fix(colors): change color converison, fix #275

tools/gfx4snes/src/images.c

@@ -34,54 +34,6 @@
 
 t_image snesimage={0};														// current image converted
 
-#if 0
-// Un-bitpacks a source image into an 8-bit-per-pixel destination buffer
-// Acceptable range is 1-8 bits per pixel
-static void image_bitunpack(const vector<uint8_t> & src_image_data, vector<uint8_t> & unpacked_image_data, uint8_t bitdepth) {
-
-    int pixels_per_byte = (8 / bitdepth);
-
-    // Loop through all pixels in source image buffer
-    for (const uint8_t & it_src: src_image_data) {
-
-        // Unpack grouped pixel data
-        uint8_t packed_bits = it_src;
-        for (int b = 0; b < pixels_per_byte; b++) {
-            unpacked_image_data.push_back(packed_bits >> (8 - bitdepth)); // Save extracted pixel bits
-            packed_bits <<= bitdepth;                                     // Shift out the extracted bits
-        }
-    }
-}
-
-
-// Converts indexed image with bit depths 1- 8 bpp to indexed 8 bits per pixel
-// Replaces incoming image buffer with unpacked image buffer if successful
-bool image_indexed_ensure_8bpp(vector<uint8_t> & src_image_data, int width, int height, int bitdepth, int colortype) {
-
-    vector<uint8_t> unpacked_image_data;
-
-    if (colortype != LCT_PALETTE) {
-        printf("png2asset: Error: keep_palette_order only works with indexed png images (pngtype: %d, bits:%d)\n",
-               colortype, bitdepth);
-        return false;
-    }
-    else if ((bitdepth < 1) || (bitdepth > 8)) {
-        printf("png2asset: Error: Indexed mode PNG requires between 1 - 8 bits per pixel (pngtype: %d, bits:%d)\n",
-                colortype, bitdepth);
-        return false;
-    }
-
-    image_bitunpack(src_image_data, unpacked_image_data, bitdepth);
-
-    // Replace source image pixel data with unpacked pixels
-    src_image_data.clear();
-    for (const uint8_t & it_unpacked: unpacked_image_data)
-        src_image_data.push_back(it_unpacked);
-
-    return true;
-}
-
-#endif
 //-------------------------------------------------------------------------------------------------
 void image_load_png(const char *filename, t_image *img, bool isquiet) 
 {
@@ -102,12 +54,11 @@ void image_load_png(const char *filename, t_image *img, bool isquiet)
 	}
 	sprintf(outputname,"%s.png",filename);
 
-#if 1
     // optionally customize the state
     lodepng_state_init(&pngstate);
 
     // no conversion of color (to keep palette mode)  
-    pngstate.decoder.color_convert = 0;
+    pngstate.decoder.color_convert = true;
 
 	// always in 8 bits and palette mode
 	pngstate.info_raw.colortype=LCT_PALETTE;
@@ -119,35 +70,7 @@ void image_load_png(const char *filename, t_image *img, bool isquiet)
     {
         pngerror = lodepng_decode(&pngimage, &pngwidth, &pngheight, &pngstate, pngbuff, pngsize);
     }
-#else
-	// load the png file and try to decode it
-    pngerror = lodepng_load_file(&pngbuff, &pngsize, outputname);
-    if (!pngerror)
-    {
-		//Calling with keep_palette_order means
-		//-The image should be png indexed (1-8 bits per pixel)
-		//-For CGB: Each 4 colors define a gbc palette, the first color is the transparent one
-		//-Each rectangle with dimension(tile_w, tile_h) in the image has colors from one of those palettes only
-		pngstate.info_raw.colortype = LCT_PALETTE;
-		pngstate.info_raw.bitdepth = 8;
 
-		// * Do *NOT* turn color_convert ON here.
-		// When source PNG is indexed with bit depth was less than 8 bits per pixel then
-		// color_convert may mangle the packed indexed values. Instead manually unpack them.
-		//
-		// This is necessary since some PNG encoders will use the minimum possible number of bits.
-		//   For example 2 colors in the palette -> 1bpp -> 8 pixels per byte in the decoded image.
-		//     Also see below about requirement to use palette from source image
-		pngstate.decoder.color_convert = false;
-        pngerror = lodepng_decode(&pngimage, &pngwidth, &pngheight, &pngstate, pngbuff, pngsize);
-
-		//unsigned error = lodepng::decode(image.data, image.w, image.h, state, buffer);
-		// Unpack the image if needed. Also checks and errors on incompatible palette type if needed
-		if (! image_indexed_ensure_8bpp(&pngimage, &pngwidth, &pngheight,, (int)pngstate.info_png.color.bitdepth, (int)pngstate.info_png.color.colortype)) {
-			return 1;
-		}
-	}
-#endif
     if (pngerror)
     {
         free(pngbuff);