| |
| /* pngtrans.c - transforms the data in a row (used by both readers and writers) |
| * |
| * libpng 1.0.1 |
| * For conditions of distribution and use, see copyright notice in png.h |
| * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. |
| * Copyright (c) 1996, 1997 Andreas Dilger |
| * Copyright (c) 1998, Glenn Randers-Pehrson |
| * March 9, 1998 |
| */ |
| |
| #define PNG_INTERNAL |
| #include "png.h" |
| |
| #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) |
| /* turn on bgr to rgb mapping */ |
| void |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 avoiding problems with some compilers |
| * which don't like bytes as parameters. |
| */ |
| void |
| 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 */ |
| if (png_ptr->color_type == PNG_COLOR_TYPE_RGB && png_ptr->bit_depth == 8) |
| { |
| png_ptr->usr_channels = 4; |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ |
| defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) |
| void |
| 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 |
| 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 |
| png_set_invert_mono(png_structp png_ptr) |
| { |
| png_debug(1, "in png_set_invert_mono\n"); |
| png_ptr->transformations |= PNG_INVERT_MONO; |
| } |
| |
| /* invert monocrome grayscale data */ |
| void |
| 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; |
| png_uint_32 i; |
| |
| for (i = 0, rp = row; i < row_info->rowbytes; i++, rp++) |
| { |
| *rp = (png_byte)(~(*rp)); |
| } |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) |
| /* swaps byte order on 16 bit depth images */ |
| void |
| 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; |
| png_byte t; |
| png_uint_32 i; |
| |
| for (i = 0, rp = row; |
| i < row_info->width * row_info->channels; |
| i++, rp += 2) |
| { |
| 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 |
| 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 |
| 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) |
| */ |
| 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) |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| |
| for (i = 1, sp = row + 4, dp = row + 3; i < row_info->width; i++) |
| { |
| *dp++ = *sp++; |
| *dp++ = *sp++; |
| *dp++ = *sp++; |
| sp++; |
| } |
| } |
| /* This converts from XRGB or ARGB to RGB */ |
| else |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| |
| for (i = 0, sp = row, dp = row; i < row_info->width; i++) |
| { |
| sp++; |
| *dp++ = *sp++; |
| *dp++ = *sp++; |
| *dp++ = *sp++; |
| } |
| } |
| row_info->pixel_depth = 24; |
| row_info->rowbytes = row_info->width * 3; |
| } |
| else /* if (row_info->bit_depth == 16) */ |
| { |
| if (flags & PNG_FLAG_FILLER_AFTER) |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| |
| /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */ |
| for (i = 1, sp = row + 8, dp = row + 6; i < row_info->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 |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| |
| /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */ |
| for (i = 0, sp = row + 2, dp = row; i < row_info->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++; |
| } |
| } |
| row_info->pixel_depth = 48; |
| row_info->rowbytes = row_info->width * 6; |
| } |
| row_info->channels = 3; |
| } |
| /* |
| 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) |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| |
| for (i = 1, sp = row + 2, dp = row + 1; i < row_info->width; i++) |
| { |
| *dp++ = *sp++; |
| sp++; |
| } |
| } |
| /* This converts from XG or AG to G */ |
| else |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| |
| for (i = 0, sp = row, dp = row; i < row_info->width; i++) |
| { |
| sp++; |
| *dp++ = *sp++; |
| } |
| } |
| row_info->pixel_depth = 8; |
| row_info->rowbytes = row_info->width; |
| } |
| else /* if (row_info->bit_depth == 16) */ |
| { |
| if (flags & PNG_FLAG_FILLER_AFTER) |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| |
| /* This converts from GGXX or GGAA to GG */ |
| for (i = 1, sp = row + 4, dp = row + 2; i < row_info->width; i++) |
| { |
| *dp++ = *sp++; |
| *dp++ = *sp++; |
| sp += 2; |
| } |
| } |
| else |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| |
| /* This converts from XXGG or AAGG to GG */ |
| for (i = 0, sp = row, dp = row; i < row_info->width; i++) |
| { |
| sp += 2; |
| *dp++ = *sp++; |
| *dp++ = *sp++; |
| } |
| } |
| row_info->pixel_depth = 16; |
| row_info->rowbytes = row_info->width * 2; |
| } |
| row_info->channels = 1; |
| } |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) |
| /* swaps red and blue bytes within a pixel */ |
| void |
| 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)) |
| { |
| if (row_info->bit_depth == 8) |
| { |
| if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
| { |
| png_bytep rp; |
| png_byte save; |
| png_uint_32 i; |
| |
| for (i = 0, rp = row; i < row_info->width; i++, rp += 3) |
| { |
| save = *rp; |
| *rp = *(rp + 2); |
| *(rp + 2) = save; |
| } |
| } |
| else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
| { |
| png_bytep rp; |
| png_byte save; |
| png_uint_32 i; |
| |
| for (i = 0, rp = row; i < row_info->width; i++, rp += 4) |
| { |
| 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_byte save[2]; |
| png_uint_32 i; |
| |
| for (i = 0, rp = row; i < row_info->width; i++, rp += 6) |
| { |
| save[0] = *rp; |
| save[1] = *(rp + 1); |
| *rp = *(rp + 4); |
| *(rp + 1) = *(rp + 5); |
| *(rp + 4) = save[0]; |
| *(rp + 5) = save[1]; |
| } |
| } |
| else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
| { |
| png_bytep rp; |
| png_byte save[2]; |
| png_uint_32 i; |
| |
| for (i = 0, rp = row; i < row_info->width; i++, rp += 8) |
| { |
| save[0] = *rp; |
| save[1] = *(rp + 1); |
| *rp = *(rp + 4); |
| *(rp + 1) = *(rp + 5); |
| *(rp + 4) = save[0]; |
| *(rp + 5) = save[1]; |
| } |
| } |
| } |
| } |
| } |
| #endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */ |
| |
