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plfreetype.c
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1 // Copyright (C) 2002, 2004, 2005 Andrew Roach
2 // Copyright (C) 2002 Maurice LeBrun
3 // Copyright (C) 2002-2014 Alan W. Irwin
4 // Copyright (C) 2003, 2004 Joao Cardoso
5 // Copyright (C) 2003, 2004, 2005 Rafael Laboissiere
6 // Copyright (C) 2004 Andrew Ross
7 //
8 // This file is part of PLplot.
9 //
10 // PLplot is free software; you can redistribute it and/or modify
11 // it under the terms of the GNU Library General Public License as published
12 // by the Free Software Foundation; either version 2 of the License, or
13 // (at your option) any later version.
14 //
15 // PLplot is distributed in the hope that it will be useful,
16 // but WITHOUT ANY WARRANTY; without even the implied warranty of
17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 // GNU Library General Public License for more details.
19 //
20 // You should have received a copy of the GNU Library General Public License
21 // along with PLplot; if not, write to the Free Software
22 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 //
24 //
25 // Support routines for freetype font engine
26 //
27 // This file contains a series of support routines for drivers interested
28 // in using freetype rendered fonts instead of plplot plotter fonts.
29 // Freetype supports a gerth of font formats including TrueType, OpenType,
30 // Adobe Type1, Type42 etc... the list seems almost endless. Any bitmap
31 // driver should be able to use any of these freetype fonts from plplot if
32 // these routines are properly initialised.
33 //
34 // Freetype support is not intended to be a "feature" of the common API,
35 // but is implemented as a driver-specific optional extra invoked via the
36 // -drvopt command line toggle. It is intended to be used in the context of
37 // "PLESC_HAS_TEXT" for any bitmap drivers without native font support.
38 // Implementing freetype in this manner minimise changes to the overall
39 // API. Because of this approach, there is not a "wealth" of font options
40 // available to the programmer. You can not do anything you can't do for a
41 // normal freetype plotter font like boldface. You can do most of the
42 // things that you can do with a plotter font however, like greek
43 // characters superscripting, and selecting one of the four "pre-defined"
44 // plplot font types. At present underlining and overlining are not
45 // supported.
46 //
47 // To give the user some level of control over the fonts that are used,
48 // environmental variables can be set to over-ride the definitions used by
49 // the five default plplot fonts.
50 //
51 // The exact syntax for evoking freetype fonts is dependant on each
52 // driver, but for the GD and GNUSVGA drivers I have followed the syntax of
53 // the PS driver and use the command-line switch of "-drvopt text" to
54 // activate the feature, and suggest other programmers do the same for
55 // commonality.
56 //
57 // Both anti-aliased and monochrome font rendering is supported by these
58 // routines. How these are evoked depends on the programmer, but with the
59 // GD and GNUSVGA driver families I have used the command-line switch
60 // "-drvopt smooth" to activate the feature; but, considering you also need
61 // to turn freetype on, it would probably really be more like "-drvopt
62 // text,smooth".
63 //
64 //
65 
66 #include "plConfig.h"
67 #if !PL_HAVE_UNISTD_H
68  #define F_OK 1
69  #include <stdio.h>
70 int access( char *filename, int flag )
71 {
72  FILE *infile;
73  infile = fopen( filename, "r" );
74  if ( infile != NULL )
75  {
76  fclose( infile );
77  return 0;
78  }
79  else
80  {
81  return 1;
82  }
83 }
84 #else
85  #include <unistd.h>
86 #endif
87 
88 #define makeunixslash( b ) do { char *I; for ( I = b; *I != 0; *I++ ) if ( *I == '\\' ) *I = '/';} while ( 0 )
89 
90 #include "plDevs.h"
91 #include "plplotP.h"
92 #include "drivers.h"
93 #ifdef PL_HAVE_FREETYPE
94 #include "plfreetype.h"
95 #include "plfci-truetype.h"
96 
97 #define FT_Data _FT_Data_
98 
99 // Font lookup table that is constructed in plD_FreeType_init
101 // TOP LEVEL DEFINES
102 
103 // Freetype lets you set the text size absolutely. It also takes into
104 // account the DPI when doing so. So does plplot. Why, then, is it that the
105 // size of the text drawn by plplot is bigger than the text drawn by
106 // freetype when given IDENTICAL parameters ? Perhaps I am missing
107 // something somewhere, but to fix this up we use TEXT_SCALING_FACTOR to
108 // set a scaling factor to try and square things up a bit.
109 //
110 
111 #define TEXT_SCALING_FACTOR .7
112 
113 // default size of temporary text buffer
114 // If we wanted to be fancy we could add sizing, but this should be big enough
115 
116 #define NTEXT_ALLOC 1024
117 
118 //--------------------------------------------------------------------------
119 // Some debugging macros
120 //--------------------------------------------------------------------------
121 
122 #define Debug6( a, b, c, d, e, f ) do { if ( pls->debug ) { fprintf( stderr, a, b, c, d, e, f ); } } while ( 0 )
123 
124 
125 // FUNCTION PROTOTYPES
126 
127 // Public prototypes, generally available to the API
128 
129 void plD_FreeType_init( PLStream *pls );
130 void plD_render_freetype_text( PLStream *pls, EscText *args );
131 void plD_FreeType_Destroy( PLStream *pls );
132 void pl_set_extended_cmap0( PLStream *pls, int ncol0_width, int ncol0_org );
133 void pl_RemakeFreeType_text_from_buffer( PLStream *pls );
134 void plD_render_freetype_sym( PLStream *pls, EscText *args );
135 
136 // Private prototypes for use in this file only
137 
138 static void FT_PlotChar( PLStream *pls, FT_Data *FT, FT_GlyphSlot slot, int x, int y );
139 static void FT_SetFace( PLStream *pls, PLUNICODE fci );
140 static PLFLT CalculateIncrement( int bg, int fg, int levels );
141 
142 // These are never defined, maybe they will be used in the future?
143 //
144 // static void pl_save_FreeType_text_to_buffer (PLStream *pls, EscText *args);
145 // static FT_ULong hershey_to_unicode (char in);
146 //
147 //
148 
149 static void FT_WriteStrW( PLStream *pls, const PLUNICODE *text, short len, int x, int y );
150 static void FT_StrX_YW( PLStream *pls, const PLUNICODE *text, short len, int *xx, int *yy, int *overyy, int *underyy );
151 
152 //--------------------------------------------------------------------------
153 // FT_StrX_YW()
154 //
155 // Returns the dimensions of the text box. It does this by fully parsing
156 // the supplied text through the rendering engine. It does everything
157 // but draw the text. This seems, to me, the easiest and most accurate
158 // way of determining the text's dimensions. If/when caching is added,
159 // the CPU hit for this "double processing" will be minimal.
160 //--------------------------------------------------------------------------
161 
162 void
163 FT_StrX_YW( PLStream *pls, const PLUNICODE *text, short len, int *xx, int *yy, int *overyy, int *underyy )
164 {
165  FT_Data *FT = (FT_Data *) pls->FT;
166  short i = 0;
167  FT_Vector akerning, adjust;
168  int x = 0, y = 0, startingy;
169  char esc;
170 
171  plgesc( &esc );
172 
173 //
174 // Things seems to work better with this line than without it;
175 // I guess because there is no vertical kerning or advancement for most
176 // non-transformed fonts, so we need to define *something* for the y height,
177 // and this is the best thing I could think of.
178 //
179 
180  y -= (int) FT->face->size->metrics.height;
181  startingy = y;
182  *yy = y; //note height is negative!
183  *overyy = 0;
184  *underyy = 0;
185  adjust.x = 0;
186  adjust.y = 0;
187 
188 // walk through the text character by character
189  for ( i = 0; i < len; i++ )
190  {
191  if ( ( text[i] == (PLUNICODE) esc ) && ( text[i - 1] != (PLUNICODE) esc ) )
192  {
193  if ( text[i + 1] == (PLUNICODE) esc )
194  continue;
195 
196  switch ( text[i + 1] )
197  {
198  case 'u': // super script
199  case 'U': // super script
200  adjust.y = FT->face->size->metrics.height / 2;
201  adjust.x = 0;
202  FT_Vector_Transform( &adjust, &FT->matrix );
203  x += (int) adjust.x;
204  y -= (int) adjust.y;
205  //calculate excess height from superscripts, this will need changing if scale of sub/superscripts changes
206  *overyy = y - startingy < *overyy ? y - startingy : *overyy;
207  i++;
208  break;
209 
210  case 'd': // subscript
211  case 'D': // subscript
212  adjust.y = -FT->face->size->metrics.height / 2;
213  adjust.x = 0;
214  FT_Vector_Transform( &adjust, &FT->matrix );
215  x += (int) adjust.x;
216  y -= (int) adjust.y;
217  //calculate excess depth from subscripts, this will need changing if scale of sub/superscripts changes
218  *underyy = startingy - y < *underyy ? startingy - y : *underyy;
219  i++;
220  break;
221  }
222  }
223  else if ( text[i] & PL_FCI_MARK )
224  {
225  // FCI in text stream; change font accordingly.
226  FT_SetFace( pls, text[i] );
227  *yy = (int) ( FT->face->size->metrics.height > -*yy ? -FT->face->size->metrics.height : *yy );
228  }
229  else
230  {
231  // see if we have kerning for the particular character pair
232  if ( ( i > 0 ) && FT_HAS_KERNING( FT->face ) )
233  {
234  FT_Get_Kerning( FT->face,
235  text[i - 1],
236  text[i],
237  ft_kerning_default,
238  &akerning );
239  x += (int) ( akerning.x >> 6 ); // add (or subtract) the kerning
240  }
241 
242  //
243  // Next we load the char. This also draws the char, transforms it, and
244  // converts it to a bitmap. At present this is a bit wasteful, but
245  // if/when I add cache support, then this data won't go to waste.
246  // Since there is no sense in going to the trouble of doing anti-aliasing
247  // calculations since we aren't REALLY plotting anything, we will render
248  // this as monochrome since it is probably marginally quicker. If/when
249  // cache support is added, naturally this will have to change.
250  //
251 
252  FT_Load_Char( FT->face, text[i], FT_LOAD_MONOCHROME + FT_LOAD_RENDER );
253 
254  //
255  // Add in the "advancement" needed to position the cursor for the next
256  // character. Unless the text is transformed, "y" will always be zero.
257  // Y is negative because freetype does things upside down
258  //
259 
260  x += (int) ( FT->face->glyph->advance.x );
261  y -= (int) ( FT->face->glyph->advance.y );
262  }
263  }
264 
265 //
266 // Convert from unit of 1/64 of a pixel to pixels, and do it real fast with
267 // a bitwise shift (mind you, any decent compiler SHOULD optimise /64 this way
268 // anyway...)
269 //
270 
271 // (RL, on 2005-01-23) Removed the shift bellow to avoid truncation errors
272 // later.
273 //yy=y>> 6;
274 //xx=x>> 6;
275 //
276  *xx = x;
277 }
278 
279 //--------------------------------------------------------------------------
280 // FT_WriteStrW()
281 //
282 // Writes a string of FT text at the current cursor location.
283 // most of the code here is identical to "FT_StrX_Y" and I will probably
284 // collapse the two into some more efficient code eventually.
285 //--------------------------------------------------------------------------
286 
287 void
288 FT_WriteStrW( PLStream *pls, const PLUNICODE *text, short len, int x, int y )
289 {
290  FT_Data *FT = (FT_Data *) pls->FT;
291  short i = 0, last_char = -1;
292  FT_Vector akerning, adjust;
293  char esc;
294 
295  plgesc( &esc );
296 
297 
298 //
299 // Adjust for the descender - make sure the font is nice and centred
300 // vertically. Freetype assumes we have a base-line, but plplot thinks of
301 // centre-lines, so that's why we have to do this. Since this is one of our
302 // own adjustments, rather than a freetype one, we have to run it through
303 // the transform matrix manually.
304 //
305 // For some odd reason, this works best if we triple the
306 // descender's height and then adjust the height later on...
307 // Don't ask me why, 'cause I don't know. But it does seem to work.
308 //
309 // I really wish I knew *why* it worked better though...
310 //
311 // y-=FT->face->descender >> 6;
312 //
313 
314 #ifdef DODGIE_DECENDER_HACK
315  adjust.y = ( FT->face->descender >> 6 ) * 3;
316 #else
317  adjust.y = ( FT->face->descender >> 6 );
318 #endif
319 
320 // (RL) adjust.y is zeroed below,, making the code above (around
321 // DODGIE_DECENDER_HACK) completely useless. This is necessary for
322 // getting the vertical alignment of text right, which is coped with
323 // in function plD_render_freetype_text now.
324 //
325 
326  adjust.x = 0;
327  adjust.y = 0;
328  FT_Vector_Transform( &adjust, &FT->matrix );
329  x += (int) adjust.x;
330  y -= (int) adjust.y;
331 
332 // (RL, on 2005-01-25) The computation of cumulated glyph width within
333 // the text is done now with full precision, using 26.6 Freetype
334 // arithmetics. We should then shift the x and y variables by 6 bits,
335 // as below. Inside the character for loop, all operations regarding
336 // x and y will be done in 26.6 mode and these variables will be
337 // converted to integers when passed to FT_PlotChar. Notrice that we
338 // are using ROUND and float division instead of ">> 6" now. This
339 // minimizes truncation errors.
340 //
341 
342  x <<= 6;
343  y <<= 6;
344 
345 // walk through the text character by character
346 
347  for ( i = 0; i < len; i++ )
348  {
349  if ( ( text[i] == (PLUNICODE) esc ) && ( text[i - 1] != (PLUNICODE) esc ) )
350  {
351  if ( text[i + 1] == (PLUNICODE) esc )
352  continue;
353 
354  switch ( text[i + 1] )
355  {
356  //
357  // We run the OFFSET for the super-script and sub-script through the
358  // transformation matrix so we can calculate nice and easy the required
359  // offset no matter what's happened rotation wise. Everything else, like
360  // kerning and advancing from character to character is transformed
361  // automatically by freetype, but since the superscript/subscript is a
362  // feature of plplot, and not freetype, we have to make allowances.
363  //
364 
365  case 'u': // super script
366  case 'U': // super script
367  adjust.y = FT->face->size->metrics.height / 2;
368  adjust.x = 0;
369  FT_Vector_Transform( &adjust, &FT->matrix );
370  x += (int) adjust.x;
371  y -= (int) adjust.y;
372  i++;
373  break;
374 
375  case 'd': // subscript
376  case 'D': // subscript
377  adjust.y = -FT->face->size->metrics.height / 2;
378  adjust.x = 0;
379  FT_Vector_Transform( &adjust, &FT->matrix );
380  x += (int) adjust.x;
381  y -= (int) adjust.y;
382  i++;
383  break;
384  }
385  }
386  else if ( text[i] & PL_FCI_MARK )
387  {
388  // FCI in text stream; change font accordingly.
389  FT_SetFace( pls, text[i] );
390  FT = (FT_Data *) pls->FT;
391  FT_Set_Transform( FT->face, &FT->matrix, &FT->pos );
392  }
393  else
394  {
395  // see if we have kerning for the particular character pair
396  if ( ( last_char != -1 ) && ( i > 0 ) && FT_HAS_KERNING( FT->face ) )
397  {
398  FT_Get_Kerning( FT->face,
399  text[last_char],
400  text[i],
401  ft_kerning_default, &akerning );
402  x += (int) akerning.x; // add (or subtract) the kerning
403  y -= (int) akerning.y; // Do I need this in case of rotation ?
404  }
405 
406 
407  FT_Load_Char( FT->face, text[i], ( FT->smooth_text == 0 ) ? FT_LOAD_MONOCHROME + FT_LOAD_RENDER : FT_LOAD_RENDER | FT_LOAD_FORCE_AUTOHINT );
408  FT_PlotChar( pls, FT, FT->face->glyph,
409  ROUND( x / 64.0 ), ROUND( y / 64.0 ) ); // render the text
410 
411  x += (int) FT->face->glyph->advance.x;
412  y -= (int) FT->face->glyph->advance.y;
413 
414  last_char = i;
415  }
416  } // end for
417 }
418 
419 //--------------------------------------------------------------------------
420 // FT_PlotChar()
421 //
422 // Plots an individual character. I know some of this stuff, like colour
423 // could be parsed from plstream, but it was just quicker this way.
424 //--------------------------------------------------------------------------
425 
426 void
427 FT_PlotChar( PLStream *pls, FT_Data *FT, FT_GlyphSlot slot,
428  int x, int y )
429 {
430  unsigned char bittest;
431  short i, k, j;
432  int n = slot->bitmap.pitch;
433  int current_pixel_colour;
434  int R, G, B;
435  PLFLT alpha_a;
436  //PLFLT alpha_b;
437  int xx;
438  short imin, imax, kmin, kmax;
439 
440  // Corners of the clipping rectangle
441  PLINT clipxmin, clipymin, clipxmax, clipymax, tmp;
442  PLINT clpxmi, clpxma, clpymi, clpyma;
443 
444  // Convert clipping box into normal coordinates
445  clipxmin = pls->clpxmi;
446  clipxmax = pls->clpxma;
447  clipymin = pls->clpymi;
448  clipymax = pls->clpyma;
449 
450  if ( plsc->difilt )
451  {
452  difilt( &clipxmin, &clipymin, 1, &clpxmi, &clpxma, &clpymi, &clpyma );
453  difilt( &clipxmax, &clipymax, 1, &clpxmi, &clpxma, &clpymi, &clpyma );
454  }
455 
456 
457  if ( FT->scale != 0.0 ) // scale was set
458  {
459  clipxmin = (PLINT) ( clipxmin / FT->scale );
460  clipxmax = (PLINT) ( clipxmax / FT->scale );
461  if ( FT->invert_y == 1 )
462  {
463  clipymin = (PLINT) ( FT->ymax - ( clipymin / FT->scale ) );
464  clipymax = (PLINT) ( FT->ymax - ( clipymax / FT->scale ) );
465  }
466  else
467  {
468  clipymin = (PLINT) ( clipymin / FT->scale );
469  clipymax = (PLINT) ( clipymax / FT->scale );
470  }
471  }
472  else
473  {
474  clipxmin = (PLINT) ( clipxmin / FT->scalex );
475  clipxmax = (PLINT) ( clipxmax / FT->scalex );
476 
477  if ( FT->invert_y == 1 )
478  {
479  clipymin = (PLINT) ( FT->ymax - ( clipymin / FT->scaley ) );
480  clipymax = (PLINT) ( FT->ymax - ( clipymax / FT->scaley ) );
481  }
482  else
483  {
484  clipymin = (PLINT) ( clipymin / FT->scaley );
485  clipymax = (PLINT) ( clipymax / FT->scaley );
486  }
487  }
488  if ( clipxmin > clipxmax )
489  {
490  tmp = clipxmax;
491  clipxmax = clipxmin;
492  clipxmin = tmp;
493  }
494  if ( clipymin > clipymax )
495  {
496  tmp = clipymax;
497  clipymax = clipymin;
498  clipymin = tmp;
499  }
500 
501  // Comment this out as it fails for cases where we want to plot text
502  // in the background font, i.e. example 24.
503  //
504  //if ((slot->bitmap.pixel_mode==ft_pixel_mode_mono)||(pls->icol0==0)) {
505  if ( slot->bitmap.pixel_mode == ft_pixel_mode_mono )
506  {
507  x += slot->bitmap_left;
508  y -= slot->bitmap_top;
509 
510  imin = (short) MAX( 0, clipymin - y );
511  imax = (short) MIN( slot->bitmap.rows, clipymax - y );
512  for ( i = imin; i < imax; i++ )
513  {
514  for ( k = 0; k < n; k++ )
515  {
516  bittest = 128;
517  for ( j = 0; j < 8; j++ )
518  {
519  if ( ( bittest & (unsigned char) slot->bitmap.buffer[( i * n ) + k] ) == bittest )
520  {
521  xx = x + ( k * 8 ) + j;
522  if ( ( xx >= clipxmin ) && ( xx <= clipxmax ) )
523  FT->pixel( pls, xx, y + i );
524  }
525  bittest >>= 1;
526  }
527  }
528  }
529  }
530 
531 // this is the anti-aliased stuff
532 
533  else
534  {
535  x += slot->bitmap_left;
536  y -= slot->bitmap_top;
537 
538  imin = (short) MAX( 0, clipymin - y );
539  imax = (short) MIN( slot->bitmap.rows, clipymax - y );
540  kmin = (short) MAX( 0, clipxmin - x );
541  kmax = (short) MIN( slot->bitmap.width, clipxmax - x );
542  for ( i = imin; i < imax; i++ )
543  {
544  for ( k = kmin; k < kmax; k++ )
545  {
546  FT->shade = ( slot->bitmap.buffer[( i * slot->bitmap.width ) + k] );
547  if ( FT->shade > 0 )
548  {
549  if ( ( FT->BLENDED_ANTIALIASING == 1 ) && ( FT->read_pixel != NULL ) )
550  // The New anti-aliasing technique
551  {
552  if ( FT->shade == 255 )
553  {
554  FT->pixel( pls, x + k, y + i );
555  }
556  else
557  {
558  current_pixel_colour = FT->read_pixel( pls, x + k, y + i );
559 
560  G = GetGValue( current_pixel_colour );
561  R = GetRValue( current_pixel_colour );
562  B = GetBValue( current_pixel_colour );
563  alpha_a = (float) FT->shade / 255.0;
564 
565  // alpha_b=1.0-alpha_a;
566  // R=(plsc->curcolor.r*alpha_a)+(R*alpha_b);
567  // G=(plsc->curcolor.g*alpha_a)+(G*alpha_b);
568  // B=(plsc->curcolor.b*alpha_a)+(B*alpha_b);
569  //
570 
571  // This next bit of code is, I *think*, computationally
572  // more efficient than the bit above. It results in
573  // an indistinguishable plot, but file sizes are different
574  // suggesting subtle variations doubtless caused by rounding
575  // and/or floating point conversions. Questions are - which is
576  // better ? Which is more "correct" ? Does it make a difference ?
577  // Is one faster than the other so that you'd ever notice ?
578  //
579 
580  R = (int) ( ( ( plsc->curcolor.r - R ) * alpha_a ) + R );
581  G = (int) ( ( ( plsc->curcolor.g - G ) * alpha_a ) + G );
582  B = (int) ( ( ( plsc->curcolor.b - B ) * alpha_a ) + B );
583 
584  FT->set_pixel( pls, x + k, y + i, RGB( R > 255 ? 255 : R, G > 255 ? 255 : G, B > 255 ? 255 : B ) );
585  }
586  }
587  else // The old anti-aliasing technique
588  {
589  FT->col_idx = FT->ncol0_width - ( ( FT->ncol0_width * FT->shade ) / 255 );
590  FT->last_icol0 = pls->icol0;
591  plcol0( pls->icol0 + ( FT->col_idx * ( FT->ncol0_org - 1 ) ) );
592  FT->pixel( pls, x + k, y + i );
593  plcol0( FT->last_icol0 );
594  }
595  }
596  }
597  }
598  }
599 }
600 
601 //--------------------------------------------------------------------------
602 // plD_FreeType_init()
603 //
604 // Allocates memory to Freetype structure
605 // Initialises the freetype library.
606 // Initialises freetype structure
607 //--------------------------------------------------------------------------
608 
609 void plD_FreeType_init( PLStream *pls )
610 {
611  FT_Data *FT;
612  char *a;
613 // font paths and file names can be long so leave generous (1024) room
614  char font_dir[PLPLOT_MAX_PATH];
615  // N.B. must be in exactly same order as TrueTypeLookup
616  const char *env_font_names[N_TrueTypeLookup] = {
617  "PLPLOT_FREETYPE_SANS_FONT",
618  "PLPLOT_FREETYPE_SERIF_FONT",
619  "PLPLOT_FREETYPE_MONO_FONT",
620  "PLPLOT_FREETYPE_SCRIPT_FONT",
621  "PLPLOT_FREETYPE_SYMBOL_FONT",
622  "PLPLOT_FREETYPE_SANS_ITALIC_FONT",
623  "PLPLOT_FREETYPE_SERIF_ITALIC_FONT",
624  "PLPLOT_FREETYPE_MONO_ITALIC_FONT",
625  "PLPLOT_FREETYPE_SCRIPT_ITALIC_FONT",
626  "PLPLOT_FREETYPE_SYMBOL_ITALIC_FONT",
627  "PLPLOT_FREETYPE_SANS_OBLIQUE_FONT",
628  "PLPLOT_FREETYPE_SERIF_OBLIQUE_FONT",
629  "PLPLOT_FREETYPE_MONO_OBLIQUE_FONT",
630  "PLPLOT_FREETYPE_SCRIPT_OBLIQUE_FONT",
631  "PLPLOT_FREETYPE_SYMBOL_OBLIQUE_FONT",
632  "PLPLOT_FREETYPE_SANS_BOLD_FONT",
633  "PLPLOT_FREETYPE_SERIF_BOLD_FONT",
634  "PLPLOT_FREETYPE_MONO_BOLD_FONT",
635  "PLPLOT_FREETYPE_SCRIPT_BOLD_FONT",
636  "PLPLOT_FREETYPE_SYMBOL_BOLD_FONT",
637  "PLPLOT_FREETYPE_SANS_BOLD_ITALIC_FONT",
638  "PLPLOT_FREETYPE_SERIF_BOLD_ITALIC_FONT",
639  "PLPLOT_FREETYPE_MONO_BOLD_ITALIC_FONT",
640  "PLPLOT_FREETYPE_SCRIPT_BOLD_ITALIC_FONT",
641  "PLPLOT_FREETYPE_SYMBOL_BOLD_ITALIC_FONT",
642  "PLPLOT_FREETYPE_SANS_BOLD_OBLIQUE_FONT",
643  "PLPLOT_FREETYPE_SERIF_BOLD_OBLIQUE_FONT",
644  "PLPLOT_FREETYPE_MONO_BOLD_OBLIQUE_FONT",
645  "PLPLOT_FREETYPE_SCRIPT_BOLD_OBLIQUE_FONT",
646  "PLPLOT_FREETYPE_SYMBOL_BOLD_OBLIQUE_FONT"
647  };
648  short i;
649 
650 #if defined ( MSDOS ) || defined ( WIN32 )
651  static char *default_font_names[] = { "arial.ttf", "times.ttf", "timesi.ttf", "arial.ttf",
652  "symbol.ttf" };
653  char WINDIR_PATH[PLPLOT_MAX_PATH];
654  char *b;
655  b = getenv( "WINDIR" );
656  strncpy( WINDIR_PATH, b, PLPLOT_MAX_PATH - 1 );
657  WINDIR_PATH[PLPLOT_MAX_PATH - 1] = '\0';
658 #else
659  const char *default_unix_font_dir = PL_FREETYPE_FONT_DIR;
660 #endif
661 
662 
663  if ( pls->FT )
664  {
665  plwarn( "Freetype seems already to have been initialised!" );
666  return;
667  }
668 
669  if ( ( pls->FT = calloc( 1, (size_t) sizeof ( FT_Data ) ) ) == NULL )
670  plexit( "Could not allocate memory for Freetype" );
671 
672  FT = (FT_Data *) pls->FT;
673 
674  if ( ( FT->textbuf = calloc( NTEXT_ALLOC, 1 ) ) == NULL )
675  plexit( "Could not allocate memory for Freetype text buffer" );
676 
677  if ( FT_Init_FreeType( &FT->library ) )
678  plexit( "Could not initialise Freetype library" );
679 
680  // set to an impossible value for an FCI
681  FT->fci = PL_FCI_IMPOSSIBLE;
682 
683 #if defined ( MSDOS ) || defined ( WIN32 )
684 
685 // First check for a user customised location and if
686 // the fonts aren't found there try the default Windows
687 // locations
688  if ( ( a = getenv( "PLPLOT_FREETYPE_FONT_DIR" ) ) != NULL )
689  strncpy( font_dir, a, PLPLOT_MAX_PATH - 1 );
690  else if ( strlen( PL_FREETYPE_FONT_DIR ) > 0 )
691  strncpy( font_dir, PL_FREETYPE_FONT_DIR, PLPLOT_MAX_PATH - 1 );
692  else if ( WINDIR_PATH == NULL )
693  {
694  //try to guess the font location by looking for arial font on C:
695  if ( access( "c:\\windows\\fonts\\arial.ttf", F_OK ) == 0 )
696  {
697  strcpy( font_dir, "c:/windows/fonts/" );
698  }
699  else if ( access( "c:\\windows\\system\\arial.ttf", F_OK ) == 0 )
700  {
701  strcpy( font_dir, "c:/windows/system/" );
702  }
703  else
704  plwarn( "Could not find font path; I sure hope you have defined fonts manually !" );
705  }
706  else
707  {
708  //Try to guess the font location by looking for Arial font in the Windows Path
709  strncat( WINDIR_PATH, "\\fonts\\arial.ttf", PLPLOT_MAX_PATH - 1 - strlen( WINDIR_PATH ) );
710  if ( access( WINDIR_PATH, F_OK ) == 0 )
711  {
712  b = strrchr( WINDIR_PATH, '\\' );
713  b++;
714  *b = 0;
715  makeunixslash( WINDIR_PATH );
716  strcpy( font_dir, WINDIR_PATH );
717  }
718  else
719  plwarn( "Could not find font path; I sure hope you have defined fonts manually !" );
720  }
721  font_dir[PLPLOT_MAX_PATH - 1] = '\0';
722 
723  if ( pls->debug )
724  fprintf( stderr, "%s\n", font_dir );
725 #else
726 
727 //
728 // For Unix systems, we will set the font path up a little differently in
729 // that the configured PL_FREETYPE_FONT_DIR has been set as the default path,
730 // but the user can override this by setting the environmental variable
731 // "PLPLOT_FREETYPE_FONT_DIR" to something else.
732 // NOTE WELL - the trailing slash must be added for now !
733 //
734 
735  if ( ( a = getenv( "PLPLOT_FREETYPE_FONT_DIR" ) ) != NULL )
736  strncpy( font_dir, a, PLPLOT_MAX_PATH - 1 );
737  else
738  strncpy( font_dir, default_unix_font_dir, PLPLOT_MAX_PATH - 1 );
739 
740  font_dir[PLPLOT_MAX_PATH - 1] = '\0';
741 #endif
742 
743 //
744 // The driver looks for N_TrueTypeLookup environmental variables
745 // where the path and name of these fonts can be OPTIONALLY set,
746 // overriding the configured default values.
747 //
748 
749  for ( i = 0; i < N_TrueTypeLookup; i++ )
750  {
751  if ( ( a = getenv( env_font_names[i] ) ) != NULL )
752  {
753 //
754 // Work out if we have been given an absolute path to a font name, or just
755 // a font name sans-path. To do this we will look for a directory separator
756 // character, which means some system specific junk. DJGPP is all wise, and
757 // understands both Unix and DOS conventions. DOS only knows DOS, and
758 // I assume everything else knows Unix-speak. (Why Bill, didn't you just
759 // pay the extra 15c and get a REAL separator???)
760 //
761 
762 #ifdef MSDOS
763  if ( a[1] == ':' ) // check for MS-DOS absolute path
764 #else
765  if ( ( a[0] == '/' ) || ( a[0] == '~' ) ) // check for unix abs path
766 #endif
767  strncpy( FT->font_name[i], a, PLPLOT_MAX_PATH - 1 );
768 
769  else
770  {
771  strncpy( FT->font_name[i], font_dir, PLPLOT_MAX_PATH - 1 );
772  strncat( FT->font_name[i], a, PLPLOT_MAX_PATH - 1 - strlen( FT->font_name[i] ) );
773  }
774  }
775  else
776  {
777  strncpy( FT->font_name[i], font_dir, PLPLOT_MAX_PATH - 1 );
778  strncat( FT->font_name[i], (const char *) TrueTypeLookup[i].pfont, PLPLOT_MAX_PATH - 1 - strlen( FT->font_name[i] ) );
779  }
780  FT->font_name[i][PLPLOT_MAX_PATH - 1] = '\0';
781 
782  {
783  FILE *infile;
784  if ( ( infile = fopen( FT->font_name[i], "r" ) ) == NULL )
785  {
786  char msgbuf[1024];
787  snprintf( msgbuf, 1024,
788  "plD_FreeType_init: Could not find the freetype compatible font:\n %s",
789  FT->font_name[i] );
790  plwarn( msgbuf );
791  }
792  else
793  {
794  fclose( infile );
795  }
796  }
797  FontLookup[i].fci = TrueTypeLookup[i].fci;
798  if ( FT->font_name[i][0] == '\0' )
799  FontLookup[i].pfont = NULL;
800  else
801  FontLookup[i].pfont = (unsigned char *) FT->font_name[i];
802  }
803 //
804 // Next, we check to see if -drvopt has been used on the command line to
805 // over-ride any settings
806 //
807 }
808 
809 
810 //--------------------------------------------------------------------------
811 // FT_SetFace( PLStream *pls, PLUNICODE fci )
812 //
813 // Sets up the font face and size
814 //--------------------------------------------------------------------------
815 
816 void FT_SetFace( PLStream *pls, PLUNICODE fci )
817 {
818  FT_Data *FT = (FT_Data *) pls->FT;
819  double font_size = pls->chrht * 72 / 25.4; // font_size in points, chrht is in mm
820 
821  // save a copy of character height and resolution
822  FT->chrht = pls->chrht;
823  FT->xdpi = pls->xdpi;
824  FT->ydpi = pls->ydpi;
825 
826  if ( fci != FT->fci )
827  {
828  const char *font_name = plP_FCI2FontName( fci, FontLookup, N_TrueTypeLookup );
829  if ( font_name == NULL )
830  {
831  if ( FT->fci == PL_FCI_IMPOSSIBLE )
832  plexit( "FT_SetFace: Bad FCI and no previous valid font to fall back on" );
833  else
834  plwarn( "FT_SetFace: Bad FCI. Falling back to previous font." );
835  }
836  else
837  {
838  FT->fci = fci;
839 
840  if ( FT->face != NULL )
841  {
842  FT_Done_Face( FT->face );
843  FT->face = NULL;
844  }
845 
846  if ( FT->face == NULL )
847  {
848  if ( FT_New_Face( FT->library, font_name, 0, &FT->face ) )
849  plexit( "FT_SetFace: Error loading a font in freetype" );
850  }
851 
852  //check if the charmap was loaded correctly - freetype only checks for a unicode charmap
853  //if it is not set then use the first found charmap in the font
854  if ( FT->face->charmap == NULL )
855  FT_Select_Charmap( FT->face, FT->face->charmaps[0]->encoding );
856  }
857  }
858  FT_Set_Char_Size( FT->face, 0,
859  (FT_F26Dot6) ( font_size * 64 / TEXT_SCALING_FACTOR ), (FT_UInt) pls->xdpi,
860  (FT_UInt) pls->ydpi );
861 }
862 
863 //--------------------------------------------------------------------------
864 // plD_render_freetype_text()
865 //
866 // Transforms the font
867 // calculates real-world bitmap coordinates from plplot ones
868 // renders text using freetype
869 //--------------------------------------------------------------------------
870 
871 void plD_render_freetype_text( PLStream *pls, EscText *args )
872 {
873  FT_Data *FT = (FT_Data *) pls->FT;
874  int x, y;
875  int w = 0, h = 0, overh = 0, underh = 0;
876  PLFLT *t = args->xform;
877  FT_Matrix matrix;
878  PLFLT angle = PI * pls->diorot / 2;
879  PLUNICODE *line = args->unicode_array;
880  int linelen;
881  int prevlineheights = 0;
882 
883 // Used later in a commented out section (See Rotate The Page), if that
884 // section will never be used again, remove these as well.
885 // PLINT clxmin, clxmax, clymin, clymax;
886 //
887  PLFLT Sin_A, Cos_A;
888  FT_Vector adjust;
889  PLUNICODE fci;
890  FT_Fixed height;
891  PLFLT height_factor;
892 
893  if ( ( args->unicode_array_len > 0 ) )
894  {
895 //
896 // Work out if either the font size, the font face or the
897 // resolution has changed.
898 // If either has, then we will reload the font face.
899 //
900  plgfci( &fci );
901  if ( ( FT->fci != fci ) || ( FT->chrht != pls->chrht ) || ( FT->xdpi != pls->xdpi ) || ( FT->ydpi != pls->ydpi ) )
902  FT_SetFace( pls, fci );
903 
904 
905 // this will help work out underlining and overlining
906 
907  Debug6( "%s %d %d %d %d\n", "plD_render_freetype_text:",
908  FT->face->underline_position >> 6,
909  FT->face->descender >> 6,
910  FT->face->ascender >> 6,
911  ( ( FT->face->underline_position * -1 ) + FT->face->ascender ) >> 6 );
912 
913 
914 
915 //
916 // Split the text into lines based on the newline character
917 //
918  while ( line < args->unicode_array + args->unicode_array_len )
919  {
920  linelen = 0;
921  while ( line[linelen] != '\n' && line + linelen < args->unicode_array + args->unicode_array_len )
922  ++linelen;
923 
924 //
925 // Now we work out how long the text is (for justification etc...) and how
926 // high the text is. This is done on UN-TRANSFORMED text, since we will
927 // apply our own transformations on it later, so it's necessary for us
928 // to to turn all transformations off first, before calling the function
929 // that calculates the text size.
930 //
931 
932  FT->matrix.xx = 0x10000;
933  FT->matrix.xy = 0x00000;
934  FT->matrix.yx = 0x00000;
935  FT->matrix.yy = 0x10000;
936 
937  FT_Vector_Transform( &FT->pos, &FT->matrix );
938  FT_Set_Transform( FT->face, &FT->matrix, &FT->pos );
939 
940  FT_StrX_YW( pls, line, (short) linelen, &w, &h, &overh, &underh );
941 
942 //
943 // Set up the transformation Matrix
944 //
945 // Fortunately this is almost identical to plplot's own transformation matrix;
946 // you have NO idea how much effort that saves ! Some params are in a
947 // different order, and Freetype wants integers whereas plplot likes floats,
948 // but such differences are quite trivial.
949 //
950 // For some odd reason, this needs to be set a different way for DJGPP. Why ?
951 // I wish I knew.
952 //
953 
954 // (RL, on 2005-01-21) The height_factor variable is introduced below.
955 // It is used here and farther below when computing the vertical
956 // adjustment. The rationale for its introduction is as follow: up to
957 // now, the text produced with Hershey fonts was systematically taller
958 // than the same text produced with TT fonts, and tha by a factor of
959 // around 1.125 (I discovered this empirically). This corresponds
960 // roughly to the ratio between total height and the ascender of some
961 // TT faces. Hence the computation below. Remember that descender is
962 // always a negative quantity.
963 //
964 
965  height_factor = (PLFLT) ( FT->face->ascender - FT->face->descender )
966  / FT->face->ascender;
967  height = (FT_Fixed) ( 0x10000 * height_factor );
968 
969 #ifdef DJGPP
970  FT->matrix.xx = (FT_Fixed) ( (PLFLT) height * t[0] );
971  FT->matrix.xy = (FT_Fixed) ( (PLFLT) height * t[2] );
972  FT->matrix.yx = (FT_Fixed) ( (PLFLT) height * t[1] );
973  FT->matrix.yy = (FT_Fixed) ( (PLFLT) height * t[3] );
974 #else
975  FT->matrix.xx = (FT_Fixed) ( (PLFLT) height * t[0] );
976  FT->matrix.xy = (FT_Fixed) ( (PLFLT) height * t[1] );
977  FT->matrix.yx = (FT_Fixed) ( (PLFLT) height * t[2] );
978  FT->matrix.yy = (FT_Fixed) ( (PLFLT) height * t[3] );
979 #endif
980 
981 
982 // Rotate the Font
983 //
984 // If the page has been rotated using -ori, this is where we rotate the
985 // font to point in the right direction. To make things nice and easy, we
986 // will use freetypes matrix math stuff to do this for us.
987 //
988 
989  Cos_A = cos( angle );
990  Sin_A = sin( angle );
991 
992  matrix.xx = (FT_Fixed) ( (PLFLT) 0x10000 * Cos_A );
993 
994 #ifdef DJGPP
995  matrix.xy = (FT_Fixed) ( (PLFLT) 0x10000 * Sin_A * -1.0 );
996  matrix.yx = (FT_Fixed) ( (PLFLT) 0x10000 * Sin_A );
997 #else
998  matrix.xy = (FT_Fixed) ( (PLFLT) 0x10000 * Sin_A );
999  matrix.yx = (FT_Fixed) ( (PLFLT) 0x10000 * Sin_A * -1.0 );
1000 #endif
1001 
1002  matrix.yy = (FT_Fixed) ( (PLFLT) 0x10000 * Cos_A );
1003 
1004  FT_Matrix_Multiply( &matrix, &FT->matrix );
1005 
1006 
1007 // Calculate a Vector from the matrix
1008 //
1009 // This is closely related to the "transform matrix".
1010 // The matrix is used for rendering the glyph, while the vector is used for
1011 // calculating offsets of the text box, so we need both. Why ? I dunno, but
1012 // we have to live with it, and it works...
1013 //
1014 
1015 
1016  FT_Vector_Transform( &FT->pos, &FT->matrix );
1017 
1018 
1019 // Transform the font face
1020 //
1021 // This is where our matrix transformation is calculated for the font face.
1022 // This is only done once for each unique transformation since it is "sticky"
1023 // within the font. Font rendering is done later, using the supplied matrix,
1024 // but invisibly to us from here on. I don't believe the vector is used, but
1025 // it is asked for.
1026 //
1027 
1028  FT_Set_Transform( FT->face, &FT->matrix, &FT->pos );
1029 
1030 
1031 // Rotate the Page
1032 //
1033 // If the page has been rotated using -ori, this is we recalculate the
1034 // reference point for the text using plplot functions.
1035 //
1036 
1037 // difilt(&args->x, &args->y, 1, &clxmin, &clxmax, &clymin, &clymax);
1038 
1039 
1040 //
1041 // Convert into normal coordinates from virtual coordinates
1042 //
1043 
1044  if ( FT->scale != 0.0 ) // scale was set
1045  {
1046  x = (int) ( args->x / FT->scale );
1047 
1048  if ( FT->invert_y == 1 )
1049  y = (int) ( FT->ymax - ( args->y / FT->scale ) );
1050  else
1051  y = (int) ( args->y / FT->scale );
1052  }
1053  else
1054  {
1055  x = (int) ( args->x / FT->scalex );
1056 
1057  if ( FT->invert_y == 1 )
1058  y = (int) ( FT->ymax - ( args->y / FT->scaley ) );
1059  else
1060  y = (int) ( args->y / FT->scaley );
1061  }
1062 
1063  // Adjust for the justification and character height
1064  //
1065  // Eeeksss... this wasn't a nice bit of code to work out, let me tell you.
1066  // I could not work out an entirely satisfactory solution that made
1067  // logical sense, so came up with an "illogical" one as well.
1068  // The logical one works fine for text in the normal "portrait"
1069  // orientation, and does so for reasons you might expect it to work; But
1070  // for all other orientations, the text's base line is either a little
1071  // high, or a little low. This is because of the way the base-line pos
1072  // is calculated from the decender height. The "dodgie" way of calculating
1073  // the position is to use the character height here, then adjust for the
1074  // decender height by a three-fold factor later on. That approach seems to
1075  // work a little better for rotated pages, but why it should be so, I
1076  // don't understand. You can compile in or out which way you want it by
1077  // defining "DODGIE_DECENDER_HACK".
1078  //
1079  // note: the logic of the page rotation coming up next is that we pump in
1080  // the justification factor and then use freetype to rotate and transform
1081  // the values, which we then use to change the plotting location.
1082  //
1083 
1084 
1085 #ifdef DODGIE_DECENDER_HACK
1086  adjust.y = h;
1087 #else
1088  adjust.y = 0;
1089 #endif
1090 
1091 // (RL, on 2005-01-24) The code below uses floating point and division
1092 // operations instead of integer shift used before. This is slower but
1093 // gives accurate placement of text in plots.
1094 //
1095 
1096 // (RL, on 2005-01-21) The hack below is intended to align single
1097 // glyphs being generated via plpoin. The way to detect this
1098 // situation is completely hackish, I must admit, by checking whether the
1099 // length of the Unicode array is equal 2 and whether the first
1100 // character is actually a font-changing command to font number 4 (for
1101 // symbols). This is ugly because it depends on definitions set
1102 // elsewhere, but it works.
1103 //
1104 // The computation of the vertical and horizontal adjustments are
1105 // based on the bouding box of the glyph being loaded (since there is
1106 // only one glyph in the string in this case, we are okay here).
1107 //
1108 
1109  if ( ( args->unicode_array_len == 2 )
1110  && ( args->unicode_array[0] == ( PL_FCI_MARK | 0x004 ) ) )
1111  {
1112  adjust.x = (FT_Pos) ( args->just * ROUND( (PLFLT) FT->face->glyph->metrics.width / 64.0 ) );
1113  adjust.y = (FT_Pos) ROUND( (PLFLT) FT->face->glyph->metrics.height / 128.0 );
1114  }
1115  else
1116  {
1117 // (RL, on 2005-01-21) The vertical adjustment is set below, making
1118 // the DODGIE conditional moot. I use the value of h as return by FT_StrX_YW,
1119 // which should correspond to the total height of the text being
1120 // drawn. Freetype aligns text around the baseline, while PLplot
1121 // aligns to the center of the ascender portion. We must then adjust
1122 // by half of the ascender and this is why there is a division by
1123 // height_factor below.
1124 //
1125 
1126  adjust.y = (FT_Pos)
1127  ROUND( (PLFLT) FT->face->size->metrics.height / height_factor / 128.0 - ( prevlineheights + overh ) / 64.0 );
1128  adjust.x = (FT_Pos) ( args->just * ROUND( w / 64.0 ) );
1129  }
1130 
1131  FT_Vector_Transform( &adjust, &FT->matrix ); // was /&matrix); - was I using the wrong matrix all this time ?
1132 
1133  x -= (int) adjust.x;
1134  y += (int) adjust.y;
1135 
1136  FT_WriteStrW( pls, line, (short) linelen, x, y ); // write it out
1137 
1138 //
1139 // Move to the next line
1140 //
1141  line += linelen + 1;
1142  prevlineheights += h + overh + underh;
1143  }
1144  }
1145  else
1146  {
1147  plD_render_freetype_sym( pls, args );
1148  }
1149 }
1150 
1151 //--------------------------------------------------------------------------
1152 // plD_FreeType_Destroy()
1153 //
1154 // Restores cmap0 if it had been modifed for anti-aliasing
1155 // closes the freetype library.
1156 // Deallocates memory to the Freetype structure
1157 //--------------------------------------------------------------------------
1158 
1159 void plD_FreeType_Destroy( PLStream *pls )
1160 {
1161  FT_Data *FT = (FT_Data *) pls->FT;
1162  //extern int FT_Done_Library( FT_Library library );
1163 
1164  if ( FT )
1165  {
1166  if ( ( FT->smooth_text == 1 ) && ( FT->BLENDED_ANTIALIASING == 0 ) )
1167  plscmap0n( FT->ncol0_org );
1168  if ( FT->textbuf )
1169  free( FT->textbuf );
1170  FT_Done_Library( FT->library );
1171  free( pls->FT );
1172  pls->FT = NULL;
1173  }
1174 }
1175 
1176 //--------------------------------------------------------------------------
1177 // PLFLT CalculateIncrement( int bg, int fg, int levels)
1178 //
1179 // Takes the value of the foreground, and the background, and when
1180 // given the number of desired steps, calculates how much to incriment
1181 // a value to transition from fg to bg.
1182 // This function only does it for one colour channel at a time.
1183 //--------------------------------------------------------------------------
1184 
1185 static PLFLT CalculateIncrement( int bg, int fg, int levels )
1186 {
1187  PLFLT ret = 0;
1188 
1189  if ( levels > 1 )
1190  {
1191  if ( fg > bg )
1192  ret = ( ( fg + 1 ) - bg ) / levels;
1193  else if ( fg < bg )
1194  ret = ( ( ( fg - 1 ) - bg ) / levels );
1195  }
1196  return ( ret );
1197 }
1198 
1199 //--------------------------------------------------------------------------
1200 // void pl_set_extended_cmap0(PLStream *pls, int ncol0_width, int ncol0_org)
1201 //
1202 // ncol0_width - how many greyscale levels to accolate to each CMAP0 entry
1203 // ncol0_org - the originl number of CMAP0 entries.
1204 //
1205 // This function calcualtes and sets an extended CMAP0 entry for the
1206 // driver. It is assumed that the caller has checked to make sure there is
1207 // room for extending CMAP0 already.
1208 //
1209 // NOTES
1210 // We don't bother calculating an entry for CMAP[0], the background.
1211 // It is assumed the caller has already expanded the size of CMAP[0]
1212 //--------------------------------------------------------------------------
1213 
1214 void pl_set_extended_cmap0( PLStream *pls, int ncol0_width, int ncol0_org )
1215 {
1216  int i, j, k;
1217  int r, g, b;
1218  PLFLT r_inc, g_inc, b_inc;
1219 
1220  for ( i = 1; i < ncol0_org; i++ )
1221  {
1222  r = pls->cmap0[i].r;
1223  g = pls->cmap0[i].g;
1224  b = pls->cmap0[i].b;
1225 
1226  r_inc = CalculateIncrement( pls->cmap0[0].r, r, ncol0_width );
1227  g_inc = CalculateIncrement( pls->cmap0[0].g, g, ncol0_width );
1228  b_inc = CalculateIncrement( pls->cmap0[0].b, b, ncol0_width );
1229 
1230  for ( j = 0, k = ncol0_org + i - 1; j < ncol0_width; j++, k += ( ncol0_org - 1 ) )
1231  {
1232  r -= (int) r_inc;
1233  g -= (int) g_inc;
1234  b -= (int) b_inc;
1235  if ( ( r < 0 ) || ( g < 0 ) || ( b < 0 ) )
1236  plscol0( k, 0, 0, 0 );
1237  else
1238  plscol0( k, ( r > 0xff ? 0xff : r ), ( g > 0xff ? 0xff : g ), ( b > 0xff ? 0xff : b ) );
1239  }
1240  }
1241 }
1242 
1243 
1244 //--------------------------------------------------------------------------
1245 // plD_render_freetype_sym( PLStream *pls, EscText *args )
1246 // PLStream *pls - pointer to plot stream
1247 // EscText *args - pointer to standard "string" object.
1248 //
1249 // This function is a simple rendering function which draws a single
1250 // character at a time. The function is an alternative to the text
1251 // functions which are considerably, and needlessly, more complicated
1252 // than what we need here.
1253 //--------------------------------------------------------------------------
1254 
1255 
1256 void plD_render_freetype_sym( PLStream *pls, EscText *args )
1257 {
1258  FT_Data *FT = (FT_Data *) pls->FT;
1259  int x, y;
1260  FT_Vector adjust;
1261  PLUNICODE fci;
1262 
1263  if ( FT->scale != 0.0 ) // scale was set
1264  {
1265  x = (int) ( args->x / FT->scale );
1266 
1267  if ( FT->invert_y == 1 )
1268  y = (int) ( FT->ymax - ( args->y / FT->scale ) );
1269  else
1270  y = (int) ( args->y / FT->scale );
1271  }
1272  else
1273  {
1274  x = (int) ( args->x / FT->scalex );
1275 
1276  if ( FT->invert_y == 1 )
1277  y = (int) ( FT->ymax - ( args->y / FT->scaley ) );
1278  else
1279  y = (int) ( args->y / FT->scaley );
1280  }
1281 
1282 
1283 //
1284 // Adjust for the descender - make sure the font is nice and centred
1285 // vertically. Freetype assumes we have a base-line, but plplot thinks of
1286 // centre-lines, so that's why we have to do this. Since this is one of our
1287 // own adjustments, rather than a freetype one, we have to run it through
1288 // the transform matrix manually.
1289 //
1290 // For some odd reason, this works best if we triple the
1291 // descender's height and then adjust the height later on...
1292 // Don't ask me why, 'cause I don't know. But it does seem to work.
1293 //
1294 // I really wish I knew *why* it worked better though...
1295 //
1296 // y-=FT->face->descender >> 6;
1297 //
1298 
1299 #ifdef DODGIE_DECENDER_HACK
1300  adjust.y = ( FT->face->descender >> 6 ) * 3;
1301 #else
1302  adjust.y = ( FT->face->descender >> 6 );
1303 #endif
1304 
1305  adjust.x = 0;
1306  FT_Vector_Transform( &adjust, &FT->matrix );
1307  x += (int) adjust.x;
1308  y -= (int) adjust.y;
1309 
1310  plgfci( &fci );
1311  FT_SetFace( pls, fci );
1312 
1313  FT = (FT_Data *) pls->FT;
1314  FT_Set_Transform( FT->face, &FT->matrix, &FT->pos );
1315 
1316  FT_Load_Char( FT->face, args->unicode_char, ( FT->smooth_text == 0 ) ? FT_LOAD_MONOCHROME + FT_LOAD_RENDER : FT_LOAD_RENDER | FT_LOAD_FORCE_AUTOHINT );
1317 
1318 //
1319 // Now we have to try and componsate for the fact that the freetype glyphs are left
1320 // justified, and plplot's glyphs are centred. To do this, we will just work out the
1321 // advancment, halve it, and take it away from the x position. This wont be 100%
1322 // accurate because "spacing" is factored into the right hand side of the glyph,
1323 // but it is as good a way as I can think of.
1324 //
1325 
1326  x -= (int) ( ( FT->face->glyph->advance.x >> 6 ) / 2 );
1327  FT_PlotChar( pls, FT, FT->face->glyph, x, y ); // render the text
1328 }
1329 
1330 
1331 
1332 
1333 #else
1334 int
1336 {
1337  return 0;
1338 }
1339 
1340 #endif