diff --git a/DesktopEditor/agg-2.4/include/agg_pixfmt_rgba.h b/DesktopEditor/agg-2.4/include/agg_pixfmt_rgba.h
index 50b4e28494..1365926a27 100644
--- a/DesktopEditor/agg-2.4/include/agg_pixfmt_rgba.h
+++ b/DesktopEditor/agg-2.4/include/agg_pixfmt_rgba.h
@@ -207,9 +207,9 @@ namespace agg
 			}
 
 			p[Order::A] = (value_type)((alpha + a) - ((alpha * a + base_mask) >> base_shift));
-			p[Order::R] = (value_type)((alpha * cr + a * r - ((a * r * alpha + base_mask) >> base_shift)) / p[Order::A]);
-			p[Order::G] = (value_type)((alpha * cg + a * g - ((a * g * alpha + base_mask) >> base_shift)) / p[Order::A]);
-			p[Order::B] = (value_type)((alpha * cb + a * b - ((a * b * alpha + base_mask) >> base_shift)) / p[Order::A]);
+			if (r != cr) p[Order::R] = (value_type)((alpha * cr + a * r - ((a * r * alpha + base_mask) >> base_shift)) / p[Order::A]);
+			if (g != cg) p[Order::G] = (value_type)((alpha * cg + a * g - ((a * g * alpha + base_mask) >> base_shift)) / p[Order::A]);
+			if (b != cb) p[Order::B] = (value_type)((alpha * cb + a * b - ((a * b * alpha + base_mask) >> base_shift)) / p[Order::A]);
 		}
 
 		static AGG_INLINE void blend_pix_subpix(value_type* p,