- Implement stereo rendering with anaglyph images.

- Add r_greyscale for black&white rendering

code/renderer/tr_shade.c

@@ -938,6 +938,18 @@ static void ComputeColors( shaderStage_t *pStage )
 			break;
 		}
 	}
+	
+	// if in greyscale rendering mode turn all color values into greyscale.
+	if(r_greyscale->integer)
+	{
+		int scale;
+		
+		for(i = 0; i < tess.numVertexes; i++)
+		{
+			scale = (tess.svars.colors[i][0] + tess.svars.colors[i][1] + tess.svars.colors[i][2]) / 3;
+			tess.svars.colors[i][0] = tess.svars.colors[i][1] = tess.svars.colors[i][2] = scale;
+		}
+	}
 }
 
 /*