-/* makepng.c
- *
- * Copyright (c) 2013 John Cunningham Bowler
- *
- * Last changed in libpng 1.6.1 [March 28, 2013]
- *
+/* makepng.c */
+#define _ISOC99_SOURCE
+/* Copyright: */
+#define COPYRIGHT "\251 2013,2015 John Cunningham Bowler"
+/*
* 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] [--color=<color>] color-type bit-depth \
- * [file-name]
+ * 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
* 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 the PNG file has
- * a tRNS chunk, as follows:
+ * 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
* 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:
*
* 16 bits: 256x256
* More than 16 bits: 1024x1024
*
- * Row filtering is turned off (the 'none' filter is used on every row) and the
- * images are not interlaced.
+ * Row filtering is the libpng default but may be turned off (the 'none' filter
+ * is used on every row) with the --nofilters option.
*
- * 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.
+ * 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 _ISOC99_SOURCE /* for strtoull */
+#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 <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>
# 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.)
*/
png_charp parameters[1];
} chunk_insert;
-static int
+static unsigned int
channels_of_type(int color_type)
{
if (color_type & PNG_COLOR_MASK_PALETTE)
}
}
-static int
+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)
+image_size_of_type(int color_type, int bit_depth, unsigned int *colors,
+ int small)
{
if (*colors)
return 16;
{
int pixel_depth = pixel_depth_of_type(color_type, bit_depth);
- if (pixel_depth < 8)
+ 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)
else
{
unsigned int size = 1U << (bit_depth/2); /* 2, 4 or 16 */
- unsigned int x, y, ip;
+ unsigned int x, y;
+ volatile unsigned int ip = 0;
- for (x=0; x<size; ++x) for (y=0; y<size; ++y)
+ for (x=0; x<size; ++x)
{
- 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);
+ 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;
exit(1);
case 16:
- value = (unsigned int)floor(65535*pow(value/65535.,conv)+.5);
+ value = flooru(65535*pow(value/65535.,conv)+.5);
*row++ = (png_byte)(value >> 8);
*row = (png_byte)value;
return;
}
}
-static void
+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)
+ unsigned int *colors, int small)
{
- png_uint_32 size_max = image_size_of_type(color_type, bit_depth, colors)-1;
+ 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) switch (channels_of_type(color_type))
+ if (colors[0] == 0 && 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:
{
- const png_uint_32 luma = colors[1];
+ png_uint_32 luma = colors[1];
png_uint_32 x;
for (x=0; x<=size_max; ++x)
case 2:
{
- const png_uint_32 luma = colors[1];
- const png_uint_32 alpha = colors[2];
+ png_uint_32 luma = colors[1];
+ png_uint_32 alpha = colors[2];
png_uint_32 x;
for (x=0; x<size_max; ++x)
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 red = colors[1];
+ png_uint_32 green = colors[2];
+ png_uint_32 blue = colors[3];
png_uint_32 x;
for (x=0; x<=size_max; ++x)
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 red = colors[1];
+ png_uint_32 green = colors[2];
+ png_uint_32 blue = colors[3];
+ png_uint_32 alpha = colors[4];
png_uint_32 x;
for (x=0; x<=size_max; ++x)
colors[0], channels_of_type(color_type));
exit(1);
}
+
+ return filters;
}
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)
+ 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);
/* 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);
png_error(png_ptr, "OOM allocating info structure");
{
- unsigned int size = image_size_of_type(color_type, bit_depth, colors);
+ 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)
+ {
+ 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:
*/
{
unsigned int i;
- if (real_gamma == 45455) for (i=0; i<256; ++i)
+ if (real_gamma == 45455)
{
- gamma_table[i] = (png_byte)i;
- conv = 1.;
+ for (i=0; i<256; ++i)
+ {
+ gamma_table[i] = (png_byte)i;
+ conv = 1.;
+ }
}
else
gamma_table[0] = 0;
for (i=1; i<255; ++i)
- gamma_table[i] = (png_byte)floor(pow(i/255.,conv) * 255 + .5);
+ gamma_table[i] = floorb(pow(i/255.,conv) * 255 + .5);
gamma_table[255] = 255;
}
}
- png_set_IHDR(png_ptr, info_ptr, size, size, bit_depth, color_type,
+ 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)
npalette = generate_palette(palette, trans, bit_depth, gamma_table,
colors);
png_set_PLTE(png_ptr, info_ptr, palette, npalette);
- png_set_tRNS(png_ptr, info_ptr, trans, npalette-1,
- NULL/*transparent color*/);
+
+ 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);
png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, filters);
{
- int passes = png_set_interlace_handling(png_ptr);
+# 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);
+ size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
row = malloc(rowbytes);
{
unsigned int y;
- for (y=0; y<size; ++y)
+ for (y=0; y<ysize; ++y)
{
- generate_row(row, rowbytes, y, color_type, bit_depth,
- gamma_table, conv, colors);
+ 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);
}
}
return 0;
}
-static png_size_t
+static size_t
load_fake(png_charp param, png_bytepp profile)
{
char *endptr = NULL;
- unsigned long long int size = strtoull(param, &endptr, 0/*base*/);
+ uint64_t size = strtoull(param, &endptr, 0/*base*/);
/* The 'fake' format is <number>*[string] */
if (endptr != NULL && *endptr == '*')
{
case '<':
{
- png_size_t filelen = load_file(params[1]+1, &profile);
+ 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",
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);
+ size_t fake_len = load_fake(params[1], &profile);
if (fake_len > 0) /* else a simple parameter */
{
case '5': case '6': case '7': case '8': case '9':
{
png_bytep data = NULL;
- png_size_t fake_len = load_fake(param, &data);
+ size_t fake_len = load_fake(param, &data);
if (fake_len > 0) /* else a simple parameter */
{
}
static void
-insert_hIST(png_structp png_ptr, png_infop info_ptr, int nparams, png_charpp params)
+insert_hIST(png_structp png_ptr, png_infop info_ptr, int nparams,
+ png_charpp params)
{
int i;
png_uint_16 freq[256];
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)
+{
+ int ct = png_get_color_type(png_ptr, info_ptr);
+ int c = (ct & PNG_COLOR_MASK_COLOR ? 3 : 1) +
+ (ct & PNG_COLOR_MASK_ALPHA ? 1 : 0);
+ 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)
for (i=0; *param && i<nparams; ++i)
{
list[i] = param;
- while (*++param) if (*param == '\n' || *param == ':')
+ while (*++param)
{
- *param++ = 0; /* Terminate last parameter */
- break; /* And start a new one. */
+ if (*param == '\n' || *param == ':')
+ {
+ *param++ = 0; /* Terminate last parameter */
+ break; /* And start a new one. */
+ }
}
}
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);
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.
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 */
{
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;
if (color_type == 8 || bit_depth == 32)
{
- fprintf(stderr, "usage: makepng [--sRGB|--linear|--1.8] "
+ 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");
+ " 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 :
+ unsigned int lim = (color_type == PNG_COLOR_TYPE_PALETTE ? 255U :
(1U<<bit_depth)-1);
unsigned int i;
}
}
+ /* small and colors are incompatible (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)
+ if (filters == PNG_ALL_FILTERS && !small/*small provides defaults*/)
{
if ((color_type & PNG_COLOR_MASK_PALETTE) != 0 || bit_depth < 8)
filters = PNG_FILTER_NONE;
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);
+ head_insert, filters, colors, small, tRNS);
if (ret != 0 && file_name != NULL)
remove(file_name);
projects / platform / upstream / libpng.git / blobdiff