* pipi.c: implement the "--gray" flag for grayscale conversion.

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@2702 92316355-f0b4-4df1-b90c-862c8a59935f

pipi/context.c

@@ -131,6 +131,12 @@ int pipi_command(pipi_context_t *ctx, char const *cmd, ...)
         pipi_free(src);
         ctx->images[ctx->nimages - 1] = dst;
     }
+    else if(!strcmp(cmd, "gray"))
+    {
+        if(ctx->nimages <= 0)
+            return -1;
+        pipi_getpixels(ctx->images[ctx->nimages - 1], PIPI_PIXELS_Y_F);
+    }
     else if(!strcmp(cmd, "free"))
     {
         if(ctx->nimages <= 0)

src/pipi.c

@@ -36,6 +36,11 @@ int main(int argc, char *argv[])
                 return EXIT_FAILURE;
             argv++;
         }
+        else if(!strcmp(argv[0], "--gray"))
+        {
+            if(pipi_command(ctx, "gray") != 0)
+                return EXIT_FAILURE;
+        }
         else if(!strcmp(argv[0], "--output") || !strcmp(argv[0], "-o"))
         {
             if(argv[1] == NULL)