pngdump: image quantization, first attempt at shademap generation

[gbajam21] / tools / pngdump / main.c

diff --git a/tools/pngdump/main.c b/tools/pngdump/main.c
index d7aba3e..9f281cc 100644 (file)
--- a/tools/pngdump/main.c
+++ b/tools/pngdump/main.c
@@ -5,6 +5,14 @@
 #include <assert.h>
 #include "image.h"
 
+enum {
+       MODE_PIXELS,
+       MODE_CMAP,
+       MODE_INFO,
+       MODE_SHADE_CMAP,
+       MODE_SHADE_LUT
+};
+
 void print_usage(const char *argv0);
 
 int main(int argc, char **argv)
@@ -17,21 +25,39 @@ int main(int argc, char **argv)
        int num_infiles = 0;
        struct image img, tmpimg;
        FILE *out = stdout;
+       struct cmapent shade_cmap[256] = {0};
+       int *shade_lut = 0;
+       int shade_levels = 8;
 
        for(i=1; i<argc; i++) {
                if(argv[i][0] == '-') {
                        if(argv[i][2] == 0) {
                                switch(argv[i][1]) {
                                case 'p':
-                                       mode = 0;
+                                       mode = MODE_PIXELS;
                                        break;
 
                                case 'c':
-                                       mode = 1;
+                                       mode = MODE_CMAP;
                                        break;
 
                                case 'i':
-                                       mode = 2;
+                                       mode = MODE_INFO;
+                                       break;
+
+                               case 'C':
+                                       mode = MODE_SHADE_CMAP;
+                                       break;
+
+                               case 'S':
+                                       mode = MODE_SHADE_LUT;
+                                       break;
+
+                               case 's':
+                                       if(!argv[++i] || (shade_levels = atoi(argv[i])) == 0) {
+                                               fprintf(stderr, "-s must be followed by the number of shade levels\n");
+                                               return 1;
+                                       }
                                        break;
 
                                case 't':
@@ -113,11 +139,11 @@ int main(int argc, char **argv)
        }
 
        switch(mode) {
-       case 0:
+       case MODE_PIXELS:
                fwrite(img.pixels, 1, img.scansz * img.height, out);
                break;
 
-       case 1:
+       case MODE_CMAP:
                if(text) {
                        for(i=0; i<img.cmap_ncolors; i++) {
                                printf("%d %d %d\n", img.cmap[i].r, img.cmap[i].g, img.cmap[i].b);
@@ -128,7 +154,7 @@ int main(int argc, char **argv)
                }
                break;
 
-       case 2:
+       case MODE_INFO:
                printf("size: %dx%d\n", img.width, img.height);
                printf("bit depth: %d\n", img.bpp);
                printf("scanline size: %d bytes\n", img.scansz);
@@ -138,6 +164,28 @@ int main(int argc, char **argv)
                        printf("color channels: %d\n", img.nchan);
                }
                break;
+
+       case MODE_SHADE_LUT:
+               if(!(shade_lut = malloc(256 * shade_levels * sizeof *shade_lut))) {
+                       fprintf(stderr, "failed to allocate shading look-up table\n");
+                       return 1;
+               }
+       case MODE_SHADE_CMAP:
+               if(!img.cmap_ncolors) {
+                       fprintf(stderr, "can't generate shade levels for non-indexed images\n");
+                       return 1;
+               }
+               if(gen_shade_lut(&img, shade_levels, 256, shade_cmap, shade_lut) == -1) {
+                       return 1;
+               }
+               if(mode == MODE_SHADE_CMAP) {
+                       fwrite(shade_cmap, sizeof shade_cmap, 1, out);
+               } else {
+                       for(i=0; i<img.cmap_ncolors * shade_levels; i++) {
+                               fputc(shade_lut[i], out);
+                       }
+               }
+               break;
        }
 
        fclose(out);
@@ -151,6 +199,9 @@ void print_usage(const char *argv0)
        printf(" -o <output file>: specify output file (default: stdout)\n");
        printf(" -p: dump pixels (default)\n");
        printf(" -c: dump colormap (palette) entries\n");
+       printf(" -C: generate shading colormap\n");
+       printf(" -S: generate shading LUT\n");
+       printf(" -s <shade levels>: used in conjunction with -C or -S (default: 8)\n");
        printf(" -i: print image information\n");
        printf(" -t: dump as text\n");
        printf(" -n: swap the order of nibbles (for 4bpp)\n");