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1 /***************************************************************************/ | |
2 /* */ | |
3 /* ftimage.h */ | |
4 /* */ | |
5 /* FreeType glyph image formats and default raster interface */ | |
6 /* (specification). */ | |
7 /* */ | |
8 /* Copyright 1996-2010, 2013, 2014 by */ | |
9 /* David Turner, Robert Wilhelm, and Werner Lemberg. */ | |
10 /* */ | |
11 /* This file is part of the FreeType project, and may only be used, */ | |
12 /* modified, and distributed under the terms of the FreeType project */ | |
13 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ | |
14 /* this file you indicate that you have read the license and */ | |
15 /* understand and accept it fully. */ | |
16 /* */ | |
17 /***************************************************************************/ | |
18 | |
19 /*************************************************************************/ | |
20 /* */ | |
21 /* Note: A `raster' is simply a scan-line converter, used to render */ | |
22 /* FT_Outlines into FT_Bitmaps. */ | |
23 /* */ | |
24 /*************************************************************************/ | |
25 | |
26 | |
27 #ifndef __FTIMAGE_H__ | |
28 #define __FTIMAGE_H__ | |
29 | |
30 | |
31 /* _STANDALONE_ is from ftgrays.c */ | |
32 #ifndef _STANDALONE_ | |
33 #include <ft2build.h> | |
34 #endif | |
35 | |
36 | |
37 FT_BEGIN_HEADER | |
38 | |
39 | |
40 /*************************************************************************/ | |
41 /* */ | |
42 /* <Section> */ | |
43 /* basic_types */ | |
44 /* */ | |
45 /*************************************************************************/ | |
46 | |
47 | |
48 /*************************************************************************/ | |
49 /* */ | |
50 /* <Type> */ | |
51 /* FT_Pos */ | |
52 /* */ | |
53 /* <Description> */ | |
54 /* The type FT_Pos is used to store vectorial coordinates. Depending */ | |
55 /* on the context, these can represent distances in integer font */ | |
56 /* units, or 16.16, or 26.6 fixed-point pixel coordinates. */ | |
57 /* */ | |
58 typedef signed long FT_Pos; | |
59 | |
60 | |
61 /*************************************************************************/ | |
62 /* */ | |
63 /* <Struct> */ | |
64 /* FT_Vector */ | |
65 /* */ | |
66 /* <Description> */ | |
67 /* A simple structure used to store a 2D vector; coordinates are of */ | |
68 /* the FT_Pos type. */ | |
69 /* */ | |
70 /* <Fields> */ | |
71 /* x :: The horizontal coordinate. */ | |
72 /* y :: The vertical coordinate. */ | |
73 /* */ | |
74 typedef struct FT_Vector_ | |
75 { | |
76 FT_Pos x; | |
77 FT_Pos y; | |
78 | |
79 } FT_Vector; | |
80 | |
81 | |
82 /*************************************************************************/ | |
83 /* */ | |
84 /* <Struct> */ | |
85 /* FT_BBox */ | |
86 /* */ | |
87 /* <Description> */ | |
88 /* A structure used to hold an outline's bounding box, i.e., the */ | |
89 /* coordinates of its extrema in the horizontal and vertical */ | |
90 /* directions. */ | |
91 /* */ | |
92 /* <Fields> */ | |
93 /* xMin :: The horizontal minimum (left-most). */ | |
94 /* */ | |
95 /* yMin :: The vertical minimum (bottom-most). */ | |
96 /* */ | |
97 /* xMax :: The horizontal maximum (right-most). */ | |
98 /* */ | |
99 /* yMax :: The vertical maximum (top-most). */ | |
100 /* */ | |
101 /* <Note> */ | |
102 /* The bounding box is specified with the coordinates of the lower */ | |
103 /* left and the upper right corner. In PostScript, those values are */ | |
104 /* often called (llx,lly) and (urx,ury), respectively. */ | |
105 /* */ | |
106 /* If `yMin' is negative, this value gives the glyph's descender. */ | |
107 /* Otherwise, the glyph doesn't descend below the baseline. */ | |
108 /* Similarly, if `ymax' is positive, this value gives the glyph's */ | |
109 /* ascender. */ | |
110 /* */ | |
111 /* `xMin' gives the horizontal distance from the glyph's origin to */ | |
112 /* the left edge of the glyph's bounding box. If `xMin' is negative, */ | |
113 /* the glyph extends to the left of the origin. */ | |
114 /* */ | |
115 typedef struct FT_BBox_ | |
116 { | |
117 FT_Pos xMin, yMin; | |
118 FT_Pos xMax, yMax; | |
119 | |
120 } FT_BBox; | |
121 | |
122 | |
123 /*************************************************************************/ | |
124 /* */ | |
125 /* <Enum> */ | |
126 /* FT_Pixel_Mode */ | |
127 /* */ | |
128 /* <Description> */ | |
129 /* An enumeration type used to describe the format of pixels in a */ | |
130 /* given bitmap. Note that additional formats may be added in the */ | |
131 /* future. */ | |
132 /* */ | |
133 /* <Values> */ | |
134 /* FT_PIXEL_MODE_NONE :: */ | |
135 /* Value~0 is reserved. */ | |
136 /* */ | |
137 /* FT_PIXEL_MODE_MONO :: */ | |
138 /* A monochrome bitmap, using 1~bit per pixel. Note that pixels */ | |
139 /* are stored in most-significant order (MSB), which means that */ | |
140 /* the left-most pixel in a byte has value 128. */ | |
141 /* */ | |
142 /* FT_PIXEL_MODE_GRAY :: */ | |
143 /* An 8-bit bitmap, generally used to represent anti-aliased glyph */ | |
144 /* images. Each pixel is stored in one byte. Note that the number */ | |
145 /* of `gray' levels is stored in the `num_grays' field of the */ | |
146 /* @FT_Bitmap structure (it generally is 256). */ | |
147 /* */ | |
148 /* FT_PIXEL_MODE_GRAY2 :: */ | |
149 /* A 2-bit per pixel bitmap, used to represent embedded */ | |
150 /* anti-aliased bitmaps in font files according to the OpenType */ | |
151 /* specification. We haven't found a single font using this */ | |
152 /* format, however. */ | |
153 /* */ | |
154 /* FT_PIXEL_MODE_GRAY4 :: */ | |
155 /* A 4-bit per pixel bitmap, representing embedded anti-aliased */ | |
156 /* bitmaps in font files according to the OpenType specification. */ | |
157 /* We haven't found a single font using this format, however. */ | |
158 /* */ | |
159 /* FT_PIXEL_MODE_LCD :: */ | |
160 /* An 8-bit bitmap, representing RGB or BGR decimated glyph images */ | |
161 /* used for display on LCD displays; the bitmap is three times */ | |
162 /* wider than the original glyph image. See also */ | |
163 /* @FT_RENDER_MODE_LCD. */ | |
164 /* */ | |
165 /* FT_PIXEL_MODE_LCD_V :: */ | |
166 /* An 8-bit bitmap, representing RGB or BGR decimated glyph images */ | |
167 /* used for display on rotated LCD displays; the bitmap is three */ | |
168 /* times taller than the original glyph image. See also */ | |
169 /* @FT_RENDER_MODE_LCD_V. */ | |
170 /* */ | |
171 /* FT_PIXEL_MODE_BGRA :: */ | |
172 /* An image with four 8-bit channels per pixel, representing a */ | |
173 /* color image (such as emoticons) with alpha channel. For each */ | |
174 /* pixel, the format is BGRA, which means, the blue channel comes */ | |
175 /* first in memory. The color channels are pre-multiplied and in */ | |
176 /* the sRGB colorspace. For example, full red at half-translucent */ | |
177 /* opacity will be represented as `00,00,80,80', not `00,00,FF,80'. */ | |
178 /* See also @FT_LOAD_COLOR. */ | |
179 /* */ | |
180 typedef enum FT_Pixel_Mode_ | |
181 { | |
182 FT_PIXEL_MODE_NONE = 0, | |
183 FT_PIXEL_MODE_MONO, | |
184 FT_PIXEL_MODE_GRAY, | |
185 FT_PIXEL_MODE_GRAY2, | |
186 FT_PIXEL_MODE_GRAY4, | |
187 FT_PIXEL_MODE_LCD, | |
188 FT_PIXEL_MODE_LCD_V, | |
189 FT_PIXEL_MODE_BGRA, | |
190 | |
191 FT_PIXEL_MODE_MAX /* do not remove */ | |
192 | |
193 } FT_Pixel_Mode; | |
194 | |
195 | |
196 /* these constants are deprecated; use the corresponding `FT_Pixel_Mode' */ | |
197 /* values instead. */ | |
198 #define ft_pixel_mode_none FT_PIXEL_MODE_NONE | |
199 #define ft_pixel_mode_mono FT_PIXEL_MODE_MONO | |
200 #define ft_pixel_mode_grays FT_PIXEL_MODE_GRAY | |
201 #define ft_pixel_mode_pal2 FT_PIXEL_MODE_GRAY2 | |
202 #define ft_pixel_mode_pal4 FT_PIXEL_MODE_GRAY4 | |
203 | |
204 | |
205 /*************************************************************************/ | |
206 /* */ | |
207 /* <Struct> */ | |
208 /* FT_Bitmap */ | |
209 /* */ | |
210 /* <Description> */ | |
211 /* A structure used to describe a bitmap or pixmap to the raster. */ | |
212 /* Note that we now manage pixmaps of various depths through the */ | |
213 /* `pixel_mode' field. */ | |
214 /* */ | |
215 /* <Fields> */ | |
216 /* rows :: The number of bitmap rows. */ | |
217 /* */ | |
218 /* width :: The number of pixels in bitmap row. */ | |
219 /* */ | |
220 /* pitch :: The pitch's absolute value is the number of bytes */ | |
221 /* taken by one bitmap row, including padding. */ | |
222 /* However, the pitch is positive when the bitmap has */ | |
223 /* a `down' flow, and negative when it has an `up' */ | |
224 /* flow. In all cases, the pitch is an offset to add */ | |
225 /* to a bitmap pointer in order to go down one row. */ | |
226 /* */ | |
227 /* Note that `padding' means the alignment of a */ | |
228 /* bitmap to a byte border, and FreeType functions */ | |
229 /* normally align to the smallest possible integer */ | |
230 /* value. */ | |
231 /* */ | |
232 /* For the B/W rasterizer, `pitch' is always an even */ | |
233 /* number. */ | |
234 /* */ | |
235 /* To change the pitch of a bitmap (say, to make it a */ | |
236 /* multiple of 4), use @FT_Bitmap_Convert. */ | |
237 /* Alternatively, you might use callback functions to */ | |
238 /* directly render to the application's surface; see */ | |
239 /* the file `example2.cpp' in the tutorial for a */ | |
240 /* demonstration. */ | |
241 /* */ | |
242 /* buffer :: A typeless pointer to the bitmap buffer. This */ | |
243 /* value should be aligned on 32-bit boundaries in */ | |
244 /* most cases. */ | |
245 /* */ | |
246 /* num_grays :: This field is only used with */ | |
247 /* @FT_PIXEL_MODE_GRAY; it gives the number of gray */ | |
248 /* levels used in the bitmap. */ | |
249 /* */ | |
250 /* pixel_mode :: The pixel mode, i.e., how pixel bits are stored. */ | |
251 /* See @FT_Pixel_Mode for possible values. */ | |
252 /* */ | |
253 /* palette_mode :: This field is intended for paletted pixel modes; */ | |
254 /* it indicates how the palette is stored. Not */ | |
255 /* used currently. */ | |
256 /* */ | |
257 /* palette :: A typeless pointer to the bitmap palette; this */ | |
258 /* field is intended for paletted pixel modes. Not */ | |
259 /* used currently. */ | |
260 /* */ | |
261 /* <Note> */ | |
262 /* For now, the only pixel modes supported by FreeType are mono and */ | |
263 /* grays. However, drivers might be added in the future to support */ | |
264 /* more `colorful' options. */ | |
265 /* */ | |
266 typedef struct FT_Bitmap_ | |
267 { | |
268 unsigned int rows; | |
269 unsigned int width; | |
270 int pitch; | |
271 unsigned char* buffer; | |
272 unsigned short num_grays; | |
273 unsigned char pixel_mode; | |
274 unsigned char palette_mode; | |
275 void* palette; | |
276 | |
277 } FT_Bitmap; | |
278 | |
279 | |
280 /*************************************************************************/ | |
281 /* */ | |
282 /* <Section> */ | |
283 /* outline_processing */ | |
284 /* */ | |
285 /*************************************************************************/ | |
286 | |
287 | |
288 /*************************************************************************/ | |
289 /* */ | |
290 /* <Struct> */ | |
291 /* FT_Outline */ | |
292 /* */ | |
293 /* <Description> */ | |
294 /* This structure is used to describe an outline to the scan-line */ | |
295 /* converter. */ | |
296 /* */ | |
297 /* <Fields> */ | |
298 /* n_contours :: The number of contours in the outline. */ | |
299 /* */ | |
300 /* n_points :: The number of points in the outline. */ | |
301 /* */ | |
302 /* points :: A pointer to an array of `n_points' @FT_Vector */ | |
303 /* elements, giving the outline's point coordinates. */ | |
304 /* */ | |
305 /* tags :: A pointer to an array of `n_points' chars, giving */ | |
306 /* each outline point's type. */ | |
307 /* */ | |
308 /* If bit~0 is unset, the point is `off' the curve, */ | |
309 /* i.e., a Bézier control point, while it is `on' if */ | |
310 /* set. */ | |
311 /* */ | |
312 /* Bit~1 is meaningful for `off' points only. If set, */ | |
313 /* it indicates a third-order Bézier arc control point; */ | |
314 /* and a second-order control point if unset. */ | |
315 /* */ | |
316 /* If bit~2 is set, bits 5-7 contain the drop-out mode */ | |
317 /* (as defined in the OpenType specification; the value */ | |
318 /* is the same as the argument to the SCANMODE */ | |
319 /* instruction). */ | |
320 /* */ | |
321 /* Bits 3 and~4 are reserved for internal purposes. */ | |
322 /* */ | |
323 /* contours :: An array of `n_contours' shorts, giving the end */ | |
324 /* point of each contour within the outline. For */ | |
325 /* example, the first contour is defined by the points */ | |
326 /* `0' to `contours[0]', the second one is defined by */ | |
327 /* the points `contours[0]+1' to `contours[1]', etc. */ | |
328 /* */ | |
329 /* flags :: A set of bit flags used to characterize the outline */ | |
330 /* and give hints to the scan-converter and hinter on */ | |
331 /* how to convert/grid-fit it. See @FT_OUTLINE_XXX. */ | |
332 /* */ | |
333 /* <Note> */ | |
334 /* The B/W rasterizer only checks bit~2 in the `tags' array for the */ | |
335 /* first point of each contour. The drop-out mode as given with */ | |
336 /* @FT_OUTLINE_IGNORE_DROPOUTS, @FT_OUTLINE_SMART_DROPOUTS, and */ | |
337 /* @FT_OUTLINE_INCLUDE_STUBS in `flags' is then overridden. */ | |
338 /* */ | |
339 typedef struct FT_Outline_ | |
340 { | |
341 short n_contours; /* number of contours in glyph */ | |
342 short n_points; /* number of points in the glyph */ | |
343 | |
344 FT_Vector* points; /* the outline's points */ | |
345 char* tags; /* the points flags */ | |
346 short* contours; /* the contour end points */ | |
347 | |
348 int flags; /* outline masks */ | |
349 | |
350 } FT_Outline; | |
351 | |
352 /* */ | |
353 | |
354 /* Following limits must be consistent with */ | |
355 /* FT_Outline.{n_contours,n_points} */ | |
356 #define FT_OUTLINE_CONTOURS_MAX SHRT_MAX | |
357 #define FT_OUTLINE_POINTS_MAX SHRT_MAX | |
358 | |
359 | |
360 /*************************************************************************/ | |
361 /* */ | |
362 /* <Enum> */ | |
363 /* FT_OUTLINE_XXX */ | |
364 /* */ | |
365 /* <Description> */ | |
366 /* A list of bit-field constants use for the flags in an outline's */ | |
367 /* `flags' field. */ | |
368 /* */ | |
369 /* <Values> */ | |
370 /* FT_OUTLINE_NONE :: */ | |
371 /* Value~0 is reserved. */ | |
372 /* */ | |
373 /* FT_OUTLINE_OWNER :: */ | |
374 /* If set, this flag indicates that the outline's field arrays */ | |
375 /* (i.e., `points', `flags', and `contours') are `owned' by the */ | |
376 /* outline object, and should thus be freed when it is destroyed. */ | |
377 /* */ | |
378 /* FT_OUTLINE_EVEN_ODD_FILL :: */ | |
379 /* By default, outlines are filled using the non-zero winding rule. */ | |
380 /* If set to 1, the outline will be filled using the even-odd fill */ | |
381 /* rule (only works with the smooth rasterizer). */ | |
382 /* */ | |
383 /* FT_OUTLINE_REVERSE_FILL :: */ | |
384 /* By default, outside contours of an outline are oriented in */ | |
385 /* clock-wise direction, as defined in the TrueType specification. */ | |
386 /* This flag is set if the outline uses the opposite direction */ | |
387 /* (typically for Type~1 fonts). This flag is ignored by the scan */ | |
388 /* converter. */ | |
389 /* */ | |
390 /* FT_OUTLINE_IGNORE_DROPOUTS :: */ | |
391 /* By default, the scan converter will try to detect drop-outs in */ | |
392 /* an outline and correct the glyph bitmap to ensure consistent */ | |
393 /* shape continuity. If set, this flag hints the scan-line */ | |
394 /* converter to ignore such cases. See below for more information. */ | |
395 /* */ | |
396 /* FT_OUTLINE_SMART_DROPOUTS :: */ | |
397 /* Select smart dropout control. If unset, use simple dropout */ | |
398 /* control. Ignored if @FT_OUTLINE_IGNORE_DROPOUTS is set. See */ | |
399 /* below for more information. */ | |
400 /* */ | |
401 /* FT_OUTLINE_INCLUDE_STUBS :: */ | |
402 /* If set, turn pixels on for `stubs', otherwise exclude them. */ | |
403 /* Ignored if @FT_OUTLINE_IGNORE_DROPOUTS is set. See below for */ | |
404 /* more information. */ | |
405 /* */ | |
406 /* FT_OUTLINE_HIGH_PRECISION :: */ | |
407 /* This flag indicates that the scan-line converter should try to */ | |
408 /* convert this outline to bitmaps with the highest possible */ | |
409 /* quality. It is typically set for small character sizes. Note */ | |
410 /* that this is only a hint that might be completely ignored by a */ | |
411 /* given scan-converter. */ | |
412 /* */ | |
413 /* FT_OUTLINE_SINGLE_PASS :: */ | |
414 /* This flag is set to force a given scan-converter to only use a */ | |
415 /* single pass over the outline to render a bitmap glyph image. */ | |
416 /* Normally, it is set for very large character sizes. It is only */ | |
417 /* a hint that might be completely ignored by a given */ | |
418 /* scan-converter. */ | |
419 /* */ | |
420 /* <Note> */ | |
421 /* The flags @FT_OUTLINE_IGNORE_DROPOUTS, @FT_OUTLINE_SMART_DROPOUTS, */ | |
422 /* and @FT_OUTLINE_INCLUDE_STUBS are ignored by the smooth */ | |
423 /* rasterizer. */ | |
424 /* */ | |
425 /* There exists a second mechanism to pass the drop-out mode to the */ | |
426 /* B/W rasterizer; see the `tags' field in @FT_Outline. */ | |
427 /* */ | |
428 /* Please refer to the description of the `SCANTYPE' instruction in */ | |
429 /* the OpenType specification (in file `ttinst1.doc') how simple */ | |
430 /* drop-outs, smart drop-outs, and stubs are defined. */ | |
431 /* */ | |
432 #define FT_OUTLINE_NONE 0x0 | |
433 #define FT_OUTLINE_OWNER 0x1 | |
434 #define FT_OUTLINE_EVEN_ODD_FILL 0x2 | |
435 #define FT_OUTLINE_REVERSE_FILL 0x4 | |
436 #define FT_OUTLINE_IGNORE_DROPOUTS 0x8 | |
437 #define FT_OUTLINE_SMART_DROPOUTS 0x10 | |
438 #define FT_OUTLINE_INCLUDE_STUBS 0x20 | |
439 | |
440 #define FT_OUTLINE_HIGH_PRECISION 0x100 | |
441 #define FT_OUTLINE_SINGLE_PASS 0x200 | |
442 | |
443 | |
444 /* these constants are deprecated; use the corresponding */ | |
445 /* `FT_OUTLINE_XXX' values instead */ | |
446 #define ft_outline_none FT_OUTLINE_NONE | |
447 #define ft_outline_owner FT_OUTLINE_OWNER | |
448 #define ft_outline_even_odd_fill FT_OUTLINE_EVEN_ODD_FILL | |
449 #define ft_outline_reverse_fill FT_OUTLINE_REVERSE_FILL | |
450 #define ft_outline_ignore_dropouts FT_OUTLINE_IGNORE_DROPOUTS | |
451 #define ft_outline_high_precision FT_OUTLINE_HIGH_PRECISION | |
452 #define ft_outline_single_pass FT_OUTLINE_SINGLE_PASS | |
453 | |
454 /* */ | |
455 | |
456 #define FT_CURVE_TAG( flag ) ( flag & 3 ) | |
457 | |
458 #define FT_CURVE_TAG_ON 1 | |
459 #define FT_CURVE_TAG_CONIC 0 | |
460 #define FT_CURVE_TAG_CUBIC 2 | |
461 | |
462 #define FT_CURVE_TAG_HAS_SCANMODE 4 | |
463 | |
464 #define FT_CURVE_TAG_TOUCH_X 8 /* reserved for the TrueType hinter */ | |
465 #define FT_CURVE_TAG_TOUCH_Y 16 /* reserved for the TrueType hinter */ | |
466 | |
467 #define FT_CURVE_TAG_TOUCH_BOTH ( FT_CURVE_TAG_TOUCH_X | \ | |
468 FT_CURVE_TAG_TOUCH_Y ) | |
469 | |
470 #define FT_Curve_Tag_On FT_CURVE_TAG_ON | |
471 #define FT_Curve_Tag_Conic FT_CURVE_TAG_CONIC | |
472 #define FT_Curve_Tag_Cubic FT_CURVE_TAG_CUBIC | |
473 #define FT_Curve_Tag_Touch_X FT_CURVE_TAG_TOUCH_X | |
474 #define FT_Curve_Tag_Touch_Y FT_CURVE_TAG_TOUCH_Y | |
475 | |
476 | |
477 /*************************************************************************/ | |
478 /* */ | |
479 /* <FuncType> */ | |
480 /* FT_Outline_MoveToFunc */ | |
481 /* */ | |
482 /* <Description> */ | |
483 /* A function pointer type used to describe the signature of a `move */ | |
484 /* to' function during outline walking/decomposition. */ | |
485 /* */ | |
486 /* A `move to' is emitted to start a new contour in an outline. */ | |
487 /* */ | |
488 /* <Input> */ | |
489 /* to :: A pointer to the target point of the `move to'. */ | |
490 /* */ | |
491 /* user :: A typeless pointer, which is passed from the caller of the */ | |
492 /* decomposition function. */ | |
493 /* */ | |
494 /* <Return> */ | |
495 /* Error code. 0~means success. */ | |
496 /* */ | |
497 typedef int | |
498 (*FT_Outline_MoveToFunc)( const FT_Vector* to, | |
499 void* user ); | |
500 | |
501 #define FT_Outline_MoveTo_Func FT_Outline_MoveToFunc | |
502 | |
503 | |
504 /*************************************************************************/ | |
505 /* */ | |
506 /* <FuncType> */ | |
507 /* FT_Outline_LineToFunc */ | |
508 /* */ | |
509 /* <Description> */ | |
510 /* A function pointer type used to describe the signature of a `line */ | |
511 /* to' function during outline walking/decomposition. */ | |
512 /* */ | |
513 /* A `line to' is emitted to indicate a segment in the outline. */ | |
514 /* */ | |
515 /* <Input> */ | |
516 /* to :: A pointer to the target point of the `line to'. */ | |
517 /* */ | |
518 /* user :: A typeless pointer, which is passed from the caller of the */ | |
519 /* decomposition function. */ | |
520 /* */ | |
521 /* <Return> */ | |
522 /* Error code. 0~means success. */ | |
523 /* */ | |
524 typedef int | |
525 (*FT_Outline_LineToFunc)( const FT_Vector* to, | |
526 void* user ); | |
527 | |
528 #define FT_Outline_LineTo_Func FT_Outline_LineToFunc | |
529 | |
530 | |
531 /*************************************************************************/ | |
532 /* */ | |
533 /* <FuncType> */ | |
534 /* FT_Outline_ConicToFunc */ | |
535 /* */ | |
536 /* <Description> */ | |
537 /* A function pointer type used to describe the signature of a `conic */ | |
538 /* to' function during outline walking or decomposition. */ | |
539 /* */ | |
540 /* A `conic to' is emitted to indicate a second-order Bézier arc in */ | |
541 /* the outline. */ | |
542 /* */ | |
543 /* <Input> */ | |
544 /* control :: An intermediate control point between the last position */ | |
545 /* and the new target in `to'. */ | |
546 /* */ | |
547 /* to :: A pointer to the target end point of the conic arc. */ | |
548 /* */ | |
549 /* user :: A typeless pointer, which is passed from the caller of */ | |
550 /* the decomposition function. */ | |
551 /* */ | |
552 /* <Return> */ | |
553 /* Error code. 0~means success. */ | |
554 /* */ | |
555 typedef int | |
556 (*FT_Outline_ConicToFunc)( const FT_Vector* control, | |
557 const FT_Vector* to, | |
558 void* user ); | |
559 | |
560 #define FT_Outline_ConicTo_Func FT_Outline_ConicToFunc | |
561 | |
562 | |
563 /*************************************************************************/ | |
564 /* */ | |
565 /* <FuncType> */ | |
566 /* FT_Outline_CubicToFunc */ | |
567 /* */ | |
568 /* <Description> */ | |
569 /* A function pointer type used to describe the signature of a `cubic */ | |
570 /* to' function during outline walking or decomposition. */ | |
571 /* */ | |
572 /* A `cubic to' is emitted to indicate a third-order Bézier arc. */ | |
573 /* */ | |
574 /* <Input> */ | |
575 /* control1 :: A pointer to the first Bézier control point. */ | |
576 /* */ | |
577 /* control2 :: A pointer to the second Bézier control point. */ | |
578 /* */ | |
579 /* to :: A pointer to the target end point. */ | |
580 /* */ | |
581 /* user :: A typeless pointer, which is passed from the caller of */ | |
582 /* the decomposition function. */ | |
583 /* */ | |
584 /* <Return> */ | |
585 /* Error code. 0~means success. */ | |
586 /* */ | |
587 typedef int | |
588 (*FT_Outline_CubicToFunc)( const FT_Vector* control1, | |
589 const FT_Vector* control2, | |
590 const FT_Vector* to, | |
591 void* user ); | |
592 | |
593 #define FT_Outline_CubicTo_Func FT_Outline_CubicToFunc | |
594 | |
595 | |
596 /*************************************************************************/ | |
597 /* */ | |
598 /* <Struct> */ | |
599 /* FT_Outline_Funcs */ | |
600 /* */ | |
601 /* <Description> */ | |
602 /* A structure to hold various function pointers used during outline */ | |
603 /* decomposition in order to emit segments, conic, and cubic Béziers. */ | |
604 /* */ | |
605 /* <Fields> */ | |
606 /* move_to :: The `move to' emitter. */ | |
607 /* */ | |
608 /* line_to :: The segment emitter. */ | |
609 /* */ | |
610 /* conic_to :: The second-order Bézier arc emitter. */ | |
611 /* */ | |
612 /* cubic_to :: The third-order Bézier arc emitter. */ | |
613 /* */ | |
614 /* shift :: The shift that is applied to coordinates before they */ | |
615 /* are sent to the emitter. */ | |
616 /* */ | |
617 /* delta :: The delta that is applied to coordinates before they */ | |
618 /* are sent to the emitter, but after the shift. */ | |
619 /* */ | |
620 /* <Note> */ | |
621 /* The point coordinates sent to the emitters are the transformed */ | |
622 /* version of the original coordinates (this is important for high */ | |
623 /* accuracy during scan-conversion). The transformation is simple: */ | |
624 /* */ | |
625 /* { */ | |
626 /* x' = (x << shift) - delta */ | |
627 /* y' = (x << shift) - delta */ | |
628 /* } */ | |
629 /* */ | |
630 /* Set the values of `shift' and `delta' to~0 to get the original */ | |
631 /* point coordinates. */ | |
632 /* */ | |
633 typedef struct FT_Outline_Funcs_ | |
634 { | |
635 FT_Outline_MoveToFunc move_to; | |
636 FT_Outline_LineToFunc line_to; | |
637 FT_Outline_ConicToFunc conic_to; | |
638 FT_Outline_CubicToFunc cubic_to; | |
639 | |
640 int shift; | |
641 FT_Pos delta; | |
642 | |
643 } FT_Outline_Funcs; | |
644 | |
645 | |
646 /*************************************************************************/ | |
647 /* */ | |
648 /* <Section> */ | |
649 /* basic_types */ | |
650 /* */ | |
651 /*************************************************************************/ | |
652 | |
653 | |
654 /*************************************************************************/ | |
655 /* */ | |
656 /* <Macro> */ | |
657 /* FT_IMAGE_TAG */ | |
658 /* */ | |
659 /* <Description> */ | |
660 /* This macro converts four-letter tags to an unsigned long type. */ | |
661 /* */ | |
662 /* <Note> */ | |
663 /* Since many 16-bit compilers don't like 32-bit enumerations, you */ | |
664 /* should redefine this macro in case of problems to something like */ | |
665 /* this: */ | |
666 /* */ | |
667 /* { */ | |
668 /* #define FT_IMAGE_TAG( value, _x1, _x2, _x3, _x4 ) value */ | |
669 /* } */ | |
670 /* */ | |
671 /* to get a simple enumeration without assigning special numbers. */ | |
672 /* */ | |
673 #ifndef FT_IMAGE_TAG | |
674 #define FT_IMAGE_TAG( value, _x1, _x2, _x3, _x4 ) \ | |
675 value = ( ( (unsigned long)_x1 << 24 ) | \ | |
676 ( (unsigned long)_x2 << 16 ) | \ | |
677 ( (unsigned long)_x3 << 8 ) | \ | |
678 (unsigned long)_x4 ) | |
679 #endif /* FT_IMAGE_TAG */ | |
680 | |
681 | |
682 /*************************************************************************/ | |
683 /* */ | |
684 /* <Enum> */ | |
685 /* FT_Glyph_Format */ | |
686 /* */ | |
687 /* <Description> */ | |
688 /* An enumeration type used to describe the format of a given glyph */ | |
689 /* image. Note that this version of FreeType only supports two image */ | |
690 /* formats, even though future font drivers will be able to register */ | |
691 /* their own format. */ | |
692 /* */ | |
693 /* <Values> */ | |
694 /* FT_GLYPH_FORMAT_NONE :: */ | |
695 /* The value~0 is reserved. */ | |
696 /* */ | |
697 /* FT_GLYPH_FORMAT_COMPOSITE :: */ | |
698 /* The glyph image is a composite of several other images. This */ | |
699 /* format is _only_ used with @FT_LOAD_NO_RECURSE, and is used to */ | |
700 /* report compound glyphs (like accented characters). */ | |
701 /* */ | |
702 /* FT_GLYPH_FORMAT_BITMAP :: */ | |
703 /* The glyph image is a bitmap, and can be described as an */ | |
704 /* @FT_Bitmap. You generally need to access the `bitmap' field of */ | |
705 /* the @FT_GlyphSlotRec structure to read it. */ | |
706 /* */ | |
707 /* FT_GLYPH_FORMAT_OUTLINE :: */ | |
708 /* The glyph image is a vectorial outline made of line segments */ | |
709 /* and Bézier arcs; it can be described as an @FT_Outline; you */ | |
710 /* generally want to access the `outline' field of the */ | |
711 /* @FT_GlyphSlotRec structure to read it. */ | |
712 /* */ | |
713 /* FT_GLYPH_FORMAT_PLOTTER :: */ | |
714 /* The glyph image is a vectorial path with no inside and outside */ | |
715 /* contours. Some Type~1 fonts, like those in the Hershey family, */ | |
716 /* contain glyphs in this format. These are described as */ | |
717 /* @FT_Outline, but FreeType isn't currently capable of rendering */ | |
718 /* them correctly. */ | |
719 /* */ | |
720 typedef enum FT_Glyph_Format_ | |
721 { | |
722 FT_IMAGE_TAG( FT_GLYPH_FORMAT_NONE, 0, 0, 0, 0 ), | |
723 | |
724 FT_IMAGE_TAG( FT_GLYPH_FORMAT_COMPOSITE, 'c', 'o', 'm', 'p' ), | |
725 FT_IMAGE_TAG( FT_GLYPH_FORMAT_BITMAP, 'b', 'i', 't', 's' ), | |
726 FT_IMAGE_TAG( FT_GLYPH_FORMAT_OUTLINE, 'o', 'u', 't', 'l' ), | |
727 FT_IMAGE_TAG( FT_GLYPH_FORMAT_PLOTTER, 'p', 'l', 'o', 't' ) | |
728 | |
729 } FT_Glyph_Format; | |
730 | |
731 | |
732 /* these constants are deprecated; use the corresponding */ | |
733 /* `FT_Glyph_Format' values instead. */ | |
734 #define ft_glyph_format_none FT_GLYPH_FORMAT_NONE | |
735 #define ft_glyph_format_composite FT_GLYPH_FORMAT_COMPOSITE | |
736 #define ft_glyph_format_bitmap FT_GLYPH_FORMAT_BITMAP | |
737 #define ft_glyph_format_outline FT_GLYPH_FORMAT_OUTLINE | |
738 #define ft_glyph_format_plotter FT_GLYPH_FORMAT_PLOTTER | |
739 | |
740 | |
741 /*************************************************************************/ | |
742 /*************************************************************************/ | |
743 /*************************************************************************/ | |
744 /***** *****/ | |
745 /***** R A S T E R D E F I N I T I O N S *****/ | |
746 /***** *****/ | |
747 /*************************************************************************/ | |
748 /*************************************************************************/ | |
749 /*************************************************************************/ | |
750 | |
751 | |
752 /*************************************************************************/ | |
753 /* */ | |
754 /* A raster is a scan converter, in charge of rendering an outline into */ | |
755 /* a a bitmap. This section contains the public API for rasters. */ | |
756 /* */ | |
757 /* Note that in FreeType 2, all rasters are now encapsulated within */ | |
758 /* specific modules called `renderers'. See `ftrender.h' for more */ | |
759 /* details on renderers. */ | |
760 /* */ | |
761 /*************************************************************************/ | |
762 | |
763 | |
764 /*************************************************************************/ | |
765 /* */ | |
766 /* <Section> */ | |
767 /* raster */ | |
768 /* */ | |
769 /* <Title> */ | |
770 /* Scanline Converter */ | |
771 /* */ | |
772 /* <Abstract> */ | |
773 /* How vectorial outlines are converted into bitmaps and pixmaps. */ | |
774 /* */ | |
775 /* <Description> */ | |
776 /* This section contains technical definitions. */ | |
777 /* */ | |
778 /* <Order> */ | |
779 /* FT_Raster */ | |
780 /* FT_Span */ | |
781 /* FT_SpanFunc */ | |
782 /* */ | |
783 /* FT_Raster_Params */ | |
784 /* FT_RASTER_FLAG_XXX */ | |
785 /* */ | |
786 /* FT_Raster_NewFunc */ | |
787 /* FT_Raster_DoneFunc */ | |
788 /* FT_Raster_ResetFunc */ | |
789 /* FT_Raster_SetModeFunc */ | |
790 /* FT_Raster_RenderFunc */ | |
791 /* FT_Raster_Funcs */ | |
792 /* */ | |
793 /*************************************************************************/ | |
794 | |
795 | |
796 /*************************************************************************/ | |
797 /* */ | |
798 /* <Type> */ | |
799 /* FT_Raster */ | |
800 /* */ | |
801 /* <Description> */ | |
802 /* An opaque handle (pointer) to a raster object. Each object can be */ | |
803 /* used independently to convert an outline into a bitmap or pixmap. */ | |
804 /* */ | |
805 typedef struct FT_RasterRec_* FT_Raster; | |
806 | |
807 | |
808 /*************************************************************************/ | |
809 /* */ | |
810 /* <Struct> */ | |
811 /* FT_Span */ | |
812 /* */ | |
813 /* <Description> */ | |
814 /* A structure used to model a single span of gray pixels when */ | |
815 /* rendering an anti-aliased bitmap. */ | |
816 /* */ | |
817 /* <Fields> */ | |
818 /* x :: The span's horizontal start position. */ | |
819 /* */ | |
820 /* len :: The span's length in pixels. */ | |
821 /* */ | |
822 /* coverage :: The span color/coverage, ranging from 0 (background) */ | |
823 /* to 255 (foreground). */ | |
824 /* */ | |
825 /* <Note> */ | |
826 /* This structure is used by the span drawing callback type named */ | |
827 /* @FT_SpanFunc that takes the y~coordinate of the span as a */ | |
828 /* parameter. */ | |
829 /* */ | |
830 /* The coverage value is always between 0 and 255. If you want less */ | |
831 /* gray values, the callback function has to reduce them. */ | |
832 /* */ | |
833 typedef struct FT_Span_ | |
834 { | |
835 short x; | |
836 unsigned short len; | |
837 unsigned char coverage; | |
838 | |
839 } FT_Span; | |
840 | |
841 | |
842 /*************************************************************************/ | |
843 /* */ | |
844 /* <FuncType> */ | |
845 /* FT_SpanFunc */ | |
846 /* */ | |
847 /* <Description> */ | |
848 /* A function used as a call-back by the anti-aliased renderer in */ | |
849 /* order to let client applications draw themselves the gray pixel */ | |
850 /* spans on each scan line. */ | |
851 /* */ | |
852 /* <Input> */ | |
853 /* y :: The scanline's y~coordinate. */ | |
854 /* */ | |
855 /* count :: The number of spans to draw on this scanline. */ | |
856 /* */ | |
857 /* spans :: A table of `count' spans to draw on the scanline. */ | |
858 /* */ | |
859 /* user :: User-supplied data that is passed to the callback. */ | |
860 /* */ | |
861 /* <Note> */ | |
862 /* This callback allows client applications to directly render the */ | |
863 /* gray spans of the anti-aliased bitmap to any kind of surfaces. */ | |
864 /* */ | |
865 /* This can be used to write anti-aliased outlines directly to a */ | |
866 /* given background bitmap, and even perform translucency. */ | |
867 /* */ | |
868 /* Note that the `count' field cannot be greater than a fixed value */ | |
869 /* defined by the `FT_MAX_GRAY_SPANS' configuration macro in */ | |
870 /* `ftoption.h'. By default, this value is set to~32, which means */ | |
871 /* that if there are more than 32~spans on a given scanline, the */ | |
872 /* callback is called several times with the same `y' parameter in */ | |
873 /* order to draw all callbacks. */ | |
874 /* */ | |
875 /* Otherwise, the callback is only called once per scan-line, and */ | |
876 /* only for those scanlines that do have `gray' pixels on them. */ | |
877 /* */ | |
878 typedef void | |
879 (*FT_SpanFunc)( int y, | |
880 int count, | |
881 const FT_Span* spans, | |
882 void* user ); | |
883 | |
884 #define FT_Raster_Span_Func FT_SpanFunc | |
885 | |
886 | |
887 /*************************************************************************/ | |
888 /* */ | |
889 /* <FuncType> */ | |
890 /* FT_Raster_BitTest_Func */ | |
891 /* */ | |
892 /* <Description> */ | |
893 /* Deprecated, unimplemented. */ | |
894 /* */ | |
895 typedef int | |
896 (*FT_Raster_BitTest_Func)( int y, | |
897 int x, | |
898 void* user ); | |
899 | |
900 | |
901 /*************************************************************************/ | |
902 /* */ | |
903 /* <FuncType> */ | |
904 /* FT_Raster_BitSet_Func */ | |
905 /* */ | |
906 /* <Description> */ | |
907 /* Deprecated, unimplemented. */ | |
908 /* */ | |
909 typedef void | |
910 (*FT_Raster_BitSet_Func)( int y, | |
911 int x, | |
912 void* user ); | |
913 | |
914 | |
915 /*************************************************************************/ | |
916 /* */ | |
917 /* <Enum> */ | |
918 /* FT_RASTER_FLAG_XXX */ | |
919 /* */ | |
920 /* <Description> */ | |
921 /* A list of bit flag constants as used in the `flags' field of a */ | |
922 /* @FT_Raster_Params structure. */ | |
923 /* */ | |
924 /* <Values> */ | |
925 /* FT_RASTER_FLAG_DEFAULT :: This value is 0. */ | |
926 /* */ | |
927 /* FT_RASTER_FLAG_AA :: This flag is set to indicate that an */ | |
928 /* anti-aliased glyph image should be */ | |
929 /* generated. Otherwise, it will be */ | |
930 /* monochrome (1-bit). */ | |
931 /* */ | |
932 /* FT_RASTER_FLAG_DIRECT :: This flag is set to indicate direct */ | |
933 /* rendering. In this mode, client */ | |
934 /* applications must provide their own span */ | |
935 /* callback. This lets them directly */ | |
936 /* draw or compose over an existing bitmap. */ | |
937 /* If this bit is not set, the target */ | |
938 /* pixmap's buffer _must_ be zeroed before */ | |
939 /* rendering. */ | |
940 /* */ | |
941 /* Direct rendering is only possible with */ | |
942 /* anti-aliased glyphs. */ | |
943 /* */ | |
944 /* FT_RASTER_FLAG_CLIP :: This flag is only used in direct */ | |
945 /* rendering mode. If set, the output will */ | |
946 /* be clipped to a box specified in the */ | |
947 /* `clip_box' field of the */ | |
948 /* @FT_Raster_Params structure. */ | |
949 /* */ | |
950 /* Note that by default, the glyph bitmap */ | |
951 /* is clipped to the target pixmap, except */ | |
952 /* in direct rendering mode where all spans */ | |
953 /* are generated if no clipping box is set. */ | |
954 /* */ | |
955 #define FT_RASTER_FLAG_DEFAULT 0x0 | |
956 #define FT_RASTER_FLAG_AA 0x1 | |
957 #define FT_RASTER_FLAG_DIRECT 0x2 | |
958 #define FT_RASTER_FLAG_CLIP 0x4 | |
959 | |
960 /* these constants are deprecated; use the corresponding */ | |
961 /* `FT_RASTER_FLAG_XXX' values instead */ | |
962 #define ft_raster_flag_default FT_RASTER_FLAG_DEFAULT | |
963 #define ft_raster_flag_aa FT_RASTER_FLAG_AA | |
964 #define ft_raster_flag_direct FT_RASTER_FLAG_DIRECT | |
965 #define ft_raster_flag_clip FT_RASTER_FLAG_CLIP | |
966 | |
967 | |
968 /*************************************************************************/ | |
969 /* */ | |
970 /* <Struct> */ | |
971 /* FT_Raster_Params */ | |
972 /* */ | |
973 /* <Description> */ | |
974 /* A structure to hold the arguments used by a raster's render */ | |
975 /* function. */ | |
976 /* */ | |
977 /* <Fields> */ | |
978 /* target :: The target bitmap. */ | |
979 /* */ | |
980 /* source :: A pointer to the source glyph image (e.g., an */ | |
981 /* @FT_Outline). */ | |
982 /* */ | |
983 /* flags :: The rendering flags. */ | |
984 /* */ | |
985 /* gray_spans :: The gray span drawing callback. */ | |
986 /* */ | |
987 /* black_spans :: Unused. */ | |
988 /* */ | |
989 /* bit_test :: Unused. */ | |
990 /* */ | |
991 /* bit_set :: Unused. */ | |
992 /* */ | |
993 /* user :: User-supplied data that is passed to each drawing */ | |
994 /* callback. */ | |
995 /* */ | |
996 /* clip_box :: An optional clipping box. It is only used in */ | |
997 /* direct rendering mode. Note that coordinates here */ | |
998 /* should be expressed in _integer_ pixels (and not in */ | |
999 /* 26.6 fixed-point units). */ | |
1000 /* */ | |
1001 /* <Note> */ | |
1002 /* An anti-aliased glyph bitmap is drawn if the @FT_RASTER_FLAG_AA */ | |
1003 /* bit flag is set in the `flags' field, otherwise a monochrome */ | |
1004 /* bitmap is generated. */ | |
1005 /* */ | |
1006 /* If the @FT_RASTER_FLAG_DIRECT bit flag is set in `flags', the */ | |
1007 /* raster will call the `gray_spans' callback to draw gray pixel */ | |
1008 /* spans. This allows direct composition over a pre-existing bitmap */ | |
1009 /* through user-provided callbacks to perform the span drawing and */ | |
1010 /* composition. Not supported by the monochrome rasterizer. */ | |
1011 /* */ | |
1012 typedef struct FT_Raster_Params_ | |
1013 { | |
1014 const FT_Bitmap* target; | |
1015 const void* source; | |
1016 int flags; | |
1017 FT_SpanFunc gray_spans; | |
1018 FT_SpanFunc black_spans; /* unused */ | |
1019 FT_Raster_BitTest_Func bit_test; /* unused */ | |
1020 FT_Raster_BitSet_Func bit_set; /* unused */ | |
1021 void* user; | |
1022 FT_BBox clip_box; | |
1023 | |
1024 } FT_Raster_Params; | |
1025 | |
1026 | |
1027 /*************************************************************************/ | |
1028 /* */ | |
1029 /* <FuncType> */ | |
1030 /* FT_Raster_NewFunc */ | |
1031 /* */ | |
1032 /* <Description> */ | |
1033 /* A function used to create a new raster object. */ | |
1034 /* */ | |
1035 /* <Input> */ | |
1036 /* memory :: A handle to the memory allocator. */ | |
1037 /* */ | |
1038 /* <Output> */ | |
1039 /* raster :: A handle to the new raster object. */ | |
1040 /* */ | |
1041 /* <Return> */ | |
1042 /* Error code. 0~means success. */ | |
1043 /* */ | |
1044 /* <Note> */ | |
1045 /* The `memory' parameter is a typeless pointer in order to avoid */ | |
1046 /* un-wanted dependencies on the rest of the FreeType code. In */ | |
1047 /* practice, it is an @FT_Memory object, i.e., a handle to the */ | |
1048 /* standard FreeType memory allocator. However, this field can be */ | |
1049 /* completely ignored by a given raster implementation. */ | |
1050 /* */ | |
1051 typedef int | |
1052 (*FT_Raster_NewFunc)( void* memory, | |
1053 FT_Raster* raster ); | |
1054 | |
1055 #define FT_Raster_New_Func FT_Raster_NewFunc | |
1056 | |
1057 | |
1058 /*************************************************************************/ | |
1059 /* */ | |
1060 /* <FuncType> */ | |
1061 /* FT_Raster_DoneFunc */ | |
1062 /* */ | |
1063 /* <Description> */ | |
1064 /* A function used to destroy a given raster object. */ | |
1065 /* */ | |
1066 /* <Input> */ | |
1067 /* raster :: A handle to the raster object. */ | |
1068 /* */ | |
1069 typedef void | |
1070 (*FT_Raster_DoneFunc)( FT_Raster raster ); | |
1071 | |
1072 #define FT_Raster_Done_Func FT_Raster_DoneFunc | |
1073 | |
1074 | |
1075 /*************************************************************************/ | |
1076 /* */ | |
1077 /* <FuncType> */ | |
1078 /* FT_Raster_ResetFunc */ | |
1079 /* */ | |
1080 /* <Description> */ | |
1081 /* FreeType provides an area of memory called the `render pool', */ | |
1082 /* available to all registered rasters. This pool can be freely used */ | |
1083 /* during a given scan-conversion but is shared by all rasters. Its */ | |
1084 /* content is thus transient. */ | |
1085 /* */ | |
1086 /* This function is called each time the render pool changes, or just */ | |
1087 /* after a new raster object is created. */ | |
1088 /* */ | |
1089 /* <Input> */ | |
1090 /* raster :: A handle to the new raster object. */ | |
1091 /* */ | |
1092 /* pool_base :: The address in memory of the render pool. */ | |
1093 /* */ | |
1094 /* pool_size :: The size in bytes of the render pool. */ | |
1095 /* */ | |
1096 /* <Note> */ | |
1097 /* Rasters can ignore the render pool and rely on dynamic memory */ | |
1098 /* allocation if they want to (a handle to the memory allocator is */ | |
1099 /* passed to the raster constructor). However, this is not */ | |
1100 /* recommended for efficiency purposes. */ | |
1101 /* */ | |
1102 typedef void | |
1103 (*FT_Raster_ResetFunc)( FT_Raster raster, | |
1104 unsigned char* pool_base, | |
1105 unsigned long pool_size ); | |
1106 | |
1107 #define FT_Raster_Reset_Func FT_Raster_ResetFunc | |
1108 | |
1109 | |
1110 /*************************************************************************/ | |
1111 /* */ | |
1112 /* <FuncType> */ | |
1113 /* FT_Raster_SetModeFunc */ | |
1114 /* */ | |
1115 /* <Description> */ | |
1116 /* This function is a generic facility to change modes or attributes */ | |
1117 /* in a given raster. This can be used for debugging purposes, or */ | |
1118 /* simply to allow implementation-specific `features' in a given */ | |
1119 /* raster module. */ | |
1120 /* */ | |
1121 /* <Input> */ | |
1122 /* raster :: A handle to the new raster object. */ | |
1123 /* */ | |
1124 /* mode :: A 4-byte tag used to name the mode or property. */ | |
1125 /* */ | |
1126 /* args :: A pointer to the new mode/property to use. */ | |
1127 /* */ | |
1128 typedef int | |
1129 (*FT_Raster_SetModeFunc)( FT_Raster raster, | |
1130 unsigned long mode, | |
1131 void* args ); | |
1132 | |
1133 #define FT_Raster_Set_Mode_Func FT_Raster_SetModeFunc | |
1134 | |
1135 | |
1136 /*************************************************************************/ | |
1137 /* */ | |
1138 /* <FuncType> */ | |
1139 /* FT_Raster_RenderFunc */ | |
1140 /* */ | |
1141 /* <Description> */ | |
1142 /* Invoke a given raster to scan-convert a given glyph image into a */ | |
1143 /* target bitmap. */ | |
1144 /* */ | |
1145 /* <Input> */ | |
1146 /* raster :: A handle to the raster object. */ | |
1147 /* */ | |
1148 /* params :: A pointer to an @FT_Raster_Params structure used to */ | |
1149 /* store the rendering parameters. */ | |
1150 /* */ | |
1151 /* <Return> */ | |
1152 /* Error code. 0~means success. */ | |
1153 /* */ | |
1154 /* <Note> */ | |
1155 /* The exact format of the source image depends on the raster's glyph */ | |
1156 /* format defined in its @FT_Raster_Funcs structure. It can be an */ | |
1157 /* @FT_Outline or anything else in order to support a large array of */ | |
1158 /* glyph formats. */ | |
1159 /* */ | |
1160 /* Note also that the render function can fail and return a */ | |
1161 /* `FT_Err_Unimplemented_Feature' error code if the raster used does */ | |
1162 /* not support direct composition. */ | |
1163 /* */ | |
1164 /* XXX: For now, the standard raster doesn't support direct */ | |
1165 /* composition but this should change for the final release (see */ | |
1166 /* the files `demos/src/ftgrays.c' and `demos/src/ftgrays2.c' */ | |
1167 /* for examples of distinct implementations that support direct */ | |
1168 /* composition). */ | |
1169 /* */ | |
1170 typedef int | |
1171 (*FT_Raster_RenderFunc)( FT_Raster raster, | |
1172 const FT_Raster_Params* params ); | |
1173 | |
1174 #define FT_Raster_Render_Func FT_Raster_RenderFunc | |
1175 | |
1176 | |
1177 /*************************************************************************/ | |
1178 /* */ | |
1179 /* <Struct> */ | |
1180 /* FT_Raster_Funcs */ | |
1181 /* */ | |
1182 /* <Description> */ | |
1183 /* A structure used to describe a given raster class to the library. */ | |
1184 /* */ | |
1185 /* <Fields> */ | |
1186 /* glyph_format :: The supported glyph format for this raster. */ | |
1187 /* */ | |
1188 /* raster_new :: The raster constructor. */ | |
1189 /* */ | |
1190 /* raster_reset :: Used to reset the render pool within the raster. */ | |
1191 /* */ | |
1192 /* raster_render :: A function to render a glyph into a given bitmap. */ | |
1193 /* */ | |
1194 /* raster_done :: The raster destructor. */ | |
1195 /* */ | |
1196 typedef struct FT_Raster_Funcs_ | |
1197 { | |
1198 FT_Glyph_Format glyph_format; | |
1199 FT_Raster_NewFunc raster_new; | |
1200 FT_Raster_ResetFunc raster_reset; | |
1201 FT_Raster_SetModeFunc raster_set_mode; | |
1202 FT_Raster_RenderFunc raster_render; | |
1203 FT_Raster_DoneFunc raster_done; | |
1204 | |
1205 } FT_Raster_Funcs; | |
1206 | |
1207 /* */ | |
1208 | |
1209 | |
1210 FT_END_HEADER | |
1211 | |
1212 #endif /* __FTIMAGE_H__ */ | |
1213 | |
1214 | |
1215 /* END */ | |
1216 | |
1217 | |
1218 /* Local Variables: */ | |
1219 /* coding: utf-8 */ | |
1220 /* End: */ | |
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