void save_as_png(T1 & file,
T2 const& image,
png_options const& opts)
{
png_voidp error_ptr=0;
png_structp png_ptr=png_create_write_struct(PNG_LIBPNG_VER_STRING,
error_ptr,0, 0);
if (!png_ptr) return;
// switch on optimization only if supported
#if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200) && defined(PNG_MMX_CODE_SUPPORTED)
png_uint_32 mask, flags;
flags = png_get_asm_flags(png_ptr);
mask = png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
png_set_asm_flags(png_ptr, flags | mask);
#endif
png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_FILTER_NONE);
png_infop info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
png_destroy_write_struct(&png_ptr,static_cast<png_infopp>(0));
return;
}
jmp_buf* jmp_context = static_cast<jmp_buf*>(png_get_error_ptr(png_ptr));
if (jmp_context)
{
png_destroy_write_struct(&png_ptr, &info_ptr);
return;
}
png_set_write_fn (png_ptr, &file, &write_data<T1>, &flush_data<T1>);
png_set_compression_level(png_ptr, opts.compression);
png_set_compression_strategy(png_ptr, opts.strategy);
png_set_compression_buffer_size(png_ptr, 32768);
png_set_IHDR(png_ptr, info_ptr,image.width(),image.height(),8,
(opts.trans_mode == 0) ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA,PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT,PNG_FILTER_TYPE_DEFAULT);
const std::unique_ptr<png_bytep[]> row_pointers(new png_bytep[image.height()]);
for (unsigned int i = 0; i < image.height(); i++)
{
row_pointers[i] = const_cast<png_bytep>(reinterpret_cast<const unsigned char *>(image.get_row(i)));
}
png_set_rows(png_ptr, info_ptr, row_pointers.get());
png_write_png(png_ptr, info_ptr, (opts.trans_mode == 0) ? PNG_TRANSFORM_STRIP_FILLER_AFTER : PNG_TRANSFORM_IDENTITY, nullptr);
png_destroy_write_struct(&png_ptr, &info_ptr);
}
void save_as_png(T1 & file , T2 const& image, int compression = Z_DEFAULT_COMPRESSION, int strategy = Z_DEFAULT_STRATEGY)
{
png_voidp error_ptr=0;
png_structp png_ptr=png_create_write_struct(PNG_LIBPNG_VER_STRING,
error_ptr,0, 0);
if (!png_ptr) return;
// switch on optimization only if supported
#if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200) && defined(PNG_MMX_CODE_SUPPORTED)
png_uint_32 mask, flags;
flags = png_get_asm_flags(png_ptr);
mask = png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
png_set_asm_flags(png_ptr, flags | mask);
#endif
png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_FILTER_NONE);
png_infop info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
png_destroy_write_struct(&png_ptr,(png_infopp)0);
return;
}
jmp_buf* jmp_context = (jmp_buf*) png_get_error_ptr(png_ptr);
if (jmp_context)
{
png_destroy_write_struct(&png_ptr, &info_ptr);
return;
}
png_set_write_fn (png_ptr, &file, &write_data<T1>, &flush_data<T1>);
png_set_compression_level(png_ptr, compression);
png_set_compression_strategy(png_ptr, strategy);
png_set_compression_buffer_size(png_ptr, 32768);
png_set_IHDR(png_ptr, info_ptr,image.width(),image.height(),8,
PNG_COLOR_TYPE_RGB_ALPHA,PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT,PNG_FILTER_TYPE_DEFAULT);
png_write_info(png_ptr, info_ptr);
for (unsigned i=0;i<image.height();i++)
{
png_write_row(png_ptr,(png_bytep)image.getRow(i));
}
png_write_end(png_ptr, info_ptr);
png_destroy_write_struct(&png_ptr, &info_ptr);
}
void save_as_png(T & file, std::vector<mapnik::rgb> const& palette,
mapnik::image_gray8 const& image,
unsigned width,
unsigned height,
unsigned color_depth,
std::vector<unsigned> const&alpha,
png_options const& opts)
{
png_voidp error_ptr=0;
png_structp png_ptr=png_create_write_struct(PNG_LIBPNG_VER_STRING,
error_ptr,0, 0);
if (!png_ptr)
{
return;
}
// switch on optimization only if supported
#if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200) && defined(PNG_MMX_CODE_SUPPORTED)
png_uint_32 mask, flags;
flags = png_get_asm_flags(png_ptr);
mask = png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
png_set_asm_flags(png_ptr, flags | mask);
#endif
png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_FILTER_NONE);
png_infop info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
png_destroy_write_struct(&png_ptr,static_cast<png_infopp>(0));
return;
}
jmp_buf* jmp_context = static_cast<jmp_buf*>(png_get_error_ptr(png_ptr));
if (jmp_context)
{
png_destroy_write_struct(&png_ptr, &info_ptr);
return;
}
png_set_write_fn (png_ptr, &file, &write_data<T>, &flush_data<T>);
png_set_compression_level(png_ptr, opts.compression);
png_set_compression_strategy(png_ptr, opts.strategy);
png_set_compression_buffer_size(png_ptr, 32768);
png_set_IHDR(png_ptr, info_ptr,width,height,color_depth,
PNG_COLOR_TYPE_PALETTE,PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT,PNG_FILTER_TYPE_DEFAULT);
png_color* pal = const_cast<png_color*>(reinterpret_cast<const png_color*>(&palette[0]));
png_set_PLTE(png_ptr, info_ptr, pal, static_cast<unsigned>(palette.size()));
// make transparent lowest indexes, so tRNS is small
if (alpha.size()>0)
{
std::vector<png_byte> trans(alpha.size());
unsigned alphaSize=0;//truncate to nonopaque values
for(unsigned i=0; i < alpha.size(); i++)
{
trans[i]=alpha[i];
if (alpha[i]<255)
{
alphaSize = i+1;
}
}
if (alphaSize>0)
{
png_set_tRNS(png_ptr, info_ptr, static_cast<png_bytep>(&trans[0]), alphaSize, 0);
}
}
png_write_info(png_ptr, info_ptr);
for (unsigned i=0;i<height;i++)
{
png_write_row(png_ptr,const_cast<png_bytep>(image.get_row(i)));
}
png_write_end(png_ptr, info_ptr);
png_destroy_write_struct(&png_ptr, &info_ptr);
}
void save_as_png(T1 & file,
T2 const& image,
int compression = Z_DEFAULT_COMPRESSION,
int strategy = Z_DEFAULT_STRATEGY,
int alpha = false,
bool use_miniz = false)
{
if (use_miniz) {
MiniZ::PNGWriter writer(compression);
if (alpha) {
writer.writeIHDR(image.width(), image.height(), 32);
writer.writeIDAT(image);
} else {
writer.writeIHDR(image.width(), image.height(), 24);
writer.writeIDATStripAlpha(image);
}
writer.writeIEND();
writer.toStream(file);
return;
}
png_voidp error_ptr=0;
png_structp png_ptr=png_create_write_struct(PNG_LIBPNG_VER_STRING,
error_ptr,0, 0);
if (!png_ptr) return;
// switch on optimization only if supported
#if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200) && defined(PNG_MMX_CODE_SUPPORTED)
png_uint_32 mask, flags;
flags = png_get_asm_flags(png_ptr);
mask = png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
png_set_asm_flags(png_ptr, flags | mask);
#endif
png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_FILTER_NONE);
png_infop info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
png_destroy_write_struct(&png_ptr,(png_infopp)0);
return;
}
jmp_buf* jmp_context = (jmp_buf*) png_get_error_ptr(png_ptr);
if (jmp_context)
{
png_destroy_write_struct(&png_ptr, &info_ptr);
return;
}
png_set_write_fn (png_ptr, &file, &write_data<T1>, &flush_data<T1>);
png_set_compression_level(png_ptr, compression);
png_set_compression_strategy(png_ptr, strategy);
png_set_compression_buffer_size(png_ptr, 32768);
png_set_IHDR(png_ptr, info_ptr, image.width(), image.height(), 8,
alpha ? PNG_COLOR_TYPE_RGB_ALPHA : PNG_COLOR_TYPE_RGB,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
PNG_FILTER_TYPE_DEFAULT);
png_bytep row_pointers[image.height()];
for (unsigned int i = 0; i < image.height(); i++) {
row_pointers[i] = (png_bytep)image.getRow(i);
}
png_set_rows(png_ptr, info_ptr, (png_bytepp)&row_pointers);
png_write_png(png_ptr, info_ptr, alpha ? PNG_TRANSFORM_IDENTITY : PNG_TRANSFORM_STRIP_FILLER_AFTER, NULL);
png_destroy_write_struct(&png_ptr, &info_ptr);
}
void save_as_png(T & file, std::vector<rgb> const& palette,
image_data_8 const& image,
unsigned width,
unsigned height,
unsigned color_depth,
int compression,
int strategy,
std::vector<unsigned> const&alpha,
bool use_miniz)
{
if (use_miniz) {
MiniZ::PNGWriter writer(compression);
// image.width()/height() does not reflect the actual image dimensions; it
// refers to the quantized scanlines.
writer.writeIHDR(width, height, color_depth);
writer.writePLTE(palette);
writer.writetRNS(alpha);
writer.writeIDAT(image);
writer.writeIEND();
writer.toStream(file);
return;
}
png_voidp error_ptr=0;
png_structp png_ptr=png_create_write_struct(PNG_LIBPNG_VER_STRING,
error_ptr,0, 0);
if (!png_ptr) return;
// switch on optimization only if supported
#if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200) && defined(PNG_MMX_CODE_SUPPORTED)
png_uint_32 mask, flags;
flags = png_get_asm_flags(png_ptr);
mask = png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
png_set_asm_flags(png_ptr, flags | mask);
#endif
png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_FILTER_NONE);
png_infop info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
png_destroy_write_struct(&png_ptr,(png_infopp)0);
return;
}
jmp_buf* jmp_context = (jmp_buf*) png_get_error_ptr(png_ptr);
if (jmp_context)
{
png_destroy_write_struct(&png_ptr, &info_ptr);
return;
}
png_set_write_fn (png_ptr, &file, &write_data<T>, &flush_data<T>);
png_set_compression_level(png_ptr, compression);
png_set_compression_strategy(png_ptr, strategy);
png_set_compression_buffer_size(png_ptr, 32768);
png_set_IHDR(png_ptr, info_ptr,width,height,color_depth,
PNG_COLOR_TYPE_PALETTE,PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT,PNG_FILTER_TYPE_DEFAULT);
png_color* pal = const_cast<png_color*>(reinterpret_cast<const png_color*>(&palette[0]));
png_set_PLTE(png_ptr, info_ptr, pal, palette.size());
// make transparent lowest indexes, so tRNS is small
if (alpha.size()>0)
{
std::vector<png_byte> trans(alpha.size());
unsigned alphaSize=0;//truncate to nonopaque values
for(unsigned i=0; i < alpha.size(); i++)
{
trans[i]=alpha[i];
if (alpha[i]<255)
alphaSize = i+1;
}
if (alphaSize>0)
png_set_tRNS(png_ptr, info_ptr, (png_bytep)&trans[0], alphaSize, 0);
}
png_write_info(png_ptr, info_ptr);
for (unsigned i=0; i<height; i++)
{
png_write_row(png_ptr,(png_bytep)image.getRow(i));
}
png_write_end(png_ptr, info_ptr);
png_destroy_write_struct(&png_ptr, &info_ptr);
}
// ######################################################################
PngParser::PngParser(const char* filename)
:
rep(new Rep(filename))
{
errno = 0;
rep->file = fopen(filename, "rb");
if (rep->file == 0) rep->onError("couldn't open file for png reading");
const size_t nheader = 8;
png_byte header[nheader];
if (fread(header, 1, nheader, rep->file) != nheader) rep->onError("short read on png file header");
int is_png = !png_sig_cmp(header, 0, nheader);
if (!is_png) rep->onError("file was not a png image file");
rep->pngPtr = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
if (rep->pngPtr == 0) rep->onError("png_create_read_struct failed");
rep->infoPtr = png_create_info_struct(rep->pngPtr);
if (rep->infoPtr == 0) rep->onError("png_create_info_struct failed");
rep->endPtr = png_create_info_struct(rep->pngPtr);
if (rep->endPtr == 0) rep->onError("png_create_info_struct failed");
png_init_io(rep->pngPtr, rep->file);
png_set_sig_bytes(rep->pngPtr, nheader);
png_read_info(rep->pngPtr, rep->infoPtr);
rep->bitDepth = png_get_bit_depth(rep->pngPtr, rep->infoPtr);
rep->colorType = png_get_color_type(rep->pngPtr, rep->infoPtr);
if (rep->bitDepth == 16)
png_set_strip_16(rep->pngPtr);
else if (rep->bitDepth < 8 && (rep->colorType == PNG_COLOR_TYPE_GRAY))
png_set_gray_1_2_4_to_8(rep->pngPtr);
else if (rep->bitDepth != 8 && (rep->colorType != PNG_COLOR_TYPE_PALETTE))
rep->onError(sformat("invalid bit-depth(%d)/color-mode(%d) "
"combination", rep->bitDepth, rep->colorType));
// Strip out the alpha channel, if present
if (rep->colorType & PNG_COLOR_MASK_ALPHA)
png_set_strip_alpha(rep->pngPtr);
if (rep->colorType & PNG_COLOR_MASK_PALETTE)
png_set_palette_to_rgb(rep->pngPtr);
// This must come after any+all transformations are specified
png_read_update_info(rep->pngPtr, rep->infoPtr);
// These calls must come after png_read_update_info, so that we get
// values that reflect any transformations
rep->width = png_get_image_width(rep->pngPtr, rep->infoPtr);
rep->height = png_get_image_height(rep->pngPtr, rep->infoPtr);
rep->rowBytes = png_get_rowbytes(rep->pngPtr, rep->infoPtr);
rep->numChannels = png_get_channels(rep->pngPtr, rep->infoPtr);
ASSERT(rep->rowBytes = rep->width*rep->numChannels);
// run-time mmx PNG optimizations (nate)
#if defined(HAVE_PNG_ASM_FLAGS)
const png_uint_32 flags = png_get_asm_flags(rep->pngPtr);
const png_uint_32 mask =
png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
png_set_asm_flags(rep->pngPtr, flags | mask);
#endif
}
int readpng2_init(mainprog_info *mainprog_ptr)
{
png_structp png_ptr; /* note: temporary variables! */
png_infop info_ptr;
/* could also replace libpng warning-handler (final NULL), but no need: */
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
readpng2_error_handler, NULL);
if (!png_ptr)
return 4; /* out of memory */
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
png_destroy_read_struct(&png_ptr, NULL, NULL);
return 4; /* out of memory */
}
/* we could create a second info struct here (end_info), but it's only
* useful if we want to keep pre- and post-IDAT chunk info separated
* (mainly for PNG-aware image editors and converters) */
/* setjmp() must be called in every function that calls a PNG-reading
* libpng function, unless an alternate error handler was installed--
* but compatible error handlers must either use longjmp() themselves
* (as in this program) or exit immediately, so here we are: */
if (setjmp(mainprog_ptr->jmpbuf)) {
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return 2;
}
#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
/* prepare the reader to ignore all recognized chunks whose data won't be
* used, i.e., all chunks recognized by libpng except for IHDR, PLTE, IDAT,
* IEND, tRNS, bKGD, gAMA, and sRGB (small performance improvement) */
{
/* These byte strings were copied from png.h. If a future libpng
* version recognizes more chunks, add them to this list. If a
* future version of readpng2.c recognizes more chunks, delete them
* from this list. */
static const png_byte chunks_to_ignore[] = {
99, 72, 82, 77, '\0', /* cHRM */
104, 73, 83, 84, '\0', /* hIST */
105, 67, 67, 80, '\0', /* iCCP */
105, 84, 88, 116, '\0', /* iTXt */
111, 70, 70, 115, '\0', /* oFFs */
112, 67, 65, 76, '\0', /* pCAL */
112, 72, 89, 115, '\0', /* pHYs */
115, 66, 73, 84, '\0', /* sBIT */
115, 67, 65, 76, '\0', /* sCAL */
115, 80, 76, 84, '\0', /* sPLT */
115, 84, 69, 82, '\0', /* sTER */
116, 69, 88, 116, '\0', /* tEXt */
116, 73, 77, 69, '\0', /* tIME */
122, 84, 88, 116, '\0' /* zTXt */
};
png_set_keep_unknown_chunks(png_ptr, 1 /* PNG_HANDLE_CHUNK_NEVER */,
chunks_to_ignore, sizeof(chunks_to_ignore)/5);
}
#endif /* PNG_UNKNOWN_CHUNKS_SUPPORTED */
/* instead of doing png_init_io() here, now we set up our callback
* functions for progressive decoding */
png_set_progressive_read_fn(png_ptr, mainprog_ptr,
readpng2_info_callback, readpng2_row_callback, readpng2_end_callback);
/*
* may as well enable or disable MMX routines here, if supported;
*
* to enable all: mask = png_get_mmx_flagmask (
* PNG_SELECT_READ | PNG_SELECT_WRITE, &compilerID);
* flags = png_get_asm_flags (png_ptr);
* flags |= mask;
* png_set_asm_flags (png_ptr, flags);
*
* to disable all: mask = png_get_mmx_flagmask (
* PNG_SELECT_READ | PNG_SELECT_WRITE, &compilerID);
* flags = png_get_asm_flags (png_ptr);
* flags &= ~mask;
* png_set_asm_flags (png_ptr, flags);
*/
#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__)) && \
defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
/*
* WARNING: This preprocessor approach means that the following code
* cannot be used with a libpng DLL older than 1.2.0--the
* compiled-in symbols for the new functions will not exist.
* (Could use dlopen() and dlsym() on Unix and corresponding
* calls for Windows, but not portable...)
*/
{
#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
png_uint_32 mmx_disable_mask = 0;
png_uint_32 asm_flags, mmx_mask;
int compilerID;
if (mainprog_ptr->nommxfilters)
mmx_disable_mask |= ( PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
| PNG_ASM_FLAG_MMX_READ_FILTER_UP \
| PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
| PNG_ASM_FLAG_MMX_READ_FILTER_PAETH );
if (mainprog_ptr->nommxcombine)
mmx_disable_mask |= PNG_ASM_FLAG_MMX_READ_COMBINE_ROW;
if (mainprog_ptr->nommxinterlace)
mmx_disable_mask |= PNG_ASM_FLAG_MMX_READ_INTERLACE;
asm_flags = png_get_asm_flags(png_ptr);
png_set_asm_flags(png_ptr, asm_flags & ~mmx_disable_mask);
/* Now query libpng's asm settings, just for yuks. Note that this
* differs from the querying of its *potential* MMX capabilities
* in readpng2_version_info(); this is true runtime verification. */
asm_flags = png_get_asm_flags(png_ptr);
mmx_mask = png_get_mmx_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE,
&compilerID);
if (asm_flags & PNG_ASM_FLAG_MMX_SUPPORT_COMPILED)
fprintf(stderr,
" MMX support (%s version) is compiled into libpng\n",
compilerID == 1? "MSVC++" :
(compilerID == 2? "GNU C" : "unknown"));
else
fprintf(stderr, " MMX support is not compiled into libpng\n");
fprintf(stderr, " MMX instructions are %ssupported by CPU\n",
(asm_flags & PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU)? "" : "not ");
fprintf(stderr, " MMX read support for combining rows is %sabled\n",
(asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)? "en" : "dis");
fprintf(stderr,
" MMX read support for expanding interlacing is %sabled\n",
(asm_flags & PNG_ASM_FLAG_MMX_READ_INTERLACE)? "en" : "dis");
fprintf(stderr, " MMX read support for \"sub\" filter is %sabled\n",
(asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_SUB)? "en" : "dis");
fprintf(stderr, " MMX read support for \"up\" filter is %sabled\n",
(asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_UP)? "en" : "dis");
fprintf(stderr, " MMX read support for \"avg\" filter is %sabled\n",
(asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_AVG)? "en" : "dis");
fprintf(stderr, " MMX read support for \"Paeth\" filter is %sabled\n",
(asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_PAETH)? "en" : "dis");
asm_flags &= (mmx_mask & ~( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW \
| PNG_ASM_FLAG_MMX_READ_INTERLACE \
| PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
| PNG_ASM_FLAG_MMX_READ_FILTER_UP \
| PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
| PNG_ASM_FLAG_MMX_READ_FILTER_PAETH ));
if (asm_flags)
fprintf(stderr,
" additional MMX support is also enabled (0x%02lx)\n",
asm_flags);
#else /* !PNG_ASSEMBLER_CODE_SUPPORTED */
fprintf(stderr, " MMX querying is disabled in libpng.\n");
#endif /* ?PNG_ASSEMBLER_CODE_SUPPORTED */
}
#endif
/* make sure we save our pointers for use in readpng2_decode_data() */
mainprog_ptr->png_ptr = png_ptr;
mainprog_ptr->info_ptr = info_ptr;
/* and that's all there is to initialization */
return 0;
}
void save_as_png(T & file, std::vector<mapnik::rgb> & palette,
mapnik::image_data_8 const& image,
unsigned width,
unsigned height,
unsigned color_depth,
std::vector<unsigned> &alpha)
{
png_voidp error_ptr=0;
png_structp png_ptr=png_create_write_struct(PNG_LIBPNG_VER_STRING,
error_ptr,0, 0);
if (!png_ptr) return;
// switch on optimization only if supported
#if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200) && defined(PNG_MMX_CODE_SUPPORTED)
png_uint_32 mask, flags;
flags = png_get_asm_flags(png_ptr);
mask = png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
png_set_asm_flags(png_ptr, flags | mask);
#endif
png_set_filter (png_ptr, 0, PNG_FILTER_NONE);
png_infop info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
png_destroy_write_struct(&png_ptr,(png_infopp)0);
return;
}
if (setjmp(png_jmpbuf(png_ptr)))
{
png_destroy_write_struct(&png_ptr, &info_ptr);
return;
}
png_set_write_fn (png_ptr, &file, &write_data<T>, &flush_data<T>);
png_set_IHDR(png_ptr, info_ptr,width,height,color_depth,
PNG_COLOR_TYPE_PALETTE,PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT,PNG_FILTER_TYPE_DEFAULT);
png_set_PLTE(png_ptr,info_ptr,reinterpret_cast<png_color*>(&palette[0]),palette.size());
// make transparent lowest indexes, so tRNS is small
if (alpha.size()>0)
{
std::vector<png_byte> trans(alpha.size());
unsigned alphaSize=0;//truncate to nonopaque values
for(unsigned i=0; i < alpha.size(); i++)
{
trans[i]=alpha[i];
if (alpha[i]<255)
alphaSize = i+1;
}
if (alphaSize>0)
png_set_tRNS(png_ptr, info_ptr, (png_bytep)&trans[0], alphaSize, 0);
}
png_write_info(png_ptr, info_ptr);
for (unsigned i=0;i<height;i++)
{
png_write_row(png_ptr,(png_bytep)image.getRow(i));
}
png_write_end(png_ptr, info_ptr);
png_destroy_write_struct(&png_ptr, &info_ptr);
}