/* pngtrans.c - transforms the data in a row (used by both readers and writers) * * libpng 1.0.8beta3 - July 11, 2000 * For conditions of distribution and use, see copyright notice in png.h * Copyright (c) 1998, 1999, 2000 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.) */ #define PNG_INTERNAL #include "png.h" #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) /* turn on BGR-to-RGB mapping */ void PNGAPI png_set_bgr(png_structp png_ptr) { png_debug(1, "in png_set_bgr\n"); png_ptr->transformations |= PNG_BGR; } #endif #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) /* turn on 16 bit byte swapping */ void PNGAPI png_set_swap(png_structp png_ptr) { png_debug(1, "in png_set_swap\n"); if (png_ptr->bit_depth == 16) png_ptr->transformations |= PNG_SWAP_BYTES; } #endif #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) /* turn on pixel packing */ void PNGAPI png_set_packing(png_structp png_ptr) { png_debug(1, "in png_set_packing\n"); if (png_ptr->bit_depth < 8) { png_ptr->transformations |= PNG_PACK; png_ptr->usr_bit_depth = 8; } } #endif #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) /* turn on packed pixel swapping */ void PNGAPI png_set_packswap(png_structp png_ptr) { png_debug(1, "in png_set_packswap\n"); if (png_ptr->bit_depth < 8) png_ptr->transformations |= PNG_PACKSWAP; } #endif #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) void PNGAPI png_set_shift(png_structp png_ptr, png_color_8p true_bits) { png_debug(1, "in png_set_shift\n"); png_ptr->transformations |= PNG_SHIFT; png_ptr->shift = *true_bits; } #endif #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ defined(PNG_WRITE_INTERLACING_SUPPORTED) int PNGAPI png_set_interlace_handling(png_structp png_ptr) { png_debug(1, "in png_set_interlace handling\n"); if (png_ptr->interlaced) { png_ptr->transformations |= PNG_INTERLACE; return (7); } return (1); } #endif #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) /* Add a filler byte on read, or remove a filler or alpha byte on write. * The filler type has changed in v0.95 to allow future 2-byte fillers * for 48-bit input data, as well as to avoid problems with some compilers * that don't like bytes as parameters. */ void PNGAPI png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc) { png_debug(1, "in png_set_filler\n"); png_ptr->transformations |= PNG_FILLER; png_ptr->filler = (png_byte)filler; if (filler_loc == PNG_FILLER_AFTER) png_ptr->flags |= PNG_FLAG_FILLER_AFTER; else png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER; /* This should probably go in the "do_filler" routine. * I attempted to do that in libpng-1.0.1a but that caused problems * so I restored it in libpng-1.0.2a */ if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) { png_ptr->usr_channels = 4; } /* Also I added this in libpng-1.0.2a (what happens when we expand * a less-than-8-bit grayscale to GA? */ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8) { png_ptr->usr_channels = 2; } } #endif #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) void PNGAPI png_set_swap_alpha(png_structp png_ptr) { png_debug(1, "in png_set_swap_alpha\n"); png_ptr->transformations |= PNG_SWAP_ALPHA; } #endif #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) void PNGAPI png_set_invert_alpha(png_structp png_ptr) { png_debug(1, "in png_set_invert_alpha\n"); png_ptr->transformations |= PNG_INVERT_ALPHA; } #endif #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) void PNGAPI png_set_invert_mono(png_structp png_ptr) { png_debug(1, "in png_set_invert_mono\n"); png_ptr->transformations |= PNG_INVERT_MONO; } /* invert monochrome grayscale data */ void /* PRIVATE */ png_do_invert(png_row_infop row_info, png_bytep row) { png_debug(1, "in png_do_invert\n"); if (row_info->bit_depth == 1 && #if defined(PNG_USELESS_TESTS_SUPPORTED) row != NULL && row_info != NULL && #endif row_info->color_type == PNG_COLOR_TYPE_GRAY) { png_bytep rp = row; png_uint_32 i; png_uint_32 istop = row_info->rowbytes; for (i = 0; i < istop; i++) { *rp = (png_byte)(~(*rp)); rp++; } } } #endif #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) /* swaps byte order on 16 bit depth images */ void /* PRIVATE */ png_do_swap(png_row_infop row_info, png_bytep row) { png_debug(1, "in png_do_swap\n"); if ( #if defined(PNG_USELESS_TESTS_SUPPORTED) row != NULL && row_info != NULL && #endif row_info->bit_depth == 16) { png_bytep rp = row; png_uint_32 i; png_uint_32 istop= row_info->width * row_info->channels; for (i = 0; i < istop; i++, rp += 2) { png_byte t = *rp; *rp = *(rp + 1); *(rp + 1) = t; } } } #endif #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) static png_byte onebppswaptable[256] = { 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0, 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8, 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4, 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC, 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2, 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA, 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6, 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE, 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1, 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9, 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5, 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD, 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3, 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB, 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7, 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF }; static png_byte twobppswaptable[256] = { 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0, 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0, 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4, 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4, 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8, 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8, 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC, 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC, 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1, 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1, 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5, 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5, 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9, 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9, 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD, 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD, 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2, 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2, 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6, 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6, 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA, 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA, 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE, 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE, 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3, 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3, 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7, 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7, 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB, 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB, 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF, 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF }; static png_byte fourbppswaptable[256] = { 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0, 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71, 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1, 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72, 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2, 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73, 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3, 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74, 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4, 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75, 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5, 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76, 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6, 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77, 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7, 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78, 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8, 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79, 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9, 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A, 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA, 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B, 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB, 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C, 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC, 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D, 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD, 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E, 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE, 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F, 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF }; /* swaps pixel packing order within bytes */ void /* PRIVATE */ png_do_packswap(png_row_infop row_info, png_bytep row) { png_debug(1, "in png_do_packswap\n"); if ( #if defined(PNG_USELESS_TESTS_SUPPORTED) row != NULL && row_info != NULL && #endif row_info->bit_depth < 8) { png_bytep rp, end, table; end = row + row_info->rowbytes; if (row_info->bit_depth == 1) table = onebppswaptable; else if (row_info->bit_depth == 2) table = twobppswaptable; else if (row_info->bit_depth == 4) table = fourbppswaptable; else return; for (rp = row; rp < end; rp++) *rp = table[*rp]; } } #endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */ #if defined(PNG_WRITE_FILLER_SUPPORTED) || \ defined(PNG_READ_STRIP_ALPHA_SUPPORTED) /* remove filler or alpha byte(s) */ void /* PRIVATE */ png_do_strip_filler(png_row_infop row_info, png_bytep row, png_uint_32 flags) { png_debug(1, "in png_do_strip_filler\n"); #if defined(PNG_USELESS_TESTS_SUPPORTED) if (row != NULL && row_info != NULL) #endif { /* if (row_info->color_type == PNG_COLOR_TYPE_RGB || row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) */ png_bytep sp=row; png_bytep dp=row; png_uint_32 row_width=row_info->width; png_uint_32 i; if (row_info->channels == 4) { if (row_info->bit_depth == 8) { /* This converts from RGBX or RGBA to RGB */ if (flags & PNG_FLAG_FILLER_AFTER) { dp+=3; sp+=4; for (i = 1; i < row_width; i++) { *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp++; sp++; } } /* This converts from XRGB or ARGB to RGB */ else { for (i = 0; i < row_width; i++) { sp++; *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp++; } } row_info->pixel_depth = 24; row_info->rowbytes = row_width * 3; } else /* if (row_info->bit_depth == 16) */ { if (flags & PNG_FLAG_FILLER_AFTER) { /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */ sp += 8; dp += 6; for (i = 1; i < row_width; i++) { /* This could be (although memcpy is probably slower): png_memcpy(dp, sp, 6); sp += 8; dp += 6; */ *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp++; sp += 2; } } else { /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */ for (i = 0; i < row_width; i++) { /* This could be (although memcpy is probably slower): png_memcpy(dp, sp, 6); sp += 8; dp += 6; */ sp+=2; *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp++; } } row_info->pixel_depth = 48; row_info->rowbytes = row_width * 6; } row_info->channels = 3; row_info->color_type &= ~PNG_COLOR_MASK_ALPHA; } /* else if (row_info->color_type == PNG_COLOR_TYPE_GRAY || row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) */ else if (row_info->channels == 2) { if (row_info->bit_depth == 8) { /* This converts from GX or GA to G */ if (flags & PNG_FLAG_FILLER_AFTER) { for (i = 0; i < row_width; i++) { *dp++ = *sp++; sp++; } } /* This converts from XG or AG to G */ else { for (i = 0; i < row_width; i++) { sp++; *dp++ = *sp++; } } row_info->pixel_depth = 8; row_info->rowbytes = row_width; } else /* if (row_info->bit_depth == 16) */ { if (flags & PNG_FLAG_FILLER_AFTER) { /* This converts from GGXX or GGAA to GG */ sp += 4; dp += 2; for (i = 1; i < row_width; i++) { *dp++ = *sp++; *dp++ = *sp++; sp += 2; } } else { /* This converts from XXGG or AAGG to GG */ for (i = 0; i < row_width; i++) { sp += 2; *dp++ = *sp++; *dp++ = *sp++; } } row_info->pixel_depth = 16; row_info->rowbytes = row_width * 2; } row_info->channels = 1; row_info->color_type &= ~PNG_COLOR_MASK_ALPHA; } } } #endif #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) /* swaps red and blue bytes within a pixel */ void /* PRIVATE */ png_do_bgr(png_row_infop row_info, png_bytep row) { png_debug(1, "in png_do_bgr\n"); if ( #if defined(PNG_USELESS_TESTS_SUPPORTED) row != NULL && row_info != NULL && #endif (row_info->color_type & PNG_COLOR_MASK_COLOR)) { png_uint_32 row_width = row_info->width; if (row_info->bit_depth == 8) { if (row_info->color_type == PNG_COLOR_TYPE_RGB) { png_bytep rp; png_uint_32 i; for (i = 0, rp = row; i < row_width; i++, rp += 3) { png_byte save = *rp; *rp = *(rp + 2); *(rp + 2) = save; } } else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { png_bytep rp; png_uint_32 i; for (i = 0, rp = row; i < row_width; i++, rp += 4) { png_byte save = *rp; *rp = *(rp + 2); *(rp + 2) = save; } } } else if (row_info->bit_depth == 16) { if (row_info->color_type == PNG_COLOR_TYPE_RGB) { png_bytep rp; png_uint_32 i; for (i = 0, rp = row; i < row_width; i++, rp += 6) { png_byte save = *rp; *rp = *(rp + 4); *(rp + 4) = save; save = *(rp + 1); *(rp + 1) = *(rp + 5); *(rp + 5) = save; } } else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { png_bytep rp; png_uint_32 i; for (i = 0, rp = row; i < row_width; i++, rp += 8) { png_byte save = *rp; *rp = *(rp + 4); *(rp + 4) = save; save = *(rp + 1); *(rp + 1) = *(rp + 5); *(rp + 5) = save; } } } } } #endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */ #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \ defined(PNG_LEGACY_SUPPORTED) void PNGAPI png_set_user_transform_info(png_structp png_ptr, png_voidp user_transform_ptr, int user_transform_depth, int user_transform_channels) { png_debug(1, "in png_set_user_transform_info\n"); #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) png_ptr->user_transform_ptr = user_transform_ptr; png_ptr->user_transform_depth = (png_byte)user_transform_depth; png_ptr->user_transform_channels = (png_byte)user_transform_channels; #else if(user_transform_ptr || user_transform_depth || user_transform_channels) png_warning(png_ptr, "This version of libpng does not support user transform info"); #endif } #endif /* This function returns a pointer to the user_transform_ptr associated with * the user transform functions. The application should free any memory * associated with this pointer before png_write_destroy and png_read_destroy * are called. */ png_voidp PNGAPI png_get_user_transform_ptr(png_structp png_ptr) { #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) return ((png_voidp)png_ptr->user_transform_ptr); #else if(png_ptr) return (NULL); return (NULL); #endif }