From 6cef3ddecc1b8a614ba4d47bf9daf6b04bea9995 Mon Sep 17 00:00:00 2001
From: Tom Hughes <tom@compton.nu>
Date: Sun, 19 May 2013 15:43:18 +0100
Subject: [PATCH 07/11] Implement grain-extract blending mode (GIMP)
---
include/agg_pixfmt_rgba.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/include/agg_pixfmt_rgba.h b/include/agg_pixfmt_rgba.h
index 99b1c9f..e0a6dc1 100644
--- a/include/agg_pixfmt_rgba.h
+++ b/include/agg_pixfmt_rgba.h
@@ -1442,6 +1442,51 @@ namespace agg
}
};
+ //==============================================comp_op_rgba_grain_extract
+ template <typename ColorT, typename Order> struct comp_op_rgba_grain_extract
+ {
+ typedef ColorT color_type;
+ typedef Order order_type;
+ typedef typename color_type::value_type value_type;
+ typedef typename color_type::calc_type calc_type;
+ typedef typename color_type::long_type long_type;
+ enum base_scale_e
+ {
+ base_shift = color_type::base_shift,
+ base_mask = color_type::base_mask
+ };
+
+ // E = I - M + 128
+ static AGG_INLINE void blend_pix(value_type* p,
+ unsigned sr, unsigned sg, unsigned sb,
+ unsigned sa, unsigned cover)
+ {
+ calc_type da = (p[Order::A] * sa + 255) >> 8;
+ calc_type dr = p[Order::R] - sr + 128;
+ calc_type dg = p[Order::G] - sg + 128;
+ calc_type db = p[Order::B] - sb + 128;
+
+ dr = dr < 0 ? 0 : (dr > 255 ? 255 : dr);
+ dg = dg < 0 ? 0 : (dg > 255 ? 255 : dg);
+ db = db < 0 ? 0 : (db > 255 ? 255 : db);
+
+ p[Order::A] = da;
+
+ if(da < 255)
+ {
+ p[Order::R] = (dr * da + 255) >> 8;
+ p[Order::G] = (dg * da + 255) >> 8;
+ p[Order::B] = (db * da + 255) >> 8;
+ }
+ else
+ {
+ p[Order::R] = dr;
+ p[Order::G] = dg;
+ p[Order::B] = db;
+ }
+ }
+ };
+
//======================================================comp_op_table_rgba
template<class ColorT, class Order> struct comp_op_table_rgba
{
@@ -1489,6 +1534,7 @@ namespace agg
comp_op_rgba_invert <ColorT,Order>::blend_pix,
comp_op_rgba_invert_rgb <ColorT,Order>::blend_pix,
comp_op_rgba_grain_merge<ColorT,Order>::blend_pix,
+ comp_op_rgba_grain_extract<ColorT,Order>::blend_pix,
0
};
@@ -1525,6 +1571,7 @@ namespace agg
comp_op_invert, //----comp_op_invert
comp_op_invert_rgb, //----comp_op_invert_rgb
comp_op_grain_merge, //----comp_op_grain_merge
+ comp_op_grain_extract, //----comp_op_grain_extract
end_of_comp_op_e
};
--
1.8.1.4