Repo created

3party/agg/agg_span_interpolator_trans.h

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+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 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: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// Horizontal span interpolator for use with an arbitrary transformer
+// The efficiency highly depends on the operations done in the transformer
+//
+//----------------------------------------------------------------------------
+
+#ifndef AGG_SPAN_INTERPOLATOR_TRANS_INCLUDED
+#define AGG_SPAN_INTERPOLATOR_TRANS_INCLUDED
+
+#include "agg_basics.h"
+
+namespace agg
+{
+    //=================================================span_interpolator_trans
+    template<class Transformer, unsigned SubpixelShift = 8> 
+    class span_interpolator_trans
+    {
+    public:
+        typedef Transformer trans_type;
+        enum subpixel_scale_e
+        {
+            subpixel_shift = SubpixelShift,
+            subpixel_scale = 1 << subpixel_shift
+        };
+
+        //--------------------------------------------------------------------
+        span_interpolator_trans() {}
+        span_interpolator_trans(const trans_type& trans) : m_trans(&trans) {}
+        span_interpolator_trans(const trans_type& trans,
+                                double x, double y, unsigned) :
+            m_trans(&trans)
+        {
+            begin(x, y, 0);
+        }
+
+        //----------------------------------------------------------------
+        const trans_type& transformer() const { return *m_trans; }
+        void transformer(const trans_type& trans) { m_trans = &trans; }
+
+        //----------------------------------------------------------------
+        void begin(double x, double y, unsigned)
+        {
+            m_x = x;
+            m_y = y;
+            m_trans->transform(&x, &y);
+            m_ix = iround(x * subpixel_scale);
+            m_iy = iround(y * subpixel_scale);
+        }
+
+        //----------------------------------------------------------------
+        void operator++()
+        {
+            m_x += 1.0;
+            double x = m_x;
+            double y = m_y;
+            m_trans->transform(&x, &y);
+            m_ix = iround(x * subpixel_scale);
+            m_iy = iround(y * subpixel_scale);
+        }
+
+        //----------------------------------------------------------------
+        void coordinates(int* x, int* y) const
+        {
+            *x = m_ix;
+            *y = m_iy;
+        }
+
+    private:
+        const trans_type* m_trans;
+        double            m_x;
+        double            m_y;
+        int               m_ix;
+        int               m_iy;
+    };
+
+}
+
+#endif