1 /***************************************************************************/
2 /*                                                                         */
3 /*  afloader.c                                                             */
4 /*                                                                         */
5 /*    Auto-fitter glyph loading routines (body).                           */
6 /*                                                                         */
7 /*  Copyright 2003-2015 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 #include "afglobal.h"
20 #include "afloader.h"
21 #include "afhints.h"
22 #include "aferrors.h"
23 #include "afmodule.h"
24 #include "afpic.h"
25 
26 
27   /* Initialize glyph loader. */
28 
29   FT_LOCAL_DEF( void )
af_loader_init(AF_Loader loader,AF_GlyphHints hints)30   af_loader_init( AF_Loader      loader,
31                   AF_GlyphHints  hints )
32   {
33     FT_ZERO( loader );
34 
35     loader->hints = hints;
36   }
37 
38 
39   /* Reset glyph loader and compute globals if necessary. */
40 
41   FT_LOCAL_DEF( FT_Error )
af_loader_reset(AF_Loader loader,AF_Module module,FT_Face face)42   af_loader_reset( AF_Loader  loader,
43                    AF_Module  module,
44                    FT_Face    face )
45   {
46     FT_Error  error = FT_Err_Ok;
47 
48 
49     loader->face    = face;
50     loader->globals = (AF_FaceGlobals)face->autohint.data;
51 
52     if ( loader->globals == NULL )
53     {
54       error = af_face_globals_new( face, &loader->globals, module );
55       if ( !error )
56       {
57         face->autohint.data =
58           (FT_Pointer)loader->globals;
59         face->autohint.finalizer =
60           (FT_Generic_Finalizer)af_face_globals_free;
61       }
62     }
63 
64     return error;
65   }
66 
67 
68   /* Finalize glyph loader. */
69 
70   FT_LOCAL_DEF( void )
af_loader_done(AF_Loader loader)71   af_loader_done( AF_Loader  loader )
72   {
73     loader->face    = NULL;
74     loader->globals = NULL;
75     loader->hints   = NULL;
76   }
77 
78 
79   /* Do the main work of `af_loader_load_glyph'.  Note that we never   */
80   /* have to deal with composite glyphs as those get loaded into       */
81   /* FT_GLYPH_FORMAT_OUTLINE by the recursed `FT_Load_Glyph' function. */
82   /* In the rare cases where FT_LOAD_NO_RECURSE is set, it implies     */
83   /* FT_LOAD_NO_SCALE and as such the auto-hinter is never called.     */
84 
85   static FT_Error
af_loader_load_g(AF_Loader loader,AF_Scaler scaler,FT_UInt glyph_index,FT_Int32 load_flags)86   af_loader_load_g( AF_Loader  loader,
87                     AF_Scaler  scaler,
88                     FT_UInt    glyph_index,
89                     FT_Int32   load_flags )
90   {
91     FT_Error          error;
92     FT_Face           face     = loader->face;
93     AF_StyleMetrics   metrics  = loader->metrics;
94     AF_GlyphHints     hints    = loader->hints;
95     FT_GlyphSlot      slot     = face->glyph;
96     FT_Slot_Internal  internal = slot->internal;
97     FT_GlyphLoader    gloader  = internal->loader;
98     FT_Int32          flags;
99 
100 
101     flags = load_flags | FT_LOAD_LINEAR_DESIGN;
102     error = FT_Load_Glyph( face, glyph_index, flags );
103     if ( error )
104       goto Exit;
105 
106     loader->transformed = internal->glyph_transformed;
107     if ( loader->transformed )
108     {
109       FT_Matrix  inverse;
110 
111 
112       loader->trans_matrix = internal->glyph_matrix;
113       loader->trans_delta  = internal->glyph_delta;
114 
115       inverse = loader->trans_matrix;
116       if ( !FT_Matrix_Invert( &inverse ) )
117         FT_Vector_Transform( &loader->trans_delta, &inverse );
118     }
119 
120     switch ( slot->format )
121     {
122     case FT_GLYPH_FORMAT_OUTLINE:
123       /* translate the loaded glyph when an internal transform is needed */
124       if ( loader->transformed )
125         FT_Outline_Translate( &slot->outline,
126                               loader->trans_delta.x,
127                               loader->trans_delta.y );
128 
129       /* compute original horizontal phantom points (and ignore */
130       /* vertical ones)                                         */
131       loader->pp1.x = hints->x_delta;
132       loader->pp1.y = hints->y_delta;
133       loader->pp2.x = FT_MulFix( slot->metrics.horiAdvance,
134                                  hints->x_scale ) + hints->x_delta;
135       loader->pp2.y = hints->y_delta;
136 
137       /* be sure to check for spacing glyphs */
138       if ( slot->outline.n_points == 0 )
139         goto Hint_Metrics;
140 
141       /* now load the slot image into the auto-outline and run the */
142       /* automatic hinting process                                 */
143       {
144 #ifdef FT_CONFIG_OPTION_PIC
145         AF_FaceGlobals         globals = loader->globals;
146 #endif
147         AF_StyleClass          style_class = metrics->style_class;
148         AF_WritingSystemClass  writing_system_class =
149           AF_WRITING_SYSTEM_CLASSES_GET[style_class->writing_system];
150 
151 
152         if ( writing_system_class->style_hints_apply )
153           writing_system_class->style_hints_apply( hints,
154                                                    &gloader->base.outline,
155                                                    metrics );
156       }
157 
158       /* we now need to adjust the metrics according to the change in */
159       /* width/positioning that occurred during the hinting process   */
160       if ( scaler->render_mode != FT_RENDER_MODE_LIGHT )
161       {
162         FT_Pos        old_rsb, old_lsb, new_lsb;
163         FT_Pos        pp1x_uh, pp2x_uh;
164         AF_AxisHints  axis  = &hints->axis[AF_DIMENSION_HORZ];
165         AF_Edge       edge1 = axis->edges;         /* leftmost edge  */
166         AF_Edge       edge2 = edge1 +
167                               axis->num_edges - 1; /* rightmost edge */
168 
169 
170         if ( axis->num_edges > 1 && AF_HINTS_DO_ADVANCE( hints ) )
171         {
172           old_rsb = loader->pp2.x - edge2->opos;
173           old_lsb = edge1->opos;
174           new_lsb = edge1->pos;
175 
176           /* remember unhinted values to later account */
177           /* for rounding errors                       */
178 
179           pp1x_uh = new_lsb    - old_lsb;
180           pp2x_uh = edge2->pos + old_rsb;
181 
182           /* prefer too much space over too little space */
183           /* for very small sizes                        */
184 
185           if ( old_lsb < 24 )
186             pp1x_uh -= 8;
187 
188           if ( old_rsb < 24 )
189             pp2x_uh += 8;
190 
191           loader->pp1.x = FT_PIX_ROUND( pp1x_uh );
192           loader->pp2.x = FT_PIX_ROUND( pp2x_uh );
193 
194           if ( loader->pp1.x >= new_lsb && old_lsb > 0 )
195             loader->pp1.x -= 64;
196 
197           if ( loader->pp2.x <= edge2->pos && old_rsb > 0 )
198             loader->pp2.x += 64;
199 
200           slot->lsb_delta = loader->pp1.x - pp1x_uh;
201           slot->rsb_delta = loader->pp2.x - pp2x_uh;
202         }
203         else
204         {
205           FT_Pos  pp1x = loader->pp1.x;
206           FT_Pos  pp2x = loader->pp2.x;
207 
208 
209           loader->pp1.x = FT_PIX_ROUND( pp1x );
210           loader->pp2.x = FT_PIX_ROUND( pp2x );
211 
212           slot->lsb_delta = loader->pp1.x - pp1x;
213           slot->rsb_delta = loader->pp2.x - pp2x;
214         }
215       }
216       else
217       {
218         FT_Pos  pp1x = loader->pp1.x;
219         FT_Pos  pp2x = loader->pp2.x;
220 
221 
222         loader->pp1.x = FT_PIX_ROUND( pp1x + hints->xmin_delta );
223         loader->pp2.x = FT_PIX_ROUND( pp2x + hints->xmax_delta );
224 
225         slot->lsb_delta = loader->pp1.x - pp1x;
226         slot->rsb_delta = loader->pp2.x - pp2x;
227       }
228 
229       break;
230 
231     default:
232       /* we don't support other formats (yet?) */
233       error = FT_THROW( Unimplemented_Feature );
234     }
235 
236   Hint_Metrics:
237     {
238       FT_BBox    bbox;
239       FT_Vector  vvector;
240 
241 
242       vvector.x = slot->metrics.vertBearingX - slot->metrics.horiBearingX;
243       vvector.y = slot->metrics.vertBearingY - slot->metrics.horiBearingY;
244       vvector.x = FT_MulFix( vvector.x, metrics->scaler.x_scale );
245       vvector.y = FT_MulFix( vvector.y, metrics->scaler.y_scale );
246 
247       /* transform the hinted outline if needed */
248       if ( loader->transformed )
249       {
250         FT_Outline_Transform( &gloader->base.outline, &loader->trans_matrix );
251         FT_Vector_Transform( &vvector, &loader->trans_matrix );
252       }
253 #if 1
254       /* we must translate our final outline by -pp1.x and compute */
255       /* the new metrics                                           */
256       if ( loader->pp1.x )
257         FT_Outline_Translate( &gloader->base.outline, -loader->pp1.x, 0 );
258 #endif
259       FT_Outline_Get_CBox( &gloader->base.outline, &bbox );
260 
261       bbox.xMin = FT_PIX_FLOOR( bbox.xMin );
262       bbox.yMin = FT_PIX_FLOOR( bbox.yMin );
263       bbox.xMax = FT_PIX_CEIL(  bbox.xMax );
264       bbox.yMax = FT_PIX_CEIL(  bbox.yMax );
265 
266       slot->metrics.width        = bbox.xMax - bbox.xMin;
267       slot->metrics.height       = bbox.yMax - bbox.yMin;
268       slot->metrics.horiBearingX = bbox.xMin;
269       slot->metrics.horiBearingY = bbox.yMax;
270 
271       slot->metrics.vertBearingX = FT_PIX_FLOOR( bbox.xMin + vvector.x );
272       slot->metrics.vertBearingY = FT_PIX_FLOOR( bbox.yMax + vvector.y );
273 
274       /* for mono-width fonts (like Andale, Courier, etc.) we need */
275       /* to keep the original rounded advance width; ditto for     */
276       /* digits if all have the same advance width                 */
277 #if 0
278       if ( !FT_IS_FIXED_WIDTH( slot->face ) )
279         slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
280       else
281         slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
282                                                x_scale );
283 #else
284       if ( scaler->render_mode != FT_RENDER_MODE_LIGHT                      &&
285            ( FT_IS_FIXED_WIDTH( slot->face )                              ||
286              ( af_face_globals_is_digit( loader->globals, glyph_index ) &&
287                metrics->digits_have_same_width                          ) ) )
288       {
289         slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
290                                                metrics->scaler.x_scale );
291 
292         /* Set delta values to 0.  Otherwise code that uses them is */
293         /* going to ruin the fixed advance width.                   */
294         slot->lsb_delta = 0;
295         slot->rsb_delta = 0;
296       }
297       else
298       {
299         /* non-spacing glyphs must stay as-is */
300         if ( slot->metrics.horiAdvance )
301           slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
302       }
303 #endif
304 
305       slot->metrics.vertAdvance = FT_MulFix( slot->metrics.vertAdvance,
306                                              metrics->scaler.y_scale );
307 
308       slot->metrics.horiAdvance = FT_PIX_ROUND( slot->metrics.horiAdvance );
309       slot->metrics.vertAdvance = FT_PIX_ROUND( slot->metrics.vertAdvance );
310 
311 #if 0
312       /* reassign all outline fields except flags to protect them */
313       slot->outline.n_contours = internal->loader->base.outline.n_contours;
314       slot->outline.n_points   = internal->loader->base.outline.n_points;
315       slot->outline.points     = internal->loader->base.outline.points;
316       slot->outline.tags       = internal->loader->base.outline.tags;
317       slot->outline.contours   = internal->loader->base.outline.contours;
318 #endif
319 
320       slot->format  = FT_GLYPH_FORMAT_OUTLINE;
321     }
322 
323   Exit:
324     return error;
325   }
326 
327 
328   /* Load a glyph. */
329 
330   FT_LOCAL_DEF( FT_Error )
af_loader_load_glyph(AF_Loader loader,AF_Module module,FT_Face face,FT_UInt gindex,FT_Int32 load_flags)331   af_loader_load_glyph( AF_Loader  loader,
332                         AF_Module  module,
333                         FT_Face    face,
334                         FT_UInt    gindex,
335                         FT_Int32   load_flags )
336   {
337     FT_Error      error;
338     FT_Size       size   = face->size;
339     AF_ScalerRec  scaler;
340 
341 
342     if ( !size )
343       return FT_THROW( Invalid_Size_Handle );
344 
345     FT_ZERO( &scaler );
346 
347     scaler.face    = face;
348     scaler.x_scale = size->metrics.x_scale;
349     scaler.x_delta = 0;  /* XXX: TODO: add support for sub-pixel hinting */
350     scaler.y_scale = size->metrics.y_scale;
351     scaler.y_delta = 0;  /* XXX: TODO: add support for sub-pixel hinting */
352 
353     scaler.render_mode = FT_LOAD_TARGET_MODE( load_flags );
354     scaler.flags       = 0;  /* XXX: fix this */
355 
356     error = af_loader_reset( loader, module, face );
357     if ( !error )
358     {
359       AF_StyleMetrics  metrics;
360       FT_UInt          options = AF_STYLE_NONE_DFLT;
361 
362 
363 #ifdef FT_OPTION_AUTOFIT2
364       /* XXX: undocumented hook to activate the latin2 writing system */
365       if ( load_flags & ( 1UL << 20 ) )
366         options = AF_STYLE_LTN2_DFLT;
367 #endif
368 
369       error = af_face_globals_get_metrics( loader->globals, gindex,
370                                            options, &metrics );
371       if ( !error )
372       {
373 #ifdef FT_CONFIG_OPTION_PIC
374         AF_FaceGlobals         globals = loader->globals;
375 #endif
376         AF_StyleClass          style_class = metrics->style_class;
377         AF_WritingSystemClass  writing_system_class =
378           AF_WRITING_SYSTEM_CLASSES_GET[style_class->writing_system];
379 
380 
381         loader->metrics = metrics;
382 
383         if ( writing_system_class->style_metrics_scale )
384           writing_system_class->style_metrics_scale( metrics, &scaler );
385         else
386           metrics->scaler = scaler;
387 
388         load_flags |=  FT_LOAD_NO_SCALE | FT_LOAD_IGNORE_TRANSFORM;
389         load_flags &= ~FT_LOAD_RENDER;
390 
391         if ( writing_system_class->style_hints_init )
392         {
393           error = writing_system_class->style_hints_init( loader->hints,
394                                                           metrics );
395           if ( error )
396             goto Exit;
397         }
398 
399         error = af_loader_load_g( loader, &scaler, gindex, load_flags );
400       }
401     }
402   Exit:
403     return error;
404   }
405 
406 
407 /* END */
408