From 749c8cd11e9e6f81e93ae5ce19258431722b6bdf Mon Sep 17 00:00:00 2001

From: Tom Hughes <tom@compton.nu>

Date: Sun, 19 May 2013 16:43:25 +0100

Subject: [PATCH 10/15] Add renderer_scanline_aa_alpha

---

 include/agg_pixfmt_rgba.h       | 24 +++++++++++++-

 include/agg_renderer_base.h     | 28 ++++++++++++++++

 include/agg_renderer_scanline.h | 71 +++++++++++++++++++++++++++++++++++++++++

 3 files changed, 122 insertions(+), 1 deletion(-)

diff --git a/include/agg_pixfmt_rgba.h b/include/agg_pixfmt_rgba.h

index 42f0a05..6c4bc37 100644

--- a/include/agg_pixfmt_rgba.h

+++ b/include/agg_pixfmt_rgba.h

@@ -2247,7 +2247,6 @@ namespace agg

         }

-

         //--------------------------------------------------------------------

         void blend_color_vspan(int x, int y,

                                unsigned len, 

@@ -2751,6 +2750,29 @@ namespace agg

         }

         //--------------------------------------------------------------------

+        void blend_color_hspan_alpha(int x, int y, unsigned len,

+                                     const color_type* colors,

+                                     value_type alpha,

+                                     const int8u* covers,

+                                     int8u cover)

+        {

+            value_type* p = (value_type*)m_rbuf->row_ptr(x, y, len) + (x << 2);

+            do

+            {

+                blender_type::blend_pix(m_comp_op,

+                                        p,

+                                        (colors->r * alpha + 255) >> 8,

+                                        (colors->g * alpha + 255) >> 8,

+                                        (colors->b * alpha + 255) >> 8,

+                                        (colors->a * alpha + 255) >> 8,

+                                        covers ? *covers++ : cover);

+                p += 4;

+                ++colors;

+            }

+            while(--len);

+        }

+

+        //--------------------------------------------------------------------

         void blend_color_vspan(int x, int y, unsigned len, 

                                const color_type* colors, 

                                const int8u* covers,

diff --git a/include/agg_renderer_base.h b/include/agg_renderer_base.h

index 1808944..25f07c3 100644

--- a/include/agg_renderer_base.h

+++ b/include/agg_renderer_base.h

@@ -37,6 +37,7 @@ namespace agg

     public:

         typedef PixelFormat pixfmt_type;

         typedef typename pixfmt_type::color_type color_type;

+        typedef typename pixfmt_type::color_type::value_type value_type;

         typedef typename pixfmt_type::row_data row_data;

         //--------------------------------------------------------------------

@@ -383,6 +384,33 @@ namespace agg

         }

         //--------------------------------------------------------------------

+        void blend_color_hspan_alpha(int x, int y, int len,

+                               const color_type* colors,

+                               value_type alpha,

+                               const cover_type* covers,

+                               cover_type cover = agg::cover_full)

+        {

+            if(y > ymax()) return;

+            if(y < ymin()) return;

+

+            if(x < xmin())

+            {

+                int d = xmin() - x;

+                len -= d;

+                if(len <= 0) return;

+                if(covers) covers += d;

+                colors += d;

+                x = xmin();

+            }

+            if(x + len > xmax())

+            {

+                len = xmax() - x + 1;

+                if(len <= 0) return;

+            }

+            m_ren->blend_color_hspan_alpha(x, y, len, colors, alpha,  covers, cover);

+        }

+

+        //--------------------------------------------------------------------

         void blend_color_vspan(int x, int y, int len, 

                                const color_type* colors, 

                                const cover_type* covers,

diff --git a/include/agg_renderer_scanline.h b/include/agg_renderer_scanline.h

index c27ca60..4fcb557 100644

--- a/include/agg_renderer_scanline.h

+++ b/include/agg_renderer_scanline.h

@@ -156,6 +156,35 @@ namespace agg

         }

     }

+    //================================================render_scanline_aa_alpha

+    template

+             class SpanAllocator, class SpanGenerator>

+    void render_scanline_aa_alpha(const Scanline& sl, BaseRenderer& ren,

+                                  SpanAllocator& alloc, SpanGenerator& span_gen,

+                                  unsigned alpha)

+    {

+        int y = sl.y();

+

+        unsigned num_spans = sl.num_spans();

+        typename Scanline::const_iterator span = sl.begin();

+        for(;;)

+        {

+            int x = span->x;

+            int len = span->len;

+            const typename Scanline::cover_type* covers = span->covers;

+

+            if(len < 0) len = -len;

+            typename BaseRenderer::color_type* colors = alloc.allocate(len);

+            span_gen.generate(colors, x, y, len);

+            ren.blend_color_hspan_alpha(x, y, len, colors, alpha,

+                                  (span->len < 0) ? 0 : covers, *covers);

+

+            if(--num_spans == 0) break;

+            ++span;

+        }

+    }

+

+

     //=====================================================render_scanlines_aa

     template

              class SpanAllocator, class SpanGenerator>

@@ -216,8 +245,50 @@ namespace agg

     };

+    //==============================================renderer_scanline_aa_alpha

+    template<class BaseRenderer, class SpanAllocator, class SpanGenerator>

+    class renderer_scanline_aa_alpha

+    {

+    public:

+        typedef BaseRenderer  base_ren_type;

+        typedef SpanAllocator alloc_type;

+        typedef SpanGenerator span_gen_type;

+        //--------------------------------------------------------------------

+        renderer_scanline_aa_alpha() : m_ren(0), m_alloc(0), m_span_gen(0), m_alpha(1.0) {}

+        renderer_scanline_aa_alpha(base_ren_type& ren,

+                             alloc_type& alloc,

+                             span_gen_type& span_gen,

+                             unsigned alpha) :

+            m_ren(&ren),

+            m_alloc(&alloc),

+            m_span_gen(&span_gen),

+            m_alpha(alpha)

+        {}

+        void attach(base_ren_type& ren,

+                    alloc_type& alloc,

+                    span_gen_type& span_gen)

+        {

+            m_ren = &ren;

+            m_alloc = &alloc;

+            m_span_gen = &span_gen;

+        }

+        //--------------------------------------------------------------------

+        void prepare() { m_span_gen->prepare(); }

+

+        //--------------------------------------------------------------------

+        template<class Scanline> void render(const Scanline& sl)

+        {

+            render_scanline_aa_alpha(sl, *m_ren, *m_alloc, *m_span_gen, m_alpha);

+        }

+

+    private:

+        base_ren_type* m_ren;

+        alloc_type*    m_alloc;

+        span_gen_type* m_span_gen;

+        unsigned       m_alpha;

+    };

     //===============================================render_scanline_bin_solid

-- 

1.8.1.4