src/freetype/autohint/ahoptim.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ahoptim.h                                                              */
   4 /*                                                                         */
   5 /*    FreeType auto hinting outline optimization (declaration).            */
   6 /*                                                                         */
   7 /*  Copyright 2000 Catharon Productions Inc.                               */
   8 /*  Author: David Turner                                                   */
   9 /*                                                                         */
  10 /*  This file is part of the Catharon Typography Project and shall only    */
  11 /*  be used, modified, and distributed under the terms of the Catharon     */
  12 /*  Open Source License that should come with this file under the name     */
  13 /*  `CatharonLicense.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 /*  Note that this license is compatible with the FreeType license.        */
  18 /*                                                                         */
  19 /***************************************************************************/
  20
  21
  22 #ifndef AHOPTIM_H
  23 #define AHOPTIM_H
  24
  25
  26 #ifdef FT_FLAT_COMPILE
  27
  28 #include "ahtypes.h"
  29
  30 #else
  31
  32 #include <autohint/ahtypes.h>
  33
  34 #endif
  35
  36
  37   /* the maximal number of stem configurations to record */
  38   /* during optimization                                 */
  39 #define AH_MAX_CONFIGS  8
  40
  41
  42   typedef struct  AH_Stem_
  43   {
  44     FT_Pos    pos;       /* current position        */
  45     FT_Pos    velocity;  /* current velocity        */
  46     FT_Pos    force;     /* sum of current forces   */
  47     FT_Pos    width;     /* normalized width        */
  48
  49     FT_Pos    min_pos;   /* minimum grid position */
  50     FT_Pos    max_pos;   /* maximum grid position */
  51
  52     AH_Edge*  edge1;     /* left/bottom edge */
  53     AH_Edge*  edge2;     /* right/top edge   */
  54
  55     FT_Pos    opos;      /* original position */
  56     FT_Pos    owidth;    /* original width    */
  57
  58     FT_Pos    min_coord; /* minimum coordinate */
  59     FT_Pos    max_coord; /* maximum coordinate */
  60
  61   } AH_Stem;
  62
  63
  64   /* A spring between two stems */
  65   typedef struct  AH_Spring_
  66   {
  67     AH_Stem*  stem1;
  68     AH_Stem*  stem2;
  69     FT_Pos    owidth;   /* original width  */
  70     FT_Pos    tension;  /* current tension */
  71
  72   } AH_Spring;
  73
  74
  75   /* A configuration records the position of each stem at a given time  */
  76   /* as well as the associated distortion                               */
  77   typedef struct AH_Configuration_
  78   {
  79     FT_Pos*  positions;
  80     FT_Long  distortion;
  81
  82   } AH_Configuration;
  83
  84
  85   typedef struct  AH_Optimizer_
  86   {
  87     FT_Memory         memory;
  88     AH_Outline*       outline;
  89
  90     FT_Int            num_hstems;
  91     AH_Stem*          horz_stems;
  92
  93     FT_Int            num_vstems;
  94     AH_Stem*          vert_stems;
  95
  96     FT_Int            num_hsprings;
  97     FT_Int            num_vsprings;
  98     AH_Spring*        horz_springs;
  99     AH_Spring*        vert_springs;
 100
 101     FT_Int            num_configs;
 102     AH_Configuration  configs[AH_MAX_CONFIGS];
 103     FT_Pos*           positions;
 104
 105     /* during each pass, use these instead */
 106     FT_Int            num_stems;
 107     AH_Stem*          stems;
 108
 109     FT_Int            num_springs;
 110     AH_Spring*        springs;
 111     FT_Bool           vertical;
 112
 113     FT_Fixed          tension_scale;
 114     FT_Pos            tension_threshold;
 115
 116   } AH_Optimizer;
 117
 118
 119   /* loads the outline into the optimizer */
 120   int  AH_Optimizer_Init( AH_Optimizer*  optimizer,
 121                           AH_Outline*    outline,
 122                           FT_Memory      memory );
 123
 124
 125   /* compute optimal outline */
 126   void  AH_Optimizer_Compute( AH_Optimizer*  optimizer );
 127
 128
 129   /* release the optimization data */
 130   void AH_Optimizer_Done( AH_Optimizer*  optimizer );
 131
 132
 133 #endif /* AHOPTIM_H */
 134
 135
 136 /* END */