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| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Sun, 02 Feb 2014 00:35:22 +0200 |
| parents | |
| children |
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1 /***************************************************************************/
2 /* */
3 /* ftimage.h */
4 /* */
5 /* FreeType glyph image formats and default raster interface */
6 /* (specification). */
7 /* */
8 /* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, */
9 /* 2010 by */
10 /* David Turner, Robert Wilhelm, and Werner Lemberg. */
11 /* */
12 /* This file is part of the FreeType project, and may only be used, */
13 /* modified, and distributed under the terms of the FreeType project */
14 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */
15 /* this file you indicate that you have read the license and */
16 /* understand and accept it fully. */
17 /* */
18 /***************************************************************************/
20 /*************************************************************************/
21 /* */
22 /* Note: A `raster' is simply a scan-line converter, used to render */
23 /* FT_Outlines into FT_Bitmaps. */
24 /* */
25 /*************************************************************************/
28 #ifndef __FTIMAGE_H__
29 #define __FTIMAGE_H__
32 /* _STANDALONE_ is from ftgrays.c */
33 #ifndef _STANDALONE_
34 #include <ft2build.h>
35 #endif
38 FT_BEGIN_HEADER
41 /*************************************************************************/
42 /* */
43 /* <Section> */
44 /* basic_types */
45 /* */
46 /*************************************************************************/
49 /*************************************************************************/
50 /* */
51 /* <Type> */
52 /* FT_Pos */
53 /* */
54 /* <Description> */
55 /* The type FT_Pos is used to store vectorial coordinates. Depending */
56 /* on the context, these can represent distances in integer font */
57 /* units, or 16.16, or 26.6 fixed float pixel coordinates. */
58 /* */
59 typedef signed long FT_Pos;
62 /*************************************************************************/
63 /* */
64 /* <Struct> */
65 /* FT_Vector */
66 /* */
67 /* <Description> */
68 /* A simple structure used to store a 2D vector; coordinates are of */
69 /* the FT_Pos type. */
70 /* */
71 /* <Fields> */
72 /* x :: The horizontal coordinate. */
73 /* y :: The vertical coordinate. */
74 /* */
75 typedef struct FT_Vector_
76 {
77 FT_Pos x;
78 FT_Pos y;
80 } FT_Vector;
83 /*************************************************************************/
84 /* */
85 /* <Struct> */
86 /* FT_BBox */
87 /* */
88 /* <Description> */
89 /* A structure used to hold an outline's bounding box, i.e., the */
90 /* coordinates of its extrema in the horizontal and vertical */
91 /* directions. */
92 /* */
93 /* <Fields> */
94 /* xMin :: The horizontal minimum (left-most). */
95 /* */
96 /* yMin :: The vertical minimum (bottom-most). */
97 /* */
98 /* xMax :: The horizontal maximum (right-most). */
99 /* */
100 /* yMax :: The vertical maximum (top-most). */
101 /* */
102 /* <Note> */
103 /* The bounding box is specified with the coordinates of the lower */
104 /* left and the upper right corner. In PostScript, those values are */
105 /* often called (llx,lly) and (urx,ury), respectively. */
106 /* */
107 /* If `yMin' is negative, this value gives the glyph's descender. */
108 /* Otherwise, the glyph doesn't descend below the baseline. */
109 /* Similarly, if `ymax' is positive, this value gives the glyph's */
110 /* ascender. */
111 /* */
112 /* `xMin' gives the horizontal distance from the glyph's origin to */
113 /* the left edge of the glyph's bounding box. If `xMin' is negative, */
114 /* the glyph extends to the left of the origin. */
115 /* */
116 typedef struct FT_BBox_
117 {
118 FT_Pos xMin, yMin;
119 FT_Pos xMax, yMax;
121 } FT_BBox;
124 /*************************************************************************/
125 /* */
126 /* <Enum> */
127 /* FT_Pixel_Mode */
128 /* */
129 /* <Description> */
130 /* An enumeration type used to describe the format of pixels in a */
131 /* given bitmap. Note that additional formats may be added in the */
132 /* future. */
133 /* */
134 /* <Values> */
135 /* FT_PIXEL_MODE_NONE :: */
136 /* Value~0 is reserved. */
137 /* */
138 /* FT_PIXEL_MODE_MONO :: */
139 /* A monochrome bitmap, using 1~bit per pixel. Note that pixels */
140 /* are stored in most-significant order (MSB), which means that */
141 /* the left-most pixel in a byte has value 128. */
142 /* */
143 /* FT_PIXEL_MODE_GRAY :: */
144 /* An 8-bit bitmap, generally used to represent anti-aliased glyph */
145 /* images. Each pixel is stored in one byte. Note that the number */
146 /* of `gray' levels is stored in the `num_grays' field of the */
147 /* @FT_Bitmap structure (it generally is 256). */
148 /* */
149 /* FT_PIXEL_MODE_GRAY2 :: */
150 /* A 2-bit per pixel bitmap, used to represent embedded */
151 /* anti-aliased bitmaps in font files according to the OpenType */
152 /* specification. We haven't found a single font using this */
153 /* format, however. */
154 /* */
155 /* FT_PIXEL_MODE_GRAY4 :: */
156 /* A 4-bit per pixel bitmap, representing embedded anti-aliased */
157 /* bitmaps in font files according to the OpenType specification. */
158 /* We haven't found a single font using this format, however. */
159 /* */
160 /* FT_PIXEL_MODE_LCD :: */
161 /* An 8-bit bitmap, representing RGB or BGR decimated glyph images */
162 /* used for display on LCD displays; the bitmap is three times */
163 /* wider than the original glyph image. See also */
164 /* @FT_RENDER_MODE_LCD. */
165 /* */
166 /* FT_PIXEL_MODE_LCD_V :: */
167 /* An 8-bit bitmap, representing RGB or BGR decimated glyph images */
168 /* used for display on rotated LCD displays; the bitmap is three */
169 /* times taller than the original glyph image. See also */
170 /* @FT_RENDER_MODE_LCD_V. */
171 /* */
172 typedef enum FT_Pixel_Mode_
173 {
174 FT_PIXEL_MODE_NONE = 0,
175 FT_PIXEL_MODE_MONO,
176 FT_PIXEL_MODE_GRAY,
177 FT_PIXEL_MODE_GRAY2,
178 FT_PIXEL_MODE_GRAY4,
179 FT_PIXEL_MODE_LCD,
180 FT_PIXEL_MODE_LCD_V,
182 FT_PIXEL_MODE_MAX /* do not remove */
184 } FT_Pixel_Mode;
187 /*************************************************************************/
188 /* */
189 /* <Enum> */
190 /* ft_pixel_mode_xxx */
191 /* */
192 /* <Description> */
193 /* A list of deprecated constants. Use the corresponding */
194 /* @FT_Pixel_Mode values instead. */
195 /* */
196 /* <Values> */
197 /* ft_pixel_mode_none :: See @FT_PIXEL_MODE_NONE. */
198 /* ft_pixel_mode_mono :: See @FT_PIXEL_MODE_MONO. */
199 /* ft_pixel_mode_grays :: See @FT_PIXEL_MODE_GRAY. */
200 /* ft_pixel_mode_pal2 :: See @FT_PIXEL_MODE_GRAY2. */
201 /* ft_pixel_mode_pal4 :: See @FT_PIXEL_MODE_GRAY4. */
202 /* */
203 #define ft_pixel_mode_none FT_PIXEL_MODE_NONE
204 #define ft_pixel_mode_mono FT_PIXEL_MODE_MONO
205 #define ft_pixel_mode_grays FT_PIXEL_MODE_GRAY
206 #define ft_pixel_mode_pal2 FT_PIXEL_MODE_GRAY2
207 #define ft_pixel_mode_pal4 FT_PIXEL_MODE_GRAY4
209 /* */
211 #if 0
213 /*************************************************************************/
214 /* */
215 /* <Enum> */
216 /* FT_Palette_Mode */
217 /* */
218 /* <Description> */
219 /* THIS TYPE IS DEPRECATED. DO NOT USE IT! */
220 /* */
221 /* An enumeration type to describe the format of a bitmap palette, */
222 /* used with ft_pixel_mode_pal4 and ft_pixel_mode_pal8. */
223 /* */
224 /* <Values> */
225 /* ft_palette_mode_rgb :: The palette is an array of 3-byte RGB */
226 /* records. */
227 /* */
228 /* ft_palette_mode_rgba :: The palette is an array of 4-byte RGBA */
229 /* records. */
230 /* */
231 /* <Note> */
232 /* As ft_pixel_mode_pal2, pal4 and pal8 are currently unused by */
233 /* FreeType, these types are not handled by the library itself. */
234 /* */
235 typedef enum FT_Palette_Mode_
236 {
237 ft_palette_mode_rgb = 0,
238 ft_palette_mode_rgba,
240 ft_palette_mode_max /* do not remove */
242 } FT_Palette_Mode;
244 /* */
246 #endif
249 /*************************************************************************/
250 /* */
251 /* <Struct> */
252 /* FT_Bitmap */
253 /* */
254 /* <Description> */
255 /* A structure used to describe a bitmap or pixmap to the raster. */
256 /* Note that we now manage pixmaps of various depths through the */
257 /* `pixel_mode' field. */
258 /* */
259 /* <Fields> */
260 /* rows :: The number of bitmap rows. */
261 /* */
262 /* width :: The number of pixels in bitmap row. */
263 /* */
264 /* pitch :: The pitch's absolute value is the number of bytes */
265 /* taken by one bitmap row, including padding. */
266 /* However, the pitch is positive when the bitmap has */
267 /* a `down' flow, and negative when it has an `up' */
268 /* flow. In all cases, the pitch is an offset to add */
269 /* to a bitmap pointer in order to go down one row. */
270 /* */
271 /* Note that `padding' means the alignment of a */
272 /* bitmap to a byte border, and FreeType functions */
273 /* normally align to the smallest possible integer */
274 /* value. */
275 /* */
276 /* For the B/W rasterizer, `pitch' is always an even */
277 /* number. */
278 /* */
279 /* To change the pitch of a bitmap (say, to make it a */
280 /* multiple of 4), use @FT_Bitmap_Convert. */
281 /* Alternatively, you might use callback functions to */
282 /* directly render to the application's surface; see */
283 /* the file `example2.cpp' in the tutorial for a */
284 /* demonstration. */
285 /* */
286 /* buffer :: A typeless pointer to the bitmap buffer. This */
287 /* value should be aligned on 32-bit boundaries in */
288 /* most cases. */
289 /* */
290 /* num_grays :: This field is only used with */
291 /* @FT_PIXEL_MODE_GRAY; it gives the number of gray */
292 /* levels used in the bitmap. */
293 /* */
294 /* pixel_mode :: The pixel mode, i.e., how pixel bits are stored. */
295 /* See @FT_Pixel_Mode for possible values. */
296 /* */
297 /* palette_mode :: This field is intended for paletted pixel modes; */
298 /* it indicates how the palette is stored. Not */
299 /* used currently. */
300 /* */
301 /* palette :: A typeless pointer to the bitmap palette; this */
302 /* field is intended for paletted pixel modes. Not */
303 /* used currently. */
304 /* */
305 /* <Note> */
306 /* For now, the only pixel modes supported by FreeType are mono and */
307 /* grays. However, drivers might be added in the future to support */
308 /* more `colorful' options. */
309 /* */
310 typedef struct FT_Bitmap_
311 {
312 int rows;
313 int width;
314 int pitch;
315 unsigned char* buffer;
316 short num_grays;
317 char pixel_mode;
318 char palette_mode;
319 void* palette;
321 } FT_Bitmap;
324 /*************************************************************************/
325 /* */
326 /* <Section> */
327 /* outline_processing */
328 /* */
329 /*************************************************************************/
332 /*************************************************************************/
333 /* */
334 /* <Struct> */
335 /* FT_Outline */
336 /* */
337 /* <Description> */
338 /* This structure is used to describe an outline to the scan-line */
339 /* converter. */
340 /* */
341 /* <Fields> */
342 /* n_contours :: The number of contours in the outline. */
343 /* */
344 /* n_points :: The number of points in the outline. */
345 /* */
346 /* points :: A pointer to an array of `n_points' @FT_Vector */
347 /* elements, giving the outline's point coordinates. */
348 /* */
349 /* tags :: A pointer to an array of `n_points' chars, giving */
350 /* each outline point's type. */
351 /* */
352 /* If bit~0 is unset, the point is `off' the curve, */
353 /* i.e., a Bézier control point, while it is `on' if */
354 /* set. */
355 /* */
356 /* Bit~1 is meaningful for `off' points only. If set, */
357 /* it indicates a third-order Bézier arc control point; */
358 /* and a second-order control point if unset. */
359 /* */
360 /* If bit~2 is set, bits 5-7 contain the drop-out mode */
361 /* (as defined in the OpenType specification; the value */
362 /* is the same as the argument to the SCANMODE */
363 /* instruction). */
364 /* */
365 /* Bits 3 and~4 are reserved for internal purposes. */
366 /* */
367 /* contours :: An array of `n_contours' shorts, giving the end */
368 /* point of each contour within the outline. For */
369 /* example, the first contour is defined by the points */
370 /* `0' to `contours[0]', the second one is defined by */
371 /* the points `contours[0]+1' to `contours[1]', etc. */
372 /* */
373 /* flags :: A set of bit flags used to characterize the outline */
374 /* and give hints to the scan-converter and hinter on */
375 /* how to convert/grid-fit it. See @FT_OUTLINE_FLAGS. */
376 /* */
377 /* <Note> */
378 /* The B/W rasterizer only checks bit~2 in the `tags' array for the */
379 /* first point of each contour. The drop-out mode as given with */
380 /* @FT_OUTLINE_IGNORE_DROPOUTS, @FT_OUTLINE_SMART_DROPOUTS, and */
381 /* @FT_OUTLINE_INCLUDE_STUBS in `flags' is then overridden. */
382 /* */
383 typedef struct FT_Outline_
384 {
385 short n_contours; /* number of contours in glyph */
386 short n_points; /* number of points in the glyph */
388 FT_Vector* points; /* the outline's points */
389 char* tags; /* the points flags */
390 short* contours; /* the contour end points */
392 int flags; /* outline masks */
394 } FT_Outline;
396 /* Following limits must be consistent with */
397 /* FT_Outline.{n_contours,n_points} */
398 #define FT_OUTLINE_CONTOURS_MAX SHRT_MAX
399 #define FT_OUTLINE_POINTS_MAX SHRT_MAX
402 /*************************************************************************/
403 /* */
404 /* <Enum> */
405 /* FT_OUTLINE_FLAGS */
406 /* */
407 /* <Description> */
408 /* A list of bit-field constants use for the flags in an outline's */
409 /* `flags' field. */
410 /* */
411 /* <Values> */
412 /* FT_OUTLINE_NONE :: */
413 /* Value~0 is reserved. */
414 /* */
415 /* FT_OUTLINE_OWNER :: */
416 /* If set, this flag indicates that the outline's field arrays */
417 /* (i.e., `points', `flags', and `contours') are `owned' by the */
418 /* outline object, and should thus be freed when it is destroyed. */
419 /* */
420 /* FT_OUTLINE_EVEN_ODD_FILL :: */
421 /* By default, outlines are filled using the non-zero winding rule. */
422 /* If set to 1, the outline will be filled using the even-odd fill */
423 /* rule (only works with the smooth rasterizer). */
424 /* */
425 /* FT_OUTLINE_REVERSE_FILL :: */
426 /* By default, outside contours of an outline are oriented in */
427 /* clock-wise direction, as defined in the TrueType specification. */
428 /* This flag is set if the outline uses the opposite direction */
429 /* (typically for Type~1 fonts). This flag is ignored by the scan */
430 /* converter. */
431 /* */
432 /* FT_OUTLINE_IGNORE_DROPOUTS :: */
433 /* By default, the scan converter will try to detect drop-outs in */
434 /* an outline and correct the glyph bitmap to ensure consistent */
435 /* shape continuity. If set, this flag hints the scan-line */
436 /* converter to ignore such cases. See below for more information. */
437 /* */
438 /* FT_OUTLINE_SMART_DROPOUTS :: */
439 /* Select smart dropout control. If unset, use simple dropout */
440 /* control. Ignored if @FT_OUTLINE_IGNORE_DROPOUTS is set. See */
441 /* below for more information. */
442 /* */
443 /* FT_OUTLINE_INCLUDE_STUBS :: */
444 /* If set, turn pixels on for `stubs', otherwise exclude them. */
445 /* Ignored if @FT_OUTLINE_IGNORE_DROPOUTS is set. See below for */
446 /* more information. */
447 /* */
448 /* FT_OUTLINE_HIGH_PRECISION :: */
449 /* This flag indicates that the scan-line converter should try to */
450 /* convert this outline to bitmaps with the highest possible */
451 /* quality. It is typically set for small character sizes. Note */
452 /* that this is only a hint that might be completely ignored by a */
453 /* given scan-converter. */
454 /* */
455 /* FT_OUTLINE_SINGLE_PASS :: */
456 /* This flag is set to force a given scan-converter to only use a */
457 /* single pass over the outline to render a bitmap glyph image. */
458 /* Normally, it is set for very large character sizes. It is only */
459 /* a hint that might be completely ignored by a given */
460 /* scan-converter. */
461 /* */
462 /* <Note> */
463 /* The flags @FT_OUTLINE_IGNORE_DROPOUTS, @FT_OUTLINE_SMART_DROPOUTS, */
464 /* and @FT_OUTLINE_INCLUDE_STUBS are ignored by the smooth */
465 /* rasterizer. */
466 /* */
467 /* There exists a second mechanism to pass the drop-out mode to the */
468 /* B/W rasterizer; see the `tags' field in @FT_Outline. */
469 /* */
470 /* Please refer to the description of the `SCANTYPE' instruction in */
471 /* the OpenType specification (in file `ttinst1.doc') how simple */
472 /* drop-outs, smart drop-outs, and stubs are defined. */
473 /* */
474 #define FT_OUTLINE_NONE 0x0
475 #define FT_OUTLINE_OWNER 0x1
476 #define FT_OUTLINE_EVEN_ODD_FILL 0x2
477 #define FT_OUTLINE_REVERSE_FILL 0x4
478 #define FT_OUTLINE_IGNORE_DROPOUTS 0x8
479 #define FT_OUTLINE_SMART_DROPOUTS 0x10
480 #define FT_OUTLINE_INCLUDE_STUBS 0x20
482 #define FT_OUTLINE_HIGH_PRECISION 0x100
483 #define FT_OUTLINE_SINGLE_PASS 0x200
486 /*************************************************************************
487 *
488 * @enum:
489 * ft_outline_flags
490 *
491 * @description:
492 * These constants are deprecated. Please use the corresponding
493 * @FT_OUTLINE_FLAGS values.
494 *
495 * @values:
496 * ft_outline_none :: See @FT_OUTLINE_NONE.
497 * ft_outline_owner :: See @FT_OUTLINE_OWNER.
498 * ft_outline_even_odd_fill :: See @FT_OUTLINE_EVEN_ODD_FILL.
499 * ft_outline_reverse_fill :: See @FT_OUTLINE_REVERSE_FILL.
500 * ft_outline_ignore_dropouts :: See @FT_OUTLINE_IGNORE_DROPOUTS.
501 * ft_outline_high_precision :: See @FT_OUTLINE_HIGH_PRECISION.
502 * ft_outline_single_pass :: See @FT_OUTLINE_SINGLE_PASS.
503 */
504 #define ft_outline_none FT_OUTLINE_NONE
505 #define ft_outline_owner FT_OUTLINE_OWNER
506 #define ft_outline_even_odd_fill FT_OUTLINE_EVEN_ODD_FILL
507 #define ft_outline_reverse_fill FT_OUTLINE_REVERSE_FILL
508 #define ft_outline_ignore_dropouts FT_OUTLINE_IGNORE_DROPOUTS
509 #define ft_outline_high_precision FT_OUTLINE_HIGH_PRECISION
510 #define ft_outline_single_pass FT_OUTLINE_SINGLE_PASS
512 /* */
514 #define FT_CURVE_TAG( flag ) ( flag & 3 )
516 #define FT_CURVE_TAG_ON 1
517 #define FT_CURVE_TAG_CONIC 0
518 #define FT_CURVE_TAG_CUBIC 2
520 #define FT_CURVE_TAG_HAS_SCANMODE 4
522 #define FT_CURVE_TAG_TOUCH_X 8 /* reserved for the TrueType hinter */
523 #define FT_CURVE_TAG_TOUCH_Y 16 /* reserved for the TrueType hinter */
525 #define FT_CURVE_TAG_TOUCH_BOTH ( FT_CURVE_TAG_TOUCH_X | \
526 FT_CURVE_TAG_TOUCH_Y )
528 #define FT_Curve_Tag_On FT_CURVE_TAG_ON
529 #define FT_Curve_Tag_Conic FT_CURVE_TAG_CONIC
530 #define FT_Curve_Tag_Cubic FT_CURVE_TAG_CUBIC
531 #define FT_Curve_Tag_Touch_X FT_CURVE_TAG_TOUCH_X
532 #define FT_Curve_Tag_Touch_Y FT_CURVE_TAG_TOUCH_Y
535 /*************************************************************************/
536 /* */
537 /* <FuncType> */
538 /* FT_Outline_MoveToFunc */
539 /* */
540 /* <Description> */
541 /* A function pointer type used to describe the signature of a `move */
542 /* to' function during outline walking/decomposition. */
543 /* */
544 /* A `move to' is emitted to start a new contour in an outline. */
545 /* */
546 /* <Input> */
547 /* to :: A pointer to the target point of the `move to'. */
548 /* */
549 /* user :: A typeless pointer which is passed from the caller of the */
550 /* decomposition function. */
551 /* */
552 /* <Return> */
553 /* Error code. 0~means success. */
554 /* */
555 typedef int
556 (*FT_Outline_MoveToFunc)( const FT_Vector* to,
557 void* user );
559 #define FT_Outline_MoveTo_Func FT_Outline_MoveToFunc
562 /*************************************************************************/
563 /* */
564 /* <FuncType> */
565 /* FT_Outline_LineToFunc */
566 /* */
567 /* <Description> */
568 /* A function pointer type used to describe the signature of a `line */
569 /* to' function during outline walking/decomposition. */
570 /* */
571 /* A `line to' is emitted to indicate a segment in the outline. */
572 /* */
573 /* <Input> */
574 /* to :: A pointer to the target point of the `line to'. */
575 /* */
576 /* user :: A typeless pointer which is passed from the caller of the */
577 /* decomposition function. */
578 /* */
579 /* <Return> */
580 /* Error code. 0~means success. */
581 /* */
582 typedef int
583 (*FT_Outline_LineToFunc)( const FT_Vector* to,
584 void* user );
586 #define FT_Outline_LineTo_Func FT_Outline_LineToFunc
589 /*************************************************************************/
590 /* */
591 /* <FuncType> */
592 /* FT_Outline_ConicToFunc */
593 /* */
594 /* <Description> */
595 /* A function pointer type used to describe the signature of a `conic */
596 /* to' function during outline walking or decomposition. */
597 /* */
598 /* A `conic to' is emitted to indicate a second-order Bézier arc in */
599 /* the outline. */
600 /* */
601 /* <Input> */
602 /* control :: An intermediate control point between the last position */
603 /* and the new target in `to'. */
604 /* */
605 /* to :: A pointer to the target end point of the conic arc. */
606 /* */
607 /* user :: A typeless pointer which is passed from the caller of */
608 /* the decomposition function. */
609 /* */
610 /* <Return> */
611 /* Error code. 0~means success. */
612 /* */
613 typedef int
614 (*FT_Outline_ConicToFunc)( const FT_Vector* control,
615 const FT_Vector* to,
616 void* user );
618 #define FT_Outline_ConicTo_Func FT_Outline_ConicToFunc
621 /*************************************************************************/
622 /* */
623 /* <FuncType> */
624 /* FT_Outline_CubicToFunc */
625 /* */
626 /* <Description> */
627 /* A function pointer type used to describe the signature of a `cubic */
628 /* to' function during outline walking or decomposition. */
629 /* */
630 /* A `cubic to' is emitted to indicate a third-order Bézier arc. */
631 /* */
632 /* <Input> */
633 /* control1 :: A pointer to the first Bézier control point. */
634 /* */
635 /* control2 :: A pointer to the second Bézier control point. */
636 /* */
637 /* to :: A pointer to the target end point. */
638 /* */
639 /* user :: A typeless pointer which is passed from the caller of */
640 /* the decomposition function. */
641 /* */
642 /* <Return> */
643 /* Error code. 0~means success. */
644 /* */
645 typedef int
646 (*FT_Outline_CubicToFunc)( const FT_Vector* control1,
647 const FT_Vector* control2,
648 const FT_Vector* to,
649 void* user );
651 #define FT_Outline_CubicTo_Func FT_Outline_CubicToFunc
654 /*************************************************************************/
655 /* */
656 /* <Struct> */
657 /* FT_Outline_Funcs */
658 /* */
659 /* <Description> */
660 /* A structure to hold various function pointers used during outline */
661 /* decomposition in order to emit segments, conic, and cubic Béziers. */
662 /* */
663 /* <Fields> */
664 /* move_to :: The `move to' emitter. */
665 /* */
666 /* line_to :: The segment emitter. */
667 /* */
668 /* conic_to :: The second-order Bézier arc emitter. */
669 /* */
670 /* cubic_to :: The third-order Bézier arc emitter. */
671 /* */
672 /* shift :: The shift that is applied to coordinates before they */
673 /* are sent to the emitter. */
674 /* */
675 /* delta :: The delta that is applied to coordinates before they */
676 /* are sent to the emitter, but after the shift. */
677 /* */
678 /* <Note> */
679 /* The point coordinates sent to the emitters are the transformed */
680 /* version of the original coordinates (this is important for high */
681 /* accuracy during scan-conversion). The transformation is simple: */
682 /* */
683 /* { */
684 /* x' = (x << shift) - delta */
685 /* y' = (x << shift) - delta */
686 /* } */
687 /* */
688 /* Set the values of `shift' and `delta' to~0 to get the original */
689 /* point coordinates. */
690 /* */
691 typedef struct FT_Outline_Funcs_
692 {
693 FT_Outline_MoveToFunc move_to;
694 FT_Outline_LineToFunc line_to;
695 FT_Outline_ConicToFunc conic_to;
696 FT_Outline_CubicToFunc cubic_to;
698 int shift;
699 FT_Pos delta;
701 } FT_Outline_Funcs;
704 /*************************************************************************/
705 /* */
706 /* <Section> */
707 /* basic_types */
708 /* */
709 /*************************************************************************/
712 /*************************************************************************/
713 /* */
714 /* <Macro> */
715 /* FT_IMAGE_TAG */
716 /* */
717 /* <Description> */
718 /* This macro converts four-letter tags to an unsigned long type. */
719 /* */
720 /* <Note> */
721 /* Since many 16-bit compilers don't like 32-bit enumerations, you */
722 /* should redefine this macro in case of problems to something like */
723 /* this: */
724 /* */
725 /* { */
726 /* #define FT_IMAGE_TAG( value, _x1, _x2, _x3, _x4 ) value */
727 /* } */
728 /* */
729 /* to get a simple enumeration without assigning special numbers. */
730 /* */
731 #ifndef FT_IMAGE_TAG
732 #define FT_IMAGE_TAG( value, _x1, _x2, _x3, _x4 ) \
733 value = ( ( (unsigned long)_x1 << 24 ) | \
734 ( (unsigned long)_x2 << 16 ) | \
735 ( (unsigned long)_x3 << 8 ) | \
736 (unsigned long)_x4 )
737 #endif /* FT_IMAGE_TAG */
740 /*************************************************************************/
741 /* */
742 /* <Enum> */
743 /* FT_Glyph_Format */
744 /* */
745 /* <Description> */
746 /* An enumeration type used to describe the format of a given glyph */
747 /* image. Note that this version of FreeType only supports two image */
748 /* formats, even though future font drivers will be able to register */
749 /* their own format. */
750 /* */
751 /* <Values> */
752 /* FT_GLYPH_FORMAT_NONE :: */
753 /* The value~0 is reserved. */
754 /* */
755 /* FT_GLYPH_FORMAT_COMPOSITE :: */
756 /* The glyph image is a composite of several other images. This */
757 /* format is _only_ used with @FT_LOAD_NO_RECURSE, and is used to */
758 /* report compound glyphs (like accented characters). */
759 /* */
760 /* FT_GLYPH_FORMAT_BITMAP :: */
761 /* The glyph image is a bitmap, and can be described as an */
762 /* @FT_Bitmap. You generally need to access the `bitmap' field of */
763 /* the @FT_GlyphSlotRec structure to read it. */
764 /* */
765 /* FT_GLYPH_FORMAT_OUTLINE :: */
766 /* The glyph image is a vectorial outline made of line segments */
767 /* and Bézier arcs; it can be described as an @FT_Outline; you */
768 /* generally want to access the `outline' field of the */
769 /* @FT_GlyphSlotRec structure to read it. */
770 /* */
771 /* FT_GLYPH_FORMAT_PLOTTER :: */
772 /* The glyph image is a vectorial path with no inside and outside */
773 /* contours. Some Type~1 fonts, like those in the Hershey family, */
774 /* contain glyphs in this format. These are described as */
775 /* @FT_Outline, but FreeType isn't currently capable of rendering */
776 /* them correctly. */
777 /* */
778 typedef enum FT_Glyph_Format_
779 {
780 FT_IMAGE_TAG( FT_GLYPH_FORMAT_NONE, 0, 0, 0, 0 ),
782 FT_IMAGE_TAG( FT_GLYPH_FORMAT_COMPOSITE, 'c', 'o', 'm', 'p' ),
783 FT_IMAGE_TAG( FT_GLYPH_FORMAT_BITMAP, 'b', 'i', 't', 's' ),
784 FT_IMAGE_TAG( FT_GLYPH_FORMAT_OUTLINE, 'o', 'u', 't', 'l' ),
785 FT_IMAGE_TAG( FT_GLYPH_FORMAT_PLOTTER, 'p', 'l', 'o', 't' )
787 } FT_Glyph_Format;
790 /*************************************************************************/
791 /* */
792 /* <Enum> */
793 /* ft_glyph_format_xxx */
794 /* */
795 /* <Description> */
796 /* A list of deprecated constants. Use the corresponding */
797 /* @FT_Glyph_Format values instead. */
798 /* */
799 /* <Values> */
800 /* ft_glyph_format_none :: See @FT_GLYPH_FORMAT_NONE. */
801 /* ft_glyph_format_composite :: See @FT_GLYPH_FORMAT_COMPOSITE. */
802 /* ft_glyph_format_bitmap :: See @FT_GLYPH_FORMAT_BITMAP. */
803 /* ft_glyph_format_outline :: See @FT_GLYPH_FORMAT_OUTLINE. */
804 /* ft_glyph_format_plotter :: See @FT_GLYPH_FORMAT_PLOTTER. */
805 /* */
806 #define ft_glyph_format_none FT_GLYPH_FORMAT_NONE
807 #define ft_glyph_format_composite FT_GLYPH_FORMAT_COMPOSITE
808 #define ft_glyph_format_bitmap FT_GLYPH_FORMAT_BITMAP
809 #define ft_glyph_format_outline FT_GLYPH_FORMAT_OUTLINE
810 #define ft_glyph_format_plotter FT_GLYPH_FORMAT_PLOTTER
813 /*************************************************************************/
814 /*************************************************************************/
815 /*************************************************************************/
816 /***** *****/
817 /***** R A S T E R D E F I N I T I O N S *****/
818 /***** *****/
819 /*************************************************************************/
820 /*************************************************************************/
821 /*************************************************************************/
824 /*************************************************************************/
825 /* */
826 /* A raster is a scan converter, in charge of rendering an outline into */
827 /* a a bitmap. This section contains the public API for rasters. */
828 /* */
829 /* Note that in FreeType 2, all rasters are now encapsulated within */
830 /* specific modules called `renderers'. See `freetype/ftrender.h' for */
831 /* more details on renderers. */
832 /* */
833 /*************************************************************************/
836 /*************************************************************************/
837 /* */
838 /* <Section> */
839 /* raster */
840 /* */
841 /* <Title> */
842 /* Scanline Converter */
843 /* */
844 /* <Abstract> */
845 /* How vectorial outlines are converted into bitmaps and pixmaps. */
846 /* */
847 /* <Description> */
848 /* This section contains technical definitions. */
849 /* */
850 /*************************************************************************/
853 /*************************************************************************/
854 /* */
855 /* <Type> */
856 /* FT_Raster */
857 /* */
858 /* <Description> */
859 /* A handle (pointer) to a raster object. Each object can be used */
860 /* independently to convert an outline into a bitmap or pixmap. */
861 /* */
862 typedef struct FT_RasterRec_* FT_Raster;
865 /*************************************************************************/
866 /* */
867 /* <Struct> */
868 /* FT_Span */
869 /* */
870 /* <Description> */
871 /* A structure used to model a single span of gray (or black) pixels */
872 /* when rendering a monochrome or anti-aliased bitmap. */
873 /* */
874 /* <Fields> */
875 /* x :: The span's horizontal start position. */
876 /* */
877 /* len :: The span's length in pixels. */
878 /* */
879 /* coverage :: The span color/coverage, ranging from 0 (background) */
880 /* to 255 (foreground). Only used for anti-aliased */
881 /* rendering. */
882 /* */
883 /* <Note> */
884 /* This structure is used by the span drawing callback type named */
885 /* @FT_SpanFunc which takes the y~coordinate of the span as a */
886 /* a parameter. */
887 /* */
888 /* The coverage value is always between 0 and 255. If you want less */
889 /* gray values, the callback function has to reduce them. */
890 /* */
891 typedef struct FT_Span_
892 {
893 short x;
894 unsigned short len;
895 unsigned char coverage;
897 } FT_Span;
900 /*************************************************************************/
901 /* */
902 /* <FuncType> */
903 /* FT_SpanFunc */
904 /* */
905 /* <Description> */
906 /* A function used as a call-back by the anti-aliased renderer in */
907 /* order to let client applications draw themselves the gray pixel */
908 /* spans on each scan line. */
909 /* */
910 /* <Input> */
911 /* y :: The scanline's y~coordinate. */
912 /* */
913 /* count :: The number of spans to draw on this scanline. */
914 /* */
915 /* spans :: A table of `count' spans to draw on the scanline. */
916 /* */
917 /* user :: User-supplied data that is passed to the callback. */
918 /* */
919 /* <Note> */
920 /* This callback allows client applications to directly render the */
921 /* gray spans of the anti-aliased bitmap to any kind of surfaces. */
922 /* */
923 /* This can be used to write anti-aliased outlines directly to a */
924 /* given background bitmap, and even perform translucency. */
925 /* */
926 /* Note that the `count' field cannot be greater than a fixed value */
927 /* defined by the `FT_MAX_GRAY_SPANS' configuration macro in */
928 /* `ftoption.h'. By default, this value is set to~32, which means */
929 /* that if there are more than 32~spans on a given scanline, the */
930 /* callback is called several times with the same `y' parameter in */
931 /* order to draw all callbacks. */
932 /* */
933 /* Otherwise, the callback is only called once per scan-line, and */
934 /* only for those scanlines that do have `gray' pixels on them. */
935 /* */
936 typedef void
937 (*FT_SpanFunc)( int y,
938 int count,
939 const FT_Span* spans,
940 void* user );
942 #define FT_Raster_Span_Func FT_SpanFunc
945 /*************************************************************************/
946 /* */
947 /* <FuncType> */
948 /* FT_Raster_BitTest_Func */
949 /* */
950 /* <Description> */
951 /* THIS TYPE IS DEPRECATED. DO NOT USE IT. */
952 /* */
953 /* A function used as a call-back by the monochrome scan-converter */
954 /* to test whether a given target pixel is already set to the drawing */
955 /* `color'. These tests are crucial to implement drop-out control */
956 /* per-se the TrueType spec. */
957 /* */
958 /* <Input> */
959 /* y :: The pixel's y~coordinate. */
960 /* */
961 /* x :: The pixel's x~coordinate. */
962 /* */
963 /* user :: User-supplied data that is passed to the callback. */
964 /* */
965 /* <Return> */
966 /* 1~if the pixel is `set', 0~otherwise. */
967 /* */
968 typedef int
969 (*FT_Raster_BitTest_Func)( int y,
970 int x,
971 void* user );
974 /*************************************************************************/
975 /* */
976 /* <FuncType> */
977 /* FT_Raster_BitSet_Func */
978 /* */
979 /* <Description> */
980 /* THIS TYPE IS DEPRECATED. DO NOT USE IT. */
981 /* */
982 /* A function used as a call-back by the monochrome scan-converter */
983 /* to set an individual target pixel. This is crucial to implement */
984 /* drop-out control according to the TrueType specification. */
985 /* */
986 /* <Input> */
987 /* y :: The pixel's y~coordinate. */
988 /* */
989 /* x :: The pixel's x~coordinate. */
990 /* */
991 /* user :: User-supplied data that is passed to the callback. */
992 /* */
993 /* <Return> */
994 /* 1~if the pixel is `set', 0~otherwise. */
995 /* */
996 typedef void
997 (*FT_Raster_BitSet_Func)( int y,
998 int x,
999 void* user );
1002 /*************************************************************************/
1003 /* */
1004 /* <Enum> */
1005 /* FT_RASTER_FLAG_XXX */
1006 /* */
1007 /* <Description> */
1008 /* A list of bit flag constants as used in the `flags' field of a */
1009 /* @FT_Raster_Params structure. */
1010 /* */
1011 /* <Values> */
1012 /* FT_RASTER_FLAG_DEFAULT :: This value is 0. */
1013 /* */
1014 /* FT_RASTER_FLAG_AA :: This flag is set to indicate that an */
1015 /* anti-aliased glyph image should be */
1016 /* generated. Otherwise, it will be */
1017 /* monochrome (1-bit). */
1018 /* */
1019 /* FT_RASTER_FLAG_DIRECT :: This flag is set to indicate direct */
1020 /* rendering. In this mode, client */
1021 /* applications must provide their own span */
1022 /* callback. This lets them directly */
1023 /* draw or compose over an existing bitmap. */
1024 /* If this bit is not set, the target */
1025 /* pixmap's buffer _must_ be zeroed before */
1026 /* rendering. */
1027 /* */
1028 /* Note that for now, direct rendering is */
1029 /* only possible with anti-aliased glyphs. */
1030 /* */
1031 /* FT_RASTER_FLAG_CLIP :: This flag is only used in direct */
1032 /* rendering mode. If set, the output will */
1033 /* be clipped to a box specified in the */
1034 /* `clip_box' field of the */
1035 /* @FT_Raster_Params structure. */
1036 /* */
1037 /* Note that by default, the glyph bitmap */
1038 /* is clipped to the target pixmap, except */
1039 /* in direct rendering mode where all spans */
1040 /* are generated if no clipping box is set. */
1041 /* */
1042 #define FT_RASTER_FLAG_DEFAULT 0x0
1043 #define FT_RASTER_FLAG_AA 0x1
1044 #define FT_RASTER_FLAG_DIRECT 0x2
1045 #define FT_RASTER_FLAG_CLIP 0x4
1047 /* deprecated */
1048 #define ft_raster_flag_default FT_RASTER_FLAG_DEFAULT
1049 #define ft_raster_flag_aa FT_RASTER_FLAG_AA
1050 #define ft_raster_flag_direct FT_RASTER_FLAG_DIRECT
1051 #define ft_raster_flag_clip FT_RASTER_FLAG_CLIP
1054 /*************************************************************************/
1055 /* */
1056 /* <Struct> */
1057 /* FT_Raster_Params */
1058 /* */
1059 /* <Description> */
1060 /* A structure to hold the arguments used by a raster's render */
1061 /* function. */
1062 /* */
1063 /* <Fields> */
1064 /* target :: The target bitmap. */
1065 /* */
1066 /* source :: A pointer to the source glyph image (e.g., an */
1067 /* @FT_Outline). */
1068 /* */
1069 /* flags :: The rendering flags. */
1070 /* */
1071 /* gray_spans :: The gray span drawing callback. */
1072 /* */
1073 /* black_spans :: The black span drawing callback. UNIMPLEMENTED! */
1074 /* */
1075 /* bit_test :: The bit test callback. UNIMPLEMENTED! */
1076 /* */
1077 /* bit_set :: The bit set callback. UNIMPLEMENTED! */
1078 /* */
1079 /* user :: User-supplied data that is passed to each drawing */
1080 /* callback. */
1081 /* */
1082 /* clip_box :: An optional clipping box. It is only used in */
1083 /* direct rendering mode. Note that coordinates here */
1084 /* should be expressed in _integer_ pixels (and not in */
1085 /* 26.6 fixed-point units). */
1086 /* */
1087 /* <Note> */
1088 /* An anti-aliased glyph bitmap is drawn if the @FT_RASTER_FLAG_AA */
1089 /* bit flag is set in the `flags' field, otherwise a monochrome */
1090 /* bitmap is generated. */
1091 /* */
1092 /* If the @FT_RASTER_FLAG_DIRECT bit flag is set in `flags', the */
1093 /* raster will call the `gray_spans' callback to draw gray pixel */
1094 /* spans, in the case of an aa glyph bitmap, it will call */
1095 /* `black_spans', and `bit_test' and `bit_set' in the case of a */
1096 /* monochrome bitmap. This allows direct composition over a */
1097 /* pre-existing bitmap through user-provided callbacks to perform the */
1098 /* span drawing/composition. */
1099 /* */
1100 /* Note that the `bit_test' and `bit_set' callbacks are required when */
1101 /* rendering a monochrome bitmap, as they are crucial to implement */
1102 /* correct drop-out control as defined in the TrueType specification. */
1103 /* */
1104 typedef struct FT_Raster_Params_
1105 {
1106 const FT_Bitmap* target;
1107 const void* source;
1108 int flags;
1109 FT_SpanFunc gray_spans;
1110 FT_SpanFunc black_spans; /* doesn't work! */
1111 FT_Raster_BitTest_Func bit_test; /* doesn't work! */
1112 FT_Raster_BitSet_Func bit_set; /* doesn't work! */
1113 void* user;
1114 FT_BBox clip_box;
1116 } FT_Raster_Params;
1119 /*************************************************************************/
1120 /* */
1121 /* <FuncType> */
1122 /* FT_Raster_NewFunc */
1123 /* */
1124 /* <Description> */
1125 /* A function used to create a new raster object. */
1126 /* */
1127 /* <Input> */
1128 /* memory :: A handle to the memory allocator. */
1129 /* */
1130 /* <Output> */
1131 /* raster :: A handle to the new raster object. */
1132 /* */
1133 /* <Return> */
1134 /* Error code. 0~means success. */
1135 /* */
1136 /* <Note> */
1137 /* The `memory' parameter is a typeless pointer in order to avoid */
1138 /* un-wanted dependencies on the rest of the FreeType code. In */
1139 /* practice, it is an @FT_Memory object, i.e., a handle to the */
1140 /* standard FreeType memory allocator. However, this field can be */
1141 /* completely ignored by a given raster implementation. */
1142 /* */
1143 typedef int
1144 (*FT_Raster_NewFunc)( void* memory,
1145 FT_Raster* raster );
1147 #define FT_Raster_New_Func FT_Raster_NewFunc
1150 /*************************************************************************/
1151 /* */
1152 /* <FuncType> */
1153 /* FT_Raster_DoneFunc */
1154 /* */
1155 /* <Description> */
1156 /* A function used to destroy a given raster object. */
1157 /* */
1158 /* <Input> */
1159 /* raster :: A handle to the raster object. */
1160 /* */
1161 typedef void
1162 (*FT_Raster_DoneFunc)( FT_Raster raster );
1164 #define FT_Raster_Done_Func FT_Raster_DoneFunc
1167 /*************************************************************************/
1168 /* */
1169 /* <FuncType> */
1170 /* FT_Raster_ResetFunc */
1171 /* */
1172 /* <Description> */
1173 /* FreeType provides an area of memory called the `render pool', */
1174 /* available to all registered rasters. This pool can be freely used */
1175 /* during a given scan-conversion but is shared by all rasters. Its */
1176 /* content is thus transient. */
1177 /* */
1178 /* This function is called each time the render pool changes, or just */
1179 /* after a new raster object is created. */
1180 /* */
1181 /* <Input> */
1182 /* raster :: A handle to the new raster object. */
1183 /* */
1184 /* pool_base :: The address in memory of the render pool. */
1185 /* */
1186 /* pool_size :: The size in bytes of the render pool. */
1187 /* */
1188 /* <Note> */
1189 /* Rasters can ignore the render pool and rely on dynamic memory */
1190 /* allocation if they want to (a handle to the memory allocator is */
1191 /* passed to the raster constructor). However, this is not */
1192 /* recommended for efficiency purposes. */
1193 /* */
1194 typedef void
1195 (*FT_Raster_ResetFunc)( FT_Raster raster,
1196 unsigned char* pool_base,
1197 unsigned long pool_size );
1199 #define FT_Raster_Reset_Func FT_Raster_ResetFunc
1202 /*************************************************************************/
1203 /* */
1204 /* <FuncType> */
1205 /* FT_Raster_SetModeFunc */
1206 /* */
1207 /* <Description> */
1208 /* This function is a generic facility to change modes or attributes */
1209 /* in a given raster. This can be used for debugging purposes, or */
1210 /* simply to allow implementation-specific `features' in a given */
1211 /* raster module. */
1212 /* */
1213 /* <Input> */
1214 /* raster :: A handle to the new raster object. */
1215 /* */
1216 /* mode :: A 4-byte tag used to name the mode or property. */
1217 /* */
1218 /* args :: A pointer to the new mode/property to use. */
1219 /* */
1220 typedef int
1221 (*FT_Raster_SetModeFunc)( FT_Raster raster,
1222 unsigned long mode,
1223 void* args );
1225 #define FT_Raster_Set_Mode_Func FT_Raster_SetModeFunc
1228 /*************************************************************************/
1229 /* */
1230 /* <FuncType> */
1231 /* FT_Raster_RenderFunc */
1232 /* */
1233 /* <Description> */
1234 /* Invoke a given raster to scan-convert a given glyph image into a */
1235 /* target bitmap. */
1236 /* */
1237 /* <Input> */
1238 /* raster :: A handle to the raster object. */
1239 /* */
1240 /* params :: A pointer to an @FT_Raster_Params structure used to */
1241 /* store the rendering parameters. */
1242 /* */
1243 /* <Return> */
1244 /* Error code. 0~means success. */
1245 /* */
1246 /* <Note> */
1247 /* The exact format of the source image depends on the raster's glyph */
1248 /* format defined in its @FT_Raster_Funcs structure. It can be an */
1249 /* @FT_Outline or anything else in order to support a large array of */
1250 /* glyph formats. */
1251 /* */
1252 /* Note also that the render function can fail and return a */
1253 /* `FT_Err_Unimplemented_Feature' error code if the raster used does */
1254 /* not support direct composition. */
1255 /* */
1256 /* XXX: For now, the standard raster doesn't support direct */
1257 /* composition but this should change for the final release (see */
1258 /* the files `demos/src/ftgrays.c' and `demos/src/ftgrays2.c' */
1259 /* for examples of distinct implementations which support direct */
1260 /* composition). */
1261 /* */
1262 typedef int
1263 (*FT_Raster_RenderFunc)( FT_Raster raster,
1264 const FT_Raster_Params* params );
1266 #define FT_Raster_Render_Func FT_Raster_RenderFunc
1269 /*************************************************************************/
1270 /* */
1271 /* <Struct> */
1272 /* FT_Raster_Funcs */
1273 /* */
1274 /* <Description> */
1275 /* A structure used to describe a given raster class to the library. */
1276 /* */
1277 /* <Fields> */
1278 /* glyph_format :: The supported glyph format for this raster. */
1279 /* */
1280 /* raster_new :: The raster constructor. */
1281 /* */
1282 /* raster_reset :: Used to reset the render pool within the raster. */
1283 /* */
1284 /* raster_render :: A function to render a glyph into a given bitmap. */
1285 /* */
1286 /* raster_done :: The raster destructor. */
1287 /* */
1288 typedef struct FT_Raster_Funcs_
1289 {
1290 FT_Glyph_Format glyph_format;
1291 FT_Raster_NewFunc raster_new;
1292 FT_Raster_ResetFunc raster_reset;
1293 FT_Raster_SetModeFunc raster_set_mode;
1294 FT_Raster_RenderFunc raster_render;
1295 FT_Raster_DoneFunc raster_done;
1297 } FT_Raster_Funcs;
1300 /* */
1303 FT_END_HEADER
1305 #endif /* __FTIMAGE_H__ */
1308 /* END */
1311 /* Local Variables: */
1312 /* coding: utf-8 */
1313 /* End: */