Reactivate pipi_dither_24to16, it's wrong but useful.

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@4737 92316355-f0b4-4df1-b90c-862c8a59935f

pipi/dither.c

@@ -25,32 +25,34 @@
 #include "pipi.h"
 #include "pipi_internals.h"
 
+/* FIXME: this is not the right place for this... see pixels.c instead */
 void pipi_dither_24to16(pipi_image_t *img)
 {
-/* XXX: disabled because this is not the right place... see pixels.c instead */
-#if 0
     int *error, *nexterror;
+    pipi_pixels_t *p;
     uint32_t *p32;
     int x, y;
 
-    error = malloc(sizeof(int) * 3 * (img->width + 2));
-    nexterror = malloc(sizeof(int) * 3 * (img->width + 2));
-    p32 = (uint32_t *)img->pixels;
+    error = malloc(sizeof(int) * 3 * (img->w + 2));
+    nexterror = malloc(sizeof(int) * 3 * (img->w + 2));
+    p = pipi_get_pixels(img, PIPI_PIXELS_RGBA_U8);
+    p32 = (uint32_t *)p->pixels;
 
-    memset(error, 0, sizeof(int) * 3 * (img->width + 2));
+    memset(error, 0, sizeof(int) * 3 * (img->w + 2));
 
-    for(y = 0; y < img->height; y++)
+    for(y = 0; y < img->h; y++)
     {
         int er = 0, eg = 0, eb = 0;
 
-        memset(nexterror, 0, sizeof(int) * 3 * (img->width + 2));
+        memset(nexterror, 0, sizeof(int) * 3 * (img->w + 2));
 
-        for(x = 0; x < img->width; x++)
+        for(x = 0; x < img->w; x++)
         {
-            int r, g, b, r2, g2, b2;
-            r = p32[y * img->width + x] & 0xff;
-            g = (p32[y * img->width + x] >> 8) & 0xff;
-            b = (p32[y * img->width + x] >> 16) & 0xff;
+            int r, g, b, a, r2, g2, b2;
+            r = p32[y * img->w + x] & 0xff;
+            g = (p32[y * img->w + x] >> 8) & 0xff;
+            b = (p32[y * img->w + x] >> 16) & 0xff;
+            a = (p32[y * img->w + x] >> 24) & 0xff;
             r += er + error[x * 3 + 3];
             g += eg + error[x * 3 + 4];
             b += eb + error[x * 3 + 5];
@@ -61,7 +63,7 @@ void pipi_dither_24to16(pipi_image_t *img)
             /* hack */
             if(r2 == 0x88 && g2 == 0x88 && b2 == 0x88) g2 = 0x84;
             /* hack */
-            p32[y * img->width + x] = (b2 << 16) | (g2 << 8)  | r2;
+            p32[y * img->w + x] = (a << 24) | (b2 << 16) | (g2 << 8)  | r2;
 
             er = r - (r2 / 8 * 255 / 31);
             eg = g - (g2 / 4 * 255 / 63);
@@ -80,11 +82,12 @@ void pipi_dither_24to16(pipi_image_t *img)
             eb -= eb * 3 / 8 + eb * 7 / 8 + eb * 1 / 8;
         }
 
-        memcpy(error, nexterror, sizeof(int) * 3 * (img->width + 2));
+        memcpy(error, nexterror, sizeof(int) * 3 * (img->w + 2));
     }
 
+    pipi_release_pixels(img, p);
+
     free(error);
     free(nexterror);
-#endif
 }