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// Framework
#include "maplib.h"
#if defined(__MACOSX__)
# include <Png/png.h>
#else
# include <png.h>
#endif
#include "pngsave.h"
static inline void PNGWriteCleanup(png_infop *info_ptr, png_structp *png_ptr, FILE* fileHandle)
{
if (*info_ptr != NULL)
png_destroy_info_struct(*png_ptr, info_ptr);
if (*png_ptr != NULL)
png_destroy_write_struct(png_ptr, NULL);
if (fileHandle != NULL)
fclose(fileHandle);
}
static bool savePngInternal(const char *fileName, uint8_t *pixels, int w, int h, int bitdepth, int color_type)
{
uint8_t **scanlines = NULL;
png_infop info_ptr = NULL;
png_structp png_ptr = NULL;
FILE *fp;
if (fileName == NULL || *fileName == '\0' || pixels == NULL)
{
return false;
}
if (w <= 0 || h <= 0)
{
debug(LOG_ERROR, "Unsupported image dimensions: %d x %d", w, h);
return false;
}
if (bitdepth <= 0)
{
debug(LOG_ERROR, "Unsupported bit depth: %d", bitdepth);
return false;
}
if (!(fp = fopen(fileName, "wb")))
{
debug(LOG_ERROR, "%s won't open for writing!", fileName);
return false;
}
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (png_ptr == NULL)
{
debug(LOG_ERROR, "savePng: Unable to create png struct\n");
PNGWriteCleanup(&info_ptr, &png_ptr, fp);
return false;
}
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL)
{
debug(LOG_ERROR, "savePng: Unable to create png info struct\n");
PNGWriteCleanup(&info_ptr, &png_ptr, fp);
return false;
}
// If libpng encounters an error, it will jump into this if-branch
if (setjmp(png_jmpbuf(png_ptr)))
{
debug(LOG_ERROR, "savePng: Error encoding PNG data\n");
PNGWriteCleanup(&info_ptr, &png_ptr, fp);
return false;
}
else
{
unsigned currentRow, row_stride;
unsigned channelsPerPixel;
switch (color_type)
{
case PNG_COLOR_TYPE_GRAY:
channelsPerPixel = 1;
break;
case PNG_COLOR_TYPE_RGB:
channelsPerPixel = 3;
break;
case PNG_COLOR_TYPE_RGBA:
channelsPerPixel = 4;
break;
default:
debug(LOG_ERROR, "Unsupported pixel format.\n");
PNGWriteCleanup(&info_ptr, &png_ptr, fp);
return false;
}
row_stride = w * channelsPerPixel * bitdepth / 8;
scanlines = (uint8_t **)malloc(sizeof(uint8_t *) * h);
if (scanlines == NULL)
{
debug(LOG_ERROR, "Couldn't allocate memory\n");
PNGWriteCleanup(&info_ptr, &png_ptr, fp);
return false;
}
png_init_io(png_ptr, fp);
//png_set_write_fn(png_ptr, fp, wzpng_write_data, wzpng_flush_data);
// Set the compression level of ZLIB
// Right now we stick with the default, since that one is the
// fastest which still produces acceptable filesizes.
// The highest compression level hardly produces smaller files than default.
//
// Below are some benchmarks done while taking screenshots at 1280x1024
// Z_NO_COMPRESSION:
// black (except for GUI): 398 msec
// 381, 391, 404, 360 msec
//
// Z_BEST_SPEED:
// black (except for GUI): 325 msec
// 611, 406, 461, 608 msec
//
// Z_DEFAULT_COMPRESSION:
// black (except for GUI): 374 msec
// 1154, 1121, 627, 790 msec
//
// Z_BEST_COMPRESSION:
// black (except for GUI): 439 msec
// 1600, 1078, 1613, 1700 msec
// Not calling this function is equal to using the default
// so to spare some CPU cycles we comment this out.
// png_set_compression_level(png_ptr, Z_DEFAULT_COMPRESSION);
png_set_IHDR(png_ptr, info_ptr, w, h, bitdepth,
color_type, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
png_write_info(png_ptr, info_ptr);
// Create an array of scanlines
for (currentRow = 0; currentRow < h; ++currentRow)
{
// png scanlines are ordered from top-to-bottom
// so we fill the scanline from the top to the bottom here
// otherwise we'd have a vertically mirrored image.
scanlines[currentRow] = pixels + row_stride * (h - currentRow - 1);
}
png_write_image(png_ptr, (png_bytepp)scanlines);
png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
png_write_end(png_ptr, NULL);
}
free(scanlines);
PNGWriteCleanup(&info_ptr, &png_ptr, fp);
return true;
}
/**************************************************************************
Save an RGB888 image buffer to a PNG file.
**************************************************************************/
bool savePng(const char *filename, uint8_t *pixels, int w, int h)
{
return savePngInternal(filename, pixels, w, h, 8, PNG_COLOR_TYPE_RGB);
}
/**************************************************************************
Save an ARGB8888 image buffer to a PNG file.
**************************************************************************/
bool savePngARGB32(const char *filename, uint8_t *pixels, int w, int h)
{
return savePngInternal(filename, pixels, w, h, 8, PNG_COLOR_TYPE_RGBA);
}
/**************************************************************************
Save an I16 image buffer to a PNG file.
**************************************************************************/
bool savePngI16(const char *filename, uint16_t *pixels, int w, int h)
{
return savePngInternal(filename, (uint8_t *)pixels, w, h, 16, PNG_COLOR_TYPE_GRAY);
}
/**************************************************************************
Save an I8 image buffer to a PNG file.
**************************************************************************/
bool savePngI8(const char *filename, uint8_t *pixels, int w, int h)
{
return savePngInternal(filename, pixels, w, h, 8, PNG_COLOR_TYPE_GRAY);
}
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