Sync to AGG tree to support stippi's Painter classes

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@10693 a95241bf-73f2-0310-859d-f6bbb57e9c96
2005-01-12 11:05:58 +00:00
parent 75d0f2ba9b
commit abd0030237
52 changed files with 2979 additions and 287 deletions
@@ -0,0 +1,126 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.2
+// Copyright (C) 2002-2004 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: [email protected]
+//          [email protected]
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+
+#ifndef AGG_SPAN_GRADIENT_ALPHA_INCLUDED
+#define AGG_SPAN_GRADIENT_ALPHA_INCLUDED
+
+#include "agg_span_gradient.h"
+
+namespace agg
+{
+    //======================================================span_gradient_alpha
+    template<class ColorT, 
+             class Interpolator,
+             class GradientF, 
+             class AlphaF>
+    class span_gradient_alpha
+    {
+    public:
+        typedef Interpolator interpolator_type;
+        typedef ColorT color_type;
+        typedef typename color_type::alpha_type alpha_type;
+
+        enum
+        {
+            base_shift = 8,
+            base_size  = 1 << base_shift,
+            base_mask  = base_size - 1,
+            downscale_shift = interpolator_type::subpixel_shift - gradient_subpixel_shift
+        };
+
+
+        //--------------------------------------------------------------------
+        span_gradient_alpha() {}
+
+        //--------------------------------------------------------------------
+        span_gradient_alpha(interpolator_type& inter,
+                            const GradientF& gradient_function,
+                            AlphaF alpha_function,
+                            double d1, double d2) : 
+            m_interpolator(&inter),
+            m_gradient_function(&gradient_function),
+            m_alpha_function(alpha_function),
+            m_d1(int(d1 * gradient_subpixel_size)),
+            m_d2(int(d2 * gradient_subpixel_size))
+        {}
+
+        //--------------------------------------------------------------------
+        interpolator_type& interpolator() { return *m_interpolator; }
+        const GradientF& gradient_function() const { return *m_gradient_function; }
+        const AlphaF alpha_function() const { return m_alpha_function; }
+        double d1() const { return double(m_d1) / gradient_subpixel_size; }
+        double d2() const { return double(m_d2) / gradient_subpixel_size; }
+
+        //--------------------------------------------------------------------
+        void interpolator(interpolator_type& i) { m_interpolator = &i; }
+        void gradient_function(const GradientF& gf) { m_gradient_function = &gf; }
+        void alpha_function(AlphaF af) { m_alpha_function = af; }
+        void d1(double v) { m_d1 = int(v * gradient_subpixel_size); }
+        void d2(double v) { m_d2 = int(v * gradient_subpixel_size); }
+
+        //--------------------------------------------------------------------
+        void convert(color_type* span, int x, int y, unsigned len)
+        {   
+            int dd = m_d2 - m_d1;
+            if(dd < 1) dd = 1;
+            m_interpolator->begin(x+0.5, y+0.5, len);
+            do
+            {
+                m_interpolator->coordinates(&x, &y);
+                int d = m_gradient_function->calculate(x >> downscale_shift, 
+                                                       y >> downscale_shift, dd);
+                d = ((d - m_d1) << base_shift) / dd;
+                if(d < 0) d = 0;
+                if(d > base_mask) d = base_mask;
+                span->a = m_alpha_function[d];
+                ++span;
+                ++(*m_interpolator);
+            }
+            while(--len);
+        }
+
+    private:
+        interpolator_type* m_interpolator;
+        const GradientF*   m_gradient_function;
+        AlphaF             m_alpha_function;
+        int                m_d1;
+        int                m_d2;
+    };
+
+
+    //=======================================================gradient_alpha_x
+    template<class ColorT> struct gradient_alpha_x
+    {
+        typedef typename ColorT::alpha_type alpha_type;
+        alpha_type operator [] (alpha_type x) const { return x; }
+    };
+
+    //====================================================gradient_alpha_x_u8
+    struct gradient_alpha_x_u8
+    {
+        typedef int8u alpha_type;
+        alpha_type operator [] (alpha_type x) const { return x; }
+    };
+
+    //==========================================gradient_alpha_one_munus_x_u8
+    struct gradient_alpha_one_munus_x_u8
+    {
+        typedef int8u alpha_type;
+        alpha_type operator [] (alpha_type x) const { return 255-x; }
+    };
+
+}
+
+#endif