Use Agg workarounds in image module as well

mdboom · mdboom · commit 14448fabcebc · 2014-11-11T08:40:36.000-05:00
diff --git a/src/_backend_agg.h b/src/_backend_agg.h
@@ -37,45 +37,7 @@
 #include "_backend_agg_basic_types.h"
 #include "path_converters.h"
 #include "array.h"
-
-/**********************************************************************
- WORKAROUND: This class is to workaround a bug in Agg SVN where the
- blending of RGBA32 pixels does not preserve enough precision
-*/
-
-template<class ColorT, class Order>
-struct fixed_blender_rgba_plain : agg::conv_rgba_plain<ColorT, Order>
-{
-    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 };
-
-    //--------------------------------------------------------------------
-    static AGG_INLINE void blend_pix(value_type* p,
-                                     value_type cr, value_type cg, value_type cb, value_type alpha, agg::cover_type cover)
-    {
-        blend_pix(p, cr, cg, cb, color_type::mult_cover(alpha, cover));
-    }
-
-    //--------------------------------------------------------------------
-    static AGG_INLINE void blend_pix(value_type* p,
-                                     value_type cr, value_type cg, value_type cb, value_type alpha)
-    {
-        if(alpha == 0) return;
-        calc_type a = p[Order::A];
-        calc_type r = p[Order::R] * a;
-        calc_type g = p[Order::G] * a;
-        calc_type b = p[Order::B] * a;
-        a = ((alpha + a) << base_shift) - alpha * a;
-        p[Order::A] = (value_type)(a >> base_shift);
-        p[Order::R] = (value_type)((((cr << base_shift) - r) * alpha + (r << base_shift)) / a);
-        p[Order::G] = (value_type)((((cg << base_shift) - g) * alpha + (g << base_shift)) / a);
-        p[Order::B] = (value_type)((((cb << base_shift) - b) * alpha + (b << base_shift)) / a);
-    }
-};
+#include "agg_workaround.h"
 
 /**********************************************************************/
 
diff --git a/src/_image.cpp b/src/_image.cpp
@@ -25,9 +25,12 @@
 
 #include "_image.h"
 #include "mplutils.h"
+#include "agg_workaround.h"
 
-typedef agg::pixfmt_rgba32_plain pixfmt;
-typedef agg::pixfmt_rgba32_pre pixfmt_pre;
+typedef fixed_blender_rgba_plain<agg::rgba8, agg::order_rgba> fixed_blender_rgba32_plain;
+typedef agg::pixfmt_alpha_blend_rgba<fixed_blender_rgba32_plain, agg::rendering_buffer> pixfmt;
+typedef fixed_blender_rgba_pre<agg::rgba8, agg::order_rgba> fixed_blender_rgba32_pre;
+typedef agg::pixfmt_alpha_blend_rgba<fixed_blender_rgba32_pre, agg::rendering_buffer> pixfmt_pre;
 typedef agg::renderer_base<pixfmt> renderer_base;
 typedef agg::span_interpolator_linear<> interpolator_type;
 typedef agg::rasterizer_scanline_aa<agg::rasterizer_sl_clip_dbl> rasterizer;
