From d9354e6e6863bc1f82b9581726c43f3bd76bc44b Mon Sep 17 00:00:00 2001 From: Benjamin Poulain Date: Tue, 9 Feb 2010 16:58:56 +0100 Subject: Skip the transparent pixels when doing the sourceOver MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Blending fully transparent pixels take a non-negligible time when webkit use transparent layer. We can avoid that be skipping those pixels since they have no impact on the final result. Reviewed-by: Samuel Rødal --- src/gui/painting/qdrawhelper_mmx_p.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/src/gui/painting/qdrawhelper_mmx_p.h b/src/gui/painting/qdrawhelper_mmx_p.h index f8bc480..59b3804 100644 --- a/src/gui/painting/qdrawhelper_mmx_p.h +++ b/src/gui/painting/qdrawhelper_mmx_p.h @@ -240,7 +240,10 @@ static void QT_FASTCALL comp_func_SourceOver(uint *dest, const uint *src, int le C_FF; C_80; C_00; if (const_alpha == 255) { for (int i = 0; i < length; ++i) { - if ((0xff000000 & src[i]) == 0xff000000) { + const uint alphaMaskedSource = 0xff000000 & src[i]; + if (alphaMaskedSource == 0) + continue; + if (alphaMaskedSource == 0xff000000) { dest[i] = src[i]; } else { m64 s = MM::load(src[i]); @@ -251,6 +254,8 @@ static void QT_FASTCALL comp_func_SourceOver(uint *dest, const uint *src, int le } else { m64 ca = MM::load_alpha(const_alpha); for (int i = 0; i < length; ++i) { + if ((0xff000000 & src[i]) == 0) + continue; m64 s = MM::byte_mul(MM::load(src[i]), ca); m64 ia = MM::negate(MM::alpha(s)); dest[i] = MM::store(MM::add(s, MM::byte_mul(MM::load(dest[i]), ia))); -- cgit v0.12