XFA: merge patch from CL 815103002
[pdfium.git] / third_party / freetype / include / ftimage.h
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:             */