>0)
SwapIndex((uint8_t)info.nBkgndIndex,0);
/* It is REQUIRED to call this to finish writing the rest of the file */
png_write_end(png_ptr, info_ptr);
/* if you malloced the palette, free it here */
if (info_ptr->palette){
delete [] (info_ptr->palette);
info_ptr->palette = NULL;
}
/* clean up after the write, and free any memory allocated */
png_destroy_write_struct(&png_ptr, (png_infopp)&info_ptr);
} cx_catch {
if (strcmp(message,"")) strncpy(info.szLastError,message,255);
return FALSE;
}
/* that's it */
return TRUE;
}
////////////////////////////////////////////////////////////////////////////////
#endif // CXIMAGE_SUPPORT_ENCODE
////////////////////////////////////////////////////////////////////////////////
#endif // CXIMAGE_SUPPORT_PNG