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@@ -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;
+ }
+}