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Diffstat (limited to 'Build/source/libs/libpng/libpng-src/contrib/libtests/makepng.c')
-rw-r--r-- | Build/source/libs/libpng/libpng-src/contrib/libtests/makepng.c | 1941 |
1 files changed, 1941 insertions, 0 deletions
diff --git a/Build/source/libs/libpng/libpng-src/contrib/libtests/makepng.c b/Build/source/libs/libpng/libpng-src/contrib/libtests/makepng.c new file mode 100644 index 00000000000..60d96d198dc --- /dev/null +++ b/Build/source/libs/libpng/libpng-src/contrib/libtests/makepng.c @@ -0,0 +1,1941 @@ +/* makepng.c */ +#define _ISOC99_SOURCE +/* Copyright: */ +#define COPYRIGHT "\251 2013,2015 John Cunningham Bowler" +/* + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * Make a test PNG image. The arguments are as follows: + * + * makepng [--sRGB|--linear|--1.8] [--tRNS] [--nofilters] \ + * color-type bit-depth [file-name] + * + * The color-type may be numeric (and must match the numbers used by the PNG + * specification) or one of the format names listed below. The bit-depth is the + * component bit depth, or the pixel bit-depth for a color-mapped image. + * + * Without any options no color-space information is written, with the options + * an sRGB or the appropriate gAMA chunk is written. "1.8" refers to the + * display system used on older Apple computers to correct for high ambient + * light levels in the viewing environment; it applies a transform of + * approximately value^(1/1.45) to the color values and so a gAMA chunk of 65909 + * is written (1.45/2.2). + * + * The image data is generated internally. Unless --color is given the images + * used are as follows: + * + * 1 channel: a square image with a diamond, the least luminous colors are on + * the edge of the image, the most luminous in the center. + * + * 2 channels: the color channel increases in luminosity from top to bottom, the + * alpha channel increases in opacity from left to right. + * + * 3 channels: linear combinations of, from the top-left corner clockwise, + * black, green, white, red. + * + * 4 channels: linear combinations of, from the top-left corner clockwise, + * transparent, red, green, blue. + * + * For color-mapped images a four channel color-map is used and if --tRNS is + * given the PNG file has a tRNS chunk, as follows: + * + * 1-bit: entry 0 is transparent-red, entry 1 is opaque-white + * 2-bit: entry 0: transparent-green + * entry 1: 40%-red + * entry 2: 80%-blue + * entry 3: opaque-white + * 4-bit: the 16 combinations of the 2-bit case + * 8-bit: the 256 combinations of the 4-bit case + * + * The palette always has 2^bit-depth entries and the tRNS chunk one fewer. The + * image is the 1-channel diamond, but using palette index, not luminosity. + * + * For formats other than color-mapped ones if --tRNS is specified a tRNS chunk + * is generated with all channels equal to the low bits of 0x0101. + * + * Image size is determined by the final pixel depth in bits, i.e. channels x + * bit-depth, as follows: + * + * 8 bits or less: 64x64 + * 16 bits: 256x256 + * More than 16 bits: 1024x1024 + * + * Row filtering is the libpng default but may be turned off (the 'none' filter + * is used on every row) with the --nofilters option. + * + * The images are not interlaced. + * + * If file-name is given then the PNG is written to that file, else it is + * written to stdout. Notice that stdout is not supported on systems where, by + * default, it assumes text output; this program makes no attempt to change the + * text mode of stdout! + * + * makepng --color=<color> ... + * + * If --color is given then the whole image has that color, color-mapped images + * will have exactly one palette entry and all image files with be 16x16 in + * size. The color value is 1 to 4 decimal numbers as appropriate for the color + * type. + * + * makepng --small ... + * + * If --small is given the images are no larger than required to include every + * possible pixel value for the format. + * + * For formats with pixels 8 bits or fewer in size the images consist of a + * single row with 2^pixel-depth pixels, one of every possible value. + * + * For formats with 16-bit pixels a 256x256 image is generated containing every + * possible pixel value. + * + * For larger pixel sizes a 256x256 image is generated where the first row + * consists of each pixel that has identical byte values throughout the pixel + * followed by rows where the byte values differ within the pixel. + * + * In all cases the pixel values are arranged in such a way that the SUB and UP + * filters give byte sequences for maximal zlib compression. By default (if + * --nofilters is not given) the SUB filter is used on the first row and the UP + * filter on all following rows. + * + * The --small option is meant to provide good test-case coverage, however the + * images are not easy to examine visually. Without the --small option the + * images contain identical color values; the pixel values are adjusted + * according to the gamma encoding with no gamma encoding being interpreted as + * sRGB. + * + * LICENSING + * ========= + * + * This code is copyright of the authors, see the COPYRIGHT define above. The + * code is licensed as above, using the libpng license. The code generates + * images which are solely the product of the code; the options choose which of + * the many possibilities to generate. The images that result (but not the code + * which generates them) are licensed as defined here: + * + * IMPORTANT: the COPYRIGHT #define must contain ISO-Latin-1 characters, the + * IMAGE_LICENSING #define must contain UTF-8 characters. The 'copyright' + * symbol 0xA9U (\251) in ISO-Latin-1 encoding and 0xC20xA9 (\302\251) in UTF-8. + */ +#define IMAGE_LICENSING "Dedicated to the public domain per Creative Commons "\ + "license \"CC0 1.0\"; https://creativecommons.org/publicdomain/zero/1.0/" + +#include <stddef.h> /* for offsetof */ +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <ctype.h> +#include <math.h> +#include <errno.h> +#include <assert.h> +#include <stdint.h> + +#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) +# include <config.h> +#endif + +/* Define the following to use this test against your installed libpng, rather + * than the one being built here: + */ +#ifdef PNG_FREESTANDING_TESTS +# include <png.h> +#else +# include "../../png.h" +#endif + +#include <zlib.h> + +/* Work round for GCC complaints about casting a (double) function result to + * an unsigned: + */ +static unsigned int +flooru(double d) +{ + d = floor(d); + return (unsigned int)d; +} + +static png_byte +floorb(double d) +{ + d = floor(d); + return (png_byte)d; +} + +/* This structure is used for inserting extra chunks (the --insert argument, not + * documented above.) + */ +typedef struct chunk_insert +{ + struct chunk_insert *next; + void (*insert)(png_structp, png_infop, int, png_charpp); + int nparams; + png_charp parameters[1]; +} chunk_insert; + +static unsigned int +channels_of_type(int color_type) +{ + if (color_type & PNG_COLOR_MASK_PALETTE) + return 1; + + else + { + int channels = 1; + + if (color_type & PNG_COLOR_MASK_COLOR) + channels = 3; + + if (color_type & PNG_COLOR_MASK_ALPHA) + return channels + 1; + + else + return channels; + } +} + +static unsigned int +pixel_depth_of_type(int color_type, int bit_depth) +{ + return channels_of_type(color_type) * bit_depth; +} + +static unsigned int +image_size_of_type(int color_type, int bit_depth, unsigned int *colors, + int small) +{ + if (*colors) + return 16; + + else + { + int pixel_depth = pixel_depth_of_type(color_type, bit_depth); + + if (small) + { + if (pixel_depth <= 8) /* there will be one row */ + return 1 << pixel_depth; + + else + return 256; + } + + else if (pixel_depth < 8) + return 64; + + else if (pixel_depth > 16) + return 1024; + + else + return 256; + } +} + +static void +set_color(png_colorp color, png_bytep trans, unsigned int red, + unsigned int green, unsigned int blue, unsigned int alpha, + png_const_bytep gamma_table) +{ + color->red = gamma_table[red]; + color->green = gamma_table[green]; + color->blue = gamma_table[blue]; + *trans = (png_byte)alpha; +} + +static int +generate_palette(png_colorp palette, png_bytep trans, int bit_depth, + png_const_bytep gamma_table, unsigned int *colors) +{ + /* + * 1-bit: entry 0 is transparent-red, entry 1 is opaque-white + * 2-bit: entry 0: transparent-green + * entry 1: 40%-red + * entry 2: 80%-blue + * entry 3: opaque-white + * 4-bit: the 16 combinations of the 2-bit case + * 8-bit: the 256 combinations of the 4-bit case + */ + switch (colors[0]) + { + default: + fprintf(stderr, "makepng: --colors=...: invalid count %u\n", + colors[0]); + exit(1); + + case 1: + set_color(palette+0, trans+0, colors[1], colors[1], colors[1], 255, + gamma_table); + return 1; + + case 2: + set_color(palette+0, trans+0, colors[1], colors[1], colors[1], + colors[2], gamma_table); + return 1; + + case 3: + set_color(palette+0, trans+0, colors[1], colors[2], colors[3], 255, + gamma_table); + return 1; + + case 4: + set_color(palette+0, trans+0, colors[1], colors[2], colors[3], + colors[4], gamma_table); + return 1; + + case 0: + if (bit_depth == 1) + { + set_color(palette+0, trans+0, 255, 0, 0, 0, gamma_table); + set_color(palette+1, trans+1, 255, 255, 255, 255, gamma_table); + return 2; + } + + else + { + unsigned int size = 1U << (bit_depth/2); /* 2, 4 or 16 */ + unsigned int x, y; + volatile unsigned int ip = 0; + + for (x=0; x<size; ++x) for (y=0; y<size; ++y) + { + ip = x + (size * y); + + /* size is at most 16, so the scaled value below fits in 16 bits + */ +# define interp(pos, c1, c2) ((pos * c1) + ((size-pos) * c2)) +# define xyinterp(x, y, c1, c2, c3, c4) (((size * size / 2) +\ + (interp(x, c1, c2) * y + (size-y) * interp(x, c3, c4))) /\ + (size*size)) + + set_color(palette+ip, trans+ip, + /* color: green, red,blue,white */ + xyinterp(x, y, 0, 255, 0, 255), + xyinterp(x, y, 255, 0, 0, 255), + xyinterp(x, y, 0, 0, 255, 255), + /* alpha: 0, 102, 204, 255) */ + xyinterp(x, y, 0, 102, 204, 255), + gamma_table); + } + + return ip+1; + } + } +} + +static void +set_value(png_bytep row, size_t rowbytes, png_uint_32 x, unsigned int bit_depth, + png_uint_32 value, png_const_bytep gamma_table, double conv) +{ + unsigned int mask = (1U << bit_depth)-1; + + x *= bit_depth; /* Maximum x is 4*1024, maximum bit_depth is 16 */ + + if (value <= mask) + { + png_uint_32 offset = x >> 3; + + if (offset < rowbytes && (bit_depth < 16 || offset+1 < rowbytes)) + { + row += offset; + + switch (bit_depth) + { + case 1: + case 2: + case 4: + /* Don't gamma correct - values get smashed */ + { + unsigned int shift = (8 - bit_depth) - (x & 0x7U); + + mask <<= shift; + value = (value << shift) & mask; + *row = (png_byte)((*row & ~mask) | value); + } + return; + + default: + fprintf(stderr, "makepng: bad bit depth (internal error)\n"); + exit(1); + + case 16: + value = flooru(65535*pow(value/65535.,conv)+.5); + *row++ = (png_byte)(value >> 8); + *row = (png_byte)value; + return; + + case 8: + *row = gamma_table[value]; + return; + } + } + + else + { + fprintf(stderr, "makepng: row buffer overflow (internal error)\n"); + exit(1); + } + } + + else + { + fprintf(stderr, "makepng: component overflow (internal error)\n"); + exit(1); + } +} + +static int /* filter mask for row */ +generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type, + int bit_depth, png_const_bytep gamma_table, double conv, + unsigned int *colors, int small) +{ + int filters = 0; /* file *MASK*, 0 means the default, not NONE */ + png_uint_32 size_max = + image_size_of_type(color_type, bit_depth, colors, small)-1; + png_uint_32 depth_max = (1U << bit_depth)-1; /* up to 65536 */ + + if (colors[0] == 0) if (small) + { + unsigned int pixel_depth = pixel_depth_of_type(color_type, bit_depth); + + /* For pixel depths less than 16 generate a single row containing all the + * possible pixel values. For 16 generate all 65536 byte pair + * combinations in a 256x256 pixel array. + */ + switch (pixel_depth) + { + case 1: + assert(y == 0 && rowbytes == 1 && size_max == 1); + row[0] = 0x6CU; /* binary: 01101100, only top 2 bits used */ + filters = PNG_FILTER_NONE; + break; + + case 2: + assert(y == 0 && rowbytes == 1 && size_max == 3); + row[0] = 0x1BU; /* binary 00011011, all bits used */ + filters = PNG_FILTER_NONE; + break; + + case 4: + assert(y == 0 && rowbytes == 8 && size_max == 15); + row[0] = 0x01U; + row[1] = 0x23U; /* SUB gives 0x22U for all following bytes */ + row[2] = 0x45U; + row[3] = 0x67U; + row[4] = 0x89U; + row[5] = 0xABU; + row[6] = 0xCDU; + row[7] = 0xEFU; + filters = PNG_FILTER_SUB; + break; + + case 8: + /* The row will have all the pixel values in order starting with + * '1', the SUB filter will change every byte into '1' (including + * the last, which generates pixel value '0'). Since the SUB filter + * has value 1 this should result in maximum compression. + */ + assert(y == 0 && rowbytes == 256 && size_max == 255); + for (;;) + { + row[size_max] = 0xFFU & (size_max+1); + if (size_max == 0) + break; + --size_max; + } + filters = PNG_FILTER_SUB; + break; + + case 16: + /* Rows are generated such that each row has a constant difference + * between the first and second byte of each pixel and so that the + * difference increases by 1 at each row. The rows start with the + * first byte value of 0 and the value increases to 255 across the + * row. + * + * The difference starts at 1, so the first row is: + * + * 0 1 1 2 2 3 3 4 ... 254 255 255 0 + * + * This means that running the SUB filter on the first row produces: + * + * [SUB==1] 0 1 0 1 0 1... + * + * Then the difference is 2 on the next row, giving: + * + * 0 2 1 3 2 4 3 5 ... 254 0 255 1 + * + * When the UP filter is run on this libpng produces: + * + * [UP ==2] 0 1 0 1 0 1... + * + * And so on for all the remain rows to the final two * rows: + * + * row 254: 0 255 1 0 2 1 3 2 4 3 ... 254 253 255 254 + * row 255: 0 0 1 1 2 2 3 3 4 4 ... 254 254 255 255 + */ + assert(rowbytes == 512 && size_max == 255); + for (;;) + { + row[2*size_max ] = 0xFFU & size_max; + row[2*size_max+1] = 0xFFU & (size_max+y+1); + if (size_max == 0) + break; + --size_max; + } + /* The first row must include PNG_FILTER_UP so that libpng knows we + * need to keep it for the following row: + */ + filters = (y == 0 ? PNG_FILTER_SUB+PNG_FILTER_UP : PNG_FILTER_UP); + break; + + case 24: + case 32: + case 48: + case 64: + /* The rows are filled by an alogorithm similar to the above, in the + * first row pixel bytes are all equal, increasing from 0 by 1 for + * each pixel. In the second row the bytes within a pixel are + * incremented 1,3,5,7,... from the previous row byte. Using an odd + * number ensures all the possible byte values are used. + */ + assert(size_max == 255 && rowbytes == 256*(pixel_depth>>3)); + pixel_depth >>= 3; /* now in bytes */ + while (rowbytes > 0) + { + const size_t pixel_index = --rowbytes/pixel_depth; + + if (y == 0) + row[rowbytes] = 0xFFU & pixel_index; + + else + { + const size_t byte_offset = + rowbytes - pixel_index * pixel_depth; + + row[rowbytes] = + 0xFFU & (pixel_index + (byte_offset * 2*y) + 1); + } + } + filters = (y == 0 ? PNG_FILTER_SUB+PNG_FILTER_UP : PNG_FILTER_UP); + break; + + default: + assert(0/*NOT REACHED*/); + } + } + + else switch (channels_of_type(color_type)) + { + /* 1 channel: a square image with a diamond, the least luminous colors are on + * the edge of the image, the most luminous in the center. + */ + case 1: + { + png_uint_32 x; + png_uint_32 base = 2*size_max - abs(2*y-size_max); + + for (x=0; x<=size_max; ++x) + { + png_uint_32 luma = base - abs(2*x-size_max); + + /* 'luma' is now in the range 0..2*size_max, we need + * 0..depth_max + */ + luma = (luma*depth_max + size_max) / (2*size_max); + set_value(row, rowbytes, x, bit_depth, luma, gamma_table, conv); + } + } + break; + + /* 2 channels: the color channel increases in luminosity from top to bottom, + * the alpha channel increases in opacity from left to right. + */ + case 2: + { + png_uint_32 alpha = (depth_max * y * 2 + size_max) / (2 * size_max); + png_uint_32 x; + + for (x=0; x<=size_max; ++x) + { + set_value(row, rowbytes, 2*x, bit_depth, + (depth_max * x * 2 + size_max) / (2 * size_max), gamma_table, + conv); + set_value(row, rowbytes, 2*x+1, bit_depth, alpha, gamma_table, + conv); + } + } + break; + + /* 3 channels: linear combinations of, from the top-left corner clockwise, + * black, green, white, red. + */ + case 3: + { + /* x0: the black->red scale (the value of the red component) at the + * start of the row (blue and green are 0). + * x1: the green->white scale (the value of the red and blue + * components at the end of the row; green is depth_max). + */ + png_uint_32 Y = (depth_max * y * 2 + size_max) / (2 * size_max); + png_uint_32 x; + + /* Interpolate x/depth_max from start to end: + * + * start end difference + * red: Y Y 0 + * green: 0 depth_max depth_max + * blue: 0 Y Y + */ + for (x=0; x<=size_max; ++x) + { + set_value(row, rowbytes, 3*x+0, bit_depth, /* red */ Y, + gamma_table, conv); + set_value(row, rowbytes, 3*x+1, bit_depth, /* green */ + (depth_max * x * 2 + size_max) / (2 * size_max), + gamma_table, conv); + set_value(row, rowbytes, 3*x+2, bit_depth, /* blue */ + (Y * x * 2 + size_max) / (2 * size_max), + gamma_table, conv); + } + } + break; + + /* 4 channels: linear combinations of, from the top-left corner clockwise, + * transparent, red, green, blue. + */ + case 4: + { + /* x0: the transparent->blue scale (the value of the blue and alpha + * components) at the start of the row (red and green are 0). + * x1: the red->green scale (the value of the red and green + * components at the end of the row; blue is 0 and alpha is + * depth_max). + */ + png_uint_32 Y = (depth_max * y * 2 + size_max) / (2 * size_max); + png_uint_32 x; + + /* Interpolate x/depth_max from start to end: + * + * start end difference + * red: 0 depth_max-Y depth_max-Y + * green: 0 Y Y + * blue: Y 0 -Y + * alpha: Y depth_max depth_max-Y + */ + for (x=0; x<=size_max; ++x) + { + set_value(row, rowbytes, 4*x+0, bit_depth, /* red */ + ((depth_max-Y) * x * 2 + size_max) / (2 * size_max), + gamma_table, conv); + set_value(row, rowbytes, 4*x+1, bit_depth, /* green */ + (Y * x * 2 + size_max) / (2 * size_max), + gamma_table, conv); + set_value(row, rowbytes, 4*x+2, bit_depth, /* blue */ + Y - (Y * x * 2 + size_max) / (2 * size_max), + gamma_table, conv); + set_value(row, rowbytes, 4*x+3, bit_depth, /* alpha */ + Y + ((depth_max-Y) * x * 2 + size_max) / (2 * size_max), + gamma_table, conv); + } + } + break; + + default: + fprintf(stderr, "makepng: internal bad channel count\n"); + exit(2); + } + + else if (color_type & PNG_COLOR_MASK_PALETTE) + { + /* Palette with fixed color: the image rows are all 0 and the image width + * is 16. + */ + memset(row, 0, rowbytes); + } + + else if (colors[0] == channels_of_type(color_type)) + switch (channels_of_type(color_type)) + { + case 1: + { + const png_uint_32 luma = colors[1]; + png_uint_32 x; + + for (x=0; x<=size_max; ++x) + set_value(row, rowbytes, x, bit_depth, luma, gamma_table, + conv); + } + break; + + case 2: + { + const png_uint_32 luma = colors[1]; + const png_uint_32 alpha = colors[2]; + png_uint_32 x; + + for (x=0; x<size_max; ++x) + { + set_value(row, rowbytes, 2*x, bit_depth, luma, gamma_table, + conv); + set_value(row, rowbytes, 2*x+1, bit_depth, alpha, gamma_table, + conv); + } + } + break; + + case 3: + { + const png_uint_32 red = colors[1]; + const png_uint_32 green = colors[2]; + const png_uint_32 blue = colors[3]; + png_uint_32 x; + + for (x=0; x<=size_max; ++x) + { + set_value(row, rowbytes, 3*x+0, bit_depth, red, gamma_table, + conv); + set_value(row, rowbytes, 3*x+1, bit_depth, green, gamma_table, + conv); + set_value(row, rowbytes, 3*x+2, bit_depth, blue, gamma_table, + conv); + } + } + break; + + case 4: + { + const png_uint_32 red = colors[1]; + const png_uint_32 green = colors[2]; + const png_uint_32 blue = colors[3]; + const png_uint_32 alpha = colors[4]; + png_uint_32 x; + + for (x=0; x<=size_max; ++x) + { + set_value(row, rowbytes, 4*x+0, bit_depth, red, gamma_table, + conv); + set_value(row, rowbytes, 4*x+1, bit_depth, green, gamma_table, + conv); + set_value(row, rowbytes, 4*x+2, bit_depth, blue, gamma_table, + conv); + set_value(row, rowbytes, 4*x+3, bit_depth, alpha, gamma_table, + conv); + } + } + break; + + default: + fprintf(stderr, "makepng: internal bad channel count\n"); + exit(2); + } + + else + { + fprintf(stderr, + "makepng: --color: count(%u) does not match channels(%u)\n", + colors[0], channels_of_type(color_type)); + exit(1); + } + + return filters; +} + + +static void PNGCBAPI +makepng_warning(png_structp png_ptr, png_const_charp message) +{ + const char **ep = png_get_error_ptr(png_ptr); + const char *name; + + if (ep != NULL && *ep != NULL) + name = *ep; + + else + name = "makepng"; + + fprintf(stderr, "%s: warning: %s\n", name, message); +} + +static void PNGCBAPI +makepng_error(png_structp png_ptr, png_const_charp message) +{ + makepng_warning(png_ptr, message); + png_longjmp(png_ptr, 1); +} + +static int /* 0 on success, else an error code */ +write_png(const char **name, FILE *fp, int color_type, int bit_depth, + volatile png_fixed_point gamma, chunk_insert * volatile insert, + unsigned int filters, unsigned int *colors, int small, int tRNS) +{ + png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, + name, makepng_error, makepng_warning); + volatile png_infop info_ptr = NULL; + volatile png_bytep row = NULL; + + if (png_ptr == NULL) + { + fprintf(stderr, "makepng: OOM allocating write structure\n"); + return 1; + } + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_structp nv_ptr = png_ptr; + png_infop nv_info = info_ptr; + + png_ptr = NULL; + info_ptr = NULL; + png_destroy_write_struct(&nv_ptr, &nv_info); + if (row != NULL) free(row); + return 1; + } + + /* Allow benign errors so that we can write PNGs with errors */ + png_set_benign_errors(png_ptr, 1/*allowed*/); + + /* Max out the text compression level in an attempt to make the license + * small. If --small then do the same for the IDAT. + */ + if (small) + png_set_compression_level(png_ptr, Z_BEST_COMPRESSION); + + png_set_text_compression_level(png_ptr, Z_BEST_COMPRESSION); + + png_init_io(png_ptr, fp); + + info_ptr = png_create_info_struct(png_ptr); + if (info_ptr == NULL) + png_error(png_ptr, "OOM allocating info structure"); + + { + const unsigned int size = + image_size_of_type(color_type, bit_depth, colors, small); + unsigned int ysize; + png_fixed_point real_gamma = 45455; /* For sRGB */ + png_byte gamma_table[256]; + double conv; + + /* Normally images are square, but with 'small' we want to simply generate + * all the pixel values, or all that we reasonably can: + */ + if (small) + { + const unsigned int pixel_depth = + pixel_depth_of_type(color_type, bit_depth); + + if (pixel_depth <= 8U) + { + assert(size == (1U<<pixel_depth)); + ysize = 1U; + } + + else + { + assert(size == 256U); + ysize = 256U; + } + } + + else + ysize = size; + + /* This function uses the libpng values used on read to carry extra + * information about the gamma: + */ + if (gamma == PNG_GAMMA_MAC_18) + gamma = 65909; + + else if (gamma > 0 && gamma < 1000) + gamma = PNG_FP_1; + + if (gamma > 0) + real_gamma = gamma; + + { + unsigned int i; + + if (real_gamma == 45455) for (i=0; i<256; ++i) + { + gamma_table[i] = (png_byte)i; + conv = 1.; + } + + else + { + /* Convert 'i' from sRGB (45455) to real_gamma, this makes + * the images look the same regardless of the gAMA chunk. + */ + conv = real_gamma; + conv /= 45455; + + gamma_table[0] = 0; + + for (i=1; i<255; ++i) + gamma_table[i] = floorb(pow(i/255.,conv) * 255 + .5); + + gamma_table[255] = 255; + } + } + + png_set_IHDR(png_ptr, info_ptr, size, ysize, bit_depth, color_type, + PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + if (color_type & PNG_COLOR_MASK_PALETTE) + { + int npalette; + png_color palette[256]; + png_byte trans[256]; + + npalette = generate_palette(palette, trans, bit_depth, gamma_table, + colors); + png_set_PLTE(png_ptr, info_ptr, palette, npalette); + + if (tRNS) + png_set_tRNS(png_ptr, info_ptr, trans, npalette-1, + NULL/*transparent color*/); + + /* Reset gamma_table to prevent the image rows being changed */ + for (npalette=0; npalette<256; ++npalette) + gamma_table[npalette] = (png_byte)npalette; + } + + else if (tRNS) + { + png_color_16 col; + + col.red = col.green = col.blue = col.gray = + 0x0101U & ((1U<<bit_depth)-1U); + col.index = 0U; + png_set_tRNS(png_ptr, info_ptr, NULL/*trans*/, 1U, &col); + } + + if (gamma == PNG_DEFAULT_sRGB) + png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_ABSOLUTE); + + else if (gamma > 0) /* Else don't set color space information */ + { + png_set_gAMA_fixed(png_ptr, info_ptr, real_gamma); + + /* Just use the sRGB values here. */ + png_set_cHRM_fixed(png_ptr, info_ptr, + /* color x y */ + /* white */ 31270, 32900, + /* red */ 64000, 33000, + /* green */ 30000, 60000, + /* blue */ 15000, 6000 + ); + } + + /* Insert extra information. */ + while (insert != NULL) + { + insert->insert(png_ptr, info_ptr, insert->nparams, insert->parameters); + insert = insert->next; + } + + /* Write the file header. */ + png_write_info(png_ptr, info_ptr); + + /* Restrict the filters */ + png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, filters); + + { +# ifdef PNG_WRITE_INTERLACING_SUPPORTED + int passes = png_set_interlace_handling(png_ptr); +# else /* !WRITE_INTERLACING */ + int passes = 1; +# endif /* !WRITE_INTERLACING */ + int pass; + png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr); + + row = malloc(rowbytes); + + if (row == NULL) + png_error(png_ptr, "OOM allocating row buffer"); + + for (pass = 0; pass < passes; ++pass) + { + unsigned int y; + + for (y=0; y<ysize; ++y) + { + unsigned int row_filters = + generate_row(row, rowbytes, y, color_type, bit_depth, + gamma_table, conv, colors, small); + + if (row_filters != 0 && filters == PNG_ALL_FILTERS) + png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, row_filters); + + png_write_row(png_ptr, row); + } + } + } + } + + /* Finish writing the file. */ + png_write_end(png_ptr, info_ptr); + + { + png_structp nv_ptr = png_ptr; + png_infop nv_info = info_ptr; + + png_ptr = NULL; + info_ptr = NULL; + png_destroy_write_struct(&nv_ptr, &nv_info); + } + free(row); + return 0; +} + + +static size_t +load_file(png_const_charp name, png_bytepp result) +{ + FILE *fp = tmpfile(); + + if (fp != NULL) + { + FILE *ip = fopen(name, "rb"); + + if (ip != NULL) + { + size_t total = 0; + int ch; + + for (;;) + { + ch = getc(ip); + if (ch == EOF) break; + putc(ch, fp); + ++total; + } + + if (ferror(ip)) + { + perror(name); + fprintf(stderr, "%s: read error\n", name); + (void)fclose(ip); + } + + else + { + (void)fclose(ip); + + if (ferror(fp)) + { + perror("temporary file"); + fprintf(stderr, "temporary file write error\n"); + } + + else + { + rewind(fp); + + if (total > 0) + { + /* Round up to a multiple of 4 here to allow an iCCP profile + * to be padded to a 4x boundary. + */ + png_bytep data = malloc((total+3)&~3); + + if (data != NULL) + { + size_t new_size = 0; + + for (;;) + { + ch = getc(fp); + if (ch == EOF) break; + data[new_size++] = (png_byte)ch; + } + + if (ferror(fp) || new_size != total) + { + perror("temporary file"); + fprintf(stderr, "temporary file read error\n"); + free(data); + } + + else + { + (void)fclose(fp); + *result = data; + return total; + } + } + + else + fprintf(stderr, "%s: out of memory loading file\n", name); + } + + else + fprintf(stderr, "%s: empty file\n", name); + } + } + } + + else + { + perror(name); + fprintf(stderr, "%s: open failed\n", name); + } + + fclose(fp); + } + + else + fprintf(stderr, "makepng: %s: could not open temporary file\n", name); + + exit(1); + return 0; +} + +static png_size_t +load_fake(png_charp param, png_bytepp profile) +{ + char *endptr = NULL; + uint64_t size = strtoull(param, &endptr, 0/*base*/); + + /* The 'fake' format is <number>*[string] */ + if (endptr != NULL && *endptr == '*') + { + size_t len = strlen(++endptr); + size_t result = (size_t)size; + + if (len == 0) len = 1; /* capture the terminating '\0' */ + + /* Now repeat that string to fill 'size' bytes. */ + if (result == size && (*profile = malloc(result)) != NULL) + { + png_bytep out = *profile; + + if (len == 1) + memset(out, *endptr, result); + + else + { + while (size >= len) + { + memcpy(out, endptr, len); + out += len; + size -= len; + } + memcpy(out, endptr, size); + } + + return result; + } + + else + { + fprintf(stderr, "%s: size exceeds system limits\n", param); + exit(1); + } + } + + return 0; +} + +static void +check_param_count(int nparams, int expect) +{ + if (nparams != expect) + { + fprintf(stderr, "bad parameter count (internal error)\n"); + exit(1); + } +} + +static void +insert_iCCP(png_structp png_ptr, png_infop info_ptr, int nparams, + png_charpp params) +{ + png_bytep profile = NULL; + png_uint_32 proflen = 0; + int result; + + check_param_count(nparams, 2); + + switch (params[1][0]) + { + case '<': + { + png_size_t filelen = load_file(params[1]+1, &profile); + if (filelen > 0xfffffffc) /* Maximum profile length */ + { + fprintf(stderr, "%s: file too long (%lu) for an ICC profile\n", + params[1]+1, (unsigned long)filelen); + exit(1); + } + + proflen = (png_uint_32)filelen; + } + break; + + case '0': case '1': case '2': case '3': case '4': + case '5': case '6': case '7': case '8': case '9': + { + png_size_t fake_len = load_fake(params[1], &profile); + + if (fake_len > 0) /* else a simple parameter */ + { + if (fake_len > 0xffffffff) /* Maximum profile length */ + { + fprintf(stderr, + "%s: fake data too long (%lu) for an ICC profile\n", + params[1], (unsigned long)fake_len); + exit(1); + } + proflen = (png_uint_32)(fake_len & ~3U); + /* Always fix up the profile length. */ + png_save_uint_32(profile, proflen); + break; + } + } + + default: + fprintf(stderr, "--insert iCCP \"%s\": unrecognized\n", params[1]); + fprintf(stderr, " use '<' to read a file: \"<filename\"\n"); + exit(1); + } + + result = 1; + + if (proflen & 3) + { + fprintf(stderr, + "makepng: --insert iCCP %s: profile length made a multiple of 4\n", + params[1]); + + /* load_file allocates extra space for this padding, the ICC spec requires + * padding with zero bytes. + */ + while (proflen & 3) + profile[proflen++] = 0; + } + + if (profile != NULL && proflen > 3) + { + png_uint_32 prof_header = png_get_uint_32(profile); + + if (prof_header != proflen) + { + fprintf(stderr, "--insert iCCP %s: profile length field wrong:\n", + params[1]); + fprintf(stderr, " actual %lu, recorded value %lu (corrected)\n", + (unsigned long)proflen, (unsigned long)prof_header); + png_save_uint_32(profile, proflen); + } + } + + if (result && profile != NULL && proflen >=4) + png_set_iCCP(png_ptr, info_ptr, params[0], PNG_COMPRESSION_TYPE_BASE, + profile, proflen); + + if (profile) + free(profile); + + if (!result) + exit(1); +} + +static void +clear_text(png_text *text, png_charp keyword) +{ + text->compression = -1; /* none */ + text->key = keyword; + text->text = NULL; + text->text_length = 0; /* libpng calculates this */ + text->itxt_length = 0; /* libpng calculates this */ + text->lang = NULL; + text->lang_key = NULL; +} + +static void +set_text(png_structp png_ptr, png_infop info_ptr, png_textp text, + png_charp param) +{ + switch (param[0]) + { + case '<': + { + png_bytep file = NULL; + + text->text_length = load_file(param+1, &file); + text->text = (png_charp)file; + } + break; + + case '0': case '1': case '2': case '3': case '4': + case '5': case '6': case '7': case '8': case '9': + { + png_bytep data = NULL; + png_size_t fake_len = load_fake(param, &data); + + if (fake_len > 0) /* else a simple parameter */ + { + text->text_length = fake_len; + text->text = (png_charp)data; + break; + } + } + + default: + text->text = param; + break; + } + + png_set_text(png_ptr, info_ptr, text, 1); + + if (text->text != param) + free(text->text); +} + +static void +insert_tEXt(png_structp png_ptr, png_infop info_ptr, int nparams, + png_charpp params) +{ + png_text text; + + check_param_count(nparams, 2); + clear_text(&text, params[0]); + set_text(png_ptr, info_ptr, &text, params[1]); +} + +static void +insert_zTXt(png_structp png_ptr, png_infop info_ptr, int nparams, + png_charpp params) +{ + png_text text; + + check_param_count(nparams, 2); + clear_text(&text, params[0]); + text.compression = 0; /* deflate */ + set_text(png_ptr, info_ptr, &text, params[1]); +} + +static void +insert_iTXt(png_structp png_ptr, png_infop info_ptr, int nparams, + png_charpp params) +{ + png_text text; + + check_param_count(nparams, 4); + clear_text(&text, params[0]); + text.compression = 2; /* iTXt + deflate */ + text.lang = params[1];/* language tag */ + text.lang_key = params[2]; /* translated keyword */ + set_text(png_ptr, info_ptr, &text, params[3]); +} + +static void +insert_hIST(png_structp png_ptr, png_infop info_ptr, int nparams, + png_charpp params) +{ + int i; + png_uint_16 freq[256]; + + /* libpng takes the count from the PLTE count; we don't check it here but we + * do set the array to 0 for unspecified entries. + */ + memset(freq, 0, sizeof freq); + for (i=0; i<nparams; ++i) + { + char *endptr = NULL; + unsigned long int l = strtoul(params[i], &endptr, 0/*base*/); + + if (params[i][0] && *endptr == 0 && l <= 65535) + freq[i] = (png_uint_16)l; + + else + { + fprintf(stderr, "hIST[%d]: %s: invalid frequency\n", i, params[i]); + exit(1); + } + } + + png_set_hIST(png_ptr, info_ptr, freq); +} + +static png_byte +bval(png_const_structrp png_ptr, png_charp param, unsigned int maxval) +{ + char *endptr = NULL; + unsigned long int l = strtoul(param, &endptr, 0/*base*/); + + if (param[0] && *endptr == 0 && l <= maxval) + return (png_byte)l; + + else + png_error(png_ptr, "sBIT: invalid sBIT value"); +} + +static void +insert_sBIT(png_structp png_ptr, png_infop info_ptr, int nparams, + png_charpp params) +{ + const int ct = png_get_color_type(png_ptr, info_ptr); + const int c = (ct & PNG_COLOR_MASK_COLOR ? 3 : 1) + + (ct & PNG_COLOR_MASK_ALPHA ? 1 : 0); + const unsigned int maxval = + ct & PNG_COLOR_MASK_PALETTE ? 8U : png_get_bit_depth(png_ptr, info_ptr); + png_color_8 sBIT; + + if (nparams != c) + png_error(png_ptr, "sBIT: incorrect parameter count"); + + if (ct & PNG_COLOR_MASK_COLOR) + { + sBIT.red = bval(png_ptr, params[0], maxval); + sBIT.green = bval(png_ptr, params[1], maxval); + sBIT.blue = bval(png_ptr, params[2], maxval); + sBIT.gray = 42; + } + + else + { + sBIT.red = sBIT.green = sBIT.blue = 42; + sBIT.gray = bval(png_ptr, params[0], maxval); + } + + if (ct & PNG_COLOR_MASK_ALPHA) + sBIT.alpha = bval(png_ptr, params[nparams-1], maxval); + + else + sBIT.alpha = 42; + + png_set_sBIT(png_ptr, info_ptr, &sBIT); +} + +#if 0 +static void +insert_sPLT(png_structp png_ptr, png_infop info_ptr, int nparams, png_charpp params) +{ + fprintf(stderr, "insert sPLT: NYI\n"); +} +#endif + +static int +find_parameters(png_const_charp what, png_charp param, png_charp *list, + int nparams) +{ + /* Parameters are separated by '\n' or ':' characters, up to nparams are + * accepted (more is an error) and the number found is returned. + */ + int i; + for (i=0; *param && i<nparams; ++i) + { + list[i] = param; + while (*++param) if (*param == '\n' || *param == ':') + { + *param++ = 0; /* Terminate last parameter */ + break; /* And start a new one. */ + } + } + + if (*param) + { + fprintf(stderr, "--insert %s: too many parameters (%s)\n", what, param); + exit(1); + } + + list[i] = NULL; /* terminates list */ + return i; /* number of parameters filled in */ +} + +static void +bad_parameter_count(png_const_charp what, int nparams) +{ + fprintf(stderr, "--insert %s: bad parameter count %d\n", what, nparams); + exit(1); +} + +static chunk_insert * +make_insert(png_const_charp what, + void (*insert)(png_structp, png_infop, int, png_charpp), + int nparams, png_charpp list) +{ + int i; + chunk_insert *cip; + + cip = malloc(offsetof(chunk_insert,parameters) + + nparams * sizeof (png_charp)); + + if (cip == NULL) + { + fprintf(stderr, "--insert %s: out of memory allocating %d parameters\n", + what, nparams); + exit(1); + } + + cip->next = NULL; + cip->insert = insert; + cip->nparams = nparams; + for (i=0; i<nparams; ++i) + cip->parameters[i] = list[i]; + + return cip; +} + +static chunk_insert * +find_insert(png_const_charp what, png_charp param) +{ + png_uint_32 chunk = 0; + png_charp parameter_list[1024]; + int i, nparams; + + /* Assemble the chunk name */ + for (i=0; i<4; ++i) + { + char ch = what[i]; + + if ((ch >= 65 && ch <= 90) || (ch >= 97 && ch <= 122)) + chunk = (chunk << 8) + what[i]; + + else + break; + } + + if (i < 4 || what[4] != 0) + { + fprintf(stderr, "makepng --insert \"%s\": invalid chunk name\n", what); + exit(1); + } + + /* Assemble the parameter list. */ + nparams = find_parameters(what, param, parameter_list, 1024); + +# define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d)) + + switch (chunk) + { + case CHUNK(105,67,67,80): /* iCCP */ + if (nparams == 2) + return make_insert(what, insert_iCCP, nparams, parameter_list); + break; + + case CHUNK(116,69,88,116): /* tEXt */ + if (nparams == 2) + return make_insert(what, insert_tEXt, nparams, parameter_list); + break; + + case CHUNK(122,84,88,116): /* zTXt */ + if (nparams == 2) + return make_insert(what, insert_zTXt, nparams, parameter_list); + break; + + case CHUNK(105,84,88,116): /* iTXt */ + if (nparams == 4) + return make_insert(what, insert_iTXt, nparams, parameter_list); + break; + + case CHUNK(104,73,83,84): /* hIST */ + if (nparams <= 256) + return make_insert(what, insert_hIST, nparams, parameter_list); + break; + + case CHUNK(115,66,73,84): /* sBIT */ + if (nparams <= 4) + return make_insert(what, insert_sBIT, nparams, parameter_list); + break; + +#if 0 + case CHUNK(115,80,76,84): /* sPLT */ + return make_insert(what, insert_sPLT, nparams, parameter_list); +#endif + + default: + fprintf(stderr, "makepng --insert \"%s\": unrecognized chunk name\n", + what); + exit(1); + } + + bad_parameter_count(what, nparams); + return NULL; +} + +/* This is necessary because libpng expects writeable strings for things like + * text chunks (maybe this should be fixed...) + */ +static png_charp +strstash(png_const_charp foo) +{ + /* The program indicates a memory allocation error by crashing, this is by + * design. + */ + if (foo != NULL) + { + png_charp bar = malloc(strlen(foo)+1); + return strcpy(bar, foo); + } + + return NULL; +} + +static png_charp +strstash_list(const png_const_charp *text) +{ + size_t foo = 0; + png_charp result, bar; + const png_const_charp *line = text; + + while (*line != NULL) + foo += strlen(*line++); + + result = bar = malloc(foo+1); + + line = text; + while (*line != NULL) + { + foo = strlen(*line); + memcpy(bar, *line++, foo); + bar += foo; + } + + *bar = 0; + return result; +} + +/* These are used to insert Copyright and Licence fields, they allow the text to + * have \n unlike the --insert option. + */ +static chunk_insert * +add_tEXt(const char *key, const png_const_charp *text) +{ + static char what[5] = { 116, 69, 88, 116, 0 }; + png_charp parameter_list[3]; + + parameter_list[0] = strstash(key); + parameter_list[1] = strstash_list(text); + parameter_list[2] = NULL; + + return make_insert(what, insert_tEXt, 2, parameter_list); +} + +static chunk_insert * +add_iTXt(const char *key, const char *language, const char *language_key, + const png_const_charp *text) +{ + static char what[5] = { 105, 84, 88, 116, 0 }; + png_charp parameter_list[5]; + + parameter_list[0] = strstash(key); + parameter_list[1] = strstash(language); + parameter_list[2] = strstash(language_key); + parameter_list[3] = strstash_list(text); + parameter_list[4] = NULL; + + return make_insert(what, insert_iTXt, 4, parameter_list); +} + +/* This is a not-very-good parser for a sequence of numbers (including 0). It + * doesn't accept some apparently valid things, but it accepts all the sensible + * combinations. + */ +static void +parse_color(char *arg, unsigned int *colors) +{ + unsigned int ncolors = 0; + + while (*arg && ncolors < 4) + { + char *ep = arg; + + unsigned long ul = strtoul(arg, &ep, 0); + + if (ul > 65535) + { + fprintf(stderr, "makepng --color=...'%s': too big\n", arg); + exit(1); + } + + if (ep == arg) + { + fprintf(stderr, "makepng --color=...'%s': not a valid color\n", arg); + exit(1); + } + + if (*ep) ++ep; /* skip a separator */ + arg = ep; + + colors[++ncolors] = (unsigned int)ul; /* checked above */ + } + + if (*arg) + { + fprintf(stderr, "makepng --color=...'%s': too many values\n", arg); + exit(1); + } + + *colors = ncolors; +} + +int +main(int argc, char **argv) +{ + FILE *fp = stdout; + const char *file_name = NULL; + int color_type = 8; /* invalid */ + int bit_depth = 32; /* invalid */ + int small = 0; /* make full size images */ + int tRNS = 0; /* don't output a tRNS chunk */ + unsigned int colors[5]; + unsigned int filters = PNG_ALL_FILTERS; + png_fixed_point gamma = 0; /* not set */ + chunk_insert *head_insert = NULL; + chunk_insert **insert_ptr = &head_insert; + + memset(colors, 0, sizeof colors); + + while (--argc > 0) + { + char *arg = *++argv; + + if (strcmp(arg, "--small") == 0) + { + small = 1; + continue; + } + + if (strcmp(arg, "--tRNS") == 0) + { + tRNS = 1; + continue; + } + + if (strcmp(arg, "--sRGB") == 0) + { + gamma = PNG_DEFAULT_sRGB; + continue; + } + + if (strcmp(arg, "--linear") == 0) + { + gamma = PNG_FP_1; + continue; + } + + if (strcmp(arg, "--1.8") == 0) + { + gamma = PNG_GAMMA_MAC_18; + continue; + } + + if (strcmp(arg, "--nofilters") == 0) + { + filters = PNG_FILTER_NONE; + continue; + } + + if (strncmp(arg, "--color=", 8) == 0) + { + parse_color(arg+8, colors); + continue; + } + + if (argc >= 3 && strcmp(arg, "--insert") == 0) + { + png_const_charp what = *++argv; + png_charp param = *++argv; + chunk_insert *new_insert; + + argc -= 2; + + new_insert = find_insert(what, param); + + if (new_insert != NULL) + { + *insert_ptr = new_insert; + insert_ptr = &new_insert->next; + } + + continue; + } + + if (arg[0] == '-') + { + fprintf(stderr, "makepng: %s: invalid option\n", arg); + exit(1); + } + + if (strcmp(arg, "palette") == 0) + { + color_type = PNG_COLOR_TYPE_PALETTE; + continue; + } + + if (strncmp(arg, "gray", 4) == 0) + { + if (arg[4] == 0) + { + color_type = PNG_COLOR_TYPE_GRAY; + continue; + } + + else if (strcmp(arg+4, "a") == 0 || + strcmp(arg+4, "alpha") == 0 || + strcmp(arg+4, "-alpha") == 0) + { + color_type = PNG_COLOR_TYPE_GRAY_ALPHA; + continue; + } + } + + if (strncmp(arg, "rgb", 3) == 0) + { + if (arg[3] == 0) + { + color_type = PNG_COLOR_TYPE_RGB; + continue; + } + + else if (strcmp(arg+3, "a") == 0 || + strcmp(arg+3, "alpha") == 0 || + strcmp(arg+3, "-alpha") == 0) + { + color_type = PNG_COLOR_TYPE_RGB_ALPHA; + continue; + } + } + + if (color_type == 8 && isdigit(arg[0])) + { + color_type = atoi(arg); + if (color_type < 0 || color_type > 6 || color_type == 1 || + color_type == 5) + { + fprintf(stderr, "makepng: %s: not a valid color type\n", arg); + exit(1); + } + + continue; + } + + if (bit_depth == 32 && isdigit(arg[0])) + { + bit_depth = atoi(arg); + if (bit_depth <= 0 || bit_depth > 16 || + (bit_depth & -bit_depth) != bit_depth) + { + fprintf(stderr, "makepng: %s: not a valid bit depth\n", arg); + exit(1); + } + + continue; + } + + if (argc == 1) /* It's the file name */ + { + fp = fopen(arg, "wb"); + if (fp == NULL) + { + fprintf(stderr, "%s: %s: could not open\n", arg, strerror(errno)); + exit(1); + } + + file_name = arg; + continue; + } + + fprintf(stderr, "makepng: %s: unknown argument\n", arg); + exit(1); + } /* argument while loop */ + + if (color_type == 8 || bit_depth == 32) + { + fprintf(stderr, "usage: makepng [--small] [--sRGB|--linear|--1.8] " + "[--color=...] color-type bit-depth [file-name]\n" + " Make a test PNG file, by default writes to stdout.\n" + " Other options are available, UTSL.\n"); + exit(1); + } + + /* Check the colors */ + { + const unsigned int lim = (color_type == PNG_COLOR_TYPE_PALETTE ? 255U : + (1U<<bit_depth)-1); + unsigned int i; + + for (i=1; i<=colors[0]; ++i) + if (colors[i] > lim) + { + fprintf(stderr, "makepng: --color=...: %u out of range [0..%u]\n", + colors[i], lim); + exit(1); + } + } + + /* small and colors are incomparible (will probably crash if both are used at + * the same time!) + */ + if (small && colors[0] != 0) + { + fprintf(stderr, "makepng: --color --small: only one at a time!\n"); + exit(1); + } + + /* Restrict the filters for more speed to those we know are used for the + * generated images. + */ + if (filters == PNG_ALL_FILTERS && !small/*small provides defaults*/) + { + if ((color_type & PNG_COLOR_MASK_PALETTE) != 0 || bit_depth < 8) + filters = PNG_FILTER_NONE; + + else if (color_type & PNG_COLOR_MASK_COLOR) /* rgb */ + { + if (bit_depth == 8) + filters &= ~(PNG_FILTER_NONE | PNG_FILTER_AVG); + + else + filters = PNG_FILTER_SUB | PNG_FILTER_PAETH; + } + + else /* gray 8 or 16-bit */ + filters &= ~PNG_FILTER_NONE; + } + + /* Insert standard copyright and licence text. */ + { + static png_const_charp copyright[] = + { + COPYRIGHT, /* ISO-Latin-1 */ + NULL + }; + static png_const_charp licensing[] = + { + IMAGE_LICENSING, /* UTF-8 */ + NULL + }; + + chunk_insert *new_insert; + + new_insert = add_tEXt("Copyright", copyright); + if (new_insert != NULL) + { + *insert_ptr = new_insert; + insert_ptr = &new_insert->next; + } + + new_insert = add_iTXt("Licensing", "en", NULL, licensing); + if (new_insert != NULL) + { + *insert_ptr = new_insert; + insert_ptr = &new_insert->next; + } + } + + { + int ret = write_png(&file_name, fp, color_type, bit_depth, gamma, + head_insert, filters, colors, small, tRNS); + + if (ret != 0 && file_name != NULL) + remove(file_name); + + return ret; + } +} |