particle rendering now uses premultiplied alpha (texture is

[xonotic/darkplaces.git] / gl_textures.c

diff --git a/gl_textures.c b/gl_textures.c
index 455924b68c985359be67ae5ca398a4c5d12853a8..192568fac7ed340ab2a3c8eaa5ad02536057052b 100644 (file)
--- a/gl_textures.c
+++ b/gl_textures.c
@@ -1119,6 +1119,21 @@ static void R_UploadFullTexture(gltexture_t *glt, const unsigned char *data)
                prevbuffer = colorconvertbuffer;
        }
 
+       if (glt->flags & TEXF_RGBMULTIPLYBYALPHA)
+       {
+               // multiply RGB channels by A channel before uploading
+               int alpha;
+               for (i = 0;i < width*height*depth*4;i += 4)
+               {
+                       alpha = prevbuffer[i+3];
+                       colorconvertbuffer[i] = (prevbuffer[i] * alpha) >> 8;
+                       colorconvertbuffer[i+1] = (prevbuffer[i+1] * alpha) >> 8;
+                       colorconvertbuffer[i+2] = (prevbuffer[i+2] * alpha) >> 8;
+                       colorconvertbuffer[i+3] = alpha;
+               }
+               prevbuffer = colorconvertbuffer;
+       }
+
        // scale up to a power of 2 size (if appropriate)
        if (glt->inputwidth != width || glt->inputheight != height || glt->inputdepth != depth)
        {