1 //---------------------------------------------------------------------------- 2 // Anti-Grain Geometry - Version 2.2 3 // Copyright (C) 2002-2004 Maxim Shemanarev (http://www.antigrain.com) 4 // 5 // Permission to copy, use, modify, sell and distribute this software 6 // is granted provided this copyright notice appears in all copies. 7 // This software is provided "as is" without express or implied 8 // warranty, and with no claim as to its suitability for any purpose. 9 // 10 //---------------------------------------------------------------------------- 11 // Contact: mcseem@antigrain.com 12 // mcseemagg@yahoo.com 13 // http://www.antigrain.com 14 //---------------------------------------------------------------------------- 15 16 #ifndef AGG_SPAN_INTERPOLATOR_LINEAR_INCLUDED 17 #define AGG_SPAN_INTERPOLATOR_LINEAR_INCLUDED 18 19 #include "agg_basics.h" 20 #include "agg_dda_line.h" 21 #include "agg_trans_affine.h" 22 23 namespace agg 24 { 25 26 //================================================span_interpolator_linear 27 template<class Transformer = trans_affine, unsigned SubpixelShift = 8> 28 class span_interpolator_linear 29 { 30 public: 31 typedef Transformer trans_type; 32 33 enum 34 { 35 subpixel_shift = SubpixelShift, 36 subpixel_size = 1 << subpixel_shift 37 }; 38 39 //-------------------------------------------------------------------- 40 span_interpolator_linear() {} 41 span_interpolator_linear(const trans_type& trans) : m_trans(&trans) {} 42 span_interpolator_linear(const trans_type& trans, 43 double x, double y, unsigned len) : 44 m_trans(&trans) 45 { 46 begin(x, y, len); 47 } 48 49 //---------------------------------------------------------------- 50 const trans_type& transformer() const { return *m_trans; } 51 void transformer(const trans_type& trans) { m_trans = &trans; } 52 53 //---------------------------------------------------------------- 54 void begin(double x, double y, unsigned len) 55 { 56 double tx; 57 double ty; 58 59 tx = x; 60 ty = y; 61 m_trans->transform(&tx, &ty); 62 int x1 = int(tx * subpixel_size); 63 int y1 = int(ty * subpixel_size); 64 65 tx = x + len; 66 ty = y; 67 m_trans->transform(&tx, &ty); 68 int x2 = int(tx * subpixel_size); 69 int y2 = int(ty * subpixel_size); 70 71 m_li_x = dda2_line_interpolator(x1, x2, len); 72 m_li_y = dda2_line_interpolator(y1, y2, len); 73 } 74 75 //---------------------------------------------------------------- 76 void operator++() 77 { 78 ++m_li_x; 79 ++m_li_y; 80 } 81 82 //---------------------------------------------------------------- 83 void coordinates(int* x, int* y) const 84 { 85 *x = m_li_x.y(); 86 *y = m_li_y.y(); 87 } 88 89 private: 90 const trans_type* m_trans; 91 dda2_line_interpolator m_li_x; 92 dda2_line_interpolator m_li_y; 93 }; 94 95 } 96 97 98 99 #endif 100 101 102