gfx/harfbuzz/src/hb-paint-extents.cc

   1 /*
   2  * Copyright © 2022 Behdad Esfahbod
   3  *
   4  *  This is part of HarfBuzz, a text shaping library.
   5  *
   6  * Permission is hereby granted, without written agreement and without
   7  * license or royalty fees, to use, copy, modify, and distribute this
   8  * software and its documentation for any purpose, provided that the
   9  * above copyright notice and the following two paragraphs appear in
  10  * all copies of this software.
  11  *
  12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  16  * DAMAGE.
  17  *
  18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  23  */
  24
  25 #include "hb.hh"
  26
  27 #ifndef HB_NO_PAINT
  28
  29 #include "hb-paint-extents.hh"
  30
  31 #include "hb-draw.h"
  32
  33 #include "hb-machinery.hh"
  34
  35
  36 /*
  37  * This file implements bounds-extraction as well as boundedness
  38  * computation of COLRv1 fonts as described in:
  39  *
  40  * https://learn.microsoft.com/en-us/typography/opentype/spec/colr#glyph-metrics-and-boundedness
  41  */
  42
  43 static void
  44 hb_paint_extents_push_transform (hb_paint_funcs_t *funcs HB_UNUSED,
  45                                  void *paint_data,
  46                                  float xx, float yx,
  47                                  float xy, float yy,
  48                                  float dx, float dy,
  49                                  void *user_data HB_UNUSED)
  50 {
  51   hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
  52
  53   c->push_transform (hb_transform_t {xx, yx, xy, yy, dx, dy});
  54 }
  55
  56 static void
  57 hb_paint_extents_pop_transform (hb_paint_funcs_t *funcs HB_UNUSED,
  58                                 void *paint_data,
  59                                 void *user_data HB_UNUSED)
  60 {
  61   hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
  62
  63   c->pop_transform ();
  64 }
  65
  66 static void
  67 hb_draw_extents_move_to (hb_draw_funcs_t *dfuncs HB_UNUSED,
  68                          void *data,
  69                          hb_draw_state_t *st,
  70                          float to_x, float to_y,
  71                          void *user_data HB_UNUSED)
  72 {
  73   hb_extents_t *extents = (hb_extents_t *) data;
  74
  75   extents->add_point (to_x, to_y);
  76 }
  77
  78 static void
  79 hb_draw_extents_line_to (hb_draw_funcs_t *dfuncs HB_UNUSED,
  80                          void *data,
  81                          hb_draw_state_t *st,
  82                          float to_x, float to_y,
  83                          void *user_data HB_UNUSED)
  84 {
  85   hb_extents_t *extents = (hb_extents_t *) data;
  86
  87   extents->add_point (to_x, to_y);
  88 }
  89
  90 static void
  91 hb_draw_extents_quadratic_to (hb_draw_funcs_t *dfuncs HB_UNUSED,
  92                               void *data,
  93                               hb_draw_state_t *st,
  94                               float control_x, float control_y,
  95                               float to_x, float to_y,
  96                               void *user_data HB_UNUSED)
  97 {
  98   hb_extents_t *extents = (hb_extents_t *) data;
  99
 100   extents->add_point (control_x, control_y);
 101   extents->add_point (to_x, to_y);
 102 }
 103
 104 static void
 105 hb_draw_extents_cubic_to (hb_draw_funcs_t *dfuncs HB_UNUSED,
 106                           void *data,
 107                           hb_draw_state_t *st,
 108                           float control1_x, float control1_y,
 109                           float control2_x, float control2_y,
 110                           float to_x, float to_y,
 111                           void *user_data HB_UNUSED)
 112 {
 113   hb_extents_t *extents = (hb_extents_t *) data;
 114
 115   extents->add_point (control1_x, control1_y);
 116   extents->add_point (control2_x, control2_y);
 117   extents->add_point (to_x, to_y);
 118 }
 119
 120 static inline void free_static_draw_extents_funcs ();
 121
 122 static struct hb_draw_extents_funcs_lazy_loader_t : hb_draw_funcs_lazy_loader_t<hb_draw_extents_funcs_lazy_loader_t>
 123 {
 124   static hb_draw_funcs_t *create ()
 125   {
 126     hb_draw_funcs_t *funcs = hb_draw_funcs_create ();
 127
 128     hb_draw_funcs_set_move_to_func (funcs, hb_draw_extents_move_to, nullptr, nullptr);
 129     hb_draw_funcs_set_line_to_func (funcs, hb_draw_extents_line_to, nullptr, nullptr);
 130     hb_draw_funcs_set_quadratic_to_func (funcs, hb_draw_extents_quadratic_to, nullptr, nullptr);
 131     hb_draw_funcs_set_cubic_to_func (funcs, hb_draw_extents_cubic_to, nullptr, nullptr);
 132
 133     hb_draw_funcs_make_immutable (funcs);
 134
 135     hb_atexit (free_static_draw_extents_funcs);
 136
 137     return funcs;
 138   }
 139 } static_draw_extents_funcs;
 140
 141 static inline
 142 void free_static_draw_extents_funcs ()
 143 {
 144   static_draw_extents_funcs.free_instance ();
 145 }
 146
 147 static hb_draw_funcs_t *
 148 hb_draw_extents_get_funcs ()
 149 {
 150   return static_draw_extents_funcs.get_unconst ();
 151 }
 152
 153 static void
 154 hb_paint_extents_push_clip_glyph (hb_paint_funcs_t *funcs HB_UNUSED,
 155                                   void *paint_data,
 156                                   hb_codepoint_t glyph,
 157                                   hb_font_t *font,
 158                                   void *user_data HB_UNUSED)
 159 {
 160   hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
 161
 162   hb_extents_t extents;
 163   hb_draw_funcs_t *draw_extent_funcs = hb_draw_extents_get_funcs ();
 164   hb_font_draw_glyph (font, glyph, draw_extent_funcs, &extents);
 165   c->push_clip (extents);
 166 }
 167
 168 static void
 169 hb_paint_extents_push_clip_rectangle (hb_paint_funcs_t *funcs HB_UNUSED,
 170                                       void *paint_data,
 171                                       float xmin, float ymin, float xmax, float ymax,
 172                                       void *user_data)
 173 {
 174   hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
 175
 176   hb_extents_t extents = {xmin, ymin, xmax, ymax};
 177   c->push_clip (extents);
 178 }
 179
 180 static void
 181 hb_paint_extents_pop_clip (hb_paint_funcs_t *funcs HB_UNUSED,
 182                            void *paint_data,
 183                            void *user_data HB_UNUSED)
 184 {
 185   hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
 186
 187   c->pop_clip ();
 188 }
 189
 190 static void
 191 hb_paint_extents_push_group (hb_paint_funcs_t *funcs HB_UNUSED,
 192                              void *paint_data,
 193                              void *user_data HB_UNUSED)
 194 {
 195   hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
 196
 197   c->push_group ();
 198 }
 199
 200 static void
 201 hb_paint_extents_pop_group (hb_paint_funcs_t *funcs HB_UNUSED,
 202                             void *paint_data,
 203                             hb_paint_composite_mode_t mode,
 204                             void *user_data HB_UNUSED)
 205 {
 206   hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
 207
 208   c->pop_group (mode);
 209 }
 210
 211 static hb_bool_t
 212 hb_paint_extents_paint_image (hb_paint_funcs_t *funcs HB_UNUSED,
 213                               void *paint_data,
 214                               hb_blob_t *blob HB_UNUSED,
 215                               unsigned int width HB_UNUSED,
 216                               unsigned int height HB_UNUSED,
 217                               hb_tag_t format HB_UNUSED,
 218                               float slant HB_UNUSED,
 219                               hb_glyph_extents_t *glyph_extents,
 220                               void *user_data HB_UNUSED)
 221 {
 222   hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
 223
 224   hb_extents_t extents = {(float) glyph_extents->x_bearing,
 225                           (float) glyph_extents->y_bearing + glyph_extents->height,
 226                           (float) glyph_extents->x_bearing + glyph_extents->width,
 227                           (float) glyph_extents->y_bearing};
 228   c->push_clip (extents);
 229   c->paint ();
 230   c->pop_clip ();
 231
 232   return true;
 233 }
 234
 235 static void
 236 hb_paint_extents_paint_color (hb_paint_funcs_t *funcs HB_UNUSED,
 237                               void *paint_data,
 238                               hb_bool_t use_foreground HB_UNUSED,
 239                               hb_color_t color HB_UNUSED,
 240                               void *user_data HB_UNUSED)
 241 {
 242   hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
 243
 244   c->paint ();
 245 }
 246
 247 static void
 248 hb_paint_extents_paint_linear_gradient (hb_paint_funcs_t *funcs HB_UNUSED,
 249                                         void *paint_data,
 250                                         hb_color_line_t *color_line HB_UNUSED,
 251                                         float x0 HB_UNUSED, float y0 HB_UNUSED,
 252                                         float x1 HB_UNUSED, float y1 HB_UNUSED,
 253                                         float x2 HB_UNUSED, float y2 HB_UNUSED,
 254                                         void *user_data HB_UNUSED)
 255 {
 256   hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
 257
 258   c->paint ();
 259 }
 260
 261 static void
 262 hb_paint_extents_paint_radial_gradient (hb_paint_funcs_t *funcs HB_UNUSED,
 263                                         void *paint_data,
 264                                         hb_color_line_t *color_line HB_UNUSED,
 265                                         float x0 HB_UNUSED, float y0 HB_UNUSED, float r0 HB_UNUSED,
 266                                         float x1 HB_UNUSED, float y1 HB_UNUSED, float r1 HB_UNUSED,
 267                                         void *user_data HB_UNUSED)
 268 {
 269   hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
 270
 271   c->paint ();
 272 }
 273
 274 static void
 275 hb_paint_extents_paint_sweep_gradient (hb_paint_funcs_t *funcs HB_UNUSED,
 276                                        void *paint_data,
 277                                        hb_color_line_t *color_line HB_UNUSED,
 278                                        float cx HB_UNUSED, float cy HB_UNUSED,
 279                                        float start_angle HB_UNUSED,
 280                                        float end_angle HB_UNUSED,
 281                                        void *user_data HB_UNUSED)
 282 {
 283   hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
 284
 285   c->paint ();
 286 }
 287
 288 static inline void free_static_paint_extents_funcs ();
 289
 290 static struct hb_paint_extents_funcs_lazy_loader_t : hb_paint_funcs_lazy_loader_t<hb_paint_extents_funcs_lazy_loader_t>
 291 {
 292   static hb_paint_funcs_t *create ()
 293   {
 294     hb_paint_funcs_t *funcs = hb_paint_funcs_create ();
 295
 296     hb_paint_funcs_set_push_transform_func (funcs, hb_paint_extents_push_transform, nullptr, nullptr);
 297     hb_paint_funcs_set_pop_transform_func (funcs, hb_paint_extents_pop_transform, nullptr, nullptr);
 298     hb_paint_funcs_set_push_clip_glyph_func (funcs, hb_paint_extents_push_clip_glyph, nullptr, nullptr);
 299     hb_paint_funcs_set_push_clip_rectangle_func (funcs, hb_paint_extents_push_clip_rectangle, nullptr, nullptr);
 300     hb_paint_funcs_set_pop_clip_func (funcs, hb_paint_extents_pop_clip, nullptr, nullptr);
 301     hb_paint_funcs_set_push_group_func (funcs, hb_paint_extents_push_group, nullptr, nullptr);
 302     hb_paint_funcs_set_pop_group_func (funcs, hb_paint_extents_pop_group, nullptr, nullptr);
 303     hb_paint_funcs_set_color_func (funcs, hb_paint_extents_paint_color, nullptr, nullptr);
 304     hb_paint_funcs_set_image_func (funcs, hb_paint_extents_paint_image, nullptr, nullptr);
 305     hb_paint_funcs_set_linear_gradient_func (funcs, hb_paint_extents_paint_linear_gradient, nullptr, nullptr);
 306     hb_paint_funcs_set_radial_gradient_func (funcs, hb_paint_extents_paint_radial_gradient, nullptr, nullptr);
 307     hb_paint_funcs_set_sweep_gradient_func (funcs, hb_paint_extents_paint_sweep_gradient, nullptr, nullptr);
 308
 309     hb_paint_funcs_make_immutable (funcs);
 310
 311     hb_atexit (free_static_paint_extents_funcs);
 312
 313     return funcs;
 314   }
 315 } static_paint_extents_funcs;
 316
 317 static inline
 318 void free_static_paint_extents_funcs ()
 319 {
 320   static_paint_extents_funcs.free_instance ();
 321 }
 322
 323 hb_paint_funcs_t *
 324 hb_paint_extents_get_funcs ()
 325 {
 326   return static_paint_extents_funcs.get_unconst ();
 327 }
 328
 329
 330 #endif