diff options
Diffstat (limited to 'libpng/pngread.c')
| -rw-r--r-- | libpng/pngread.c | 1398 |
1 files changed, 1398 insertions, 0 deletions
diff --git a/libpng/pngread.c b/libpng/pngread.c new file mode 100644 index 0000000..c47df62 --- /dev/null +++ b/libpng/pngread.c @@ -0,0 +1,1398 @@ + +/* pngread.c - read a PNG file + * + * libpng 1.2.1 - December 12, 2001 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1998-2001 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This file contains routines that an application calls directly to + * read a PNG file or stream. + */ + +#define PNG_INTERNAL +#include "png.h" + +/* Create a PNG structure for reading, and allocate any memory needed. */ +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) +{ + +#ifdef PNG_USER_MEM_SUPPORTED + return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn, + warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL)); +} + +/* Alternate create PNG structure for reading, and allocate any memory needed. */ +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) +{ +#endif /* PNG_USER_MEM_SUPPORTED */ + + png_structp png_ptr; + +#ifdef PNG_SETJMP_SUPPORTED +#ifdef USE_FAR_KEYWORD + jmp_buf jmpbuf; +#endif +#endif + + int i; + + png_debug(1, "in png_create_read_struct\n"); +#ifdef PNG_USER_MEM_SUPPORTED + if ((png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG, + (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr)) == NULL) +#else + if ((png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG)) == NULL) +#endif + return (NULL); + +#ifdef PNG_ASSEMBLER_CODE_SUPPORTED + png_init_mmx_flags(png_ptr); /* 1.2.0 addition */ +#endif + +#ifdef PNG_SETJMP_SUPPORTED +#ifdef USE_FAR_KEYWORD + if (setjmp(jmpbuf)) +#else + if (setjmp(png_ptr->jmpbuf)) +#endif + { + png_free(png_ptr, png_ptr->zbuf); + png_ptr->zbuf=NULL; + png_destroy_struct(png_ptr); + return (NULL); + } +#ifdef USE_FAR_KEYWORD + png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf)); +#endif +#endif + +#ifdef PNG_USER_MEM_SUPPORTED + png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn); +#endif + + png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn); + + i=0; + do + { + if(user_png_ver[i] != png_libpng_ver[i]) + png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; + } while (png_libpng_ver[i++]); + + if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) + { + /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so + * we must recompile any applications that use any older library version. + * For versions after libpng 1.0, we will be compatible, so we need + * only check the first digit. + */ + if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] || + (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) || + (user_png_ver[0] == '0' && user_png_ver[2] < '9')) + { +#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE) + char msg[80]; + if (user_png_ver) + { + sprintf(msg, "Application was compiled with png.h from libpng-%.20s", + user_png_ver); + png_warning(png_ptr, msg); + } + sprintf(msg, "Application is running with png.c from libpng-%.20s", + png_libpng_ver); + png_warning(png_ptr, msg); +#endif +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + png_ptr->flags=0; +#endif + png_error(png_ptr, + "Incompatible libpng version in application and library"); + } + } + + /* initialize zbuf - compression buffer */ + png_ptr->zbuf_size = PNG_ZBUF_SIZE; + png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, + (png_uint_32)png_ptr->zbuf_size); + png_ptr->zstream.zalloc = png_zalloc; + png_ptr->zstream.zfree = png_zfree; + png_ptr->zstream.opaque = (voidpf)png_ptr; + + switch (inflateInit(&png_ptr->zstream)) + { + case Z_OK: /* Do nothing */ break; + case Z_MEM_ERROR: + case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); break; + case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error"); break; + default: png_error(png_ptr, "Unknown zlib error"); + } + + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + + png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL); + + return (png_ptr); +} + +/* Initialize PNG structure for reading, and allocate any memory needed. + This interface is deprecated in favour of the png_create_read_struct(), + and it will eventually disappear. */ +#undef png_read_init +void PNGAPI +png_read_init(png_structp png_ptr) +{ + /* We only come here via pre-1.0.7-compiled applications */ + png_read_init_2(png_ptr, "1.0.6 or earlier", 0, 0); +} + +#undef png_read_init_2 +void PNGAPI +png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver, + png_size_t png_struct_size, png_size_t png_info_size) +{ + /* We only come here via pre-1.0.12-compiled applications */ +#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE) + if(sizeof(png_struct) > png_struct_size || sizeof(png_info) > png_info_size) + { + char msg[80]; + png_ptr->warning_fn=NULL; + if (user_png_ver) + { + sprintf(msg, "Application was compiled with png.h from libpng-%.20s", + user_png_ver); + png_warning(png_ptr, msg); + } + sprintf(msg, "Application is running with png.c from libpng-%.20s", + png_libpng_ver); + png_warning(png_ptr, msg); + } +#endif + if(sizeof(png_struct) > png_struct_size) + { + png_ptr->error_fn=NULL; +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + png_ptr->flags=0; +#endif + png_error(png_ptr, + "The png struct allocated by the application for reading is too small."); + } + if(sizeof(png_info) > png_info_size) + { + png_ptr->error_fn=NULL; +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + png_ptr->flags=0; +#endif + png_error(png_ptr, + "The info struct allocated by application for reading is too small."); + } + png_read_init_3(&png_ptr, user_png_ver, png_struct_size); +} + +void PNGAPI +png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver, + png_size_t png_struct_size) +{ +#ifdef PNG_SETJMP_SUPPORTED + jmp_buf tmp_jmp; /* to save current jump buffer */ +#endif + + int i=0; + + png_structp png_ptr=*ptr_ptr; + + do + { + if(user_png_ver[i] != png_libpng_ver[i]) + { +#ifdef PNG_LEGACY_SUPPORTED + png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; +#else + png_ptr->warning_fn=NULL; + png_warning(png_ptr, + "Application uses deprecated png_read_init() and should be recompiled."); + break; +#endif + } + } while (png_libpng_ver[i++]); + + png_debug(1, "in png_read_init_3\n"); + +#ifdef PNG_SETJMP_SUPPORTED + /* save jump buffer and error functions */ + png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf)); +#endif + + if(sizeof(png_struct) > png_struct_size) + { + png_destroy_struct(png_ptr); + *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG); + png_ptr = *ptr_ptr; + } + + /* reset all variables to 0 */ + png_memset(png_ptr, 0, sizeof (png_struct)); + +#ifdef PNG_SETJMP_SUPPORTED + /* restore jump buffer */ + png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf)); +#endif + + /* initialize zbuf - compression buffer */ + png_ptr->zbuf_size = PNG_ZBUF_SIZE; + png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, + (png_uint_32)png_ptr->zbuf_size); + png_ptr->zstream.zalloc = png_zalloc; + png_ptr->zstream.zfree = png_zfree; + png_ptr->zstream.opaque = (voidpf)png_ptr; + + switch (inflateInit(&png_ptr->zstream)) + { + case Z_OK: /* Do nothing */ break; + case Z_MEM_ERROR: + case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory"); break; + case Z_VERSION_ERROR: png_error(png_ptr, "zlib version"); break; + default: png_error(png_ptr, "Unknown zlib error"); + } + + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + + png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL); +} + +/* Read the information before the actual image data. This has been + * changed in v0.90 to allow reading a file that already has the magic + * bytes read from the stream. You can tell libpng how many bytes have + * been read from the beginning of the stream (up to the maximum of 8) + * via png_set_sig_bytes(), and we will only check the remaining bytes + * here. The application can then have access to the signature bytes we + * read if it is determined that this isn't a valid PNG file. + */ +void PNGAPI +png_read_info(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_read_info\n"); + /* save jump buffer and error functions */ + /* If we haven't checked all of the PNG signature bytes, do so now. */ + if (png_ptr->sig_bytes < 8) + { + png_size_t num_checked = png_ptr->sig_bytes, + num_to_check = 8 - num_checked; + + png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); + png_ptr->sig_bytes = 8; + + if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) + { + if (num_checked < 4 && + png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) + png_error(png_ptr, "Not a PNG file"); + else + png_error(png_ptr, "PNG file corrupted by ASCII conversion"); + } + if (num_checked < 3) + png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; + } + + for(;;) + { +#ifdef PNG_USE_LOCAL_ARRAYS + PNG_IHDR; + PNG_IDAT; + PNG_IEND; + PNG_PLTE; +#if defined(PNG_READ_bKGD_SUPPORTED) + PNG_bKGD; +#endif +#if defined(PNG_READ_cHRM_SUPPORTED) + PNG_cHRM; +#endif +#if defined(PNG_READ_gAMA_SUPPORTED) + PNG_gAMA; +#endif +#if defined(PNG_READ_hIST_SUPPORTED) + PNG_hIST; +#endif +#if defined(PNG_READ_iCCP_SUPPORTED) + PNG_iCCP; +#endif +#if defined(PNG_READ_iTXt_SUPPORTED) + PNG_iTXt; +#endif +#if defined(PNG_READ_oFFs_SUPPORTED) + PNG_oFFs; +#endif +#if defined(PNG_READ_pCAL_SUPPORTED) + PNG_pCAL; +#endif +#if defined(PNG_READ_pHYs_SUPPORTED) + PNG_pHYs; +#endif +#if defined(PNG_READ_sBIT_SUPPORTED) + PNG_sBIT; +#endif +#if defined(PNG_READ_sCAL_SUPPORTED) + PNG_sCAL; +#endif +#if defined(PNG_READ_sPLT_SUPPORTED) + PNG_sPLT; +#endif +#if defined(PNG_READ_sRGB_SUPPORTED) + PNG_sRGB; +#endif +#if defined(PNG_READ_tEXt_SUPPORTED) + PNG_tEXt; +#endif +#if defined(PNG_READ_tIME_SUPPORTED) + PNG_tIME; +#endif +#if defined(PNG_READ_tRNS_SUPPORTED) + PNG_tRNS; +#endif +#if defined(PNG_READ_zTXt_SUPPORTED) + PNG_zTXt; +#endif +#endif /* PNG_GLOBAL_ARRAYS */ + png_byte chunk_length[4]; + png_uint_32 length; + + png_read_data(png_ptr, chunk_length, 4); + length = png_get_uint_32(chunk_length); + + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + + png_debug2(0, "Reading %s chunk, length=%lu.\n", png_ptr->chunk_name, + length); + + /* This should be a binary subdivision search or a hash for + * matching the chunk name rather than a linear search. + */ + if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) + png_handle_IHDR(png_ptr, info_ptr, length); + else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) + png_handle_IEND(png_ptr, info_ptr, length); +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name)) + { + if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + png_ptr->mode |= PNG_HAVE_IDAT; + png_handle_unknown(png_ptr, info_ptr, length); + if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + png_ptr->mode |= PNG_HAVE_PLTE; + else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before IDAT"); + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + png_error(png_ptr, "Missing PLTE before IDAT"); + break; + } + } +#endif + else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + png_handle_PLTE(png_ptr, info_ptr, length); + else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before IDAT"); + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + png_error(png_ptr, "Missing PLTE before IDAT"); + + png_ptr->idat_size = length; + png_ptr->mode |= PNG_HAVE_IDAT; + break; + } +#if defined(PNG_READ_bKGD_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) + png_handle_bKGD(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_cHRM_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) + png_handle_cHRM(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_gAMA_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) + png_handle_gAMA(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_hIST_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) + png_handle_hIST(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_oFFs_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) + png_handle_oFFs(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_pCAL_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) + png_handle_pCAL(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_sCAL_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4)) + png_handle_sCAL(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_pHYs_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) + png_handle_pHYs(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_sBIT_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) + png_handle_sBIT(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_sRGB_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) + png_handle_sRGB(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_iCCP_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4)) + png_handle_iCCP(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_sPLT_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4)) + png_handle_sPLT(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_tEXt_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) + png_handle_tEXt(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_tIME_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) + png_handle_tIME(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_tRNS_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) + png_handle_tRNS(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_zTXt_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) + png_handle_zTXt(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_iTXt_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4)) + png_handle_iTXt(png_ptr, info_ptr, length); +#endif + else + png_handle_unknown(png_ptr, info_ptr, length); + } +} + +/* optional call to update the users info_ptr structure */ +void PNGAPI +png_read_update_info(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_read_update_info\n"); + /* save jump buffer and error functions */ + if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) + png_read_start_row(png_ptr); + else + png_warning(png_ptr, + "Ignoring extra png_read_update_info() call; row buffer not reallocated"); + png_read_transform_info(png_ptr, info_ptr); +} + +/* Initialize palette, background, etc, after transformations + * are set, but before any reading takes place. This allows + * the user to obtain a gamma-corrected palette, for example. + * If the user doesn't call this, we will do it ourselves. + */ +void PNGAPI +png_start_read_image(png_structp png_ptr) +{ + png_debug(1, "in png_start_read_image\n"); + /* save jump buffer and error functions */ + if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) + png_read_start_row(png_ptr); +} + +void PNGAPI +png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) +{ +#ifdef PNG_USE_LOCAL_ARRAYS + PNG_IDAT; + const int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; + const int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; +#endif + int ret; + png_debug2(1, "in png_read_row (row %lu, pass %d)\n", + png_ptr->row_number, png_ptr->pass); + /* save jump buffer and error functions */ + if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) + png_read_start_row(png_ptr); + if (png_ptr->row_number == 0 && png_ptr->pass == 0) + { + /* check for transforms that have been set but were defined out */ +#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED) + if (png_ptr->transformations & PNG_INVERT_MONO) + 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) + 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) + 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) + 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) + 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) + 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) + png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined."); +#endif + } + +#if defined(PNG_READ_INTERLACING_SUPPORTED) + /* if interlaced and we do not need a new row, combine row and return */ + if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) + { + switch (png_ptr->pass) + { + case 0: + if (png_ptr->row_number & 0x07) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + 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, + png_pass_dsp_mask[png_ptr->pass]); + 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, + png_pass_dsp_mask[png_ptr->pass]); + 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, + png_pass_dsp_mask[png_ptr->pass]); + 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, + png_pass_dsp_mask[png_ptr->pass]); + 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, + png_pass_dsp_mask[png_ptr->pass]); + png_read_finish_row(png_ptr); + return; + } + break; + case 6: + if (!(png_ptr->row_number & 1)) + { + png_read_finish_row(png_ptr); + return; + } + break; + } + } +#endif + + if (!(png_ptr->mode & PNG_HAVE_IDAT)) + png_error(png_ptr, "Invalid attempt to read row data"); + + png_ptr->zstream.next_out = png_ptr->row_buf; + png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; + do + { + if (!(png_ptr->zstream.avail_in)) + { + while (!png_ptr->idat_size) + { + png_byte chunk_length[4]; + + png_crc_finish(png_ptr, 0); + + png_read_data(png_ptr, chunk_length, 4); + png_ptr->idat_size = png_get_uint_32(chunk_length); + + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + png_error(png_ptr, "Not enough image data"); + } + png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_in = png_ptr->zbuf; + if (png_ptr->zbuf_size > png_ptr->idat_size) + png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; + png_crc_read(png_ptr, png_ptr->zbuf, + (png_size_t)png_ptr->zstream.avail_in); + png_ptr->idat_size -= png_ptr->zstream.avail_in; + } + ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); + if (ret == Z_STREAM_END) + { + if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in || + png_ptr->idat_size) + png_error(png_ptr, "Extra compressed data"); + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + break; + } + if (ret != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : + "Decompression error"); + + } while (png_ptr->zstream.avail_out); + + png_ptr->row_info.color_type = png_ptr->color_type; + png_ptr->row_info.width = png_ptr->iwidth; + png_ptr->row_info.channels = png_ptr->channels; + png_ptr->row_info.bit_depth = png_ptr->bit_depth; + png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; + png_ptr->row_info.rowbytes = ((png_ptr->row_info.width * + (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3); + + if(png_ptr->row_buf[0]) + png_read_filter_row(png_ptr, &(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->prev_row + 1, + (int)(png_ptr->row_buf[0])); + + png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf, + png_ptr->rowbytes + 1); + +#if defined(PNG_MNG_FEATURES_SUPPORTED) + if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && + (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) + { + /* Intrapixel differencing */ + png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1); + } +#endif + + if (png_ptr->transformations) + png_do_read_transformations(png_ptr); + +#if defined(PNG_READ_INTERLACING_SUPPORTED) + /* blow up interlaced rows to full size */ + if (png_ptr->interlaced && + (png_ptr->transformations & PNG_INTERLACE)) + { + if (png_ptr->pass < 6) +/* old interface (pre-1.0.9): + png_do_read_interlace(&(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); + */ + png_do_read_interlace(png_ptr); + + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + if (row != NULL) + png_combine_row(png_ptr, row, + png_pass_mask[png_ptr->pass]); + } + else +#endif + { + if (row != NULL) + png_combine_row(png_ptr, row, 0xff); + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 0xff); + } + 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); +} + +/* Read one or more rows of image data. If the image is interlaced, + * and png_set_interlace_handling() has been called, the rows need to + * contain the contents of the rows from the previous pass. If the + * image has alpha or transparency, and png_handle_alpha()[*] has been + * called, the rows contents must be initialized to the contents of the + * screen. + * + * "row" holds the actual image, and pixels are placed in it + * as they arrive. If the image is displayed after each pass, it will + * appear to "sparkle" in. "display_row" can be used to display a + * "chunky" progressive image, with finer detail added as it becomes + * available. If you do not want this "chunky" display, you may pass + * NULL for display_row. If you do not want the sparkle display, and + * you have not called png_handle_alpha(), you may pass NULL for rows. + * If you have called png_handle_alpha(), and the image has either an + * alpha channel or a transparency chunk, you must provide a buffer for + * rows. In this case, you do not have to provide a display_row buffer + * also, but you may. If the image is not interlaced, or if you have + * not called png_set_interlace_handling(), the display_row buffer will + * be ignored, so pass NULL to it. + * + * [*] png_handle_alpha() does not exist yet, as of libpng version 1.2.1 + */ + +void PNGAPI +png_read_rows(png_structp 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\n"); + /* save jump buffer and error functions */ + 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, png_bytep_NULL); + rp++; + } + else if(dp != NULL) + for (i = 0; i < num_rows; i++) + { + png_bytep dptr = *dp; + png_read_row(png_ptr, png_bytep_NULL, dptr); + dp++; + } +} + +/* Read the entire image. If the image has an alpha channel or a tRNS + * chunk, and you have called png_handle_alpha()[*], you will need to + * initialize the image to the current image that PNG will be overlaying. + * We set the num_rows again here, in case it was incorrectly set in + * png_read_start_row() by a call to png_read_update_info() or + * png_start_read_image() if png_set_interlace_handling() wasn't called + * prior to either of these functions like it should have been. You can + * only call this function once. If you desire to have an image for + * each pass of a interlaced image, use png_read_rows() instead. + * + * [*] png_handle_alpha() does not exist yet, as of libpng version 1.2.1 + */ +void PNGAPI +png_read_image(png_structp png_ptr, png_bytepp image) +{ + png_uint_32 i,image_height; + int pass, j; + png_bytepp rp; + + png_debug(1, "in png_read_image\n"); + /* save jump buffer and error functions */ + +#ifdef PNG_READ_INTERLACING_SUPPORTED + 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; + png_ptr->num_rows = image_height; /* Make sure this is set correctly */ + + for (j = 0; j < pass; j++) + { + rp = image; + for (i = 0; i < image_height; i++) + { + png_read_row(png_ptr, *rp, png_bytep_NULL); + rp++; + } + } +} + +/* Read the end of the PNG file. Will not read past the end of the + * file, will verify the end is accurate, and will read any comments + * or time information at the end of the file, if info is not NULL. + */ +void PNGAPI +png_read_end(png_structp png_ptr, png_infop info_ptr) +{ + png_byte chunk_length[4]; + png_uint_32 length; + + png_debug(1, "in png_read_end\n"); + /* save jump buffer and error functions */ + png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */ + + do + { +#ifdef PNG_USE_LOCAL_ARRAYS + PNG_IHDR; + PNG_IDAT; + PNG_IEND; + PNG_PLTE; +#if defined(PNG_READ_bKGD_SUPPORTED) + PNG_bKGD; +#endif +#if defined(PNG_READ_cHRM_SUPPORTED) + PNG_cHRM; +#endif +#if defined(PNG_READ_gAMA_SUPPORTED) + PNG_gAMA; +#endif +#if defined(PNG_READ_hIST_SUPPORTED) + PNG_hIST; +#endif +#if defined(PNG_READ_iCCP_SUPPORTED) + PNG_iCCP; +#endif +#if defined(PNG_READ_iTXt_SUPPORTED) + PNG_iTXt; +#endif +#if defined(PNG_READ_oFFs_SUPPORTED) + PNG_oFFs; +#endif +#if defined(PNG_READ_pCAL_SUPPORTED) + PNG_pCAL; +#endif +#if defined(PNG_READ_pHYs_SUPPORTED) + PNG_pHYs; +#endif +#if defined(PNG_READ_sBIT_SUPPORTED) + PNG_sBIT; +#endif +#if defined(PNG_READ_sCAL_SUPPORTED) + PNG_sCAL; +#endif +#if defined(PNG_READ_sPLT_SUPPORTED) + PNG_sPLT; +#endif +#if defined(PNG_READ_sRGB_SUPPORTED) + PNG_sRGB; +#endif +#if defined(PNG_READ_tEXt_SUPPORTED) + PNG_tEXt; +#endif +#if defined(PNG_READ_tIME_SUPPORTED) + PNG_tIME; +#endif +#if defined(PNG_READ_tRNS_SUPPORTED) + PNG_tRNS; +#endif +#if defined(PNG_READ_zTXt_SUPPORTED) + PNG_zTXt; +#endif +#endif /* PNG_GLOBAL_ARRAYS */ + + png_read_data(png_ptr, chunk_length, 4); + length = png_get_uint_32(chunk_length); + + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + + png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name); + + if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) + png_handle_IHDR(png_ptr, info_ptr, length); + else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) + png_handle_IEND(png_ptr, info_ptr, length); +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name)) + { + if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT) + png_error(png_ptr, "Too many IDAT's found"); + } + else + png_ptr->mode |= PNG_AFTER_IDAT; + png_handle_unknown(png_ptr, info_ptr, length); + if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + png_ptr->mode |= PNG_HAVE_PLTE; + } +#endif + else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + /* Zero length IDATs are legal after the last IDAT has been + * read, but not after other chunks have been read. + */ + if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT) + png_error(png_ptr, "Too many IDAT's found"); + png_crc_finish(png_ptr, length); + } + else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + png_handle_PLTE(png_ptr, info_ptr, length); +#if defined(PNG_READ_bKGD_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) + png_handle_bKGD(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_cHRM_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) + png_handle_cHRM(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_gAMA_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) + png_handle_gAMA(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_hIST_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) + png_handle_hIST(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_oFFs_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) + png_handle_oFFs(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_pCAL_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) + png_handle_pCAL(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_sCAL_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4)) + png_handle_sCAL(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_pHYs_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) + png_handle_pHYs(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_sBIT_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) + png_handle_sBIT(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_sRGB_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) + png_handle_sRGB(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_iCCP_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4)) + png_handle_iCCP(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_sPLT_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4)) + png_handle_sPLT(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_tEXt_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) + png_handle_tEXt(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_tIME_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) + png_handle_tIME(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_tRNS_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) + png_handle_tRNS(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_zTXt_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) + png_handle_zTXt(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_iTXt_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4)) + png_handle_iTXt(png_ptr, info_ptr, length); +#endif + else + png_handle_unknown(png_ptr, info_ptr, length); + } while (!(png_ptr->mode & PNG_HAVE_IEND)); +} + +/* free all memory used by the read */ +void PNGAPI +png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, + png_infopp end_info_ptr_ptr) +{ + png_structp png_ptr = NULL; + png_infop info_ptr = NULL, end_info_ptr = NULL; +#ifdef PNG_USER_MEM_SUPPORTED + png_free_ptr free_fn = NULL; + png_voidp mem_ptr = NULL; +#endif + + png_debug(1, "in png_destroy_read_struct\n"); + /* save jump buffer and error functions */ + if (png_ptr_ptr != NULL) + png_ptr = *png_ptr_ptr; + + if (info_ptr_ptr != NULL) + info_ptr = *info_ptr_ptr; + + if (end_info_ptr_ptr != NULL) + end_info_ptr = *end_info_ptr_ptr; + +#ifdef PNG_USER_MEM_SUPPORTED + free_fn = png_ptr->free_fn; + mem_ptr = png_ptr->mem_ptr; +#endif + + png_read_destroy(png_ptr, info_ptr, end_info_ptr); + + if (info_ptr != NULL) + { +#if defined(PNG_TEXT_SUPPORTED) + png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1); +#endif + +#ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn, + (png_voidp)mem_ptr); +#else + png_destroy_struct((png_voidp)info_ptr); +#endif + *info_ptr_ptr = NULL; + } + + if (end_info_ptr != NULL) + { +#if defined(PNG_READ_TEXT_SUPPORTED) + png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1); +#endif +#ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn, + (png_voidp)mem_ptr); +#else + png_destroy_struct((png_voidp)end_info_ptr); +#endif + *end_info_ptr_ptr = NULL; + } + + if (png_ptr != NULL) + { +#ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn, + (png_voidp)mem_ptr); +#else + png_destroy_struct((png_voidp)png_ptr); +#endif + *png_ptr_ptr = NULL; + } +} + +/* free all memory used by the read (old method) */ +void /* PRIVATE */ +png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr) +{ +#ifdef PNG_SETJMP_SUPPORTED + jmp_buf tmp_jmp; +#endif + png_error_ptr error_fn; + png_error_ptr warning_fn; + png_voidp error_ptr; +#ifdef PNG_USER_MEM_SUPPORTED + png_free_ptr free_fn; +#endif + + png_debug(1, "in png_read_destroy\n"); + /* save jump buffer and error functions */ + if (info_ptr != NULL) + png_info_destroy(png_ptr, info_ptr); + + if (end_info_ptr != NULL) + png_info_destroy(png_ptr, end_info_ptr); + + png_free(png_ptr, png_ptr->zbuf); + png_free(png_ptr, png_ptr->big_row_buf); + png_free(png_ptr, png_ptr->prev_row); +#if defined(PNG_READ_DITHER_SUPPORTED) + png_free(png_ptr, png_ptr->palette_lookup); + png_free(png_ptr, png_ptr->dither_index); +#endif +#if defined(PNG_READ_GAMMA_SUPPORTED) + png_free(png_ptr, png_ptr->gamma_table); +#endif +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + png_free(png_ptr, png_ptr->gamma_from_1); + png_free(png_ptr, png_ptr->gamma_to_1); +#endif +#ifdef PNG_FREE_ME_SUPPORTED + if (png_ptr->free_me & PNG_FREE_PLTE) + png_zfree(png_ptr, png_ptr->palette); + png_ptr->free_me &= ~PNG_FREE_PLTE; +#else + if (png_ptr->flags & PNG_FLAG_FREE_PLTE) + png_zfree(png_ptr, png_ptr->palette); + png_ptr->flags &= ~PNG_FLAG_FREE_PLTE; +#endif +#if defined(PNG_tRNS_SUPPORTED) || \ + defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) +#ifdef PNG_FREE_ME_SUPPORTED + if (png_ptr->free_me & PNG_FREE_TRNS) + png_free(png_ptr, png_ptr->trans); + png_ptr->free_me &= ~PNG_FREE_TRNS; +#else + if (png_ptr->flags & PNG_FLAG_FREE_TRNS) + png_free(png_ptr, png_ptr->trans); + png_ptr->flags &= ~PNG_FLAG_FREE_TRNS; +#endif +#endif +#if defined(PNG_READ_hIST_SUPPORTED) +#ifdef PNG_FREE_ME_SUPPORTED + if (png_ptr->free_me & PNG_FREE_HIST) + png_free(png_ptr, png_ptr->hist); + png_ptr->free_me &= ~PNG_FREE_HIST; +#else + if (png_ptr->flags & PNG_FLAG_FREE_HIST) + png_free(png_ptr, png_ptr->hist); + png_ptr->flags &= ~PNG_FLAG_FREE_HIST; +#endif +#endif +#if defined(PNG_READ_GAMMA_SUPPORTED) + if (png_ptr->gamma_16_table != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_table[i]); + } + png_free(png_ptr, png_ptr->gamma_16_table); + } +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr->gamma_16_from_1 != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_from_1[i]); + } + png_free(png_ptr, png_ptr->gamma_16_from_1); + } + if (png_ptr->gamma_16_to_1 != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_to_1[i]); + } + png_free(png_ptr, png_ptr->gamma_16_to_1); + } +#endif +#endif +#if defined(PNG_TIME_RFC1123_SUPPORTED) + png_free(png_ptr, png_ptr->time_buffer); +#endif + + inflateEnd(&png_ptr->zstream); +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + png_free(png_ptr, png_ptr->save_buffer); +#endif + + /* Save the important info out of the png_struct, in case it is + * being used again. + */ +#ifdef PNG_SETJMP_SUPPORTED + png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf)); +#endif + + error_fn = png_ptr->error_fn; + warning_fn = png_ptr->warning_fn; + error_ptr = png_ptr->error_ptr; +#ifdef PNG_USER_MEM_SUPPORTED + free_fn = png_ptr->free_fn; +#endif + + png_memset(png_ptr, 0, sizeof (png_struct)); + + png_ptr->error_fn = error_fn; + png_ptr->warning_fn = warning_fn; + png_ptr->error_ptr = error_ptr; +#ifdef PNG_USER_MEM_SUPPORTED + png_ptr->free_fn = free_fn; +#endif + +#ifdef PNG_SETJMP_SUPPORTED + png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf)); +#endif + +} + +void PNGAPI +png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn) +{ + png_ptr->read_row_fn = read_row_fn; +} + +#if defined(PNG_INFO_IMAGE_SUPPORTED) +void PNGAPI +png_read_png(png_structp png_ptr, png_infop info_ptr, + int transforms, + voidp params) +{ + int row; + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) + /* invert the alpha channel from opacity to transparency */ + if (transforms & PNG_TRANSFORM_INVERT_ALPHA) + png_set_invert_alpha(png_ptr); +#endif + + /* The call to png_read_info() gives us all of the information from the + * PNG file before the first IDAT (image data chunk). + */ + png_read_info(png_ptr, info_ptr); + + /* -------------- image transformations start here ------------------- */ + +#if defined(PNG_READ_16_TO_8_SUPPORTED) + /* tell libpng to strip 16 bit/color files down to 8 bits/color */ + if (transforms & PNG_TRANSFORM_STRIP_16) + png_set_strip_16(png_ptr); +#endif + +#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) + /* Strip alpha bytes from the input data without combining with the + * background (not recommended). + */ + if (transforms & PNG_TRANSFORM_STRIP_ALPHA) + png_set_strip_alpha(png_ptr); +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED) + /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single + * byte into separate bytes (useful for paletted and grayscale images). + */ + if (transforms & PNG_TRANSFORM_PACKING) + png_set_packing(png_ptr); +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED) + /* Change the order of packed pixels to least significant bit first + * (not useful if you are using png_set_packing). */ + if (transforms & PNG_TRANSFORM_PACKSWAP) + png_set_packswap(png_ptr); +#endif + +#if defined(PNG_READ_EXPAND_SUPPORTED) + /* Expand paletted colors into true RGB triplets + * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel + * Expand paletted or RGB images with transparency to full alpha + * channels so the data will be available as RGBA quartets. + */ + if (transforms & PNG_TRANSFORM_EXPAND) + if ((png_ptr->bit_depth < 8) || + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) || + (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))) + png_set_expand(png_ptr); +#endif + + /* We don't handle background color or gamma transformation or dithering. */ + +#if defined(PNG_READ_INVERT_SUPPORTED) + /* invert monochrome files to have 0 as white and 1 as black */ + if (transforms & PNG_TRANSFORM_INVERT_MONO) + png_set_invert_mono(png_ptr); +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) + /* If you want to shift the pixel values from the range [0,255] or + * [0,65535] to the original [0,7] or [0,31], or whatever range the + * colors were originally in: + */ + if ((transforms & PNG_TRANSFORM_SHIFT) + && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT)) + { + png_color_8p sig_bit; + + png_get_sBIT(png_ptr, info_ptr, &sig_bit); + png_set_shift(png_ptr, sig_bit); + } +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) + /* flip the RGB pixels to BGR (or RGBA to BGRA) */ + if (transforms & PNG_TRANSFORM_BGR) + png_set_bgr(png_ptr); +#endif + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) + /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */ + if (transforms & PNG_TRANSFORM_SWAP_ALPHA) + png_set_swap_alpha(png_ptr); +#endif + +#if defined(PNG_READ_SWAP_SUPPORTED) + /* swap bytes of 16 bit files to least significant byte first */ + if (transforms & PNG_TRANSFORM_SWAP_ENDIAN) + png_set_swap(png_ptr); +#endif + + /* We don't handle adding filler bytes */ + + /* Optional call to gamma correct and add the background to the palette + * and update info structure. REQUIRED if you are expecting libpng to + * update the palette for you (i.e., you selected such a transform above). + */ + png_read_update_info(png_ptr, info_ptr); + + /* -------------- image transformations end here ------------------- */ + +#ifdef PNG_FREE_ME_SUPPORTED + png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); +#endif + if(info_ptr->row_pointers == NULL) + { + info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr, + info_ptr->height * sizeof(png_bytep)); +#ifdef PNG_FREE_ME_SUPPORTED + info_ptr->free_me |= PNG_FREE_ROWS; +#endif + for (row = 0; row < (int)info_ptr->height; row++) + { + info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr, + png_get_rowbytes(png_ptr, info_ptr)); + } + } + + png_read_image(png_ptr, info_ptr->row_pointers); + info_ptr->valid |= PNG_INFO_IDAT; + + /* read rest of file, and get additional chunks in info_ptr - REQUIRED */ + png_read_end(png_ptr, info_ptr); + + if(transforms == 0 || params == NULL) + /* quiet compiler warnings */ return; + +} +#endif |