1 /***************************************************************************/
2 /*                                                                         */
3 /*  ftimage.h                                                              */
4 /*                                                                         */
5 /*    FreeType glyph image formats and default raster interface            */
6 /*    (specification).                                                     */
7 /*                                                                         */
8 /*  Copyright 1996-2018 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   /*      [Since 2.5] An image with four 8-bit channels per pixel,         */
173   /*      representing a color image (such as emoticons) with alpha        */
174   /*      channel.  For each pixel, the format is BGRA, which means, the   */
175   /*      blue channel comes first in memory.  The color channels are      */
176   /*      pre-multiplied and in the sRGB colorspace.  For example, full    */
177   /*      red at half-translucent opacity will be represented as           */
178   /*      `00,00,80,80', not `00,00,FF,80'.  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   typedef struct  FT_Bitmap_
262   {
263     unsigned int    rows;
264     unsigned int    width;
265     int             pitch;
266     unsigned char*  buffer;
267     unsigned short  num_grays;
268     unsigned char   pixel_mode;
269     unsigned char   palette_mode;
270     void*           palette;
271 
272   } FT_Bitmap;
273 
274 
275   /*************************************************************************/
276   /*                                                                       */
277   /* <Section>                                                             */
278   /*    outline_processing                                                 */
279   /*                                                                       */
280   /*************************************************************************/
281 
282 
283   /*************************************************************************/
284   /*                                                                       */
285   /* <Struct>                                                              */
286   /*    FT_Outline                                                         */
287   /*                                                                       */
288   /* <Description>                                                         */
289   /*    This structure is used to describe an outline to the scan-line     */
290   /*    converter.                                                         */
291   /*                                                                       */
292   /* <Fields>                                                              */
293   /*    n_contours :: The number of contours in the outline.               */
294   /*                                                                       */
295   /*    n_points   :: The number of points in the outline.                 */
296   /*                                                                       */
297   /*    points     :: A pointer to an array of `n_points' @FT_Vector       */
298   /*                  elements, giving the outline's point coordinates.    */
299   /*                                                                       */
300   /*    tags       :: A pointer to an array of `n_points' chars, giving    */
301   /*                  each outline point's type.                           */
302   /*                                                                       */
303   /*                  If bit~0 is unset, the point is `off' the curve,     */
304   /*                  i.e., a Bezier control point, while it is `on' if    */
305   /*                  set.                                                 */
306   /*                                                                       */
307   /*                  Bit~1 is meaningful for `off' points only.  If set,  */
308   /*                  it indicates a third-order Bezier arc control point; */
309   /*                  and a second-order control point if unset.           */
310   /*                                                                       */
311   /*                  If bit~2 is set, bits 5-7 contain the drop-out mode  */
312   /*                  (as defined in the OpenType specification; the value */
313   /*                  is the same as the argument to the SCANMODE          */
314   /*                  instruction).                                        */
315   /*                                                                       */
316   /*                  Bits 3 and~4 are reserved for internal purposes.     */
317   /*                                                                       */
318   /*    contours   :: An array of `n_contours' shorts, giving the end      */
319   /*                  point of each contour within the outline.  For       */
320   /*                  example, the first contour is defined by the points  */
321   /*                  `0' to `contours[0]', the second one is defined by   */
322   /*                  the points `contours[0]+1' to `contours[1]', etc.    */
323   /*                                                                       */
324   /*    flags      :: A set of bit flags used to characterize the outline  */
325   /*                  and give hints to the scan-converter and hinter on   */
326   /*                  how to convert/grid-fit it.  See @FT_OUTLINE_XXX.    */
327   /*                                                                       */
328   /* <Note>                                                                */
329   /*    The B/W rasterizer only checks bit~2 in the `tags' array for the   */
330   /*    first point of each contour.  The drop-out mode as given with      */
331   /*    @FT_OUTLINE_IGNORE_DROPOUTS, @FT_OUTLINE_SMART_DROPOUTS, and       */
332   /*    @FT_OUTLINE_INCLUDE_STUBS in `flags' is then overridden.           */
333   /*                                                                       */
334   typedef struct  FT_Outline_
335   {
336     short       n_contours;      /* number of contours in glyph        */
337     short       n_points;        /* number of points in the glyph      */
338 
339     FT_Vector*  points;          /* the outline's points               */
340     char*       tags;            /* the points flags                   */
341     short*      contours;        /* the contour end points             */
342 
343     int         flags;           /* outline masks                      */
344 
345   } FT_Outline;
346 
347   /* */
348 
349   /* Following limits must be consistent with */
350   /* FT_Outline.{n_contours,n_points}         */
351 #define FT_OUTLINE_CONTOURS_MAX  SHRT_MAX
352 #define FT_OUTLINE_POINTS_MAX    SHRT_MAX
353 
354 
355   /*************************************************************************/
356   /*                                                                       */
357   /* <Enum>                                                                */
358   /*    FT_OUTLINE_XXX                                                     */
359   /*                                                                       */
360   /* <Description>                                                         */
361   /*    A list of bit-field constants use for the flags in an outline's    */
362   /*    `flags' field.                                                     */
363   /*                                                                       */
364   /* <Values>                                                              */
365   /*    FT_OUTLINE_NONE ::                                                 */
366   /*      Value~0 is reserved.                                             */
367   /*                                                                       */
368   /*    FT_OUTLINE_OWNER ::                                                */
369   /*      If set, this flag indicates that the outline's field arrays      */
370   /*      (i.e., `points', `flags', and `contours') are `owned' by the     */
371   /*      outline object, and should thus be freed when it is destroyed.   */
372   /*                                                                       */
373   /*    FT_OUTLINE_EVEN_ODD_FILL ::                                        */
374   /*      By default, outlines are filled using the non-zero winding rule. */
375   /*      If set to 1, the outline will be filled using the even-odd fill  */
376   /*      rule (only works with the smooth rasterizer).                    */
377   /*                                                                       */
378   /*    FT_OUTLINE_REVERSE_FILL ::                                         */
379   /*      By default, outside contours of an outline are oriented in       */
380   /*      clock-wise direction, as defined in the TrueType specification.  */
381   /*      This flag is set if the outline uses the opposite direction      */
382   /*      (typically for Type~1 fonts).  This flag is ignored by the scan  */
383   /*      converter.                                                       */
384   /*                                                                       */
385   /*    FT_OUTLINE_IGNORE_DROPOUTS ::                                      */
386   /*      By default, the scan converter will try to detect drop-outs in   */
387   /*      an outline and correct the glyph bitmap to ensure consistent     */
388   /*      shape continuity.  If set, this flag hints the scan-line         */
389   /*      converter to ignore such cases.  See below for more information. */
390   /*                                                                       */
391   /*    FT_OUTLINE_SMART_DROPOUTS ::                                       */
392   /*      Select smart dropout control.  If unset, use simple dropout      */
393   /*      control.  Ignored if @FT_OUTLINE_IGNORE_DROPOUTS is set.  See    */
394   /*      below for more information.                                      */
395   /*                                                                       */
396   /*    FT_OUTLINE_INCLUDE_STUBS ::                                        */
397   /*      If set, turn pixels on for `stubs', otherwise exclude them.      */
398   /*      Ignored if @FT_OUTLINE_IGNORE_DROPOUTS is set.  See below for    */
399   /*      more information.                                                */
400   /*                                                                       */
401   /*    FT_OUTLINE_HIGH_PRECISION ::                                       */
402   /*      This flag indicates that the scan-line converter should try to   */
403   /*      convert this outline to bitmaps with the highest possible        */
404   /*      quality.  It is typically set for small character sizes.  Note   */
405   /*      that this is only a hint that might be completely ignored by a   */
406   /*      given scan-converter.                                            */
407   /*                                                                       */
408   /*    FT_OUTLINE_SINGLE_PASS ::                                          */
409   /*      This flag is set to force a given scan-converter to only use a   */
410   /*      single pass over the outline to render a bitmap glyph image.     */
411   /*      Normally, it is set for very large character sizes.  It is only  */
412   /*      a hint that might be completely ignored by a given               */
413   /*      scan-converter.                                                  */
414   /*                                                                       */
415   /* <Note>                                                                */
416   /*    The flags @FT_OUTLINE_IGNORE_DROPOUTS, @FT_OUTLINE_SMART_DROPOUTS, */
417   /*    and @FT_OUTLINE_INCLUDE_STUBS are ignored by the smooth            */
418   /*    rasterizer.                                                        */
419   /*                                                                       */
420   /*    There exists a second mechanism to pass the drop-out mode to the   */
421   /*    B/W rasterizer; see the `tags' field in @FT_Outline.               */
422   /*                                                                       */
423   /*    Please refer to the description of the `SCANTYPE' instruction in   */
424   /*    the OpenType specification (in file `ttinst1.doc') how simple      */
425   /*    drop-outs, smart drop-outs, and stubs are defined.                 */
426   /*                                                                       */
427 #define FT_OUTLINE_NONE             0x0
428 #define FT_OUTLINE_OWNER            0x1
429 #define FT_OUTLINE_EVEN_ODD_FILL    0x2
430 #define FT_OUTLINE_REVERSE_FILL     0x4
431 #define FT_OUTLINE_IGNORE_DROPOUTS  0x8
432 #define FT_OUTLINE_SMART_DROPOUTS   0x10
433 #define FT_OUTLINE_INCLUDE_STUBS    0x20
434 
435 #define FT_OUTLINE_HIGH_PRECISION   0x100
436 #define FT_OUTLINE_SINGLE_PASS      0x200
437 
438 
439   /* these constants are deprecated; use the corresponding */
440   /* `FT_OUTLINE_XXX' values instead                       */
441 #define ft_outline_none             FT_OUTLINE_NONE
442 #define ft_outline_owner            FT_OUTLINE_OWNER
443 #define ft_outline_even_odd_fill    FT_OUTLINE_EVEN_ODD_FILL
444 #define ft_outline_reverse_fill     FT_OUTLINE_REVERSE_FILL
445 #define ft_outline_ignore_dropouts  FT_OUTLINE_IGNORE_DROPOUTS
446 #define ft_outline_high_precision   FT_OUTLINE_HIGH_PRECISION
447 #define ft_outline_single_pass      FT_OUTLINE_SINGLE_PASS
448 
449   /* */
450 
451 #define FT_CURVE_TAG( flag )  ( flag & 3 )
452 
453 #define FT_CURVE_TAG_ON            1
454 #define FT_CURVE_TAG_CONIC         0
455 #define FT_CURVE_TAG_CUBIC         2
456 
457 #define FT_CURVE_TAG_HAS_SCANMODE  4
458 
459 #define FT_CURVE_TAG_TOUCH_X       8  /* reserved for the TrueType hinter */
460 #define FT_CURVE_TAG_TOUCH_Y      16  /* reserved for the TrueType hinter */
461 
462 #define FT_CURVE_TAG_TOUCH_BOTH    ( FT_CURVE_TAG_TOUCH_X | \
463                                      FT_CURVE_TAG_TOUCH_Y )
464 
465 #define FT_Curve_Tag_On       FT_CURVE_TAG_ON
466 #define FT_Curve_Tag_Conic    FT_CURVE_TAG_CONIC
467 #define FT_Curve_Tag_Cubic    FT_CURVE_TAG_CUBIC
468 #define FT_Curve_Tag_Touch_X  FT_CURVE_TAG_TOUCH_X
469 #define FT_Curve_Tag_Touch_Y  FT_CURVE_TAG_TOUCH_Y
470 
471 
472   /*************************************************************************/
473   /*                                                                       */
474   /* <FuncType>                                                            */
475   /*    FT_Outline_MoveToFunc                                              */
476   /*                                                                       */
477   /* <Description>                                                         */
478   /*    A function pointer type used to describe the signature of a `move  */
479   /*    to' function during outline walking/decomposition.                 */
480   /*                                                                       */
481   /*    A `move to' is emitted to start a new contour in an outline.       */
482   /*                                                                       */
483   /* <Input>                                                               */
484   /*    to   :: A pointer to the target point of the `move to'.            */
485   /*                                                                       */
486   /*    user :: A typeless pointer, which is passed from the caller of the */
487   /*            decomposition function.                                    */
488   /*                                                                       */
489   /* <Return>                                                              */
490   /*    Error code.  0~means success.                                      */
491   /*                                                                       */
492   typedef int
493   (*FT_Outline_MoveToFunc)( const FT_Vector*  to,
494                             void*             user );
495 
496 #define FT_Outline_MoveTo_Func  FT_Outline_MoveToFunc
497 
498 
499   /*************************************************************************/
500   /*                                                                       */
501   /* <FuncType>                                                            */
502   /*    FT_Outline_LineToFunc                                              */
503   /*                                                                       */
504   /* <Description>                                                         */
505   /*    A function pointer type used to describe the signature of a `line  */
506   /*    to' function during outline walking/decomposition.                 */
507   /*                                                                       */
508   /*    A `line to' is emitted to indicate a segment in the outline.       */
509   /*                                                                       */
510   /* <Input>                                                               */
511   /*    to   :: A pointer to the target point of the `line to'.            */
512   /*                                                                       */
513   /*    user :: A typeless pointer, which is passed from the caller of the */
514   /*            decomposition function.                                    */
515   /*                                                                       */
516   /* <Return>                                                              */
517   /*    Error code.  0~means success.                                      */
518   /*                                                                       */
519   typedef int
520   (*FT_Outline_LineToFunc)( const FT_Vector*  to,
521                             void*             user );
522 
523 #define FT_Outline_LineTo_Func  FT_Outline_LineToFunc
524 
525 
526   /*************************************************************************/
527   /*                                                                       */
528   /* <FuncType>                                                            */
529   /*    FT_Outline_ConicToFunc                                             */
530   /*                                                                       */
531   /* <Description>                                                         */
532   /*    A function pointer type used to describe the signature of a `conic */
533   /*    to' function during outline walking or decomposition.              */
534   /*                                                                       */
535   /*    A `conic to' is emitted to indicate a second-order Bezier arc in   */
536   /*    the outline.                                                       */
537   /*                                                                       */
538   /* <Input>                                                               */
539   /*    control :: An intermediate control point between the last position */
540   /*               and the new target in `to'.                             */
541   /*                                                                       */
542   /*    to      :: A pointer to the target end point of the conic arc.     */
543   /*                                                                       */
544   /*    user    :: A typeless pointer, which is passed from the caller of  */
545   /*               the decomposition function.                             */
546   /*                                                                       */
547   /* <Return>                                                              */
548   /*    Error code.  0~means success.                                      */
549   /*                                                                       */
550   typedef int
551   (*FT_Outline_ConicToFunc)( const FT_Vector*  control,
552                              const FT_Vector*  to,
553                              void*             user );
554 
555 #define FT_Outline_ConicTo_Func  FT_Outline_ConicToFunc
556 
557 
558   /*************************************************************************/
559   /*                                                                       */
560   /* <FuncType>                                                            */
561   /*    FT_Outline_CubicToFunc                                             */
562   /*                                                                       */
563   /* <Description>                                                         */
564   /*    A function pointer type used to describe the signature of a `cubic */
565   /*    to' function during outline walking or decomposition.              */
566   /*                                                                       */
567   /*    A `cubic to' is emitted to indicate a third-order Bezier arc.      */
568   /*                                                                       */
569   /* <Input>                                                               */
570   /*    control1 :: A pointer to the first Bezier control point.           */
571   /*                                                                       */
572   /*    control2 :: A pointer to the second Bezier control point.          */
573   /*                                                                       */
574   /*    to       :: A pointer to the target end point.                     */
575   /*                                                                       */
576   /*    user     :: A typeless pointer, which is passed from the caller of */
577   /*                the decomposition function.                            */
578   /*                                                                       */
579   /* <Return>                                                              */
580   /*    Error code.  0~means success.                                      */
581   /*                                                                       */
582   typedef int
583   (*FT_Outline_CubicToFunc)( const FT_Vector*  control1,
584                              const FT_Vector*  control2,
585                              const FT_Vector*  to,
586                              void*             user );
587 
588 #define FT_Outline_CubicTo_Func  FT_Outline_CubicToFunc
589 
590 
591   /*************************************************************************/
592   /*                                                                       */
593   /* <Struct>                                                              */
594   /*    FT_Outline_Funcs                                                   */
595   /*                                                                       */
596   /* <Description>                                                         */
597   /*    A structure to hold various function pointers used during outline  */
598   /*    decomposition in order to emit segments, conic, and cubic Beziers. */
599   /*                                                                       */
600   /* <Fields>                                                              */
601   /*    move_to  :: The `move to' emitter.                                 */
602   /*                                                                       */
603   /*    line_to  :: The segment emitter.                                   */
604   /*                                                                       */
605   /*    conic_to :: The second-order Bezier arc emitter.                   */
606   /*                                                                       */
607   /*    cubic_to :: The third-order Bezier arc emitter.                    */
608   /*                                                                       */
609   /*    shift    :: The shift that is applied to coordinates before they   */
610   /*                are sent to the emitter.                               */
611   /*                                                                       */
612   /*    delta    :: The delta that is applied to coordinates before they   */
613   /*                are sent to the emitter, but after the shift.          */
614   /*                                                                       */
615   /* <Note>                                                                */
616   /*    The point coordinates sent to the emitters are the transformed     */
617   /*    version of the original coordinates (this is important for high    */
618   /*    accuracy during scan-conversion).  The transformation is simple:   */
619   /*                                                                       */
620   /*    {                                                                  */
621   /*      x' = (x << shift) - delta                                        */
622   /*      y' = (y << shift) - delta                                        */
623   /*    }                                                                  */
624   /*                                                                       */
625   /*    Set the values of `shift' and `delta' to~0 to get the original     */
626   /*    point coordinates.                                                 */
627   /*                                                                       */
628   typedef struct  FT_Outline_Funcs_
629   {
630     FT_Outline_MoveToFunc   move_to;
631     FT_Outline_LineToFunc   line_to;
632     FT_Outline_ConicToFunc  conic_to;
633     FT_Outline_CubicToFunc  cubic_to;
634 
635     int                     shift;
636     FT_Pos                  delta;
637 
638   } FT_Outline_Funcs;
639 
640 
641   /*************************************************************************/
642   /*                                                                       */
643   /* <Section>                                                             */
644   /*    basic_types                                                        */
645   /*                                                                       */
646   /*************************************************************************/
647 
648 
649   /*************************************************************************/
650   /*                                                                       */
651   /* <Macro>                                                               */
652   /*    FT_IMAGE_TAG                                                       */
653   /*                                                                       */
654   /* <Description>                                                         */
655   /*    This macro converts four-letter tags to an unsigned long type.     */
656   /*                                                                       */
657   /* <Note>                                                                */
658   /*    Since many 16-bit compilers don't like 32-bit enumerations, you    */
659   /*    should redefine this macro in case of problems to something like   */
660   /*    this:                                                              */
661   /*                                                                       */
662   /*    {                                                                  */
663   /*      #define FT_IMAGE_TAG( value, _x1, _x2, _x3, _x4 )  value         */
664   /*    }                                                                  */
665   /*                                                                       */
666   /*    to get a simple enumeration without assigning special numbers.     */
667   /*                                                                       */
668 #ifndef FT_IMAGE_TAG
669 #define FT_IMAGE_TAG( value, _x1, _x2, _x3, _x4 )  \
670           value = ( ( (unsigned long)_x1 << 24 ) | \
671                     ( (unsigned long)_x2 << 16 ) | \
672                     ( (unsigned long)_x3 << 8  ) | \
673                       (unsigned long)_x4         )
674 #endif /* FT_IMAGE_TAG */
675 
676 
677   /*************************************************************************/
678   /*                                                                       */
679   /* <Enum>                                                                */
680   /*    FT_Glyph_Format                                                    */
681   /*                                                                       */
682   /* <Description>                                                         */
683   /*    An enumeration type used to describe the format of a given glyph   */
684   /*    image.  Note that this version of FreeType only supports two image */
685   /*    formats, even though future font drivers will be able to register  */
686   /*    their own format.                                                  */
687   /*                                                                       */
688   /* <Values>                                                              */
689   /*    FT_GLYPH_FORMAT_NONE ::                                            */
690   /*      The value~0 is reserved.                                         */
691   /*                                                                       */
692   /*    FT_GLYPH_FORMAT_COMPOSITE ::                                       */
693   /*      The glyph image is a composite of several other images.  This    */
694   /*      format is _only_ used with @FT_LOAD_NO_RECURSE, and is used to   */
695   /*      report compound glyphs (like accented characters).               */
696   /*                                                                       */
697   /*    FT_GLYPH_FORMAT_BITMAP ::                                          */
698   /*      The glyph image is a bitmap, and can be described as an          */
699   /*      @FT_Bitmap.  You generally need to access the `bitmap' field of  */
700   /*      the @FT_GlyphSlotRec structure to read it.                       */
701   /*                                                                       */
702   /*    FT_GLYPH_FORMAT_OUTLINE ::                                         */
703   /*      The glyph image is a vectorial outline made of line segments     */
704   /*      and Bezier arcs; it can be described as an @FT_Outline; you      */
705   /*      generally want to access the `outline' field of the              */
706   /*      @FT_GlyphSlotRec structure to read it.                           */
707   /*                                                                       */
708   /*    FT_GLYPH_FORMAT_PLOTTER ::                                         */
709   /*      The glyph image is a vectorial path with no inside and outside   */
710   /*      contours.  Some Type~1 fonts, like those in the Hershey family,  */
711   /*      contain glyphs in this format.  These are described as           */
712   /*      @FT_Outline, but FreeType isn't currently capable of rendering   */
713   /*      them correctly.                                                  */
714   /*                                                                       */
715   typedef enum  FT_Glyph_Format_
716   {
717     FT_IMAGE_TAG( FT_GLYPH_FORMAT_NONE, 0, 0, 0, 0 ),
718 
719     FT_IMAGE_TAG( FT_GLYPH_FORMAT_COMPOSITE, 'c', 'o', 'm', 'p' ),
720     FT_IMAGE_TAG( FT_GLYPH_FORMAT_BITMAP,    'b', 'i', 't', 's' ),
721     FT_IMAGE_TAG( FT_GLYPH_FORMAT_OUTLINE,   'o', 'u', 't', 'l' ),
722     FT_IMAGE_TAG( FT_GLYPH_FORMAT_PLOTTER,   'p', 'l', 'o', 't' )
723 
724   } FT_Glyph_Format;
725 
726 
727   /* these constants are deprecated; use the corresponding */
728   /* `FT_Glyph_Format' values instead.                     */
729 #define ft_glyph_format_none       FT_GLYPH_FORMAT_NONE
730 #define ft_glyph_format_composite  FT_GLYPH_FORMAT_COMPOSITE
731 #define ft_glyph_format_bitmap     FT_GLYPH_FORMAT_BITMAP
732 #define ft_glyph_format_outline    FT_GLYPH_FORMAT_OUTLINE
733 #define ft_glyph_format_plotter    FT_GLYPH_FORMAT_PLOTTER
734 
735 
736   /*************************************************************************/
737   /*************************************************************************/
738   /*************************************************************************/
739   /*****                                                               *****/
740   /*****            R A S T E R   D E F I N I T I O N S                *****/
741   /*****                                                               *****/
742   /*************************************************************************/
743   /*************************************************************************/
744   /*************************************************************************/
745 
746 
747   /*************************************************************************/
748   /*                                                                       */
749   /* A raster is a scan converter, in charge of rendering an outline into  */
750   /* a bitmap.  This section contains the public API for rasters.          */
751   /*                                                                       */
752   /* Note that in FreeType 2, all rasters are now encapsulated within      */
753   /* specific modules called `renderers'.  See `ftrender.h' for more       */
754   /* details on renderers.                                                 */
755   /*                                                                       */
756   /*************************************************************************/
757 
758 
759   /*************************************************************************/
760   /*                                                                       */
761   /* <Section>                                                             */
762   /*    raster                                                             */
763   /*                                                                       */
764   /* <Title>                                                               */
765   /*    Scanline Converter                                                 */
766   /*                                                                       */
767   /* <Abstract>                                                            */
768   /*    How vectorial outlines are converted into bitmaps and pixmaps.     */
769   /*                                                                       */
770   /* <Description>                                                         */
771   /*    This section contains technical definitions.                       */
772   /*                                                                       */
773   /* <Order>                                                               */
774   /*    FT_Raster                                                          */
775   /*    FT_Span                                                            */
776   /*    FT_SpanFunc                                                        */
777   /*                                                                       */
778   /*    FT_Raster_Params                                                   */
779   /*    FT_RASTER_FLAG_XXX                                                 */
780   /*                                                                       */
781   /*    FT_Raster_NewFunc                                                  */
782   /*    FT_Raster_DoneFunc                                                 */
783   /*    FT_Raster_ResetFunc                                                */
784   /*    FT_Raster_SetModeFunc                                              */
785   /*    FT_Raster_RenderFunc                                               */
786   /*    FT_Raster_Funcs                                                    */
787   /*                                                                       */
788   /*************************************************************************/
789 
790 
791   /*************************************************************************/
792   /*                                                                       */
793   /* <Type>                                                                */
794   /*    FT_Raster                                                          */
795   /*                                                                       */
796   /* <Description>                                                         */
797   /*    An opaque handle (pointer) to a raster object.  Each object can be */
798   /*    used independently to convert an outline into a bitmap or pixmap.  */
799   /*                                                                       */
800   typedef struct FT_RasterRec_*  FT_Raster;
801 
802 
803   /*************************************************************************/
804   /*                                                                       */
805   /* <Struct>                                                              */
806   /*    FT_Span                                                            */
807   /*                                                                       */
808   /* <Description>                                                         */
809   /*    A structure used to model a single span of gray pixels when        */
810   /*    rendering an anti-aliased bitmap.                                  */
811   /*                                                                       */
812   /* <Fields>                                                              */
813   /*    x        :: The span's horizontal start position.                  */
814   /*                                                                       */
815   /*    len      :: The span's length in pixels.                           */
816   /*                                                                       */
817   /*    coverage :: The span color/coverage, ranging from 0 (background)   */
818   /*                to 255 (foreground).                                   */
819   /*                                                                       */
820   /* <Note>                                                                */
821   /*    This structure is used by the span drawing callback type named     */
822   /*    @FT_SpanFunc that takes the y~coordinate of the span as a          */
823   /*    parameter.                                                         */
824   /*                                                                       */
825   /*    The coverage value is always between 0 and 255.  If you want less  */
826   /*    gray values, the callback function has to reduce them.             */
827   /*                                                                       */
828   typedef struct  FT_Span_
829   {
830     short           x;
831     unsigned short  len;
832     unsigned char   coverage;
833 
834   } FT_Span;
835 
836 
837   /*************************************************************************/
838   /*                                                                       */
839   /* <FuncType>                                                            */
840   /*    FT_SpanFunc                                                        */
841   /*                                                                       */
842   /* <Description>                                                         */
843   /*    A function used as a call-back by the anti-aliased renderer in     */
844   /*    order to let client applications draw themselves the gray pixel    */
845   /*    spans on each scan line.                                           */
846   /*                                                                       */
847   /* <Input>                                                               */
848   /*    y     :: The scanline's y~coordinate.                              */
849   /*                                                                       */
850   /*    count :: The number of spans to draw on this scanline.             */
851   /*                                                                       */
852   /*    spans :: A table of `count' spans to draw on the scanline.         */
853   /*                                                                       */
854   /*    user  :: User-supplied data that is passed to the callback.        */
855   /*                                                                       */
856   /* <Note>                                                                */
857   /*    This callback allows client applications to directly render the    */
858   /*    gray spans of the anti-aliased bitmap to any kind of surfaces.     */
859   /*                                                                       */
860   /*    This can be used to write anti-aliased outlines directly to a      */
861   /*    given background bitmap, and even perform translucency.            */
862   /*                                                                       */
863   typedef void
864   (*FT_SpanFunc)( int             y,
865                   int             count,
866                   const FT_Span*  spans,
867                   void*           user );
868 
869 #define FT_Raster_Span_Func  FT_SpanFunc
870 
871 
872   /*************************************************************************/
873   /*                                                                       */
874   /* <FuncType>                                                            */
875   /*    FT_Raster_BitTest_Func                                             */
876   /*                                                                       */
877   /* <Description>                                                         */
878   /*    Deprecated, unimplemented.                                         */
879   /*                                                                       */
880   typedef int
881   (*FT_Raster_BitTest_Func)( int    y,
882                              int    x,
883                              void*  user );
884 
885 
886   /*************************************************************************/
887   /*                                                                       */
888   /* <FuncType>                                                            */
889   /*    FT_Raster_BitSet_Func                                              */
890   /*                                                                       */
891   /* <Description>                                                         */
892   /*    Deprecated, unimplemented.                                         */
893   /*                                                                       */
894   typedef void
895   (*FT_Raster_BitSet_Func)( int    y,
896                             int    x,
897                             void*  user );
898 
899 
900   /*************************************************************************/
901   /*                                                                       */
902   /* <Enum>                                                                */
903   /*    FT_RASTER_FLAG_XXX                                                 */
904   /*                                                                       */
905   /* <Description>                                                         */
906   /*    A list of bit flag constants as used in the `flags' field of a     */
907   /*    @FT_Raster_Params structure.                                       */
908   /*                                                                       */
909   /* <Values>                                                              */
910   /*    FT_RASTER_FLAG_DEFAULT :: This value is 0.                         */
911   /*                                                                       */
912   /*    FT_RASTER_FLAG_AA      :: This flag is set to indicate that an     */
913   /*                              anti-aliased glyph image should be       */
914   /*                              generated.  Otherwise, it will be        */
915   /*                              monochrome (1-bit).                      */
916   /*                                                                       */
917   /*    FT_RASTER_FLAG_DIRECT  :: This flag is set to indicate direct      */
918   /*                              rendering.  In this mode, client         */
919   /*                              applications must provide their own span */
920   /*                              callback.  This lets them directly       */
921   /*                              draw or compose over an existing bitmap. */
922   /*                              If this bit is not set, the target       */
923   /*                              pixmap's buffer _must_ be zeroed before  */
924   /*                              rendering.                               */
925   /*                                                                       */
926   /*                              Direct rendering is only possible with   */
927   /*                              anti-aliased glyphs.                     */
928   /*                                                                       */
929   /*    FT_RASTER_FLAG_CLIP    :: This flag is only used in direct         */
930   /*                              rendering mode.  If set, the output will */
931   /*                              be clipped to a box specified in the     */
932   /*                              `clip_box' field of the                  */
933   /*                              @FT_Raster_Params structure.             */
934   /*                                                                       */
935   /*                              Note that by default, the glyph bitmap   */
936   /*                              is clipped to the target pixmap, except  */
937   /*                              in direct rendering mode where all spans */
938   /*                              are generated if no clipping box is set. */
939   /*                                                                       */
940 #define FT_RASTER_FLAG_DEFAULT  0x0
941 #define FT_RASTER_FLAG_AA       0x1
942 #define FT_RASTER_FLAG_DIRECT   0x2
943 #define FT_RASTER_FLAG_CLIP     0x4
944 
945   /* these constants are deprecated; use the corresponding */
946   /* `FT_RASTER_FLAG_XXX' values instead                   */
947 #define ft_raster_flag_default  FT_RASTER_FLAG_DEFAULT
948 #define ft_raster_flag_aa       FT_RASTER_FLAG_AA
949 #define ft_raster_flag_direct   FT_RASTER_FLAG_DIRECT
950 #define ft_raster_flag_clip     FT_RASTER_FLAG_CLIP
951 
952 
953   /*************************************************************************/
954   /*                                                                       */
955   /* <Struct>                                                              */
956   /*    FT_Raster_Params                                                   */
957   /*                                                                       */
958   /* <Description>                                                         */
959   /*    A structure to hold the arguments used by a raster's render        */
960   /*    function.                                                          */
961   /*                                                                       */
962   /* <Fields>                                                              */
963   /*    target      :: The target bitmap.                                  */
964   /*                                                                       */
965   /*    source      :: A pointer to the source glyph image (e.g., an       */
966   /*                   @FT_Outline).                                       */
967   /*                                                                       */
968   /*    flags       :: The rendering flags.                                */
969   /*                                                                       */
970   /*    gray_spans  :: The gray span drawing callback.                     */
971   /*                                                                       */
972   /*    black_spans :: Unused.                                             */
973   /*                                                                       */
974   /*    bit_test    :: Unused.                                             */
975   /*                                                                       */
976   /*    bit_set     :: Unused.                                             */
977   /*                                                                       */
978   /*    user        :: User-supplied data that is passed to each drawing   */
979   /*                   callback.                                           */
980   /*                                                                       */
981   /*    clip_box    :: An optional clipping box.  It is only used in       */
982   /*                   direct rendering mode.  Note that coordinates here  */
983   /*                   should be expressed in _integer_ pixels (and not in */
984   /*                   26.6 fixed-point units).                            */
985   /*                                                                       */
986   /* <Note>                                                                */
987   /*    An anti-aliased glyph bitmap is drawn if the @FT_RASTER_FLAG_AA    */
988   /*    bit flag is set in the `flags' field, otherwise a monochrome       */
989   /*    bitmap is generated.                                               */
990   /*                                                                       */
991   /*    If the @FT_RASTER_FLAG_DIRECT bit flag is set in `flags', the      */
992   /*    raster will call the `gray_spans' callback to draw gray pixel      */
993   /*    spans.  This allows direct composition over a pre-existing bitmap  */
994   /*    through user-provided callbacks to perform the span drawing and    */
995   /*    composition.    Not supported by the monochrome rasterizer.        */
996   /*                                                                       */
997   typedef struct  FT_Raster_Params_
998   {
999     const FT_Bitmap*        target;
1000     const void*             source;
1001     int                     flags;
1002     FT_SpanFunc             gray_spans;
1003     FT_SpanFunc             black_spans;  /* unused */
1004     FT_Raster_BitTest_Func  bit_test;     /* unused */
1005     FT_Raster_BitSet_Func   bit_set;      /* unused */
1006     void*                   user;
1007     FT_BBox                 clip_box;
1008 
1009   } FT_Raster_Params;
1010 
1011 
1012   /*************************************************************************/
1013   /*                                                                       */
1014   /* <FuncType>                                                            */
1015   /*    FT_Raster_NewFunc                                                  */
1016   /*                                                                       */
1017   /* <Description>                                                         */
1018   /*    A function used to create a new raster object.                     */
1019   /*                                                                       */
1020   /* <Input>                                                               */
1021   /*    memory :: A handle to the memory allocator.                        */
1022   /*                                                                       */
1023   /* <Output>                                                              */
1024   /*    raster :: A handle to the new raster object.                       */
1025   /*                                                                       */
1026   /* <Return>                                                              */
1027   /*    Error code.  0~means success.                                      */
1028   /*                                                                       */
1029   /* <Note>                                                                */
1030   /*    The `memory' parameter is a typeless pointer in order to avoid     */
1031   /*    un-wanted dependencies on the rest of the FreeType code.  In       */
1032   /*    practice, it is an @FT_Memory object, i.e., a handle to the        */
1033   /*    standard FreeType memory allocator.  However, this field can be    */
1034   /*    completely ignored by a given raster implementation.               */
1035   /*                                                                       */
1036   typedef int
1037   (*FT_Raster_NewFunc)( void*       memory,
1038                         FT_Raster*  raster );
1039 
1040 #define FT_Raster_New_Func  FT_Raster_NewFunc
1041 
1042 
1043   /*************************************************************************/
1044   /*                                                                       */
1045   /* <FuncType>                                                            */
1046   /*    FT_Raster_DoneFunc                                                 */
1047   /*                                                                       */
1048   /* <Description>                                                         */
1049   /*    A function used to destroy a given raster object.                  */
1050   /*                                                                       */
1051   /* <Input>                                                               */
1052   /*    raster :: A handle to the raster object.                           */
1053   /*                                                                       */
1054   typedef void
1055   (*FT_Raster_DoneFunc)( FT_Raster  raster );
1056 
1057 #define FT_Raster_Done_Func  FT_Raster_DoneFunc
1058 
1059 
1060   /*************************************************************************/
1061   /*                                                                       */
1062   /* <FuncType>                                                            */
1063   /*    FT_Raster_ResetFunc                                                */
1064   /*                                                                       */
1065   /* <Description>                                                         */
1066   /*    FreeType used to provide an area of memory called the `render      */
1067   /*    pool' available to all registered rasterizers.  This was not       */
1068   /*    thread safe, however, and now FreeType never allocates this pool.  */
1069   /*                                                                       */
1070   /*    This function is called after a new raster object is created.      */
1071   /*                                                                       */
1072   /* <Input>                                                               */
1073   /*    raster    :: A handle to the new raster object.                    */
1074   /*                                                                       */
1075   /*    pool_base :: Previously, the address in memory of the render pool. */
1076   /*                 Set this to NULL.                                     */
1077   /*                                                                       */
1078   /*    pool_size :: Previously, the size in bytes of the render pool.     */
1079   /*                 Set this to 0.                                        */
1080   /*                                                                       */
1081   /* <Note>                                                                */
1082   /*    Rasterizers should rely on dynamic or stack allocation if they     */
1083   /*    want to (a handle to the memory allocator is passed to the         */
1084   /*    rasterizer constructor).                                           */
1085   /*                                                                       */
1086   typedef void
1087   (*FT_Raster_ResetFunc)( FT_Raster       raster,
1088                           unsigned char*  pool_base,
1089                           unsigned long   pool_size );
1090 
1091 #define FT_Raster_Reset_Func  FT_Raster_ResetFunc
1092 
1093 
1094   /*************************************************************************/
1095   /*                                                                       */
1096   /* <FuncType>                                                            */
1097   /*    FT_Raster_SetModeFunc                                              */
1098   /*                                                                       */
1099   /* <Description>                                                         */
1100   /*    This function is a generic facility to change modes or attributes  */
1101   /*    in a given raster.  This can be used for debugging purposes, or    */
1102   /*    simply to allow implementation-specific `features' in a given      */
1103   /*    raster module.                                                     */
1104   /*                                                                       */
1105   /* <Input>                                                               */
1106   /*    raster :: A handle to the new raster object.                       */
1107   /*                                                                       */
1108   /*    mode   :: A 4-byte tag used to name the mode or property.          */
1109   /*                                                                       */
1110   /*    args   :: A pointer to the new mode/property to use.               */
1111   /*                                                                       */
1112   typedef int
1113   (*FT_Raster_SetModeFunc)( FT_Raster      raster,
1114                             unsigned long  mode,
1115                             void*          args );
1116 
1117 #define FT_Raster_Set_Mode_Func  FT_Raster_SetModeFunc
1118 
1119 
1120   /*************************************************************************/
1121   /*                                                                       */
1122   /* <FuncType>                                                            */
1123   /*    FT_Raster_RenderFunc                                               */
1124   /*                                                                       */
1125   /* <Description>                                                         */
1126   /*    Invoke a given raster to scan-convert a given glyph image into a   */
1127   /*    target bitmap.                                                     */
1128   /*                                                                       */
1129   /* <Input>                                                               */
1130   /*    raster :: A handle to the raster object.                           */
1131   /*                                                                       */
1132   /*    params :: A pointer to an @FT_Raster_Params structure used to      */
1133   /*              store the rendering parameters.                          */
1134   /*                                                                       */
1135   /* <Return>                                                              */
1136   /*    Error code.  0~means success.                                      */
1137   /*                                                                       */
1138   /* <Note>                                                                */
1139   /*    The exact format of the source image depends on the raster's glyph */
1140   /*    format defined in its @FT_Raster_Funcs structure.  It can be an    */
1141   /*    @FT_Outline or anything else in order to support a large array of  */
1142   /*    glyph formats.                                                     */
1143   /*                                                                       */
1144   /*    Note also that the render function can fail and return a           */
1145   /*    `FT_Err_Unimplemented_Feature' error code if the raster used does  */
1146   /*    not support direct composition.                                    */
1147   /*                                                                       */
1148   /*    XXX: For now, the standard raster doesn't support direct           */
1149   /*         composition but this should change for the final release (see */
1150   /*         the files `demos/src/ftgrays.c' and `demos/src/ftgrays2.c'    */
1151   /*         for examples of distinct implementations that support direct  */
1152   /*         composition).                                                 */
1153   /*                                                                       */
1154   typedef int
1155   (*FT_Raster_RenderFunc)( FT_Raster                raster,
1156                            const FT_Raster_Params*  params );
1157 
1158 #define FT_Raster_Render_Func  FT_Raster_RenderFunc
1159 
1160 
1161   /*************************************************************************/
1162   /*                                                                       */
1163   /* <Struct>                                                              */
1164   /*    FT_Raster_Funcs                                                    */
1165   /*                                                                       */
1166   /* <Description>                                                         */
1167   /*   A structure used to describe a given raster class to the library.   */
1168   /*                                                                       */
1169   /* <Fields>                                                              */
1170   /*    glyph_format  :: The supported glyph format for this raster.       */
1171   /*                                                                       */
1172   /*    raster_new    :: The raster constructor.                           */
1173   /*                                                                       */
1174   /*    raster_reset  :: Used to reset the render pool within the raster.  */
1175   /*                                                                       */
1176   /*    raster_render :: A function to render a glyph into a given bitmap. */
1177   /*                                                                       */
1178   /*    raster_done   :: The raster destructor.                            */
1179   /*                                                                       */
1180   typedef struct  FT_Raster_Funcs_
1181   {
1182     FT_Glyph_Format        glyph_format;
1183 
1184     FT_Raster_NewFunc      raster_new;
1185     FT_Raster_ResetFunc    raster_reset;
1186     FT_Raster_SetModeFunc  raster_set_mode;
1187     FT_Raster_RenderFunc   raster_render;
1188     FT_Raster_DoneFunc     raster_done;
1189 
1190   } FT_Raster_Funcs;
1191 
1192   /* */
1193 
1194 
1195 FT_END_HEADER
1196 
1197 #endif /* FTIMAGE_H_ */
1198 
1199 
1200 /* END */
1201 
1202 
1203 /* Local Variables: */
1204 /* coding: utf-8    */
1205 /* End:             */
1206