1/***************************************************************************/
2/*                                                                         */
3/*  ftmm.h                                                                 */
4/*                                                                         */
5/*    FreeType Multiple Master font interface (specification).             */
6/*                                                                         */
7/*  Copyright 1996-2001, 2003, 2004, 2006, 2009, 2013 by                   */
8/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
9/*                                                                         */
10/*  This file is part of the FreeType project, and may only be used,       */
11/*  modified, and distributed under the terms of the FreeType project      */
12/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
13/*  this file you indicate that you have read the license and              */
14/*  understand and accept it fully.                                        */
15/*                                                                         */
16/***************************************************************************/
17
18
19#ifndef __FTMM_H__
20#define __FTMM_H__
21
22
23#include <ft2build.h>
24#include FT_TYPE1_TABLES_H
25
26
27FT_BEGIN_HEADER
28
29
30  /*************************************************************************/
31  /*                                                                       */
32  /* <Section>                                                             */
33  /*    multiple_masters                                                   */
34  /*                                                                       */
35  /* <Title>                                                               */
36  /*    Multiple Masters                                                   */
37  /*                                                                       */
38  /* <Abstract>                                                            */
39  /*    How to manage Multiple Masters fonts.                              */
40  /*                                                                       */
41  /* <Description>                                                         */
42  /*    The following types and functions are used to manage Multiple      */
43  /*    Master fonts, i.e., the selection of specific design instances by  */
44  /*    setting design axis coordinates.                                   */
45  /*                                                                       */
46  /*    George Williams has extended this interface to make it work with   */
47  /*    both Type~1 Multiple Masters fonts and GX distortable (var)        */
48  /*    fonts.  Some of these routines only work with MM fonts, others     */
49  /*    will work with both types.  They are similar enough that a         */
50  /*    consistent interface makes sense.                                  */
51  /*                                                                       */
52  /*************************************************************************/
53
54
55  /*************************************************************************/
56  /*                                                                       */
57  /* <Struct>                                                              */
58  /*    FT_MM_Axis                                                         */
59  /*                                                                       */
60  /* <Description>                                                         */
61  /*    A simple structure used to model a given axis in design space for  */
62  /*    Multiple Masters fonts.                                            */
63  /*                                                                       */
64  /*    This structure can't be used for GX var fonts.                     */
65  /*                                                                       */
66  /* <Fields>                                                              */
67  /*    name    :: The axis's name.                                        */
68  /*                                                                       */
69  /*    minimum :: The axis's minimum design coordinate.                   */
70  /*                                                                       */
71  /*    maximum :: The axis's maximum design coordinate.                   */
72  /*                                                                       */
73  typedef struct  FT_MM_Axis_
74  {
75    FT_String*  name;
76    FT_Long     minimum;
77    FT_Long     maximum;
78
79  } FT_MM_Axis;
80
81
82  /*************************************************************************/
83  /*                                                                       */
84  /* <Struct>                                                              */
85  /*    FT_Multi_Master                                                    */
86  /*                                                                       */
87  /* <Description>                                                         */
88  /*    A structure used to model the axes and space of a Multiple Masters */
89  /*    font.                                                              */
90  /*                                                                       */
91  /*    This structure can't be used for GX var fonts.                     */
92  /*                                                                       */
93  /* <Fields>                                                              */
94  /*    num_axis    :: Number of axes.  Cannot exceed~4.                   */
95  /*                                                                       */
96  /*    num_designs :: Number of designs; should be normally 2^num_axis    */
97  /*                   even though the Type~1 specification strangely      */
98  /*                   allows for intermediate designs to be present. This */
99  /*                   number cannot exceed~16.                            */
100  /*                                                                       */
101  /*    axis        :: A table of axis descriptors.                        */
102  /*                                                                       */
103  typedef struct  FT_Multi_Master_
104  {
105    FT_UInt     num_axis;
106    FT_UInt     num_designs;
107    FT_MM_Axis  axis[T1_MAX_MM_AXIS];
108
109  } FT_Multi_Master;
110
111
112  /*************************************************************************/
113  /*                                                                       */
114  /* <Struct>                                                              */
115  /*    FT_Var_Axis                                                        */
116  /*                                                                       */
117  /* <Description>                                                         */
118  /*    A simple structure used to model a given axis in design space for  */
119  /*    Multiple Masters and GX var fonts.                                 */
120  /*                                                                       */
121  /* <Fields>                                                              */
122  /*    name    :: The axis's name.                                        */
123  /*               Not always meaningful for GX.                           */
124  /*                                                                       */
125  /*    minimum :: The axis's minimum design coordinate.                   */
126  /*                                                                       */
127  /*    def     :: The axis's default design coordinate.                   */
128  /*               FreeType computes meaningful default values for MM; it  */
129  /*               is then an integer value, not in 16.16 format.          */
130  /*                                                                       */
131  /*    maximum :: The axis's maximum design coordinate.                   */
132  /*                                                                       */
133  /*    tag     :: The axis's tag (the GX equivalent to `name').           */
134  /*               FreeType provides default values for MM if possible.    */
135  /*                                                                       */
136  /*    strid   :: The entry in `name' table (another GX version of        */
137  /*               `name').                                                */
138  /*               Not meaningful for MM.                                  */
139  /*                                                                       */
140  typedef struct  FT_Var_Axis_
141  {
142    FT_String*  name;
143
144    FT_Fixed    minimum;
145    FT_Fixed    def;
146    FT_Fixed    maximum;
147
148    FT_ULong    tag;
149    FT_UInt     strid;
150
151  } FT_Var_Axis;
152
153
154  /*************************************************************************/
155  /*                                                                       */
156  /* <Struct>                                                              */
157  /*    FT_Var_Named_Style                                                 */
158  /*                                                                       */
159  /* <Description>                                                         */
160  /*    A simple structure used to model a named style in a GX var font.   */
161  /*                                                                       */
162  /*    This structure can't be used for MM fonts.                         */
163  /*                                                                       */
164  /* <Fields>                                                              */
165  /*    coords :: The design coordinates for this style.                   */
166  /*              This is an array with one entry for each axis.           */
167  /*                                                                       */
168  /*    strid  :: The entry in `name' table identifying this style.        */
169  /*                                                                       */
170  typedef struct  FT_Var_Named_Style_
171  {
172    FT_Fixed*  coords;
173    FT_UInt    strid;
174
175  } FT_Var_Named_Style;
176
177
178  /*************************************************************************/
179  /*                                                                       */
180  /* <Struct>                                                              */
181  /*    FT_MM_Var                                                          */
182  /*                                                                       */
183  /* <Description>                                                         */
184  /*    A structure used to model the axes and space of a Multiple Masters */
185  /*    or GX var distortable font.                                        */
186  /*                                                                       */
187  /*    Some fields are specific to one format and not to the other.       */
188  /*                                                                       */
189  /* <Fields>                                                              */
190  /*    num_axis        :: The number of axes.  The maximum value is~4 for */
191  /*                       MM; no limit in GX.                             */
192  /*                                                                       */
193  /*    num_designs     :: The number of designs; should be normally       */
194  /*                       2^num_axis for MM fonts.  Not meaningful for GX */
195  /*                       (where every glyph could have a different       */
196  /*                       number of designs).                             */
197  /*                                                                       */
198  /*    num_namedstyles :: The number of named styles; only meaningful for */
199  /*                       GX that allows certain design coordinates to    */
200  /*                       have a string ID (in the `name' table)          */
201  /*                       associated with them.  The font can tell the    */
202  /*                       user that, for example, Weight=1.5 is `Bold'.   */
203  /*                                                                       */
204  /*    axis            :: A table of axis descriptors.                    */
205  /*                       GX fonts contain slightly more data than MM.    */
206  /*                                                                       */
207  /*    namedstyles     :: A table of named styles.                        */
208  /*                       Only meaningful with GX.                        */
209  /*                                                                       */
210  typedef struct  FT_MM_Var_
211  {
212    FT_UInt              num_axis;
213    FT_UInt              num_designs;
214    FT_UInt              num_namedstyles;
215    FT_Var_Axis*         axis;
216    FT_Var_Named_Style*  namedstyle;
217
218  } FT_MM_Var;
219
220
221  /*************************************************************************/
222  /*                                                                       */
223  /* <Function>                                                            */
224  /*    FT_Get_Multi_Master                                                */
225  /*                                                                       */
226  /* <Description>                                                         */
227  /*    Retrieve the Multiple Master descriptor of a given font.           */
228  /*                                                                       */
229  /*    This function can't be used with GX fonts.                         */
230  /*                                                                       */
231  /* <Input>                                                               */
232  /*    face    :: A handle to the source face.                            */
233  /*                                                                       */
234  /* <Output>                                                              */
235  /*    amaster :: The Multiple Masters descriptor.                        */
236  /*                                                                       */
237  /* <Return>                                                              */
238  /*    FreeType error code.  0~means success.                             */
239  /*                                                                       */
240  FT_EXPORT( FT_Error )
241  FT_Get_Multi_Master( FT_Face           face,
242                       FT_Multi_Master  *amaster );
243
244
245  /*************************************************************************/
246  /*                                                                       */
247  /* <Function>                                                            */
248  /*    FT_Get_MM_Var                                                      */
249  /*                                                                       */
250  /* <Description>                                                         */
251  /*    Retrieve the Multiple Master/GX var descriptor of a given font.    */
252  /*                                                                       */
253  /* <Input>                                                               */
254  /*    face    :: A handle to the source face.                            */
255  /*                                                                       */
256  /* <Output>                                                              */
257  /*    amaster :: The Multiple Masters/GX var descriptor.                 */
258  /*               Allocates a data structure, which the user must free.   */
259  /*                                                                       */
260  /* <Return>                                                              */
261  /*    FreeType error code.  0~means success.                             */
262  /*                                                                       */
263  FT_EXPORT( FT_Error )
264  FT_Get_MM_Var( FT_Face      face,
265                 FT_MM_Var*  *amaster );
266
267
268  /*************************************************************************/
269  /*                                                                       */
270  /* <Function>                                                            */
271  /*    FT_Set_MM_Design_Coordinates                                       */
272  /*                                                                       */
273  /* <Description>                                                         */
274  /*    For Multiple Masters fonts, choose an interpolated font design     */
275  /*    through design coordinates.                                        */
276  /*                                                                       */
277  /*    This function can't be used with GX fonts.                         */
278  /*                                                                       */
279  /* <InOut>                                                               */
280  /*    face       :: A handle to the source face.                         */
281  /*                                                                       */
282  /* <Input>                                                               */
283  /*    num_coords :: The number of design coordinates (must be equal to   */
284  /*                  the number of axes in the font).                     */
285  /*                                                                       */
286  /*    coords     :: An array of design coordinates.                      */
287  /*                                                                       */
288  /* <Return>                                                              */
289  /*    FreeType error code.  0~means success.                             */
290  /*                                                                       */
291  FT_EXPORT( FT_Error )
292  FT_Set_MM_Design_Coordinates( FT_Face   face,
293                                FT_UInt   num_coords,
294                                FT_Long*  coords );
295
296
297  /*************************************************************************/
298  /*                                                                       */
299  /* <Function>                                                            */
300  /*    FT_Set_Var_Design_Coordinates                                      */
301  /*                                                                       */
302  /* <Description>                                                         */
303  /*    For Multiple Master or GX Var fonts, choose an interpolated font   */
304  /*    design through design coordinates.                                 */
305  /*                                                                       */
306  /* <InOut>                                                               */
307  /*    face       :: A handle to the source face.                         */
308  /*                                                                       */
309  /* <Input>                                                               */
310  /*    num_coords :: The number of design coordinates (must be equal to   */
311  /*                  the number of axes in the font).                     */
312  /*                                                                       */
313  /*    coords     :: An array of design coordinates.                      */
314  /*                                                                       */
315  /* <Return>                                                              */
316  /*    FreeType error code.  0~means success.                             */
317  /*                                                                       */
318  FT_EXPORT( FT_Error )
319  FT_Set_Var_Design_Coordinates( FT_Face    face,
320                                 FT_UInt    num_coords,
321                                 FT_Fixed*  coords );
322
323
324  /*************************************************************************/
325  /*                                                                       */
326  /* <Function>                                                            */
327  /*    FT_Set_MM_Blend_Coordinates                                        */
328  /*                                                                       */
329  /* <Description>                                                         */
330  /*    For Multiple Masters and GX var fonts, choose an interpolated font */
331  /*    design through normalized blend coordinates.                       */
332  /*                                                                       */
333  /* <InOut>                                                               */
334  /*    face       :: A handle to the source face.                         */
335  /*                                                                       */
336  /* <Input>                                                               */
337  /*    num_coords :: The number of design coordinates (must be equal to   */
338  /*                  the number of axes in the font).                     */
339  /*                                                                       */
340  /*    coords     :: The design coordinates array (each element must be   */
341  /*                  between 0 and 1.0).                                  */
342  /*                                                                       */
343  /* <Return>                                                              */
344  /*    FreeType error code.  0~means success.                             */
345  /*                                                                       */
346  FT_EXPORT( FT_Error )
347  FT_Set_MM_Blend_Coordinates( FT_Face    face,
348                               FT_UInt    num_coords,
349                               FT_Fixed*  coords );
350
351
352  /*************************************************************************/
353  /*                                                                       */
354  /* <Function>                                                            */
355  /*    FT_Set_Var_Blend_Coordinates                                       */
356  /*                                                                       */
357  /* <Description>                                                         */
358  /*    This is another name of @FT_Set_MM_Blend_Coordinates.              */
359  /*                                                                       */
360  FT_EXPORT( FT_Error )
361  FT_Set_Var_Blend_Coordinates( FT_Face    face,
362                                FT_UInt    num_coords,
363                                FT_Fixed*  coords );
364
365  /* */
366
367
368FT_END_HEADER
369
370#endif /* __FTMM_H__ */
371
372
373/* END */
374