From d7918d0226da2805ff09c48963d2c79e1327c630 Mon Sep 17 00:00:00 2001 From: Nicolás Reynolds Date: Mon, 5 May 2014 04:02:14 +0000 Subject: Mon May 5 03:56:02 UTC 2014 --- ...Avoid-division-by-zero-in-color-burn-mode.patch | 58 ++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 community/agg/0011-Avoid-division-by-zero-in-color-burn-mode.patch (limited to 'community/agg/0011-Avoid-division-by-zero-in-color-burn-mode.patch') diff --git a/community/agg/0011-Avoid-division-by-zero-in-color-burn-mode.patch b/community/agg/0011-Avoid-division-by-zero-in-color-burn-mode.patch new file mode 100644 index 000000000..2a0d198fe --- /dev/null +++ b/community/agg/0011-Avoid-division-by-zero-in-color-burn-mode.patch @@ -0,0 +1,58 @@ +From 0ec68d7f5695403eccac75025ba7f6f7ecf1814e Mon Sep 17 00:00:00 2001 +From: Tom Hughes +Date: Sun, 19 May 2013 16:49:08 +0100 +Subject: [PATCH 11/15] Avoid division by zero in color-burn mode + +FIXME: re-work using latest math from http://www.w3.org/TR/SVGCompositing/ +--- + include/agg_pixfmt_rgba.h | 21 ++++++++++++++++++--- + 1 file changed, 18 insertions(+), 3 deletions(-) + +diff --git a/include/agg_pixfmt_rgba.h b/include/agg_pixfmt_rgba.h +index 6c4bc37..5d6b511 100644 +--- a/include/agg_pixfmt_rgba.h ++++ b/include/agg_pixfmt_rgba.h +@@ -1027,6 +1027,21 @@ namespace agg + // Dca' = Sa.(Sca.Da + Dca.Sa - Sa.Da)/Sca + Sca.(1 - Da) + Dca.(1 - Sa) + // + // Da' = Sa + Da - Sa.Da ++ ++ ++ // http://www.w3.org/TR/SVGCompositing/ ++ // if Sca == 0 and Dca == Da ++ // Dca' = Sa × Da + Sca × (1 - Da) + Dca × (1 - Sa) ++ // = Sa × Da + Dca × (1 - Sa) ++ // = Da = Dca ++ // otherwise if Sca == 0 ++ // Dca' = Sca × (1 - Da) + Dca × (1 - Sa) ++ // = Dca × (1 - Sa) ++ // otherwise if Sca > 0 ++ // Dca' = Sa × Da - Sa × Da × min(1, (1 - Dca/Da) × Sa/Sca) + Sca × (1 - Da) + Dca × (1 - Sa) ++ // = Sa × Da × (1 - min(1, (1 - Dca/Da) × Sa/Sca)) + Sca × (1 - Da) + Dca × (1 - Sa) ++ ++ // sa * da * (255 - std::min(255, (255 - p[0]/da)*(sa/(sc*sa)) + + static AGG_INLINE void blend_pix(value_type* p, + unsigned sr, unsigned sg, unsigned sb, + unsigned sa, unsigned cover) +@@ -1056,15 +1071,15 @@ namespace agg + + p[Order::R] = (value_type)(((srda + drsa <= sada) ? + sr * d1a + dr * s1a : +- sa * (srda + drsa - sada) / sr + sr * d1a + dr * s1a + base_mask) >> base_shift); ++ (sr > 0 ? sa * (srda + drsa - sada) / sr + sr * d1a + dr * s1a + base_mask : 0)) >> base_shift); + + p[Order::G] = (value_type)(((sgda + dgsa <= sada) ? + sg * d1a + dg * s1a : +- sa * (sgda + dgsa - sada) / sg + sg * d1a + dg * s1a + base_mask) >> base_shift); ++ (sg > 0 ? sa * (sgda + dgsa - sada) / sg + sg * d1a + dg * s1a + base_mask : 0)) >> base_shift); + + p[Order::B] = (value_type)(((sbda + dbsa <= sada) ? + sb * d1a + db * s1a : +- sa * (sbda + dbsa - sada) / sb + sb * d1a + db * s1a + base_mask) >> base_shift); ++ (sb > 0 ? sa * (sbda + dbsa - sada) / sb + sb * d1a + db * s1a + base_mask : 0)) >> base_shift); + + p[Order::A] = (value_type)(sa + da - ((sa * da + base_mask) >> base_shift)); + } +-- +1.8.1.4 + -- cgit v1.2.3-54-g00ecf