headers/libs/agg/agg_rasterizer_sl_clip.h

   1 //----------------------------------------------------------------------------
   2 // Anti-Grain Geometry - Version 2.4
   3 // Copyright (C) 2002-2005 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 #ifndef AGG_RASTERIZER_SL_CLIP_INCLUDED
  16 #define AGG_RASTERIZER_SL_CLIP_INCLUDED
  17
  18 #include "agg_clip_liang_barsky.h"
  19
  20 namespace agg
  21 {
  22     //--------------------------------------------------------poly_max_coord_e
  23     enum poly_max_coord_e
  24     {
  25         poly_max_coord = (1 << 30) - 1 //----poly_max_coord
  26     };
  27
  28     //------------------------------------------------------------ras_conv_int
  29     struct ras_conv_int
  30     {
  31         typedef int coord_type;
  32         static AGG_INLINE int mul_div(double a, double b, double c)
  33         {
  34             return iround(a * b / c);
  35         }
  36         static int xi(int v) { return v; }
  37         static int yi(int v) { return v; }
  38         static int upscale(double v) { return iround(v * poly_subpixel_scale); }
  39         static int downscale(int v)  { return v; }
  40     };
  41
  42     //--------------------------------------------------------ras_conv_int_sat
  43     struct ras_conv_int_sat
  44     {
  45         typedef int coord_type;
  46         static AGG_INLINE int mul_div(double a, double b, double c)
  47         {
  48             return saturation<poly_max_coord>::iround(a * b / c);
  49         }
  50         static int xi(int v) { return v; }
  51         static int yi(int v) { return v; }
  52         static int upscale(double v)
  53         {
  54             return saturation<poly_max_coord>::iround(v * poly_subpixel_scale);
  55         }
  56         static int downscale(int v) { return v; }
  57     };
  58
  59     //---------------------------------------------------------ras_conv_int_3x
  60     struct ras_conv_int_3x
  61     {
  62         typedef int coord_type;
  63         static AGG_INLINE int mul_div(double a, double b, double c)
  64         {
  65             return iround(a * b / c);
  66         }
  67         static int xi(int v) { return v * 3; }
  68         static int yi(int v) { return v; }
  69         static int upscale(double v) { return iround(v * poly_subpixel_scale); }
  70         static int downscale(int v)  { return v; }
  71     };
  72
  73     //-----------------------------------------------------------ras_conv_dbl
  74     struct ras_conv_dbl
  75     {
  76         typedef double coord_type;
  77         static AGG_INLINE double mul_div(double a, double b, double c)
  78         {
  79             return a * b / c;
  80         }
  81         static int xi(double v) { return iround(v * poly_subpixel_scale); }
  82         static int yi(double v) { return iround(v * poly_subpixel_scale); }
  83         static double upscale(double v) { return v; }
  84         static double downscale(int v)  { return v / double(poly_subpixel_scale); }
  85     };
  86
  87     //--------------------------------------------------------ras_conv_dbl_3x
  88     struct ras_conv_dbl_3x
  89     {
  90         typedef double coord_type;
  91         static AGG_INLINE double mul_div(double a, double b, double c)
  92         {
  93             return a * b / c;
  94         }
  95         static int xi(double v) { return iround(v * poly_subpixel_scale * 3); }
  96         static int yi(double v) { return iround(v * poly_subpixel_scale); }
  97         static double upscale(double v) { return v; }
  98         static double downscale(int v)  { return v / double(poly_subpixel_scale); }
  99     };
 100
 101
 102
 103
 104
 105     //------------------------------------------------------rasterizer_sl_clip
 106     template<class Conv> class rasterizer_sl_clip
 107     {
 108     public:
 109         typedef Conv                      conv_type;
 110         typedef typename Conv::coord_type coord_type;
 111         typedef rect_base<coord_type>     rect_type;
 112
 113         //--------------------------------------------------------------------
 114         rasterizer_sl_clip() :
 115             m_clip_box(0,0,0,0),
 116             m_x1(0),
 117             m_y1(0),
 118             m_f1(0),
 119             m_clipping(false)
 120         {}
 121
 122         //--------------------------------------------------------------------
 123         void reset_clipping()
 124         {
 125             m_clipping = false;
 126         }
 127
 128         //--------------------------------------------------------------------
 129         void clip_box(coord_type x1, coord_type y1, coord_type x2, coord_type y2)
 130         {
 131             m_clip_box = rect_type(x1, y1, x2, y2);
 132             m_clip_box.normalize();
 133             m_clipping = true;
 134         }
 135
 136         //--------------------------------------------------------------------
 137         void move_to(coord_type x1, coord_type y1)
 138         {
 139             m_x1 = x1;
 140             m_y1 = y1;
 141             if(m_clipping) m_f1 = clipping_flags(x1, y1, m_clip_box);
 142         }
 143
 144     private:
 145         //------------------------------------------------------------------------
 146         template<class Rasterizer>
 147         AGG_INLINE void line_clip_y(Rasterizer& ras,
 148                                     coord_type x1, coord_type y1,
 149                                     coord_type x2, coord_type y2,
 150                                     unsigned   f1, unsigned   f2) const
 151         {
 152             f1 &= 10;
 153             f2 &= 10;
 154             if((f1 | f2) == 0)
 155             {
 156                 // Fully visible
 157                 ras.line(Conv::xi(x1), Conv::yi(y1), Conv::xi(x2), Conv::yi(y2));
 158             }
 159             else
 160             {
 161                 if(f1 == f2)
 162                 {
 163                     // Invisible by Y
 164                     return;
 165                 }
 166
 167                 coord_type tx1 = x1;
 168                 coord_type ty1 = y1;
 169                 coord_type tx2 = x2;
 170                 coord_type ty2 = y2;
 171
 172                 if(f1 & 8) // y1 < clip.y1
 173                 {
 174                     tx1 = x1 + Conv::mul_div(m_clip_box.y1-y1, x2-x1, y2-y1);
 175                     ty1 = m_clip_box.y1;
 176                 }
 177
 178                 if(f1 & 2) // y1 > clip.y2
 179                 {
 180                     tx1 = x1 + Conv::mul_div(m_clip_box.y2-y1, x2-x1, y2-y1);
 181                     ty1 = m_clip_box.y2;
 182                 }
 183
 184                 if(f2 & 8) // y2 < clip.y1
 185                 {
 186                     tx2 = x1 + Conv::mul_div(m_clip_box.y1-y1, x2-x1, y2-y1);
 187                     ty2 = m_clip_box.y1;
 188                 }
 189
 190                 if(f2 & 2) // y2 > clip.y2
 191                 {
 192                     tx2 = x1 + Conv::mul_div(m_clip_box.y2-y1, x2-x1, y2-y1);
 193                     ty2 = m_clip_box.y2;
 194                 }
 195                 ras.line(Conv::xi(tx1), Conv::yi(ty1),
 196                          Conv::xi(tx2), Conv::yi(ty2));
 197             }
 198         }
 199
 200
 201     public:
 202         //--------------------------------------------------------------------
 203         template<class Rasterizer>
 204         void line_to(Rasterizer& ras, coord_type x2, coord_type y2)
 205         {
 206             if(m_clipping)
 207             {
 208                 unsigned f2 = clipping_flags(x2, y2, m_clip_box);
 209
 210                 if((m_f1 & 10) == (f2 & 10) && (m_f1 & 10) != 0)
 211                 {
 212                     // Invisible by Y
 213                     m_x1 = x2;
 214                     m_y1 = y2;
 215                     m_f1 = f2;
 216                     return;
 217                 }
 218
 219                 coord_type x1 = m_x1;
 220                 coord_type y1 = m_y1;
 221                 unsigned   f1 = m_f1;
 222                 coord_type y3, y4;
 223                 unsigned   f3, f4;
 224
 225                 switch(((f1 & 5) << 1) | (f2 & 5))
 226                 {
 227                 case 0: // Visible by X
 228                     line_clip_y(ras, x1, y1, x2, y2, f1, f2);
 229                     break;
 230
 231                 case 1: // x2 > clip.x2
 232                     y3 = y1 + Conv::mul_div(m_clip_box.x2-x1, y2-y1, x2-x1);
 233                     f3 = clipping_flags_y(y3, m_clip_box);
 234                     line_clip_y(ras, x1, y1, m_clip_box.x2, y3, f1, f3);
 235                     line_clip_y(ras, m_clip_box.x2, y3, m_clip_box.x2, y2, f3, f2);
 236                     break;
 237
 238                 case 2: // x1 > clip.x2
 239                     y3 = y1 + Conv::mul_div(m_clip_box.x2-x1, y2-y1, x2-x1);
 240                     f3 = clipping_flags_y(y3, m_clip_box);
 241                     line_clip_y(ras, m_clip_box.x2, y1, m_clip_box.x2, y3, f1, f3);
 242                     line_clip_y(ras, m_clip_box.x2, y3, x2, y2, f3, f2);
 243                     break;
 244
 245                 case 3: // x1 > clip.x2 && x2 > clip.x2
 246                     line_clip_y(ras, m_clip_box.x2, y1, m_clip_box.x2, y2, f1, f2);
 247                     break;
 248
 249                 case 4: // x2 < clip.x1
 250                     y3 = y1 + Conv::mul_div(m_clip_box.x1-x1, y2-y1, x2-x1);
 251                     f3 = clipping_flags_y(y3, m_clip_box);
 252                     line_clip_y(ras, x1, y1, m_clip_box.x1, y3, f1, f3);
 253                     line_clip_y(ras, m_clip_box.x1, y3, m_clip_box.x1, y2, f3, f2);
 254                     break;
 255
 256                 case 6: // x1 > clip.x2 && x2 < clip.x1
 257                     y3 = y1 + Conv::mul_div(m_clip_box.x2-x1, y2-y1, x2-x1);
 258                     y4 = y1 + Conv::mul_div(m_clip_box.x1-x1, y2-y1, x2-x1);
 259                     f3 = clipping_flags_y(y3, m_clip_box);
 260                     f4 = clipping_flags_y(y4, m_clip_box);
 261                     line_clip_y(ras, m_clip_box.x2, y1, m_clip_box.x2, y3, f1, f3);
 262                     line_clip_y(ras, m_clip_box.x2, y3, m_clip_box.x1, y4, f3, f4);
 263                     line_clip_y(ras, m_clip_box.x1, y4, m_clip_box.x1, y2, f4, f2);
 264                     break;
 265
 266                 case 8: // x1 < clip.x1
 267                     y3 = y1 + Conv::mul_div(m_clip_box.x1-x1, y2-y1, x2-x1);
 268                     f3 = clipping_flags_y(y3, m_clip_box);
 269                     line_clip_y(ras, m_clip_box.x1, y1, m_clip_box.x1, y3, f1, f3);
 270                     line_clip_y(ras, m_clip_box.x1, y3, x2, y2, f3, f2);
 271                     break;
 272
 273                 case 9:  // x1 < clip.x1 && x2 > clip.x2
 274                     y3 = y1 + Conv::mul_div(m_clip_box.x1-x1, y2-y1, x2-x1);
 275                     y4 = y1 + Conv::mul_div(m_clip_box.x2-x1, y2-y1, x2-x1);
 276                     f3 = clipping_flags_y(y3, m_clip_box);
 277                     f4 = clipping_flags_y(y4, m_clip_box);
 278                     line_clip_y(ras, m_clip_box.x1, y1, m_clip_box.x1, y3, f1, f3);
 279                     line_clip_y(ras, m_clip_box.x1, y3, m_clip_box.x2, y4, f3, f4);
 280                     line_clip_y(ras, m_clip_box.x2, y4, m_clip_box.x2, y2, f4, f2);
 281                     break;
 282
 283                 case 12: // x1 < clip.x1 && x2 < clip.x1
 284                     line_clip_y(ras, m_clip_box.x1, y1, m_clip_box.x1, y2, f1, f2);
 285                     break;
 286                 }
 287                 m_f1 = f2;
 288             }
 289             else
 290             {
 291                 ras.line(Conv::xi(m_x1), Conv::yi(m_y1),
 292                          Conv::xi(x2),   Conv::yi(y2));
 293             }
 294             m_x1 = x2;
 295             m_y1 = y2;
 296         }
 297
 298
 299     private:
 300         rect_type        m_clip_box;
 301         coord_type       m_x1;
 302         coord_type       m_y1;
 303         unsigned         m_f1;
 304         bool             m_clipping;
 305     };
 306
 307
 308
 309
 310     //---------------------------------------------------rasterizer_sl_no_clip
 311     class rasterizer_sl_no_clip
 312     {
 313     public:
 314         typedef ras_conv_int conv_type;
 315         typedef int          coord_type;
 316
 317         rasterizer_sl_no_clip() : m_x1(0), m_y1(0) {}
 318
 319         void reset_clipping() {}
 320         void clip_box(coord_type x1, coord_type y1, coord_type x2, coord_type y2) {}
 321         void move_to(coord_type x1, coord_type y1) { m_x1 = x1; m_y1 = y1; }
 322
 323         template<class Rasterizer>
 324         void line_to(Rasterizer& ras, coord_type x2, coord_type y2)
 325         {
 326             ras.line(m_x1, m_y1, x2, y2);
 327             m_x1 = x2;
 328             m_y1 = y2;
 329         }
 330
 331     private:
 332         int m_x1, m_y1;
 333     };
 334
 335
 336     //                                         -----rasterizer_sl_clip_int
 337     //                                         -----rasterizer_sl_clip_int_sat
 338     //                                         -----rasterizer_sl_clip_int_3x
 339     //                                         -----rasterizer_sl_clip_dbl
 340     //                                         -----rasterizer_sl_clip_dbl_3x
 341     //------------------------------------------------------------------------
 342     typedef rasterizer_sl_clip<ras_conv_int>     rasterizer_sl_clip_int;
 343     typedef rasterizer_sl_clip<ras_conv_int_sat> rasterizer_sl_clip_int_sat;
 344     typedef rasterizer_sl_clip<ras_conv_int_3x>  rasterizer_sl_clip_int_3x;
 345     typedef rasterizer_sl_clip<ras_conv_dbl>     rasterizer_sl_clip_dbl;
 346     typedef rasterizer_sl_clip<ras_conv_dbl_3x>  rasterizer_sl_clip_dbl_3x;
 347
 348
 349 }
 350
 351 #endif