From bf0e0b71360cfbc690a29f4abe15d7b9b61b8479 Mon Sep 17 00:00:00 2001 From: Tom Hughes Date: Sat, 22 Jun 2013 12:11:54 +0100 Subject: [PATCH 12/15] Avoid pixel artifacts when compositing Change src_over alpha to avoid pixel artifacts by reordering computations. --- include/agg_pixfmt_rgba.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/agg_pixfmt_rgba.h b/include/agg_pixfmt_rgba.h index 5d6b511..bb255cd 100644 --- a/include/agg_pixfmt_rgba.h +++ b/include/agg_pixfmt_rgba.h @@ -346,7 +346,7 @@ namespace agg p[Order::R] = (value_type)(sr + ((p[Order::R] * s1a + base_mask) >> base_shift)); p[Order::G] = (value_type)(sg + ((p[Order::G] * s1a + base_mask) >> base_shift)); p[Order::B] = (value_type)(sb + ((p[Order::B] * s1a + base_mask) >> base_shift)); - p[Order::A] = (value_type)(sa + p[Order::A] - ((sa * p[Order::A] + base_mask) >> base_shift)); + p[Order::A] = (value_type)(sa + ((p[Order::A] * s1a + base_mask) >> base_shift)); } }; -- 1.8.1.4