xref: /aosp_15_r20/external/harfbuzz_ng/src/hb-paint.h (revision 2d1272b857b1f7575e6e246373e1cb218663db8a)
1 /*
2  * Copyright © 2022 Matthias Clasen
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 #if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
26 #error "Include <hb.h> instead."
27 #endif
28 
29 #ifndef HB_PAINT_H
30 #define HB_PAINT_H
31 
32 #include "hb-common.h"
33 
34 HB_BEGIN_DECLS
35 
36 
37 /**
38  * hb_paint_funcs_t:
39  *
40  * Glyph paint callbacks.
41  *
42  * The callbacks assume that the caller maintains a stack
43  * of current transforms, clips and intermediate surfaces,
44  * as evidenced by the pairs of push/pop callbacks. The
45  * push/pop calls will be properly nested, so it is fine
46  * to store the different kinds of object on a single stack.
47  *
48  * Not all callbacks are required for all kinds of glyphs.
49  * For rendering COLRv0 or non-color outline glyphs, the
50  * gradient callbacks are not needed, and the composite
51  * callback only needs to handle simple alpha compositing
52  * (#HB_PAINT_COMPOSITE_MODE_SRC_OVER).
53  *
54  * The paint-image callback is only needed for glyphs
55  * with image blobs in the CBDT, sbix or SVG tables.
56  *
57  * The custom-palette-color callback is only necessary if
58  * you want to override colors from the font palette with
59  * custom colors.
60  *
61  * Since: 7.0.0
62  **/
63 typedef struct hb_paint_funcs_t hb_paint_funcs_t;
64 
65 HB_EXTERN hb_paint_funcs_t *
66 hb_paint_funcs_create (void);
67 
68 HB_EXTERN hb_paint_funcs_t *
69 hb_paint_funcs_get_empty (void);
70 
71 HB_EXTERN hb_paint_funcs_t *
72 hb_paint_funcs_reference (hb_paint_funcs_t *funcs);
73 
74 HB_EXTERN void
75 hb_paint_funcs_destroy (hb_paint_funcs_t *funcs);
76 
77 HB_EXTERN hb_bool_t
78 hb_paint_funcs_set_user_data (hb_paint_funcs_t *funcs,
79 			      hb_user_data_key_t *key,
80 			      void *              data,
81 			      hb_destroy_func_t   destroy,
82 			      hb_bool_t           replace);
83 
84 
85 HB_EXTERN void *
86 hb_paint_funcs_get_user_data (const hb_paint_funcs_t *funcs,
87 			      hb_user_data_key_t       *key);
88 
89 HB_EXTERN void
90 hb_paint_funcs_make_immutable (hb_paint_funcs_t *funcs);
91 
92 HB_EXTERN hb_bool_t
93 hb_paint_funcs_is_immutable (hb_paint_funcs_t *funcs);
94 
95 /**
96  * hb_paint_push_transform_func_t:
97  * @funcs: paint functions object
98  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
99  * @xx: xx component of the transform matrix
100  * @yx: yx component of the transform matrix
101  * @xy: xy component of the transform matrix
102  * @yy: yy component of the transform matrix
103  * @dx: dx component of the transform matrix
104  * @dy: dy component of the transform matrix
105  * @user_data: User data pointer passed to hb_paint_funcs_set_push_transform_func()
106  *
107  * A virtual method for the #hb_paint_funcs_t to apply
108  * a transform to subsequent paint calls.
109  *
110  * This transform is applied after the current transform,
111  * and remains in effect until a matching call to
112  * the #hb_paint_funcs_pop_transform_func_t vfunc.
113  *
114  * Since: 7.0.0
115  */
116 typedef void (*hb_paint_push_transform_func_t) (hb_paint_funcs_t *funcs,
117                                                 void *paint_data,
118                                                 float xx, float yx,
119                                                 float xy, float yy,
120                                                 float dx, float dy,
121                                                 void *user_data);
122 
123 /**
124  * hb_paint_pop_transform_func_t:
125  * @funcs: paint functions object
126  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
127  * @user_data: User data pointer passed to hb_paint_funcs_set_pop_transform_func()
128  *
129  * A virtual method for the #hb_paint_funcs_t to undo
130  * the effect of a prior call to the #hb_paint_funcs_push_transform_func_t
131  * vfunc.
132  *
133  * Since: 7.0.0
134  */
135 typedef void (*hb_paint_pop_transform_func_t) (hb_paint_funcs_t *funcs,
136                                                void *paint_data,
137                                                void *user_data);
138 
139 /**
140  * hb_paint_color_glyph_func_t:
141  * @funcs: paint functions object
142  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
143  * @glyph: the glyph ID
144  * @font: the font
145  * @user_data: User data pointer passed to hb_paint_funcs_set_color_glyph_func()
146  *
147  * A virtual method for the #hb_paint_funcs_t to render a color glyph by glyph index.
148  *
149  * Return value: %true if the glyph was painted, %false otherwise.
150  *
151  * Since: 8.2.0
152  */
153 typedef hb_bool_t (*hb_paint_color_glyph_func_t) (hb_paint_funcs_t *funcs,
154                                                   void *paint_data,
155                                                   hb_codepoint_t glyph,
156                                                   hb_font_t *font,
157                                                   void *user_data);
158 
159 /**
160  * hb_paint_push_clip_glyph_func_t:
161  * @funcs: paint functions object
162  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
163  * @glyph: the glyph ID
164  * @font: the font
165  * @user_data: User data pointer passed to hb_paint_funcs_set_push_clip_glyph_func()
166  *
167  * A virtual method for the #hb_paint_funcs_t to clip
168  * subsequent paint calls to the outline of a glyph.
169  *
170  * The coordinates of the glyph outline are interpreted according
171  * to the current transform.
172  *
173  * This clip is applied in addition to the current clip,
174  * and remains in effect until a matching call to
175  * the #hb_paint_funcs_pop_clip_func_t vfunc.
176  *
177  * Since: 7.0.0
178  */
179 typedef void (*hb_paint_push_clip_glyph_func_t) (hb_paint_funcs_t *funcs,
180                                                  void *paint_data,
181                                                  hb_codepoint_t glyph,
182                                                  hb_font_t *font,
183                                                  void *user_data);
184 
185 /**
186  * hb_paint_push_clip_rectangle_func_t:
187  * @funcs: paint functions object
188  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
189  * @xmin: min X for the rectangle
190  * @ymin: min Y for the rectangle
191  * @xmax: max X for the rectangle
192  * @ymax: max Y for the rectangle
193  * @user_data: User data pointer passed to hb_paint_funcs_set_push_clip_rectangle_func()
194  *
195  * A virtual method for the #hb_paint_funcs_t to clip
196  * subsequent paint calls to a rectangle.
197  *
198  * The coordinates of the rectangle are interpreted according
199  * to the current transform.
200  *
201  * This clip is applied in addition to the current clip,
202  * and remains in effect until a matching call to
203  * the #hb_paint_funcs_pop_clip_func_t vfunc.
204  *
205  * Since: 7.0.0
206  */
207 typedef void (*hb_paint_push_clip_rectangle_func_t) (hb_paint_funcs_t *funcs,
208                                                      void *paint_data,
209                                                      float xmin, float ymin,
210                                                      float xmax, float ymax,
211                                                      void *user_data);
212 
213 /**
214  * hb_paint_pop_clip_func_t:
215  * @funcs: paint functions object
216  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
217  * @user_data: User data pointer passed to hb_paint_funcs_set_pop_clip_func()
218  *
219  * A virtual method for the #hb_paint_funcs_t to undo
220  * the effect of a prior call to the #hb_paint_funcs_push_clip_glyph_func_t
221  * or #hb_paint_funcs_push_clip_rectangle_func_t vfuncs.
222  *
223  * Since: 7.0.0
224  */
225 typedef void (*hb_paint_pop_clip_func_t) (hb_paint_funcs_t *funcs,
226                                           void *paint_data,
227                                           void *user_data);
228 
229 /**
230  * hb_paint_color_func_t:
231  * @funcs: paint functions object
232  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
233  * @is_foreground: whether the color is the foreground
234  * @color: The color to use, unpremultiplied
235  * @user_data: User data pointer passed to hb_paint_funcs_set_color_func()
236  *
237  * A virtual method for the #hb_paint_funcs_t to paint a
238  * color everywhere within the current clip.
239  *
240  * Since: 7.0.0
241  */
242 typedef void (*hb_paint_color_func_t) (hb_paint_funcs_t *funcs,
243                                        void *paint_data,
244                                        hb_bool_t is_foreground,
245                                        hb_color_t color,
246                                        void *user_data);
247 
248 /**
249  * HB_PAINT_IMAGE_FORMAT_PNG:
250  *
251  * Tag identifying PNG images in #hb_paint_image_func_t callbacks.
252  *
253  * Since: 7.0.0
254  */
255 #define HB_PAINT_IMAGE_FORMAT_PNG HB_TAG('p','n','g',' ')
256 
257 /**
258  * HB_PAINT_IMAGE_FORMAT_SVG:
259  *
260  * Tag identifying SVG images in #hb_paint_image_func_t callbacks.
261  *
262  * Since: 7.0.0
263  */
264 #define HB_PAINT_IMAGE_FORMAT_SVG HB_TAG('s','v','g',' ')
265 
266 /**
267  * HB_PAINT_IMAGE_FORMAT_BGRA:
268  *
269  * Tag identifying raw pixel-data images in #hb_paint_image_func_t callbacks.
270  * The data is in BGRA pre-multiplied sRGBA color-space format.
271  *
272  * Since: 7.0.0
273  */
274 #define HB_PAINT_IMAGE_FORMAT_BGRA HB_TAG('B','G','R','A')
275 
276 /**
277  * hb_paint_image_func_t:
278  * @funcs: paint functions object
279  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
280  * @image: the image data
281  * @width: width of the raster image in pixels, or 0
282  * @height: height of the raster image in pixels, or 0
283  * @format: the image format as a tag
284  * @slant: the synthetic slant ratio to be applied to the image during rendering
285  * @extents: (nullable): glyph extents for desired rendering
286  * @user_data: User data pointer passed to hb_paint_funcs_set_image_func()
287  *
288  * A virtual method for the #hb_paint_funcs_t to paint a glyph image.
289  *
290  * This method is called for glyphs with image blobs in the CBDT,
291  * sbix or SVG tables. The @format identifies the kind of data that
292  * is contained in @image. Possible values include #HB_PAINT_IMAGE_FORMAT_PNG,
293  * #HB_PAINT_IMAGE_FORMAT_SVG and #HB_PAINT_IMAGE_FORMAT_BGRA.
294  *
295  * The image dimensions and glyph extents are provided if available,
296  * and should be used to size and position the image.
297  *
298  * Return value: Whether the operation was successful.
299  *
300  * Since: 7.0.0
301  */
302 typedef hb_bool_t (*hb_paint_image_func_t) (hb_paint_funcs_t *funcs,
303 					    void *paint_data,
304 					    hb_blob_t *image,
305 					    unsigned int width,
306 					    unsigned int height,
307 					    hb_tag_t format,
308 					    float slant,
309 					    hb_glyph_extents_t *extents,
310 					    void *user_data);
311 
312 /**
313  * hb_color_stop_t:
314  * @offset: the offset of the color stop
315  * @is_foreground: whether the color is the foreground
316  * @color: the color, unpremultiplied
317  *
318  * Information about a color stop on a color line.
319  *
320  * Color lines typically have offsets ranging between 0 and 1,
321  * but that is not required.
322  *
323  * Note: despite @color being unpremultiplied here, interpolation in
324  * gradients shall happen in premultiplied space. See the OpenType spec
325  * [COLR](https://learn.microsoft.com/en-us/typography/opentype/spec/colr)
326  * section for details.
327  *
328  * Since: 7.0.0
329  */
330 typedef struct {
331   float offset;
332   hb_bool_t is_foreground;
333   hb_color_t color;
334 } hb_color_stop_t;
335 
336 /**
337  * hb_paint_extend_t:
338  * @HB_PAINT_EXTEND_PAD: Outside the defined interval,
339  *   the color of the closest color stop is used.
340  * @HB_PAINT_EXTEND_REPEAT: The color line is repeated over
341  *   repeated multiples of the defined interval
342  * @HB_PAINT_EXTEND_REFLECT: The color line is repeated over
343  *      repeated intervals, as for the repeat mode.
344  *      However, in each repeated interval, the ordering of
345  *      color stops is the reverse of the adjacent interval.
346  *
347  * The values of this enumeration determine how color values
348  * outside the minimum and maximum defined offset on a #hb_color_line_t
349  * are determined.
350  *
351  * See the OpenType spec [COLR](https://learn.microsoft.com/en-us/typography/opentype/spec/colr)
352  * section for details.
353  *
354  * Since: 7.0.0
355  */
356 typedef enum {
357   HB_PAINT_EXTEND_PAD,
358   HB_PAINT_EXTEND_REPEAT,
359   HB_PAINT_EXTEND_REFLECT
360 } hb_paint_extend_t;
361 
362 typedef struct hb_color_line_t hb_color_line_t;
363 
364 /**
365  * hb_color_line_get_color_stops_func_t:
366  * @color_line: a #hb_color_line_t object
367  * @color_line_data: the data accompanying @color_line
368  * @start: the index of the first color stop to return
369  * @count: (inout) (optional): Input = the maximum number of feature tags to return;
370  *     Output = the actual number of feature tags returned (may be zero)
371  * @color_stops: (out) (array length=count) (optional): Array of #hb_color_stop_t to populate
372  * @user_data: the data accompanying this method
373  *
374  * A virtual method for the #hb_color_line_t to fetch color stops.
375  *
376  * Return value: the total number of color stops in @color_line
377  *
378  * Since: 7.0.0
379  */
380 typedef unsigned int (*hb_color_line_get_color_stops_func_t) (hb_color_line_t *color_line,
381 							      void *color_line_data,
382 							      unsigned int start,
383 							      unsigned int *count,
384 							      hb_color_stop_t *color_stops,
385 							      void *user_data);
386 
387 /**
388  * hb_color_line_get_extend_func_t:
389  * @color_line: a #hb_color_line_t object
390  * @color_line_data: the data accompanying @color_line
391  * @user_data: the data accompanying this method
392  *
393  * A virtual method for the @hb_color_line_t to fetches the extend mode.
394  *
395  * Return value: the extend mode of @color_line
396  *
397  * Since: 7.0.0
398  */
399 typedef hb_paint_extend_t (*hb_color_line_get_extend_func_t) (hb_color_line_t *color_line,
400 							      void *color_line_data,
401 							      void *user_data);
402 
403 /**
404  * hb_color_line_t:
405  *
406  * A struct containing color information for a gradient.
407  *
408  * Since: 7.0.0
409  */
410 struct hb_color_line_t {
411   void *data;
412 
413   hb_color_line_get_color_stops_func_t get_color_stops;
414   void *get_color_stops_user_data;
415 
416   hb_color_line_get_extend_func_t get_extend;
417   void *get_extend_user_data;
418 
419   void *reserved0;
420   void *reserved1;
421   void *reserved2;
422   void *reserved3;
423   void *reserved5;
424   void *reserved6;
425   void *reserved7;
426   void *reserved8;
427 };
428 
429 HB_EXTERN unsigned int
430 hb_color_line_get_color_stops (hb_color_line_t *color_line,
431                                unsigned int start,
432                                unsigned int *count,
433                                hb_color_stop_t *color_stops);
434 
435 HB_EXTERN hb_paint_extend_t
436 hb_color_line_get_extend (hb_color_line_t *color_line);
437 
438 /**
439  * hb_paint_linear_gradient_func_t:
440  * @funcs: paint functions object
441  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
442  * @color_line: Color information for the gradient
443  * @x0: X coordinate of the first point
444  * @y0: Y coordinate of the first point
445  * @x1: X coordinate of the second point
446  * @y1: Y coordinate of the second point
447  * @x2: X coordinate of the third point
448  * @y2: Y coordinate of the third point
449  * @user_data: User data pointer passed to hb_paint_funcs_set_linear_gradient_func()
450  *
451  * A virtual method for the #hb_paint_funcs_t to paint a linear
452  * gradient everywhere within the current clip.
453  *
454  * The @color_line object contains information about the colors of the gradients.
455  * It is only valid for the duration of the callback, you cannot keep it around.
456  *
457  * The coordinates of the points are interpreted according
458  * to the current transform.
459  *
460  * See the OpenType spec [COLR](https://learn.microsoft.com/en-us/typography/opentype/spec/colr)
461  * section for details on how the points define the direction
462  * of the gradient, and how to interpret the @color_line.
463  *
464  * Since: 7.0.0
465  */
466 typedef void (*hb_paint_linear_gradient_func_t) (hb_paint_funcs_t *funcs,
467                                                  void *paint_data,
468                                                  hb_color_line_t *color_line,
469                                                  float x0, float y0,
470                                                  float x1, float y1,
471                                                  float x2, float y2,
472                                                  void *user_data);
473 
474 /**
475  * hb_paint_radial_gradient_func_t:
476  * @funcs: paint functions object
477  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
478  * @color_line: Color information for the gradient
479  * @x0: X coordinate of the first circle's center
480  * @y0: Y coordinate of the first circle's center
481  * @r0: radius of the first circle
482  * @x1: X coordinate of the second circle's center
483  * @y1: Y coordinate of the second circle's center
484  * @r1: radius of the second circle
485  * @user_data: User data pointer passed to hb_paint_funcs_set_radial_gradient_func()
486  *
487  * A virtual method for the #hb_paint_funcs_t to paint a radial
488  * gradient everywhere within the current clip.
489  *
490  * The @color_line object contains information about the colors of the gradients.
491  * It is only valid for the duration of the callback, you cannot keep it around.
492  *
493  * The coordinates of the points are interpreted according
494  * to the current transform.
495  *
496  * See the OpenType spec [COLR](https://learn.microsoft.com/en-us/typography/opentype/spec/colr)
497  * section for details on how the points define the direction
498  * of the gradient, and how to interpret the @color_line.
499  *
500  * Since: 7.0.0
501  */
502 typedef void (*hb_paint_radial_gradient_func_t) (hb_paint_funcs_t *funcs,
503                                                  void *paint_data,
504                                                  hb_color_line_t *color_line,
505                                                  float x0, float y0, float r0,
506                                                  float x1, float y1, float r1,
507                                                  void *user_data);
508 
509 /**
510  * hb_paint_sweep_gradient_func_t:
511  * @funcs: paint functions object
512  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
513  * @color_line: Color information for the gradient
514  * @x0: X coordinate of the circle's center
515  * @y0: Y coordinate of the circle's center
516  * @start_angle: the start angle, in radians
517  * @end_angle: the end angle, in radians
518  * @user_data: User data pointer passed to hb_paint_funcs_set_sweep_gradient_func()
519  *
520  * A virtual method for the #hb_paint_funcs_t to paint a sweep
521  * gradient everywhere within the current clip.
522  *
523  * The @color_line object contains information about the colors of the gradients.
524  * It is only valid for the duration of the callback, you cannot keep it around.
525  *
526  * The coordinates of the points are interpreted according
527  * to the current transform.
528  *
529  * See the OpenType spec [COLR](https://learn.microsoft.com/en-us/typography/opentype/spec/colr)
530  * section for details on how the points define the direction
531  * of the gradient, and how to interpret the @color_line.
532  *
533  * Since: 7.0.0
534  */
535 typedef void (*hb_paint_sweep_gradient_func_t)  (hb_paint_funcs_t *funcs,
536                                                  void *paint_data,
537                                                  hb_color_line_t *color_line,
538                                                  float x0, float y0,
539                                                  float start_angle,
540                                                  float end_angle,
541                                                  void *user_data);
542 
543 /**
544  * hb_paint_composite_mode_t:
545  * @HB_PAINT_COMPOSITE_MODE_CLEAR: clear destination layer (bounded)
546  * @HB_PAINT_COMPOSITE_MODE_SRC: replace destination layer (bounded)
547  * @HB_PAINT_COMPOSITE_MODE_SRC_OVER: draw source layer on top of destination layer
548  * (bounded)
549  * @HB_PAINT_COMPOSITE_MODE_SRC_IN: draw source where there was destination content
550  * (unbounded)
551  * @HB_PAINT_COMPOSITE_MODE_SRC_OUT: draw source where there was no destination
552  * content (unbounded)
553  * @HB_PAINT_COMPOSITE_MODE_SRC_ATOP: draw source on top of destination content and
554  * only there
555  * @HB_PAINT_COMPOSITE_MODE_DEST: ignore the source
556  * @HB_PAINT_COMPOSITE_MODE_DEST_OVER: draw destination on top of source
557  * @HB_PAINT_COMPOSITE_MODE_DEST_IN: leave destination only where there was
558  * source content (unbounded)
559  * @HB_PAINT_COMPOSITE_MODE_DEST_OUT: leave destination only where there was no
560  * source content
561  * @HB_PAINT_COMPOSITE_MODE_DEST_ATOP: leave destination on top of source content
562  * and only there (unbounded)
563  * @HB_PAINT_COMPOSITE_MODE_XOR: source and destination are shown where there is only
564  * one of them
565  * @HB_PAINT_COMPOSITE_MODE_PLUS: source and destination layers are accumulated
566  * @HB_PAINT_COMPOSITE_MODE_MULTIPLY: source and destination layers are multiplied.
567  * This causes the result to be at least as dark as the darker inputs.
568  * @HB_PAINT_COMPOSITE_MODE_SCREEN: source and destination are complemented and
569  * multiplied. This causes the result to be at least as light as the lighter
570  * inputs.
571  * @HB_PAINT_COMPOSITE_MODE_OVERLAY: multiplies or screens, depending on the
572  * lightness of the destination color.
573  * @HB_PAINT_COMPOSITE_MODE_DARKEN: replaces the destination with the source if it
574  * is darker, otherwise keeps the source.
575  * @HB_PAINT_COMPOSITE_MODE_LIGHTEN: replaces the destination with the source if it
576  * is lighter, otherwise keeps the source.
577  * @HB_PAINT_COMPOSITE_MODE_COLOR_DODGE: brightens the destination color to reflect
578  * the source color.
579  * @HB_PAINT_COMPOSITE_MODE_COLOR_BURN: darkens the destination color to reflect
580  * the source color.
581  * @HB_PAINT_COMPOSITE_MODE_HARD_LIGHT: Multiplies or screens, dependent on source
582  * color.
583  * @HB_PAINT_COMPOSITE_MODE_SOFT_LIGHT: Darkens or lightens, dependent on source
584  * color.
585  * @HB_PAINT_COMPOSITE_MODE_DIFFERENCE: Takes the difference of the source and
586  * destination color.
587  * @HB_PAINT_COMPOSITE_MODE_EXCLUSION: Produces an effect similar to difference, but
588  * with lower contrast.
589  * @HB_PAINT_COMPOSITE_MODE_HSL_HUE: Creates a color with the hue of the source
590  * and the saturation and luminosity of the target.
591  * @HB_PAINT_COMPOSITE_MODE_HSL_SATURATION: Creates a color with the saturation
592  * of the source and the hue and luminosity of the target. Painting with
593  * this mode onto a gray area produces no change.
594  * @HB_PAINT_COMPOSITE_MODE_HSL_COLOR: Creates a color with the hue and saturation
595  * of the source and the luminosity of the target. This preserves the gray
596  * levels of the target and is useful for coloring monochrome images or
597  * tinting color images.
598  * @HB_PAINT_COMPOSITE_MODE_HSL_LUMINOSITY: Creates a color with the luminosity of
599  * the source and the hue and saturation of the target. This produces an
600  * inverse effect to @HB_PAINT_COMPOSITE_MODE_HSL_COLOR.
601  *
602  * The values of this enumeration describe the compositing modes
603  * that can be used when combining temporary redirected drawing
604  * with the backdrop.
605  *
606  * See the OpenType spec [COLR](https://learn.microsoft.com/en-us/typography/opentype/spec/colr)
607  * section for details.
608  *
609  * Since: 7.0.0
610  */
611 typedef enum {
612   HB_PAINT_COMPOSITE_MODE_CLEAR,
613   HB_PAINT_COMPOSITE_MODE_SRC,
614   HB_PAINT_COMPOSITE_MODE_DEST,
615   HB_PAINT_COMPOSITE_MODE_SRC_OVER,
616   HB_PAINT_COMPOSITE_MODE_DEST_OVER,
617   HB_PAINT_COMPOSITE_MODE_SRC_IN,
618   HB_PAINT_COMPOSITE_MODE_DEST_IN,
619   HB_PAINT_COMPOSITE_MODE_SRC_OUT,
620   HB_PAINT_COMPOSITE_MODE_DEST_OUT,
621   HB_PAINT_COMPOSITE_MODE_SRC_ATOP,
622   HB_PAINT_COMPOSITE_MODE_DEST_ATOP,
623   HB_PAINT_COMPOSITE_MODE_XOR,
624   HB_PAINT_COMPOSITE_MODE_PLUS,
625   HB_PAINT_COMPOSITE_MODE_SCREEN,
626   HB_PAINT_COMPOSITE_MODE_OVERLAY,
627   HB_PAINT_COMPOSITE_MODE_DARKEN,
628   HB_PAINT_COMPOSITE_MODE_LIGHTEN,
629   HB_PAINT_COMPOSITE_MODE_COLOR_DODGE,
630   HB_PAINT_COMPOSITE_MODE_COLOR_BURN,
631   HB_PAINT_COMPOSITE_MODE_HARD_LIGHT,
632   HB_PAINT_COMPOSITE_MODE_SOFT_LIGHT,
633   HB_PAINT_COMPOSITE_MODE_DIFFERENCE,
634   HB_PAINT_COMPOSITE_MODE_EXCLUSION,
635   HB_PAINT_COMPOSITE_MODE_MULTIPLY,
636   HB_PAINT_COMPOSITE_MODE_HSL_HUE,
637   HB_PAINT_COMPOSITE_MODE_HSL_SATURATION,
638   HB_PAINT_COMPOSITE_MODE_HSL_COLOR,
639   HB_PAINT_COMPOSITE_MODE_HSL_LUMINOSITY
640 } hb_paint_composite_mode_t;
641 
642 /**
643  * hb_paint_push_group_func_t:
644  * @funcs: paint functions object
645  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
646  * @user_data: User data pointer passed to hb_paint_funcs_set_push_group_func()
647  *
648  * A virtual method for the #hb_paint_funcs_t to use
649  * an intermediate surface for subsequent paint calls.
650  *
651  * The drawing will be redirected to an intermediate surface
652  * until a matching call to the #hb_paint_funcs_pop_group_func_t
653  * vfunc.
654  *
655  * Since: 7.0.0
656  */
657 typedef void (*hb_paint_push_group_func_t) (hb_paint_funcs_t *funcs,
658                                             void *paint_data,
659                                             void *user_data);
660 
661 /**
662  * hb_paint_pop_group_func_t:
663  * @funcs: paint functions object
664  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
665  * @mode: the compositing mode to use
666  * @user_data: User data pointer passed to hb_paint_funcs_set_pop_group_func()
667  *
668  * A virtual method for the #hb_paint_funcs_t to undo
669  * the effect of a prior call to the #hb_paint_funcs_push_group_func_t
670  * vfunc.
671  *
672  * This call stops the redirection to the intermediate surface,
673  * and then composites it on the previous surface, using the
674  * compositing mode passed to this call.
675  *
676  * Since: 7.0.0
677  */
678 typedef void (*hb_paint_pop_group_func_t) (hb_paint_funcs_t *funcs,
679                                            void *paint_data,
680                                            hb_paint_composite_mode_t mode,
681                                            void *user_data);
682 
683 /**
684  * hb_paint_custom_palette_color_func_t:
685  * @funcs: paint functions object
686  * @paint_data: The data accompanying the paint functions in hb_font_paint_glyph()
687  * @color_index: the color index
688  * @color: (out): fetched color
689  * @user_data: User data pointer passed to hb_paint_funcs_set_pop_group_func()
690  *
691  * A virtual method for the #hb_paint_funcs_t to fetch a color from the custom
692  * color palette.
693  *
694  * Custom palette colors override the colors from the fonts selected color
695  * palette. It is not necessary to override all palette entries; for entries
696  * that should be taken from the font palette, return `false`.
697  *
698  * This function might get called multiple times, but the custom palette is
699  * expected to remain unchanged for duration of a hb_font_paint_glyph() call.
700  *
701  * Return value: `true` if found, `false` otherwise
702  *
703  * Since: 7.0.0
704  */
705 typedef hb_bool_t (*hb_paint_custom_palette_color_func_t) (hb_paint_funcs_t *funcs,
706                                                            void *paint_data,
707                                                            unsigned int color_index,
708                                                            hb_color_t *color,
709                                                            void *user_data);
710 
711 
712 /**
713  * hb_paint_funcs_set_push_transform_func:
714  * @funcs: A paint functions struct
715  * @func: (closure user_data) (destroy destroy) (scope notified): The push-transform callback
716  * @user_data: Data to pass to @func
717  * @destroy: (nullable): Function to call when @user_data is no longer needed
718  *
719  * Sets the push-transform callback on the paint functions struct.
720  *
721  * Since: 7.0.0
722  */
723 HB_EXTERN void
724 hb_paint_funcs_set_push_transform_func (hb_paint_funcs_t               *funcs,
725                                         hb_paint_push_transform_func_t  func,
726                                         void                           *user_data,
727                                         hb_destroy_func_t               destroy);
728 
729 /**
730  * hb_paint_funcs_set_pop_transform_func:
731  * @funcs: A paint functions struct
732  * @func: (closure user_data) (destroy destroy) (scope notified): The pop-transform callback
733  * @user_data: Data to pass to @func
734  * @destroy: (nullable): Function to call when @user_data is no longer needed
735  *
736  * Sets the pop-transform callback on the paint functions struct.
737  *
738  * Since: 7.0.0
739  */
740 HB_EXTERN void
741 hb_paint_funcs_set_pop_transform_func (hb_paint_funcs_t              *funcs,
742                                        hb_paint_pop_transform_func_t  func,
743                                        void                          *user_data,
744                                        hb_destroy_func_t              destroy);
745 
746 /**
747  * hb_paint_funcs_set_color_glyph_func:
748  * @funcs: A paint functions struct
749  * @func: (closure user_data) (destroy destroy) (scope notified): The color-glyph callback
750  * @user_data: Data to pass to @func
751  * @destroy: (nullable): Function to call when @user_data is no longer needed
752  *
753  * Sets the color-glyph callback on the paint functions struct.
754  *
755  * Since: 8.2.0
756  */
757 HB_EXTERN void
758 hb_paint_funcs_set_color_glyph_func (hb_paint_funcs_t                *funcs,
759 				     hb_paint_color_glyph_func_t     func,
760 				     void                            *user_data,
761 				     hb_destroy_func_t                destroy);
762 
763 /**
764  * hb_paint_funcs_set_push_clip_glyph_func:
765  * @funcs: A paint functions struct
766  * @func: (closure user_data) (destroy destroy) (scope notified): The push-clip-glyph callback
767  * @user_data: Data to pass to @func
768  * @destroy: (nullable): Function to call when @user_data is no longer needed
769  *
770  * Sets the push-clip-glyph callback on the paint functions struct.
771  *
772  * Since: 7.0.0
773  */
774 HB_EXTERN void
775 hb_paint_funcs_set_push_clip_glyph_func (hb_paint_funcs_t                *funcs,
776                                          hb_paint_push_clip_glyph_func_t  func,
777                                          void                            *user_data,
778                                          hb_destroy_func_t                destroy);
779 
780 /**
781  * hb_paint_funcs_set_push_clip_rectangle_func:
782  * @funcs: A paint functions struct
783  * @func: (closure user_data) (destroy destroy) (scope notified): The push-clip-rectangle callback
784  * @user_data: Data to pass to @func
785  * @destroy: (nullable): Function to call when @user_data is no longer needed
786  *
787  * Sets the push-clip-rect callback on the paint functions struct.
788  *
789  * Since: 7.0.0
790  */
791 HB_EXTERN void
792 hb_paint_funcs_set_push_clip_rectangle_func (hb_paint_funcs_t                    *funcs,
793                                              hb_paint_push_clip_rectangle_func_t  func,
794                                              void                                *user_data,
795                                              hb_destroy_func_t                    destroy);
796 
797 /**
798  * hb_paint_funcs_set_pop_clip_func:
799  * @funcs: A paint functions struct
800  * @func: (closure user_data) (destroy destroy) (scope notified): The pop-clip callback
801  * @user_data: Data to pass to @func
802  * @destroy: (nullable): Function to call when @user_data is no longer needed
803  *
804  * Sets the pop-clip callback on the paint functions struct.
805  *
806  * Since: 7.0.0
807  */
808 HB_EXTERN void
809 hb_paint_funcs_set_pop_clip_func (hb_paint_funcs_t         *funcs,
810                                   hb_paint_pop_clip_func_t  func,
811                                   void                     *user_data,
812                                   hb_destroy_func_t         destroy);
813 
814 /**
815  * hb_paint_funcs_set_color_func:
816  * @funcs: A paint functions struct
817  * @func: (closure user_data) (destroy destroy) (scope notified): The paint-color callback
818  * @user_data: Data to pass to @func
819  * @destroy: (nullable): Function to call when @user_data is no longer needed
820  *
821  * Sets the paint-color callback on the paint functions struct.
822  *
823  * Since: 7.0.0
824  */
825 HB_EXTERN void
826 hb_paint_funcs_set_color_func (hb_paint_funcs_t      *funcs,
827                                hb_paint_color_func_t  func,
828                                void                  *user_data,
829                                hb_destroy_func_t      destroy);
830 
831 /**
832  * hb_paint_funcs_set_image_func:
833  * @funcs: A paint functions struct
834  * @func: (closure user_data) (destroy destroy) (scope notified): The paint-image callback
835  * @user_data: Data to pass to @func
836  * @destroy: (nullable): Function to call when @user_data is no longer needed
837  *
838  * Sets the paint-image callback on the paint functions struct.
839  *
840  * Since: 7.0.0
841  */
842 HB_EXTERN void
843 hb_paint_funcs_set_image_func (hb_paint_funcs_t      *funcs,
844                                hb_paint_image_func_t  func,
845                                void                  *user_data,
846                                hb_destroy_func_t      destroy);
847 
848 /**
849  * hb_paint_funcs_set_linear_gradient_func:
850  * @funcs: A paint functions struct
851  * @func: (closure user_data) (destroy destroy) (scope notified): The linear-gradient callback
852  * @user_data: Data to pass to @func
853  * @destroy: (nullable): Function to call when @user_data is no longer needed
854  *
855  * Sets the linear-gradient callback on the paint functions struct.
856  *
857  * Since: 7.0.0
858  */
859 HB_EXTERN void
860 hb_paint_funcs_set_linear_gradient_func (hb_paint_funcs_t                *funcs,
861                                          hb_paint_linear_gradient_func_t  func,
862                                          void                            *user_data,
863                                          hb_destroy_func_t                destroy);
864 
865 /**
866  * hb_paint_funcs_set_radial_gradient_func:
867  * @funcs: A paint functions struct
868  * @func: (closure user_data) (destroy destroy) (scope notified): The radial-gradient callback
869  * @user_data: Data to pass to @func
870  * @destroy: (nullable): Function to call when @user_data is no longer needed
871  *
872  * Sets the radial-gradient callback on the paint functions struct.
873  *
874  * Since: 7.0.0
875  */
876 HB_EXTERN void
877 hb_paint_funcs_set_radial_gradient_func (hb_paint_funcs_t                *funcs,
878                                          hb_paint_radial_gradient_func_t  func,
879                                          void                            *user_data,
880                                          hb_destroy_func_t                destroy);
881 
882 /**
883  * hb_paint_funcs_set_sweep_gradient_func:
884  * @funcs: A paint functions struct
885  * @func: (closure user_data) (destroy destroy) (scope notified): The sweep-gradient callback
886  * @user_data: Data to pass to @func
887  * @destroy: (nullable): Function to call when @user_data is no longer needed
888  *
889  * Sets the sweep-gradient callback on the paint functions struct.
890  *
891  * Since: 7.0.0
892  */
893 HB_EXTERN void
894 hb_paint_funcs_set_sweep_gradient_func (hb_paint_funcs_t               *funcs,
895                                         hb_paint_sweep_gradient_func_t  func,
896                                         void                           *user_data,
897                                         hb_destroy_func_t               destroy);
898 
899 /**
900  * hb_paint_funcs_set_push_group_func:
901  * @funcs: A paint functions struct
902  * @func: (closure user_data) (destroy destroy) (scope notified): The push-group callback
903  * @user_data: Data to pass to @func
904  * @destroy: (nullable): Function to call when @user_data is no longer needed
905  *
906  * Sets the push-group callback on the paint functions struct.
907  *
908  * Since: 7.0.0
909  */
910 HB_EXTERN void
911 hb_paint_funcs_set_push_group_func (hb_paint_funcs_t           *funcs,
912                                     hb_paint_push_group_func_t  func,
913                                     void                       *user_data,
914                                     hb_destroy_func_t           destroy);
915 
916 /**
917  * hb_paint_funcs_set_pop_group_func:
918  * @funcs: A paint functions struct
919  * @func: (closure user_data) (destroy destroy) (scope notified): The pop-group callback
920  * @user_data: Data to pass to @func
921  * @destroy: (nullable): Function to call when @user_data is no longer needed
922  *
923  * Sets the pop-group callback on the paint functions struct.
924  *
925  * Since: 7.0.0
926  */
927 HB_EXTERN void
928 hb_paint_funcs_set_pop_group_func (hb_paint_funcs_t          *funcs,
929                                    hb_paint_pop_group_func_t  func,
930                                    void                       *user_data,
931                                    hb_destroy_func_t           destroy);
932 
933 /**
934  * hb_paint_funcs_set_custom_palette_color_func:
935  * @funcs: A paint functions struct
936  * @func: (closure user_data) (destroy destroy) (scope notified): The custom-palette-color callback
937  * @user_data: Data to pass to @func
938  * @destroy: (nullable): Function to call when @user_data is no longer needed
939  *
940  * Sets the custom-palette-color callback on the paint functions struct.
941  *
942  * Since: 7.0.0
943  */
944 HB_EXTERN void
945 hb_paint_funcs_set_custom_palette_color_func (hb_paint_funcs_t                     *funcs,
946                                               hb_paint_custom_palette_color_func_t  func,
947                                               void                                 *user_data,
948                                               hb_destroy_func_t                     destroy);
949 /*
950  * Manual API
951  */
952 
953 HB_EXTERN void
954 hb_paint_push_transform (hb_paint_funcs_t *funcs, void *paint_data,
955                          float xx, float yx,
956                          float xy, float yy,
957                          float dx, float dy);
958 
959 HB_EXTERN void
960 hb_paint_pop_transform (hb_paint_funcs_t *funcs, void *paint_data);
961 
962 HB_EXTERN hb_bool_t
963 hb_paint_color_glyph (hb_paint_funcs_t *funcs, void *paint_data,
964                       hb_codepoint_t glyph,
965                       hb_font_t *font);
966 
967 HB_EXTERN void
968 hb_paint_push_clip_glyph (hb_paint_funcs_t *funcs, void *paint_data,
969                           hb_codepoint_t glyph,
970                           hb_font_t *font);
971 
972 HB_EXTERN void
973 hb_paint_push_clip_rectangle (hb_paint_funcs_t *funcs, void *paint_data,
974                               float xmin, float ymin,
975                               float xmax, float ymax);
976 
977 HB_EXTERN void
978 hb_paint_pop_clip (hb_paint_funcs_t *funcs, void *paint_data);
979 
980 HB_EXTERN void
981 hb_paint_color (hb_paint_funcs_t *funcs, void *paint_data,
982                 hb_bool_t is_foreground,
983                 hb_color_t color);
984 
985 HB_EXTERN void
986 hb_paint_image (hb_paint_funcs_t *funcs, void *paint_data,
987                 hb_blob_t *image,
988                 unsigned int width,
989                 unsigned int height,
990                 hb_tag_t format,
991                 float slant,
992                 hb_glyph_extents_t *extents);
993 
994 HB_EXTERN void
995 hb_paint_linear_gradient (hb_paint_funcs_t *funcs, void *paint_data,
996                           hb_color_line_t *color_line,
997                           float x0, float y0,
998                           float x1, float y1,
999                           float x2, float y2);
1000 
1001 HB_EXTERN void
1002 hb_paint_radial_gradient (hb_paint_funcs_t *funcs, void *paint_data,
1003                           hb_color_line_t *color_line,
1004                           float x0, float y0,
1005                           float r0,
1006                           float x1, float y1,
1007                           float r1);
1008 
1009 HB_EXTERN void
1010 hb_paint_sweep_gradient (hb_paint_funcs_t *funcs, void *paint_data,
1011                          hb_color_line_t *color_line,
1012                          float x0, float y0,
1013                          float start_angle, float end_angle);
1014 
1015 HB_EXTERN void
1016 hb_paint_push_group (hb_paint_funcs_t *funcs, void *paint_data);
1017 
1018 HB_EXTERN void
1019 hb_paint_pop_group (hb_paint_funcs_t *funcs, void *paint_data,
1020                     hb_paint_composite_mode_t mode);
1021 
1022 HB_EXTERN hb_bool_t
1023 hb_paint_custom_palette_color (hb_paint_funcs_t *funcs, void *paint_data,
1024                                unsigned int color_index,
1025                                hb_color_t *color);
1026 
1027 HB_END_DECLS
1028 
1029 #endif  /* HB_PAINT_H */
1030