#include "pngpriv.h"
#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
# include <errno.h>
#endif
#ifdef PNG_READ_SUPPORTED
PNG_FUNCTION(png_structp,PNGAPI
png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
{
#ifndef PNG_USER_MEM_SUPPORTED
png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
error_fn, warn_fn, NULL, NULL, NULL);
#else
return png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
warn_fn, NULL, NULL, NULL);
}
PNG_FUNCTION(png_structp,PNGAPI
png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
{
png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
#endif
if (png_ptr != NULL)
{
png_ptr->mode = PNG_IS_READ_STRUCT;
# ifdef PNG_SEQUENTIAL_READ_SUPPORTED
png_ptr->IDAT_read_size = PNG_IDAT_READ_SIZE;
# endif
# ifdef PNG_BENIGN_READ_ERRORS_SUPPORTED
png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
# if PNG_RELEASE_BUILD
png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
# endif
# endif
png_set_read_fn(png_ptr, NULL, NULL);
}
return png_ptr;
}
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
void PNGAPI
png_read_info(png_structrp png_ptr, png_inforp info_ptr)
{
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
int keep;
#endif
png_debug(1, "in png_read_info");
if (png_ptr == NULL || info_ptr == NULL)
return;
png_read_sig(png_ptr, info_ptr);
for (;;)
{
png_uint_32 length = png_read_chunk_header(png_ptr);
png_uint_32 chunk_name = png_ptr->chunk_name;
if (chunk_name == png_IDAT)
{
if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
png_chunk_error(png_ptr, "Missing IHDR before IDAT");
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
(png_ptr->mode & PNG_HAVE_PLTE) == 0)
png_chunk_error(png_ptr, "Missing PLTE before IDAT");
else if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
png_chunk_benign_error(png_ptr, "Too many IDATs found");
png_ptr->mode |= PNG_HAVE_IDAT;
}
else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
png_ptr->mode |= PNG_AFTER_IDAT;
if (chunk_name == png_IHDR)
png_handle_IHDR(png_ptr, info_ptr, length);
else if (chunk_name == png_IEND)
png_handle_IEND(png_ptr, info_ptr, length);
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
{
png_handle_unknown(png_ptr, info_ptr, length, keep);
if (chunk_name == png_PLTE)
png_ptr->mode |= PNG_HAVE_PLTE;
else if (chunk_name == png_IDAT)
{
png_ptr->idat_size = 0;
break;
}
}
#endif
else if (chunk_name == png_PLTE)
png_handle_PLTE(png_ptr, info_ptr, length);
else if (chunk_name == png_IDAT)
{
png_ptr->idat_size = length;
break;
}
#ifdef PNG_READ_bKGD_SUPPORTED
else if (chunk_name == png_bKGD)
png_handle_bKGD(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_cHRM_SUPPORTED
else if (chunk_name == png_cHRM)
png_handle_cHRM(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_gAMA_SUPPORTED
else if (chunk_name == png_gAMA)
png_handle_gAMA(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_hIST_SUPPORTED
else if (chunk_name == png_hIST)
png_handle_hIST(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_oFFs_SUPPORTED
else if (chunk_name == png_oFFs)
png_handle_oFFs(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_pCAL_SUPPORTED
else if (chunk_name == png_pCAL)
png_handle_pCAL(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sCAL_SUPPORTED
else if (chunk_name == png_sCAL)
png_handle_sCAL(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_pHYs_SUPPORTED
else if (chunk_name == png_pHYs)
png_handle_pHYs(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sBIT_SUPPORTED
else if (chunk_name == png_sBIT)
png_handle_sBIT(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sRGB_SUPPORTED
else if (chunk_name == png_sRGB)
png_handle_sRGB(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_iCCP_SUPPORTED
else if (chunk_name == png_iCCP)
png_handle_iCCP(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sPLT_SUPPORTED
else if (chunk_name == png_sPLT)
png_handle_sPLT(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_tEXt_SUPPORTED
else if (chunk_name == png_tEXt)
png_handle_tEXt(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_tIME_SUPPORTED
else if (chunk_name == png_tIME)
png_handle_tIME(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_tRNS_SUPPORTED
else if (chunk_name == png_tRNS)
png_handle_tRNS(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
else if (chunk_name == png_zTXt)
png_handle_zTXt(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
else if (chunk_name == png_iTXt)
png_handle_iTXt(png_ptr, info_ptr, length);
#endif
else
png_handle_unknown(png_ptr, info_ptr, length,
PNG_HANDLE_CHUNK_AS_DEFAULT);
}
}
#endif
void PNGAPI
png_read_update_info(png_structrp png_ptr, png_inforp info_ptr)
{
png_debug(1, "in png_read_update_info");
if (png_ptr != NULL)
{
if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
{
png_read_start_row(png_ptr);
# ifdef PNG_READ_TRANSFORMS_SUPPORTED
png_read_transform_info(png_ptr, info_ptr);
# else
PNG_UNUSED(info_ptr)
# endif
}
else
png_app_error(png_ptr,
"png_read_update_info/png_start_read_image: duplicate call");
}
}
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
void PNGAPI
png_start_read_image(png_structrp png_ptr)
{
png_debug(1, "in png_start_read_image");
if (png_ptr != NULL)
{
if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
png_read_start_row(png_ptr);
else
png_app_error(png_ptr,
"png_start_read_image/png_read_update_info: duplicate call");
}
}
#endif
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
#ifdef PNG_MNG_FEATURES_SUPPORTED
static void
png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_read_intrapixel");
if (
(row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
{
int bytes_per_pixel;
png_uint_32 row_width = row_info->width;
if (row_info->bit_depth == 8)
{
png_bytep rp;
png_uint_32 i;
if (row_info->color_type == PNG_COLOR_TYPE_RGB)
bytes_per_pixel = 3;
else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
bytes_per_pixel = 4;
else
return;
for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
{
*(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff);
*(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff);
}
}
else if (row_info->bit_depth == 16)
{
png_bytep rp;
png_uint_32 i;
if (row_info->color_type == PNG_COLOR_TYPE_RGB)
bytes_per_pixel = 6;
else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
bytes_per_pixel = 8;
else
return;
for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
{
png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
png_uint_32 red = (s0 + s1 + 65536) & 0xffff;
png_uint_32 blue = (s2 + s1 + 65536) & 0xffff;
*(rp ) = (png_byte)((red >> 8) & 0xff);
*(rp + 1) = (png_byte)(red & 0xff);
*(rp + 4) = (png_byte)((blue >> 8) & 0xff);
*(rp + 5) = (png_byte)(blue & 0xff);
}
}
}
}
#endif
void PNGAPI
png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
{
png_row_info row_info;
if (png_ptr == NULL)
return;
png_debug2(1, "in png_read_row (row %lu, pass %d)",
(unsigned long)png_ptr->row_number, png_ptr->pass);
if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
png_read_start_row(png_ptr);
row_info.width = png_ptr->iwidth;
row_info.color_type = png_ptr->color_type;
row_info.bit_depth = png_ptr->bit_depth;
row_info.channels = png_ptr->channels;
row_info.pixel_depth = png_ptr->pixel_depth;
row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
#ifdef PNG_WARNINGS_SUPPORTED
if (png_ptr->row_number == 0 && png_ptr->pass == 0)
{
#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined");
#endif
#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
if ((png_ptr->transformations & PNG_FILLER) != 0)
png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined");
#endif
#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
!defined(PNG_READ_PACKSWAP_SUPPORTED)
if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined");
#endif
#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
if ((png_ptr->transformations & PNG_PACK) != 0)
png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined");
#endif
#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
if ((png_ptr->transformations & PNG_SHIFT) != 0)
png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined");
#endif
#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
if ((png_ptr->transformations & PNG_BGR) != 0)
png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined");
#endif
#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined");
#endif
}
#endif
#ifdef PNG_READ_INTERLACING_SUPPORTED
if (png_ptr->interlaced != 0 &&
(png_ptr->transformations & PNG_INTERLACE) != 0)
{
switch (png_ptr->pass)
{
case 0:
if (png_ptr->row_number & 0x07)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row, 1);
png_read_finish_row(png_ptr);
return;
}
break;
case 1:
if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row, 1);
png_read_finish_row(png_ptr);
return;
}
break;
case 2:
if ((png_ptr->row_number & 0x07) != 4)
{
if (dsp_row != NULL && (png_ptr->row_number & 4))
png_combine_row(png_ptr, dsp_row, 1);
png_read_finish_row(png_ptr);
return;
}
break;
case 3:
if ((png_ptr->row_number & 3) || png_ptr->width < 3)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row, 1);
png_read_finish_row(png_ptr);
return;
}
break;
case 4:
if ((png_ptr->row_number & 3) != 2)
{
if (dsp_row != NULL && (png_ptr->row_number & 2))
png_combine_row(png_ptr, dsp_row, 1);
png_read_finish_row(png_ptr);
return;
}
break;
case 5:
if ((png_ptr->row_number & 1) || png_ptr->width < 2)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row, 1);
png_read_finish_row(png_ptr);
return;
}
break;
default:
case 6:
if ((png_ptr->row_number & 1) == 0)
{
png_read_finish_row(png_ptr);
return;
}
break;
}
}
#endif
if ((png_ptr->mode & PNG_HAVE_IDAT) == 0)
png_error(png_ptr, "Invalid attempt to read row data");
png_read_IDAT_data(png_ptr, png_ptr->row_buf, row_info.rowbytes + 1);
if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
{
if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
png_ptr->prev_row + 1, png_ptr->row_buf[0]);
else
png_error(png_ptr, "bad adaptive filter value");
}
memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
#ifdef PNG_MNG_FEATURES_SUPPORTED
if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
(png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
{
png_do_read_intrapixel(&row_info, png_ptr->row_buf + 1);
}
#endif
#ifdef PNG_READ_TRANSFORMS_SUPPORTED
if (png_ptr->transformations)
png_do_read_transformations(png_ptr, &row_info);
#endif
if (png_ptr->transformed_pixel_depth == 0)
{
png_ptr->transformed_pixel_depth = row_info.pixel_depth;
if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
png_error(png_ptr, "sequential row overflow");
}
else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
png_error(png_ptr, "internal sequential row size calculation error");
#ifdef PNG_READ_INTERLACING_SUPPORTED
if (png_ptr->interlaced != 0 &&
(png_ptr->transformations & PNG_INTERLACE) != 0)
{
if (png_ptr->pass < 6)
png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
png_ptr->transformations);
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row, 1);
if (row != NULL)
png_combine_row(png_ptr, row, 0);
}
else
#endif
{
if (row != NULL)
png_combine_row(png_ptr, row, -1);
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row, -1);
}
png_read_finish_row(png_ptr);
if (png_ptr->read_row_fn != NULL)
(*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
}
#endif
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
void PNGAPI
png_read_rows(png_structrp png_ptr, png_bytepp row,
png_bytepp display_row, png_uint_32 num_rows)
{
png_uint_32 i;
png_bytepp rp;
png_bytepp dp;
png_debug(1, "in png_read_rows");
if (png_ptr == NULL)
return;
rp = row;
dp = display_row;
if (rp != NULL && dp != NULL)
for (i = 0; i < num_rows; i++)
{
png_bytep rptr = *rp++;
png_bytep dptr = *dp++;
png_read_row(png_ptr, rptr, dptr);
}
else if (rp != NULL)
for (i = 0; i < num_rows; i++)
{
png_bytep rptr = *rp;
png_read_row(png_ptr, rptr, NULL);
rp++;
}
else if (dp != NULL)
for (i = 0; i < num_rows; i++)
{
png_bytep dptr = *dp;
png_read_row(png_ptr, NULL, dptr);
dp++;
}
}
#endif
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
void PNGAPI
png_read_image(png_structrp png_ptr, png_bytepp image)
{
png_uint_32 i, image_height;
int pass, j;
png_bytepp rp;
png_debug(1, "in png_read_image");
if (png_ptr == NULL)
return;
#ifdef PNG_READ_INTERLACING_SUPPORTED
if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
{
pass = png_set_interlace_handling(png_ptr);
png_start_read_image(png_ptr);
}
else
{
if (png_ptr->interlaced != 0 &&
(png_ptr->transformations & PNG_INTERLACE) == 0)
{
png_warning(png_ptr, "Interlace handling should be turned on when "
"using png_read_image");
png_ptr->num_rows = png_ptr->height;
}
pass = png_set_interlace_handling(png_ptr);
}
#else
if (png_ptr->interlaced)
png_error(png_ptr,
"Cannot read interlaced image -- interlace handler disabled");
pass = 1;
#endif
image_height=png_ptr->height;
for (j = 0; j < pass; j++)
{
rp = image;
for (i = 0; i < image_height; i++)
{
png_read_row(png_ptr, *rp, NULL);
rp++;
}
}
}
#endif
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
void PNGAPI
png_read_end(png_structrp png_ptr, png_inforp info_ptr)
{
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
int keep;
#endif
png_debug(1, "in png_read_end");
if (png_ptr == NULL)
return;
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
if (png_chunk_unknown_handling(png_ptr, png_IDAT) == 0)
#endif
png_read_finish_IDAT(png_ptr);
#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
png_ptr->num_palette_max > png_ptr->num_palette)
png_benign_error(png_ptr, "Read palette index exceeding num_palette");
#endif
do
{
png_uint_32 length = png_read_chunk_header(png_ptr);
png_uint_32 chunk_name = png_ptr->chunk_name;
if (chunk_name == png_IEND)
png_handle_IEND(png_ptr, info_ptr, length);
else if (chunk_name == png_IHDR)
png_handle_IHDR(png_ptr, info_ptr, length);
else if (info_ptr == NULL)
png_crc_finish(png_ptr, length);
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
{
if (chunk_name == png_IDAT)
{
if ((length > 0) ||
(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0)
png_benign_error(png_ptr, "Too many IDATs found");
}
png_handle_unknown(png_ptr, info_ptr, length, keep);
if (chunk_name == png_PLTE)
png_ptr->mode |= PNG_HAVE_PLTE;
}
#endif
else if (chunk_name == png_IDAT)
{
if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0)
png_benign_error(png_ptr, "Too many IDATs found");
png_crc_finish(png_ptr, length);
}
else if (chunk_name == png_PLTE)
png_handle_PLTE(png_ptr, info_ptr, length);
#ifdef PNG_READ_bKGD_SUPPORTED
else if (chunk_name == png_bKGD)
png_handle_bKGD(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_cHRM_SUPPORTED
else if (chunk_name == png_cHRM)
png_handle_cHRM(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_gAMA_SUPPORTED
else if (chunk_name == png_gAMA)
png_handle_gAMA(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_hIST_SUPPORTED
else if (chunk_name == png_hIST)
png_handle_hIST(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_oFFs_SUPPORTED
else if (chunk_name == png_oFFs)
png_handle_oFFs(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_pCAL_SUPPORTED
else if (chunk_name == png_pCAL)
png_handle_pCAL(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sCAL_SUPPORTED
else if (chunk_name == png_sCAL)
png_handle_sCAL(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_pHYs_SUPPORTED
else if (chunk_name == png_pHYs)
png_handle_pHYs(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sBIT_SUPPORTED
else if (chunk_name == png_sBIT)
png_handle_sBIT(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sRGB_SUPPORTED
else if (chunk_name == png_sRGB)
png_handle_sRGB(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_iCCP_SUPPORTED
else if (chunk_name == png_iCCP)
png_handle_iCCP(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sPLT_SUPPORTED
else if (chunk_name == png_sPLT)
png_handle_sPLT(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_tEXt_SUPPORTED
else if (chunk_name == png_tEXt)
png_handle_tEXt(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_tIME_SUPPORTED
else if (chunk_name == png_tIME)
png_handle_tIME(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_tRNS_SUPPORTED
else if (chunk_name == png_tRNS)
png_handle_tRNS(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
else if (chunk_name == png_zTXt)
png_handle_zTXt(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
else if (chunk_name == png_iTXt)
png_handle_iTXt(png_ptr, info_ptr, length);
#endif
else
png_handle_unknown(png_ptr, info_ptr, length,
PNG_HANDLE_CHUNK_AS_DEFAULT);
} while ((png_ptr->mode & PNG_HAVE_IEND) == 0);
}
#endif
static void
png_read_destroy(png_structrp png_ptr)
{
png_debug(1, "in png_read_destroy");
#ifdef PNG_READ_GAMMA_SUPPORTED
png_destroy_gamma_table(png_ptr);
#endif
png_free(png_ptr, png_ptr->big_row_buf);
png_ptr->big_row_buf = NULL;
png_free(png_ptr, png_ptr->big_prev_row);
png_ptr->big_prev_row = NULL;
png_free(png_ptr, png_ptr->read_buffer);
png_ptr->read_buffer = NULL;
#ifdef PNG_READ_QUANTIZE_SUPPORTED
png_free(png_ptr, png_ptr->palette_lookup);
png_ptr->palette_lookup = NULL;
png_free(png_ptr, png_ptr->quantize_index);
png_ptr->quantize_index = NULL;
#endif
if ((png_ptr->free_me & PNG_FREE_PLTE) != 0)
{
png_zfree(png_ptr, png_ptr->palette);
png_ptr->palette = NULL;
}
png_ptr->free_me &= ~PNG_FREE_PLTE;
#if defined(PNG_tRNS_SUPPORTED) || \
defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
if ((png_ptr->free_me & PNG_FREE_TRNS) != 0)
{
png_free(png_ptr, png_ptr->trans_alpha);
png_ptr->trans_alpha = NULL;
}
png_ptr->free_me &= ~PNG_FREE_TRNS;
#endif
inflateEnd(&png_ptr->zstream);
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
png_free(png_ptr, png_ptr->save_buffer);
png_ptr->save_buffer = NULL;
#endif
#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) && \
defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
png_free(png_ptr, png_ptr->unknown_chunk.data);
png_ptr->unknown_chunk.data = NULL;
#endif
#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
png_free(png_ptr, png_ptr->chunk_list);
png_ptr->chunk_list = NULL;
#endif
}
void PNGAPI
png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
png_infopp end_info_ptr_ptr)
{
png_structrp png_ptr = NULL;
png_debug(1, "in png_destroy_read_struct");
if (png_ptr_ptr != NULL)
png_ptr = *png_ptr_ptr;
if (png_ptr == NULL)
return;
png_destroy_info_struct(png_ptr, end_info_ptr_ptr);
png_destroy_info_struct(png_ptr, info_ptr_ptr);
*png_ptr_ptr = NULL;
png_read_destroy(png_ptr);
png_destroy_png_struct(png_ptr);
}
void PNGAPI
png_set_read_status_fn(png_structrp png_ptr, png_read_status_ptr read_row_fn)
{
if (png_ptr == NULL)
return;
png_ptr->read_row_fn = read_row_fn;
}
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
#ifdef PNG_INFO_IMAGE_SUPPORTED
void PNGAPI
png_read_png(png_structrp png_ptr, png_inforp info_ptr,
int transforms,
voidp params)
{
if (png_ptr == NULL || info_ptr == NULL)
return;
png_read_info(png_ptr, info_ptr);
if (info_ptr->height > PNG_UINT_32_MAX/(sizeof (png_bytep)))
png_error(png_ptr, "Image is too high to process with png_read_png()");
if ((transforms & PNG_TRANSFORM_SCALE_16) != 0)
#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
png_set_scale_16(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_SCALE_16 not supported");
#endif
if ((transforms & PNG_TRANSFORM_STRIP_16) != 0)
#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
png_set_strip_16(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_16 not supported");
#endif
if ((transforms & PNG_TRANSFORM_STRIP_ALPHA) != 0)
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
png_set_strip_alpha(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_ALPHA not supported");
#endif
if ((transforms & PNG_TRANSFORM_PACKING) != 0)
#ifdef PNG_READ_PACK_SUPPORTED
png_set_packing(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported");
#endif
if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0)
#ifdef PNG_READ_PACKSWAP_SUPPORTED
png_set_packswap(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported");
#endif
if ((transforms & PNG_TRANSFORM_EXPAND) != 0)
#ifdef PNG_READ_EXPAND_SUPPORTED
png_set_expand(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND not supported");
#endif
if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0)
#ifdef PNG_READ_INVERT_SUPPORTED
png_set_invert_mono(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported");
#endif
if ((transforms & PNG_TRANSFORM_SHIFT) != 0)
#ifdef PNG_READ_SHIFT_SUPPORTED
if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
png_set_shift(png_ptr, &info_ptr->sig_bit);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
#endif
if ((transforms & PNG_TRANSFORM_BGR) != 0)
#ifdef PNG_READ_BGR_SUPPORTED
png_set_bgr(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported");
#endif
if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0)
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
png_set_swap_alpha(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported");
#endif
if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0)
#ifdef PNG_READ_SWAP_SUPPORTED
png_set_swap(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported");
#endif
if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0)
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
png_set_invert_alpha(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported");
#endif
if ((transforms & PNG_TRANSFORM_GRAY_TO_RGB) != 0)
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
png_set_gray_to_rgb(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_GRAY_TO_RGB not supported");
#endif
if ((transforms & PNG_TRANSFORM_EXPAND_16) != 0)
#ifdef PNG_READ_EXPAND_16_SUPPORTED
png_set_expand_16(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND_16 not supported");
#endif
(void)png_set_interlace_handling(png_ptr);
png_read_update_info(png_ptr, info_ptr);
png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
if (info_ptr->row_pointers == NULL)
{
png_uint_32 iptr;
info_ptr->row_pointers = png_voidcast(png_bytepp, png_malloc(png_ptr,
info_ptr->height * (sizeof (png_bytep))));
for (iptr=0; iptr<info_ptr->height; iptr++)
info_ptr->row_pointers[iptr] = NULL;
info_ptr->free_me |= PNG_FREE_ROWS;
for (iptr = 0; iptr < info_ptr->height; iptr++)
info_ptr->row_pointers[iptr] = png_voidcast(png_bytep,
png_malloc(png_ptr, info_ptr->rowbytes));
}
png_read_image(png_ptr, info_ptr->row_pointers);
info_ptr->valid |= PNG_INFO_IDAT;
png_read_end(png_ptr, info_ptr);
PNG_UNUSED(params)
}
#endif
#endif
#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
# define P_NOTSET 0
# define P_sRGB 1
# define P_LINEAR 2
# define P_FILE 3
# define P_LINEAR8 4
#define PNG_CMAP_NONE 0
#define PNG_CMAP_GA 1
#define PNG_CMAP_TRANS 2
#define PNG_CMAP_RGB 3
#define PNG_CMAP_RGB_ALPHA 4
#define PNG_CMAP_NONE_BACKGROUND 256
#define PNG_CMAP_GA_BACKGROUND 231
#define PNG_CMAP_TRANS_BACKGROUND 254
#define PNG_CMAP_RGB_BACKGROUND 256
#define PNG_CMAP_RGB_ALPHA_BACKGROUND 216
typedef struct
{
png_imagep image;
png_voidp buffer;
png_int_32 row_stride;
png_voidp colormap;
png_const_colorp background;
png_voidp local_row;
png_voidp first_row;
ptrdiff_t row_bytes;
int file_encoding;
png_fixed_point gamma_to_linear;
int colormap_processing;
} png_image_read_control;
static int
png_image_read_init(png_imagep image)
{
if (image->opaque == NULL)
{
png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, image,
png_safe_error, png_safe_warning);
memset(image, 0, (sizeof *image));
image->version = PNG_IMAGE_VERSION;
if (png_ptr != NULL)
{
png_infop info_ptr = png_create_info_struct(png_ptr);
if (info_ptr != NULL)
{
png_controlp control = png_voidcast(png_controlp,
png_malloc_warn(png_ptr, (sizeof *control)));
if (control != NULL)
{
memset(control, 0, (sizeof *control));
control->png_ptr = png_ptr;
control->info_ptr = info_ptr;
control->for_write = 0;
image->opaque = control;
return 1;
}
png_destroy_info_struct(png_ptr, &info_ptr);
}
png_destroy_read_struct(&png_ptr, NULL, NULL);
}
return png_image_error(image, "png_image_read: out of memory");
}
return png_image_error(image, "png_image_read: opaque pointer not NULL");
}
static png_uint_32
png_image_format(png_structrp png_ptr)
{
png_uint_32 format = 0;
if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
format |= PNG_FORMAT_FLAG_COLOR;
if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
format |= PNG_FORMAT_FLAG_ALPHA;
else if (png_ptr->num_trans > 0)
format |= PNG_FORMAT_FLAG_ALPHA;
if (png_ptr->bit_depth == 16)
format |= PNG_FORMAT_FLAG_LINEAR;
if ((png_ptr->color_type & PNG_COLOR_MASK_PALETTE) != 0)
format |= PNG_FORMAT_FLAG_COLORMAP;
return format;
}
static int
png_gamma_not_sRGB(png_fixed_point g)
{
if (g < PNG_FP_1)
{
if (g == 0)
return 0;
return png_gamma_significant((g * 11 + 2)/5 );
}
return 1;
}
static int
png_image_read_header(png_voidp argument)
{
png_imagep image = png_voidcast(png_imagep, argument);
png_structrp png_ptr = image->opaque->png_ptr;
png_inforp info_ptr = image->opaque->info_ptr;
png_set_benign_errors(png_ptr, 1);
png_read_info(png_ptr, info_ptr);
image->width = png_ptr->width;
image->height = png_ptr->height;
{
png_uint_32 format = png_image_format(png_ptr);
image->format = format;
#ifdef PNG_COLORSPACE_SUPPORTED
if ((format & PNG_FORMAT_FLAG_COLOR) != 0 && ((png_ptr->colorspace.flags
& (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB|
PNG_COLORSPACE_INVALID)) == PNG_COLORSPACE_HAVE_ENDPOINTS))
image->flags |= PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB;
#endif
}
{
png_uint_32 cmap_entries;
switch (png_ptr->color_type)
{
case PNG_COLOR_TYPE_GRAY:
cmap_entries = 1U << png_ptr->bit_depth;
break;
case PNG_COLOR_TYPE_PALETTE:
cmap_entries = png_ptr->num_palette;
break;
default:
cmap_entries = 256;
break;
}
if (cmap_entries > 256)
cmap_entries = 256;
image->colormap_entries = cmap_entries;
}
return 1;
}
#ifdef PNG_STDIO_SUPPORTED
int PNGAPI
png_image_begin_read_from_stdio(png_imagep image, FILE* file)
{
if (image != NULL && image->version == PNG_IMAGE_VERSION)
{
if (file != NULL)
{
if (png_image_read_init(image) != 0)
{
image->opaque->png_ptr->io_ptr = file;
return png_safe_execute(image, png_image_read_header, image);
}
}
else
return png_image_error(image,
"png_image_begin_read_from_stdio: invalid argument");
}
else if (image != NULL)
return png_image_error(image,
"png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION");
return 0;
}
int PNGAPI
png_image_begin_read_from_file(png_imagep image, const char *file_name)
{
if (image != NULL && image->version == PNG_IMAGE_VERSION)
{
if (file_name != NULL)
{
FILE *fp = fopen(file_name, "rb");
if (fp != NULL)
{
if (png_image_read_init(image) != 0)
{
image->opaque->png_ptr->io_ptr = fp;
image->opaque->owned_file = 1;
return png_safe_execute(image, png_image_read_header, image);
}
(void)fclose(fp);
}
else
return png_image_error(image, strerror(errno));
}
else
return png_image_error(image,
"png_image_begin_read_from_file: invalid argument");
}
else if (image != NULL)
return png_image_error(image,
"png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION");
return 0;
}
#endif
static void PNGCBAPI
png_image_memory_read(png_structp png_ptr, png_bytep out, png_size_t need)
{
if (png_ptr != NULL)
{
png_imagep image = png_voidcast(png_imagep, png_ptr->io_ptr);
if (image != NULL)
{
png_controlp cp = image->opaque;
if (cp != NULL)
{
png_const_bytep memory = cp->memory;
png_size_t size = cp->size;
if (memory != NULL && size >= need)
{
memcpy(out, memory, need);
cp->memory = memory + need;
cp->size = size - need;
return;
}
png_error(png_ptr, "read beyond end of data");
}
}
png_error(png_ptr, "invalid memory read");
}
}
int PNGAPI png_image_begin_read_from_memory(png_imagep image,
png_const_voidp memory, png_size_t size)
{
if (image != NULL && image->version == PNG_IMAGE_VERSION)
{
if (memory != NULL && size > 0)
{
if (png_image_read_init(image) != 0)
{
image->opaque->memory = png_voidcast(png_const_bytep, memory);
image->opaque->size = size;
image->opaque->png_ptr->io_ptr = image;
image->opaque->png_ptr->read_data_fn = png_image_memory_read;
return png_safe_execute(image, png_image_read_header, image);
}
}
else
return png_image_error(image,
"png_image_begin_read_from_memory: invalid argument");
}
else if (image != NULL)
return png_image_error(image,
"png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION");
return 0;
}
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
static void
png_image_skip_unused_chunks(png_structrp png_ptr)
{
{
static PNG_CONST png_byte chunks_to_process[] = {
98, 75, 71, 68, '\0',
99, 72, 82, 77, '\0',
103, 65, 77, 65, '\0',
# ifdef PNG_READ_iCCP_SUPPORTED
105, 67, 67, 80, '\0',
# endif
115, 66, 73, 84, '\0',
115, 82, 71, 66, '\0',
};
png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_NEVER,
NULL, -1);
png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_AS_DEFAULT,
chunks_to_process, (int)(sizeof chunks_to_process)/5);
}
}
# define PNG_SKIP_CHUNKS(p) png_image_skip_unused_chunks(p)
#else
# define PNG_SKIP_CHUNKS(p) ((void)0)
#endif
#define PNG_DIV51(v8) (((v8) * 5 + 130) >> 8)
static void
set_file_encoding(png_image_read_control *display)
{
png_fixed_point g = display->image->opaque->png_ptr->colorspace.gamma;
if (png_gamma_significant(g) != 0)
{
if (png_gamma_not_sRGB(g) != 0)
{
display->file_encoding = P_FILE;
display->gamma_to_linear = png_reciprocal(g);
}
else
display->file_encoding = P_sRGB;
}
else
display->file_encoding = P_LINEAR8;
}
static unsigned int
decode_gamma(png_image_read_control *display, png_uint_32 value, int encoding)
{
if (encoding == P_FILE)
encoding = display->file_encoding;
if (encoding == P_NOTSET)
{
set_file_encoding(display);
encoding = display->file_encoding;
}
switch (encoding)
{
case P_FILE:
value = png_gamma_16bit_correct(value*257, display->gamma_to_linear);
break;
case P_sRGB:
value = png_sRGB_table[value];
break;
case P_LINEAR:
break;
case P_LINEAR8:
value *= 257;
break;
#ifdef __GNUC__
default:
png_error(display->image->opaque->png_ptr,
"unexpected encoding (internal error)");
#endif
}
return value;
}
static png_uint_32
png_colormap_compose(png_image_read_control *display,
png_uint_32 foreground, int foreground_encoding, png_uint_32 alpha,
png_uint_32 background, int encoding)
{
png_uint_32 f = decode_gamma(display, foreground, foreground_encoding);
png_uint_32 b = decode_gamma(display, background, encoding);
f = f * alpha + b * (255-alpha);
if (encoding == P_LINEAR)
{
f *= 257;
f += f >> 16;
f = (f+32768) >> 16;
}
else
f = PNG_sRGB_FROM_LINEAR(f);
return f;
}
static void
png_create_colormap_entry(png_image_read_control *display,
png_uint_32 ip, png_uint_32 red, png_uint_32 green, png_uint_32 blue,
png_uint_32 alpha, int encoding)
{
png_imagep image = display->image;
const int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) != 0 ?
P_LINEAR : P_sRGB;
const int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 &&
(red != green || green != blue);
if (ip > 255)
png_error(image->opaque->png_ptr, "color-map index out of range");
if (encoding == P_FILE)
{
if (display->file_encoding == P_NOTSET)
set_file_encoding(display);
encoding = display->file_encoding;
}
if (encoding == P_FILE)
{
png_fixed_point g = display->gamma_to_linear;
red = png_gamma_16bit_correct(red*257, g);
green = png_gamma_16bit_correct(green*257, g);
blue = png_gamma_16bit_correct(blue*257, g);
if (convert_to_Y != 0 || output_encoding == P_LINEAR)
{
alpha *= 257;
encoding = P_LINEAR;
}
else
{
red = PNG_sRGB_FROM_LINEAR(red * 255);
green = PNG_sRGB_FROM_LINEAR(green * 255);
blue = PNG_sRGB_FROM_LINEAR(blue * 255);
encoding = P_sRGB;
}
}
else if (encoding == P_LINEAR8)
{
red *= 257;
green *= 257;
blue *= 257;
alpha *= 257;
encoding = P_LINEAR;
}
else if (encoding == P_sRGB &&
(convert_to_Y != 0 || output_encoding == P_LINEAR))
{
red = png_sRGB_table[red];
green = png_sRGB_table[green];
blue = png_sRGB_table[blue];
alpha *= 257;
encoding = P_LINEAR;
}
if (encoding == P_LINEAR)
{
if (convert_to_Y != 0)
{
png_uint_32 y = (png_uint_32)6968 * red + (png_uint_32)23434 * green +
(png_uint_32)2366 * blue;
if (output_encoding == P_LINEAR)
y = (y + 16384) >> 15;
else
{
y = (y + 128) >> 8;
y *= 255;
y = PNG_sRGB_FROM_LINEAR((y + 64) >> 7);
alpha = PNG_DIV257(alpha);
encoding = P_sRGB;
}
blue = red = green = y;
}
else if (output_encoding == P_sRGB)
{
red = PNG_sRGB_FROM_LINEAR(red * 255);
green = PNG_sRGB_FROM_LINEAR(green * 255);
blue = PNG_sRGB_FROM_LINEAR(blue * 255);
alpha = PNG_DIV257(alpha);
encoding = P_sRGB;
}
}
if (encoding != output_encoding)
png_error(image->opaque->png_ptr, "bad encoding (internal error)");
{
# ifdef PNG_FORMAT_AFIRST_SUPPORTED
const int afirst = (image->format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
(image->format & PNG_FORMAT_FLAG_ALPHA) != 0;
# else
# define afirst 0
# endif
# ifdef PNG_FORMAT_BGR_SUPPORTED
const int bgr = (image->format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0;
# else
# define bgr 0
# endif
if (output_encoding == P_LINEAR)
{
png_uint_16p entry = png_voidcast(png_uint_16p, display->colormap);
entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format);
switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format))
{
case 4:
entry[afirst ? 0 : 3] = (png_uint_16)alpha;
case 3:
if (alpha < 65535)
{
if (alpha > 0)
{
blue = (blue * alpha + 32767U)/65535U;
green = (green * alpha + 32767U)/65535U;
red = (red * alpha + 32767U)/65535U;
}
else
red = green = blue = 0;
}
entry[afirst + (2 ^ bgr)] = (png_uint_16)blue;
entry[afirst + 1] = (png_uint_16)green;
entry[afirst + bgr] = (png_uint_16)red;
break;
case 2:
entry[1 ^ afirst] = (png_uint_16)alpha;
case 1:
if (alpha < 65535)
{
if (alpha > 0)
green = (green * alpha + 32767U)/65535U;
else
green = 0;
}
entry[afirst] = (png_uint_16)green;
break;
default:
break;
}
}
else
{
png_bytep entry = png_voidcast(png_bytep, display->colormap);
entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format);
switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format))
{
case 4:
entry[afirst ? 0 : 3] = (png_byte)alpha;
case 3:
entry[afirst + (2 ^ bgr)] = (png_byte)blue;
entry[afirst + 1] = (png_byte)green;
entry[afirst + bgr] = (png_byte)red;
break;
case 2:
entry[1 ^ afirst] = (png_byte)alpha;
case 1:
entry[afirst] = (png_byte)green;
break;
default:
break;
}
}
# ifdef afirst
# undef afirst
# endif
# ifdef bgr
# undef bgr
# endif
}
}
static int
make_gray_file_colormap(png_image_read_control *display)
{
unsigned int i;
for (i=0; i<256; ++i)
png_create_colormap_entry(display, i, i, i, i, 255, P_FILE);
return i;
}
static int
make_gray_colormap(png_image_read_control *display)
{
unsigned int i;
for (i=0; i<256; ++i)
png_create_colormap_entry(display, i, i, i, i, 255, P_sRGB);
return i;
}
#define PNG_GRAY_COLORMAP_ENTRIES 256
static int
make_ga_colormap(png_image_read_control *display)
{
unsigned int i, a;
i = 0;
while (i < 231)
{
unsigned int gray = (i * 256 + 115) / 231;
png_create_colormap_entry(display, i++, gray, gray, gray, 255, P_sRGB);
}
png_create_colormap_entry(display, i++, 255, 255, 255, 0, P_sRGB);
for (a=1; a<5; ++a)
{
unsigned int g;
for (g=0; g<6; ++g)
png_create_colormap_entry(display, i++, g*51, g*51, g*51, a*51,
P_sRGB);
}
return i;
}
#define PNG_GA_COLORMAP_ENTRIES 256
static int
make_rgb_colormap(png_image_read_control *display)
{
unsigned int i, r;
for (i=r=0; r<6; ++r)
{
unsigned int g;
for (g=0; g<6; ++g)
{
unsigned int b;
for (b=0; b<6; ++b)
png_create_colormap_entry(display, i++, r*51, g*51, b*51, 255,
P_sRGB);
}
}
return i;
}
#define PNG_RGB_COLORMAP_ENTRIES 216
#define PNG_RGB_INDEX(r,g,b) \
((png_byte)(6 * (6 * PNG_DIV51(r) + PNG_DIV51(g)) + PNG_DIV51(b)))
static int
png_image_read_colormap(png_voidp argument)
{
png_image_read_control *display =
png_voidcast(png_image_read_control*, argument);
const png_imagep image = display->image;
const png_structrp png_ptr = image->opaque->png_ptr;
const png_uint_32 output_format = image->format;
const int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) != 0 ?
P_LINEAR : P_sRGB;
unsigned int cmap_entries;
unsigned int output_processing;
unsigned int data_encoding = P_NOTSET;
unsigned int background_index = 256;
png_uint_32 back_r, back_g, back_b;
int expand_tRNS = 0;
if (((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0 ||
png_ptr->num_trans > 0) &&
((output_format & PNG_FORMAT_FLAG_ALPHA) == 0) )
{
if (output_encoding == P_LINEAR)
back_b = back_g = back_r = 0;
else if (display->background == NULL )
png_error(png_ptr,
"a background color must be supplied to remove alpha/transparency");
else
{
back_g = display->background->green;
if ((output_format & PNG_FORMAT_FLAG_COLOR) != 0)
{
back_r = display->background->red;
back_b = display->background->blue;
}
else
back_b = back_r = back_g;
}
}
else if (output_encoding == P_LINEAR)
back_b = back_r = back_g = 65535;
else
back_b = back_r = back_g = 255;
if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) == 0)
{
if (png_ptr->bit_depth == 16 &&
(image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0)
png_ptr->colorspace.gamma = PNG_GAMMA_LINEAR;
else
png_ptr->colorspace.gamma = PNG_GAMMA_sRGB_INVERSE;
png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
}
switch (png_ptr->color_type)
{
case PNG_COLOR_TYPE_GRAY:
if (png_ptr->bit_depth <= 8)
{
unsigned int step, i, val, trans = 256, back_alpha = 0;
cmap_entries = 1U << png_ptr->bit_depth;
if (cmap_entries > image->colormap_entries)
png_error(png_ptr, "gray[8] color-map: too few entries");
step = 255 / (cmap_entries - 1);
output_processing = PNG_CMAP_NONE;
if (png_ptr->num_trans > 0)
{
trans = png_ptr->trans_color.gray;
if ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0)
back_alpha = output_encoding == P_LINEAR ? 65535 : 255;
}
for (i=val=0; i<cmap_entries; ++i, val += step)
{
if (i != trans)
png_create_colormap_entry(display, i, val, val, val, 255,
P_FILE);
else
png_create_colormap_entry(display, i, back_r, back_g, back_b,
back_alpha, output_encoding);
}
data_encoding = P_FILE;
if (png_ptr->bit_depth < 8)
png_set_packing(png_ptr);
}
else
{
data_encoding = P_sRGB;
if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
png_error(png_ptr, "gray[16] color-map: too few entries");
cmap_entries = make_gray_colormap(display);
if (png_ptr->num_trans > 0)
{
unsigned int back_alpha;
if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
back_alpha = 0;
else
{
if (back_r == back_g && back_g == back_b)
{
png_color_16 c;
png_uint_32 gray = back_g;
if (output_encoding == P_LINEAR)
{
gray = PNG_sRGB_FROM_LINEAR(gray * 255);
png_create_colormap_entry(display, gray, back_g, back_g,
back_g, 65535, P_LINEAR);
}
c.index = 0;
c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
png_set_background_fixed(png_ptr, &c,
PNG_BACKGROUND_GAMMA_SCREEN, 0,
0);
output_processing = PNG_CMAP_NONE;
break;
}
#ifdef __COVERITY__
back_alpha = 255;
#else
back_alpha = output_encoding == P_LINEAR ? 65535 : 255;
#endif
}
expand_tRNS = 1;
output_processing = PNG_CMAP_TRANS;
background_index = 254;
png_create_colormap_entry(display, 254, back_r, back_g, back_b,
back_alpha, output_encoding);
}
else
output_processing = PNG_CMAP_NONE;
}
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
data_encoding = P_sRGB;
if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
{
if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
png_error(png_ptr, "gray+alpha color-map: too few entries");
cmap_entries = make_ga_colormap(display);
background_index = PNG_CMAP_GA_BACKGROUND;
output_processing = PNG_CMAP_GA;
}
else
{
if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0 ||
(back_r == back_g && back_g == back_b))
{
png_color_16 c;
png_uint_32 gray = back_g;
if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
png_error(png_ptr, "gray-alpha color-map: too few entries");
cmap_entries = make_gray_colormap(display);
if (output_encoding == P_LINEAR)
{
gray = PNG_sRGB_FROM_LINEAR(gray * 255);
png_create_colormap_entry(display, gray, back_g, back_g,
back_g, 65535, P_LINEAR);
}
c.index = 0;
c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
png_set_background_fixed(png_ptr, &c,
PNG_BACKGROUND_GAMMA_SCREEN, 0,
0);
output_processing = PNG_CMAP_NONE;
}
else
{
png_uint_32 i, a;
if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
png_error(png_ptr, "ga-alpha color-map: too few entries");
i = 0;
while (i < 231)
{
png_uint_32 gray = (i * 256 + 115) / 231;
png_create_colormap_entry(display, i++, gray, gray, gray,
255, P_sRGB);
}
background_index = i;
png_create_colormap_entry(display, i++, back_r, back_g, back_b,
#ifdef __COVERITY__
255U,
#else
output_encoding == P_LINEAR ? 65535U : 255U,
#endif
output_encoding);
if (output_encoding == P_sRGB)
{
back_r = png_sRGB_table[back_r];
back_g = png_sRGB_table[back_g];
back_b = png_sRGB_table[back_b];
}
for (a=1; a<5; ++a)
{
unsigned int g;
png_uint_32 alpha = 51 * a;
png_uint_32 back_rx = (255-alpha) * back_r;
png_uint_32 back_gx = (255-alpha) * back_g;
png_uint_32 back_bx = (255-alpha) * back_b;
for (g=0; g<6; ++g)
{
png_uint_32 gray = png_sRGB_table[g*51] * alpha;
png_create_colormap_entry(display, i++,
PNG_sRGB_FROM_LINEAR(gray + back_rx),
PNG_sRGB_FROM_LINEAR(gray + back_gx),
PNG_sRGB_FROM_LINEAR(gray + back_bx), 255, P_sRGB);
}
}
cmap_entries = i;
output_processing = PNG_CMAP_GA;
}
}
break;
case PNG_COLOR_TYPE_RGB:
case PNG_COLOR_TYPE_RGB_ALPHA:
if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0)
{
png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, -1,
-1);
data_encoding = P_sRGB;
if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
png_ptr->num_trans > 0) &&
(output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
{
expand_tRNS = 1;
if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
png_error(png_ptr, "rgb[ga] color-map: too few entries");
cmap_entries = make_ga_colormap(display);
background_index = PNG_CMAP_GA_BACKGROUND;
output_processing = PNG_CMAP_GA;
}
else
{
if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
png_error(png_ptr, "rgb[gray] color-map: too few entries");
if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
png_ptr->num_trans > 0) &&
png_gamma_not_sRGB(png_ptr->colorspace.gamma) != 0)
{
cmap_entries = make_gray_file_colormap(display);
data_encoding = P_FILE;
}
else
cmap_entries = make_gray_colormap(display);
if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
png_ptr->num_trans > 0)
{
png_color_16 c;
png_uint_32 gray = back_g;
if (data_encoding == P_FILE)
{
if (output_encoding == P_sRGB)
gray = png_sRGB_table[gray];
gray = PNG_DIV257(png_gamma_16bit_correct(gray,
png_ptr->colorspace.gamma));
png_create_colormap_entry(display, gray, back_g, back_g,
back_g, 0, output_encoding);
}
else if (output_encoding == P_LINEAR)
{
gray = PNG_sRGB_FROM_LINEAR(gray * 255);
png_create_colormap_entry(display, gray, back_g, back_g,
back_g, 0, P_LINEAR);
}
c.index = 0;
c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
expand_tRNS = 1;
png_set_background_fixed(png_ptr, &c,
PNG_BACKGROUND_GAMMA_SCREEN, 0,
0);
}
output_processing = PNG_CMAP_NONE;
}
}
else
{
data_encoding = P_sRGB;
if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
png_ptr->num_trans > 0)
{
if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
{
png_uint_32 r;
if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries)
png_error(png_ptr, "rgb+alpha color-map: too few entries");
cmap_entries = make_rgb_colormap(display);
png_create_colormap_entry(display, cmap_entries, 255, 255,
255, 0, P_sRGB);
background_index = cmap_entries++;
for (r=0; r<256; r = (r << 1) | 0x7f)
{
png_uint_32 g;
for (g=0; g<256; g = (g << 1) | 0x7f)
{
png_uint_32 b;
for (b=0; b<256; b = (b << 1) | 0x7f)
png_create_colormap_entry(display, cmap_entries++,
r, g, b, 128, P_sRGB);
}
}
expand_tRNS = 1;
output_processing = PNG_CMAP_RGB_ALPHA;
}
else
{
unsigned int sample_size =
PNG_IMAGE_SAMPLE_SIZE(output_format);
png_uint_32 r, g, b;
if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries)
png_error(png_ptr, "rgb-alpha color-map: too few entries");
cmap_entries = make_rgb_colormap(display);
png_create_colormap_entry(display, cmap_entries, back_r,
back_g, back_b, 0, output_encoding);
if (output_encoding == P_LINEAR)
{
r = PNG_sRGB_FROM_LINEAR(back_r * 255);
g = PNG_sRGB_FROM_LINEAR(back_g * 255);
b = PNG_sRGB_FROM_LINEAR(back_b * 255);
}
else
{
r = back_r;
g = back_g;
b = back_g;
}
if (memcmp((png_const_bytep)display->colormap +
sample_size * cmap_entries,
(png_const_bytep)display->colormap +
sample_size * PNG_RGB_INDEX(r,g,b),
sample_size) != 0)
{
background_index = cmap_entries++;
for (r=0; r<256; r = (r << 1) | 0x7f)
{
for (g=0; g<256; g = (g << 1) | 0x7f)
{
for (b=0; b<256; b = (b << 1) | 0x7f)
png_create_colormap_entry(display, cmap_entries++,
png_colormap_compose(display, r, P_sRGB, 128,
back_r, output_encoding),
png_colormap_compose(display, g, P_sRGB, 128,
back_g, output_encoding),
png_colormap_compose(display, b, P_sRGB, 128,
back_b, output_encoding),
0, output_encoding);
}
}
expand_tRNS = 1;
output_processing = PNG_CMAP_RGB_ALPHA;
}
else
{
png_color_16 c;
c.index = 0;
c.red = (png_uint_16)back_r;
c.gray = c.green = (png_uint_16)back_g;
c.blue = (png_uint_16)back_b;
png_set_background_fixed(png_ptr, &c,
PNG_BACKGROUND_GAMMA_SCREEN, 0,
0);
output_processing = PNG_CMAP_RGB;
}
}
}
else
{
if (PNG_RGB_COLORMAP_ENTRIES > image->colormap_entries)
png_error(png_ptr, "rgb color-map: too few entries");
cmap_entries = make_rgb_colormap(display);
output_processing = PNG_CMAP_RGB;
}
}
break;
case PNG_COLOR_TYPE_PALETTE:
{
unsigned int num_trans = png_ptr->num_trans;
png_const_bytep trans = num_trans > 0 ? png_ptr->trans_alpha : NULL;
png_const_colorp colormap = png_ptr->palette;
const int do_background = trans != NULL &&
(output_format & PNG_FORMAT_FLAG_ALPHA) == 0;
unsigned int i;
if (trans == NULL)
num_trans = 0;
output_processing = PNG_CMAP_NONE;
data_encoding = P_FILE;
cmap_entries = png_ptr->num_palette;
if (cmap_entries > 256)
cmap_entries = 256;
if (cmap_entries > image->colormap_entries)
png_error(png_ptr, "palette color-map: too few entries");
for (i=0; i < cmap_entries; ++i)
{
if (do_background != 0 && i < num_trans && trans[i] < 255)
{
if (trans[i] == 0)
png_create_colormap_entry(display, i, back_r, back_g,
back_b, 0, output_encoding);
else
{
png_create_colormap_entry(display, i,
png_colormap_compose(display, colormap[i].red, P_FILE,
trans[i], back_r, output_encoding),
png_colormap_compose(display, colormap[i].green, P_FILE,
trans[i], back_g, output_encoding),
png_colormap_compose(display, colormap[i].blue, P_FILE,
trans[i], back_b, output_encoding),
output_encoding == P_LINEAR ? trans[i] * 257U :
trans[i],
output_encoding);
}
}
else
png_create_colormap_entry(display, i, colormap[i].red,
colormap[i].green, colormap[i].blue,
i < num_trans ? trans[i] : 255U, P_FILE);
}
if (png_ptr->bit_depth < 8)
png_set_packing(png_ptr);
}
break;
default:
png_error(png_ptr, "invalid PNG color type");
}
if (expand_tRNS != 0 && png_ptr->num_trans > 0 &&
(png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0)
png_set_tRNS_to_alpha(png_ptr);
switch (data_encoding)
{
case P_sRGB:
png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, PNG_GAMMA_sRGB);
case P_FILE:
if (png_ptr->bit_depth > 8)
png_set_scale_16(png_ptr);
break;
#ifdef __GNUC__
default:
png_error(png_ptr, "bad data option (internal error)");
#endif
}
if (cmap_entries > 256 || cmap_entries > image->colormap_entries)
png_error(png_ptr, "color map overflow (BAD internal error)");
image->colormap_entries = cmap_entries;
switch (output_processing)
{
case PNG_CMAP_NONE:
if (background_index != PNG_CMAP_NONE_BACKGROUND)
goto bad_background;
break;
case PNG_CMAP_GA:
if (background_index != PNG_CMAP_GA_BACKGROUND)
goto bad_background;
break;
case PNG_CMAP_TRANS:
if (background_index >= cmap_entries ||
background_index != PNG_CMAP_TRANS_BACKGROUND)
goto bad_background;
break;
case PNG_CMAP_RGB:
if (background_index != PNG_CMAP_RGB_BACKGROUND)
goto bad_background;
break;
case PNG_CMAP_RGB_ALPHA:
if (background_index != PNG_CMAP_RGB_ALPHA_BACKGROUND)
goto bad_background;
break;
default:
png_error(png_ptr, "bad processing option (internal error)");
bad_background:
png_error(png_ptr, "bad background index (internal error)");
}
display->colormap_processing = output_processing;
return 1;
}
static int
png_image_read_and_map(png_voidp argument)
{
png_image_read_control *display = png_voidcast(png_image_read_control*,
argument);
png_imagep image = display->image;
png_structrp png_ptr = image->opaque->png_ptr;
int passes;
switch (png_ptr->interlaced)
{
case PNG_INTERLACE_NONE:
passes = 1;
break;
case PNG_INTERLACE_ADAM7:
passes = PNG_INTERLACE_ADAM7_PASSES;
break;
default:
png_error(png_ptr, "unknown interlace type");
}
{
png_uint_32 height = image->height;
png_uint_32 width = image->width;
int proc = display->colormap_processing;
png_bytep first_row = png_voidcast(png_bytep, display->first_row);
ptrdiff_t step_row = display->row_bytes;
int pass;
for (pass = 0; pass < passes; ++pass)
{
unsigned int startx, stepx, stepy;
png_uint_32 y;
if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
{
if (PNG_PASS_COLS(width, pass) == 0)
continue;
startx = PNG_PASS_START_COL(pass);
stepx = PNG_PASS_COL_OFFSET(pass);
y = PNG_PASS_START_ROW(pass);
stepy = PNG_PASS_ROW_OFFSET(pass);
}
else
{
y = 0;
startx = 0;
stepx = stepy = 1;
}
for (; y<height; y += stepy)
{
png_bytep inrow = png_voidcast(png_bytep, display->local_row);
png_bytep outrow = first_row + y * step_row;
png_const_bytep end_row = outrow + width;
png_read_row(png_ptr, inrow, NULL);
outrow += startx;
switch (proc)
{
case PNG_CMAP_GA:
for (; outrow < end_row; outrow += stepx)
{
unsigned int gray = *inrow++;
unsigned int alpha = *inrow++;
unsigned int entry;
if (alpha > 229)
{
entry = (231 * gray + 128) >> 8;
}
else if (alpha < 26)
{
entry = 231;
}
else
{
entry = 226 + 6 * PNG_DIV51(alpha) + PNG_DIV51(gray);
}
*outrow = (png_byte)entry;
}
break;
case PNG_CMAP_TRANS:
for (; outrow < end_row; outrow += stepx)
{
png_byte gray = *inrow++;
png_byte alpha = *inrow++;
if (alpha == 0)
*outrow = PNG_CMAP_TRANS_BACKGROUND;
else if (gray != PNG_CMAP_TRANS_BACKGROUND)
*outrow = gray;
else
*outrow = (png_byte)(PNG_CMAP_TRANS_BACKGROUND+1);
}
break;
case PNG_CMAP_RGB:
for (; outrow < end_row; outrow += stepx)
{
*outrow = PNG_RGB_INDEX(inrow[0], inrow[1], inrow[2]);
inrow += 3;
}
break;
case PNG_CMAP_RGB_ALPHA:
for (; outrow < end_row; outrow += stepx)
{
unsigned int alpha = inrow[3];
if (alpha >= 196)
*outrow = PNG_RGB_INDEX(inrow[0], inrow[1],
inrow[2]);
else if (alpha < 64)
*outrow = PNG_CMAP_RGB_ALPHA_BACKGROUND;
else
{
unsigned int back_i = PNG_CMAP_RGB_ALPHA_BACKGROUND+1;
if (inrow[0] & 0x80) back_i += 9;
if (inrow[0] & 0x40) back_i += 9;
if (inrow[0] & 0x80) back_i += 3;
if (inrow[0] & 0x40) back_i += 3;
if (inrow[0] & 0x80) back_i += 1;
if (inrow[0] & 0x40) back_i += 1;
*outrow = (png_byte)back_i;
}
inrow += 4;
}
break;
default:
break;
}
}
}
}
return 1;
}
static int
png_image_read_colormapped(png_voidp argument)
{
png_image_read_control *display = png_voidcast(png_image_read_control*,
argument);
png_imagep image = display->image;
png_controlp control = image->opaque;
png_structrp png_ptr = control->png_ptr;
png_inforp info_ptr = control->info_ptr;
int passes = 0;
PNG_SKIP_CHUNKS(png_ptr);
if (display->colormap_processing == PNG_CMAP_NONE)
passes = png_set_interlace_handling(png_ptr);
png_read_update_info(png_ptr, info_ptr);
switch (display->colormap_processing)
{
case PNG_CMAP_NONE:
if ((info_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
info_ptr->color_type == PNG_COLOR_TYPE_GRAY) &&
info_ptr->bit_depth == 8)
break;
goto bad_output;
case PNG_CMAP_TRANS:
case PNG_CMAP_GA:
if (info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
info_ptr->bit_depth == 8 &&
png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
image->colormap_entries == 256)
break;
goto bad_output;
case PNG_CMAP_RGB:
if (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
info_ptr->bit_depth == 8 &&
png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
image->colormap_entries == 216)
break;
goto bad_output;
case PNG_CMAP_RGB_ALPHA:
if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
info_ptr->bit_depth == 8 &&
png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
image->colormap_entries == 244 )
break;
default:
bad_output:
png_error(png_ptr, "bad color-map processing (internal error)");
}
{
png_voidp first_row = display->buffer;
ptrdiff_t row_bytes = display->row_stride;
if (row_bytes < 0)
{
char *ptr = png_voidcast(char*, first_row);
ptr += (image->height-1) * (-row_bytes);
first_row = png_voidcast(png_voidp, ptr);
}
display->first_row = first_row;
display->row_bytes = row_bytes;
}
if (passes == 0)
{
int result;
png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
display->local_row = row;
result = png_safe_execute(image, png_image_read_and_map, display);
display->local_row = NULL;
png_free(png_ptr, row);
return result;
}
else
{
png_alloc_size_t row_bytes = display->row_bytes;
while (--passes >= 0)
{
png_uint_32 y = image->height;
png_bytep row = png_voidcast(png_bytep, display->first_row);
while (y-- > 0)
{
png_read_row(png_ptr, row, NULL);
row += row_bytes;
}
}
return 1;
}
}
static int
png_image_read_composite(png_voidp argument)
{
png_image_read_control *display = png_voidcast(png_image_read_control*,
argument);
png_imagep image = display->image;
png_structrp png_ptr = image->opaque->png_ptr;
int passes;
switch (png_ptr->interlaced)
{
case PNG_INTERLACE_NONE:
passes = 1;
break;
case PNG_INTERLACE_ADAM7:
passes = PNG_INTERLACE_ADAM7_PASSES;
break;
default:
png_error(png_ptr, "unknown interlace type");
}
{
png_uint_32 height = image->height;
png_uint_32 width = image->width;
ptrdiff_t step_row = display->row_bytes;
unsigned int channels =
(image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1;
int pass;
for (pass = 0; pass < passes; ++pass)
{
unsigned int startx, stepx, stepy;
png_uint_32 y;
if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
{
if (PNG_PASS_COLS(width, pass) == 0)
continue;
startx = PNG_PASS_START_COL(pass) * channels;
stepx = PNG_PASS_COL_OFFSET(pass) * channels;
y = PNG_PASS_START_ROW(pass);
stepy = PNG_PASS_ROW_OFFSET(pass);
}
else
{
y = 0;
startx = 0;
stepx = channels;
stepy = 1;
}
for (; y<height; y += stepy)
{
png_bytep inrow = png_voidcast(png_bytep, display->local_row);
png_bytep outrow;
png_const_bytep end_row;
png_read_row(png_ptr, inrow, NULL);
outrow = png_voidcast(png_bytep, display->first_row);
outrow += y * step_row;
end_row = outrow + width * channels;
outrow += startx;
for (; outrow < end_row; outrow += stepx)
{
png_byte alpha = inrow[channels];
if (alpha > 0)
{
unsigned int c;
for (c=0; c<channels; ++c)
{
png_uint_32 component = inrow[c];
if (alpha < 255)
{
component *= 257*255;
component += (255-alpha)*png_sRGB_table[outrow[c]];
component = PNG_sRGB_FROM_LINEAR(component);
}
outrow[c] = (png_byte)component;
}
}
inrow += channels+1;
}
}
}
}
return 1;
}
static int
png_image_read_background(png_voidp argument)
{
png_image_read_control *display = png_voidcast(png_image_read_control*,
argument);
png_imagep image = display->image;
png_structrp png_ptr = image->opaque->png_ptr;
png_inforp info_ptr = image->opaque->info_ptr;
png_uint_32 height = image->height;
png_uint_32 width = image->width;
int pass, passes;
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
png_error(png_ptr, "lost rgb to gray");
if ((png_ptr->transformations & PNG_COMPOSE) != 0)
png_error(png_ptr, "unexpected compose");
if (png_get_channels(png_ptr, info_ptr) != 2)
png_error(png_ptr, "lost/gained channels");
if ((image->format & PNG_FORMAT_FLAG_LINEAR) == 0 &&
(image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
png_error(png_ptr, "unexpected 8-bit transformation");
switch (png_ptr->interlaced)
{
case PNG_INTERLACE_NONE:
passes = 1;
break;
case PNG_INTERLACE_ADAM7:
passes = PNG_INTERLACE_ADAM7_PASSES;
break;
default:
png_error(png_ptr, "unknown interlace type");
}
switch (info_ptr->bit_depth)
{
case 8:
{
png_bytep first_row = png_voidcast(png_bytep, display->first_row);
ptrdiff_t step_row = display->row_bytes;
for (pass = 0; pass < passes; ++pass)
{
png_bytep row = png_voidcast(png_bytep,
display->first_row);
unsigned int startx, stepx, stepy;
png_uint_32 y;
if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
{
if (PNG_PASS_COLS(width, pass) == 0)
continue;
startx = PNG_PASS_START_COL(pass);
stepx = PNG_PASS_COL_OFFSET(pass);
y = PNG_PASS_START_ROW(pass);
stepy = PNG_PASS_ROW_OFFSET(pass);
}
else
{
y = 0;
startx = 0;
stepx = stepy = 1;
}
if (display->background == NULL)
{
for (; y<height; y += stepy)
{
png_bytep inrow = png_voidcast(png_bytep,
display->local_row);
png_bytep outrow = first_row + y * step_row;
png_const_bytep end_row = outrow + width;
png_read_row(png_ptr, inrow, NULL);
outrow += startx;
for (; outrow < end_row; outrow += stepx)
{
png_byte alpha = inrow[1];
if (alpha > 0)
{
png_uint_32 component = inrow[0];
if (alpha < 255)
{
component = png_sRGB_table[component] * alpha;
component += png_sRGB_table[outrow[0]] *
(255-alpha);
component = PNG_sRGB_FROM_LINEAR(component);
}
outrow[0] = (png_byte)component;
}
inrow += 2;
}
}
}
else
{
png_byte background8 = display->background->green;
png_uint_16 background = png_sRGB_table[background8];
for (; y<height; y += stepy)
{
png_bytep inrow = png_voidcast(png_bytep,
display->local_row);
png_bytep outrow = first_row + y * step_row;
png_const_bytep end_row = outrow + width;
png_read_row(png_ptr, inrow, NULL);
outrow += startx;
for (; outrow < end_row; outrow += stepx)
{
png_byte alpha = inrow[1];
if (alpha > 0)
{
png_uint_32 component = inrow[0];
if (alpha < 255)
{
component = png_sRGB_table[component] * alpha;
component += background * (255-alpha);
component = PNG_sRGB_FROM_LINEAR(component);
}
outrow[0] = (png_byte)component;
}
else
outrow[0] = background8;
inrow += 2;
}
row += display->row_bytes;
}
}
}
}
break;
case 16:
{
png_uint_16p first_row = png_voidcast(png_uint_16p,
display->first_row);
ptrdiff_t step_row = display->row_bytes / 2;
int preserve_alpha = (image->format & PNG_FORMAT_FLAG_ALPHA) != 0;
unsigned int outchannels = 1+preserve_alpha;
int swap_alpha = 0;
# ifdef PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
if (preserve_alpha != 0 &&
(image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
swap_alpha = 1;
# endif
for (pass = 0; pass < passes; ++pass)
{
unsigned int startx, stepx, stepy;
png_uint_32 y;
if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
{
if (PNG_PASS_COLS(width, pass) == 0)
continue;
startx = PNG_PASS_START_COL(pass) * outchannels;
stepx = PNG_PASS_COL_OFFSET(pass) * outchannels;
y = PNG_PASS_START_ROW(pass);
stepy = PNG_PASS_ROW_OFFSET(pass);
}
else
{
y = 0;
startx = 0;
stepx = outchannels;
stepy = 1;
}
for (; y<height; y += stepy)
{
png_const_uint_16p inrow;
png_uint_16p outrow = first_row + y*step_row;
png_uint_16p end_row = outrow + width * outchannels;
png_read_row(png_ptr, png_voidcast(png_bytep,
display->local_row), NULL);
inrow = png_voidcast(png_const_uint_16p, display->local_row);
outrow += startx;
for (; outrow < end_row; outrow += stepx)
{
png_uint_32 component = inrow[0];
png_uint_16 alpha = inrow[1];
if (alpha > 0)
{
if (alpha < 65535)
{
component *= alpha;
component += 32767;
component /= 65535;
}
}
else
component = 0;
outrow[swap_alpha] = (png_uint_16)component;
if (preserve_alpha != 0)
outrow[1 ^ swap_alpha] = alpha;
inrow += 2;
}
}
}
}
break;
#ifdef __GNUC__
default:
png_error(png_ptr, "unexpected bit depth");
#endif
}
return 1;
}
static int
png_image_read_direct(png_voidp argument)
{
png_image_read_control *display = png_voidcast(png_image_read_control*,
argument);
png_imagep image = display->image;
png_structrp png_ptr = image->opaque->png_ptr;
png_inforp info_ptr = image->opaque->info_ptr;
png_uint_32 format = image->format;
int linear = (format & PNG_FORMAT_FLAG_LINEAR) != 0;
int do_local_compose = 0;
int do_local_background = 0;
int passes = 0;
png_set_expand(png_ptr);
{
png_uint_32 base_format = png_image_format(png_ptr) &
~PNG_FORMAT_FLAG_COLORMAP ;
png_uint_32 change = format ^ base_format;
png_fixed_point output_gamma;
int mode;
if ((change & PNG_FORMAT_FLAG_COLOR) != 0)
{
if ((format & PNG_FORMAT_FLAG_COLOR) != 0)
png_set_gray_to_rgb(png_ptr);
else
{
if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
do_local_background = 1;
png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE,
PNG_RGB_TO_GRAY_DEFAULT, PNG_RGB_TO_GRAY_DEFAULT);
}
change &= ~PNG_FORMAT_FLAG_COLOR;
}
{
png_fixed_point input_gamma_default;
if ((base_format & PNG_FORMAT_FLAG_LINEAR) != 0 &&
(image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0)
input_gamma_default = PNG_GAMMA_LINEAR;
else
input_gamma_default = PNG_DEFAULT_sRGB;
png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, input_gamma_default);
}
if (linear != 0)
{
if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
mode = PNG_ALPHA_STANDARD;
else
mode = PNG_ALPHA_PNG;
output_gamma = PNG_GAMMA_LINEAR;
}
else
{
mode = PNG_ALPHA_PNG;
output_gamma = PNG_DEFAULT_sRGB;
}
if (do_local_background != 0)
{
png_fixed_point gtest;
if (png_muldiv(>est, output_gamma, png_ptr->colorspace.gamma,
PNG_FP_1) != 0 && png_gamma_significant(gtest) == 0)
do_local_background = 0;
else if (mode == PNG_ALPHA_STANDARD)
{
do_local_background = 2;
mode = PNG_ALPHA_PNG;
}
}
if ((change & PNG_FORMAT_FLAG_LINEAR) != 0)
{
if (linear != 0 )
png_set_expand_16(png_ptr);
else
png_set_scale_16(png_ptr);
change &= ~PNG_FORMAT_FLAG_LINEAR;
}
if ((change & PNG_FORMAT_FLAG_ALPHA) != 0)
{
if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
{
if (do_local_background != 0)
do_local_background = 2;
else if (linear != 0)
png_set_strip_alpha(png_ptr);
else if (display->background != NULL)
{
png_color_16 c;
c.index = 0;
c.red = display->background->red;
c.green = display->background->green;
c.blue = display->background->blue;
c.gray = display->background->green;
png_set_background_fixed(png_ptr, &c,
PNG_BACKGROUND_GAMMA_SCREEN, 0,
0);
}
else
{
do_local_compose = 1;
mode = PNG_ALPHA_OPTIMIZED;
}
}
else
{
png_uint_32 filler;
int where;
if (linear != 0)
filler = 65535;
else
filler = 255;
# ifdef PNG_FORMAT_AFIRST_SUPPORTED
if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
{
where = PNG_FILLER_BEFORE;
change &= ~PNG_FORMAT_FLAG_AFIRST;
}
else
# endif
where = PNG_FILLER_AFTER;
png_set_add_alpha(png_ptr, filler, where);
}
change &= ~PNG_FORMAT_FLAG_ALPHA;
}
png_set_alpha_mode_fixed(png_ptr, mode, output_gamma);
# ifdef PNG_FORMAT_BGR_SUPPORTED
if ((change & PNG_FORMAT_FLAG_BGR) != 0)
{
if ((format & PNG_FORMAT_FLAG_COLOR) != 0)
png_set_bgr(png_ptr);
else
format &= ~PNG_FORMAT_FLAG_BGR;
change &= ~PNG_FORMAT_FLAG_BGR;
}
# endif
# ifdef PNG_FORMAT_AFIRST_SUPPORTED
if ((change & PNG_FORMAT_FLAG_AFIRST) != 0)
{
if ((format & PNG_FORMAT_FLAG_ALPHA) != 0)
{
if (do_local_background != 2)
png_set_swap_alpha(png_ptr);
}
else
format &= ~PNG_FORMAT_FLAG_AFIRST;
change &= ~PNG_FORMAT_FLAG_AFIRST;
}
# endif
if (linear != 0)
{
PNG_CONST png_uint_16 le = 0x0001;
if ((*(png_const_bytep) & le) != 0)
png_set_swap(png_ptr);
}
if (change != 0)
png_error(png_ptr, "png_read_image: unsupported transformation");
}
PNG_SKIP_CHUNKS(png_ptr);
if (do_local_compose == 0 && do_local_background != 2)
passes = png_set_interlace_handling(png_ptr);
png_read_update_info(png_ptr, info_ptr);
{
png_uint_32 info_format = 0;
if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
info_format |= PNG_FORMAT_FLAG_COLOR;
if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
{
if (do_local_compose == 0)
{
if (do_local_background != 2 ||
(format & PNG_FORMAT_FLAG_ALPHA) != 0)
info_format |= PNG_FORMAT_FLAG_ALPHA;
}
}
else if (do_local_compose != 0)
png_error(png_ptr, "png_image_read: alpha channel lost");
if (info_ptr->bit_depth == 16)
info_format |= PNG_FORMAT_FLAG_LINEAR;
# ifdef PNG_FORMAT_BGR_SUPPORTED
if ((png_ptr->transformations & PNG_BGR) != 0)
info_format |= PNG_FORMAT_FLAG_BGR;
# endif
# ifdef PNG_FORMAT_AFIRST_SUPPORTED
if (do_local_background == 2)
{
if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
info_format |= PNG_FORMAT_FLAG_AFIRST;
}
if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0 ||
((png_ptr->transformations & PNG_ADD_ALPHA) != 0 &&
(png_ptr->flags & PNG_FLAG_FILLER_AFTER) == 0))
{
if (do_local_background == 2)
png_error(png_ptr, "unexpected alpha swap transformation");
info_format |= PNG_FORMAT_FLAG_AFIRST;
}
# endif
if (info_format != format)
png_error(png_ptr, "png_read_image: invalid transformations");
}
{
png_voidp first_row = display->buffer;
ptrdiff_t row_bytes = display->row_stride;
if (linear != 0)
row_bytes *= 2;
if (row_bytes < 0)
{
char *ptr = png_voidcast(char*, first_row);
ptr += (image->height-1) * (-row_bytes);
first_row = png_voidcast(png_voidp, ptr);
}
display->first_row = first_row;
display->row_bytes = row_bytes;
}
if (do_local_compose != 0)
{
int result;
png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
display->local_row = row;
result = png_safe_execute(image, png_image_read_composite, display);
display->local_row = NULL;
png_free(png_ptr, row);
return result;
}
else if (do_local_background == 2)
{
int result;
png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
display->local_row = row;
result = png_safe_execute(image, png_image_read_background, display);
display->local_row = NULL;
png_free(png_ptr, row);
return result;
}
else
{
png_alloc_size_t row_bytes = display->row_bytes;
while (--passes >= 0)
{
png_uint_32 y = image->height;
png_bytep row = png_voidcast(png_bytep, display->first_row);
while (y-- > 0)
{
png_read_row(png_ptr, row, NULL);
row += row_bytes;
}
}
return 1;
}
}
int PNGAPI
png_image_finish_read(png_imagep image, png_const_colorp background,
void *buffer, png_int_32 row_stride, void *colormap)
{
if (image != NULL && image->version == PNG_IMAGE_VERSION)
{
png_uint_32 check;
if (row_stride == 0)
row_stride = PNG_IMAGE_ROW_STRIDE(*image);
if (row_stride < 0)
check = -row_stride;
else
check = row_stride;
if (image->opaque != NULL && buffer != NULL &&
check >= PNG_IMAGE_ROW_STRIDE(*image))
{
if ((image->format & PNG_FORMAT_FLAG_COLORMAP) == 0 ||
(image->colormap_entries > 0 && colormap != NULL))
{
int result;
png_image_read_control display;
memset(&display, 0, (sizeof display));
display.image = image;
display.buffer = buffer;
display.row_stride = row_stride;
display.colormap = colormap;
display.background = background;
display.local_row = NULL;
if ((image->format & PNG_FORMAT_FLAG_COLORMAP) != 0)
result =
png_safe_execute(image, png_image_read_colormap, &display) &&
png_safe_execute(image, png_image_read_colormapped, &display);
else
result =
png_safe_execute(image, png_image_read_direct, &display);
png_image_free(image);
return result;
}
else
return png_image_error(image,
"png_image_finish_read[color-map]: no color-map");
}
else
return png_image_error(image,
"png_image_finish_read: invalid argument");
}
else if (image != NULL)
return png_image_error(image,
"png_image_finish_read: damaged PNG_IMAGE_VERSION");
return 0;
}
#endif
#endif