/* [<][>][^][v][top][bottom][index][help] */
DEFINITIONS
This source file includes following definitions.
- getpid
- main
/* Bring in the gd library functions */
#include "gd.h"
/* Bring in standard I/O and string manipulation functions */
#include <stdio.h>
#include <stdlib.h> /* for atoi() */
#include <string.h>
#ifdef _WIN32
#include <process.h>
int
getpid ()
{
return _getpid ();
}
#else
#include <unistd.h> /* for getpid(), unlink() */
#endif
int
main (int argc, char **argv)
{
FILE *in;
FILE *out;
char outFn[20];
int useStdinStdout = 0;
/* Declare our image pointer */
gdImagePtr im = 0;
int i;
/* We'll clear 'no' once we know the user has made a
reasonable request. */
int no = 1;
/* We'll set 'write' once we know the user's request
requires that the image be written back to disk. */
int write = 0;
/* C programs always get at least one argument; we want at
least one more (the image), more in practice. */
if (argc < 2 || !strcmp (argv[1], "--help"))
{
no = 1;
goto usage;
}
/* The last argument should be the image. Open the file. */
if (strcmp ("-", argv[argc - 1]) == 0)
{ /* - is synonymous with STDIN */
useStdinStdout = 1;
in = stdin;
}
else
{
in = fopen (argv[argc - 1], "rb");
}
if (!in)
{
fprintf (stderr,
"Error: can't open file %s.\n", argv[argc - 1]);
exit (1);
}
/* Now load the image. */
im = gdImageCreateFromPng (in);
fclose (in);
/* If the load failed, it must not be a PNG file. */
if (!im)
{
fprintf (stderr,
"Error: %s is not a valid PNG file.\n", argv[argc - 1]);
exit (1);
}
/* Consider each argument in turn. */
for (i = 1; (i < (argc - 1)); i++)
{
/* -i turns on and off interlacing. */
if (!strcmp (argv[i], "--help"))
{
/* Every program should use this for help! :) */
no = 1;
goto usage;
}
else if (!strcmp (argv[i], "-i"))
{
if (i == (argc - 2))
{
fprintf (stderr,
"Error: -i specified without y or n.\n");
no = 1;
goto usage;
}
if (!strcmp (argv[i + 1], "y"))
{
/* Set interlace. */
gdImageInterlace (im, 1);
}
else if (!strcmp (argv[i + 1], "n"))
{
/* Clear interlace. */
gdImageInterlace (im, 0);
}
else
{
fprintf (stderr,
"Error: -i specified without y or n.\n");
no = 1;
goto usage;
}
i++;
no = 0;
write = 1;
}
else if (!strcmp (argv[i], "-t"))
{
/* Set transparent index (or none). */
int index;
if (i == (argc - 2))
{
fprintf (stderr,
"Error: -t specified without a color table index.\n");
no = 1;
goto usage;
}
if (!strcmp (argv[i + 1], "none"))
{
/* -1 means not transparent. */
gdImageColorTransparent (im, -1);
}
else
{
/* OK, get an integer and set the index. */
index = atoi (argv[i + 1]);
gdImageColorTransparent (im, index);
}
i++;
write = 1;
no = 0;
}
else if (!strcmp (argv[i], "-l"))
{
/* List the colors in the color table. */
int j;
if (!im->trueColor)
{
/* Tabs used below. */
printf ("Index Red Green Blue Alpha\n");
for (j = 0; (j < gdImageColorsTotal (im)); j++)
{
/* Use access macros to learn colors. */
printf ("%d %d %d %d %d\n",
j,
gdImageRed (im, j),
gdImageGreen (im, j),
gdImageBlue (im, j),
gdImageAlpha (im, j));
}
}
else
{
printf ("Truecolor image, no palette entries to list.\n");
}
no = 0;
}
else if (!strcmp (argv[i], "-d"))
{
/* Output dimensions, etc. */
int t;
printf ("Width: %d Height: %d Colors: %d\n",
gdImageSX (im), gdImageSY (im),
gdImageColorsTotal (im));
t = gdImageGetTransparent (im);
if (t != (-1))
{
printf ("First 100%% transparent index: %d\n", t);
}
else
{
/* -1 means the image is not transparent. */
printf ("First 100%% transparent index: none\n");
}
if (gdImageGetInterlaced (im))
{
printf ("Interlaced: yes\n");
}
else
{
printf ("Interlaced: no\n");
}
no = 0;
}
else if (!strcmp(argv[i], "-a"))
{
int maxx, maxy, x, y, alpha, pix, nalpha = 0;
maxx = gdImageSX(im);
maxy = gdImageSY(im);
printf("alpha channel information:\n");
if (im->trueColor) {
for (y = 0; y < maxy; y++) {
for (x = 0; x < maxx; x++) {
pix = gdImageGetPixel(im, x, y);
alpha = gdTrueColorGetAlpha(pix);
if (alpha > gdAlphaOpaque) {
/* Use access macros to learn colors. */
printf ("%d %d %d %d\n",
gdTrueColorGetRed(pix),
gdTrueColorGetGreen(pix),
gdTrueColorGetBlue(pix),
alpha);
nalpha++;
}
}
}
}
else
printf("NOT a true color image\n");
no = 0;
printf("%d alpha channels\n", nalpha);
}
else
{
fprintf (stderr, "Unknown argument: %s\n", argv[i]);
break;
}
}
usage:
if (no)
{
/* If the command failed, output an explanation. */
fprintf (stderr,
"Usage: webpng [-i y|n ] [-l] [-t index|none ] [-d] pngname.png\n"
" -i [y|n] Turns on/off interlace\n"
" -l Prints the table of color indexes\n"
" -t [index] Set the transparent color to the specified index (0-255 or \"none\")\n"
" -d Reports the dimensions and other characteristics of the image.\n"
" -a Prints all alpha channels that are not 100%% opaque.\n"
"\n"
"If you specify '-' as the input file, stdin/stdout will be used input/output.\n"
);
}
if (write)
{
if (useStdinStdout)
{
out = stdout;
}
else
{
/* Open a temporary file. */
/* "temp.tmp" is not good temporary filename. */
snprintf (outFn, sizeof(outFn), "webpng.tmp%d", getpid ());
out = fopen (outFn, "wb");
if (!out)
{
fprintf (stderr,
"Unable to write to %s -- exiting\n", outFn);
exit (1);
}
}
/* Write the new PNG. */
gdImagePng (im, out);
if (!useStdinStdout)
{
fclose (out);
/* Erase the old PNG. */
unlink (argv[argc - 1]);
/* Rename the new to the old. */
if (rename (outFn, argv[argc - 1]) != 0)
{
perror ("rename");
exit (1);
}
}
}
/* Delete the image from memory. */
if (im)
{
gdImageDestroy (im);
}
/* All's well that ends well. */
return 0;
}