workbench/libs/freetype2/kerning.c

   1 /*
   2  * Based on the code from the ft2.library from MorphOS and the ttf.library by
   3  * Richard Griffith
   4  */
   5 #include "kerning.h"
   6 #include "glyph.h"
   7
   8 //#define DEBUG 1
   9 #include <aros/debug.h>
  10 #include <exec/memory.h>
  11 #include <diskfont/oterrors.h>
  12 #include <diskfont/glyph.h>
  13
  14 #include <proto/exec.h>
  15 #include <proto/alib.h>
  16
  17 void FreeWidthList(FT_GlyphEngine *ge,struct MinList *list)
  18 {
  19     struct GlyphWidthEntry *work_node, *next_node;
  20
  21     //D(bug("FreeWidthList at %lx\n",list));
  22     if (list == NULL)
  23         return;
  24
  25     work_node = (struct GlyphWidthEntry *)(list->mlh_Head);
  26     while ((next_node =
  27            (struct GlyphWidthEntry *)(work_node->gwe_Node.mln_Succ)))
  28     {
  29         FreeMem(work_node, sizeof(struct GlyphWidthEntry));
  30         work_node = next_node;
  31     }
  32     FreeMem(list, sizeof(struct MinList));
  33 }
  34
  35
  36 struct MinList *GetWidthList(FT_GlyphEngine *ge)
  37 {
  38     struct MinList *gw;
  39     struct GlyphWidthEntry *node;
  40     ULONG howwide;
  41     int hold_start, c_start, c_stop, i, j;
  42     ULONG units_per_em;
  43     FT_Glyph_Metrics *metrics;
  44
  45     if (ge->instance_changed)
  46     {
  47         /* reset everything first */
  48         if(SetInstance(ge)!=OTERR_Success)
  49             return NULL;
  50     }
  51     /*if(ge->cmap_index==NO_CMAP_SET)
  52      {
  53      //if(ChooseEncoding(ge)!=0)
  54      return(NULL);
  55      }*/
  56
  57     gw = (struct MinList *) AllocMem(sizeof(struct MinList), MEMF_CLEAR);
  58
  59     if(gw==NULL)
  60     {
  61         D(bug("GetWidthList - AllocMem for list failed\n"));
  62         set_last_error(ge,OTERR_NoMemory);
  63         return NULL;
  64     }
  65     NewList((struct List *)gw);
  66
  67 #if 0
  68     units_per_em=ge->properties.header->Units_Per_EM;
  69     int yMin,yMax;
  70
  71     yMin=ge->properties.header->yMin; if(yMin>0) yMin = 0-yMin;
  72     yMax=ge->properties.header->yMax;
  73     units_per_em=yMax-yMin;
  74 #endif
  75
  76     units_per_em = ge->corrected_upem;
  77
  78     hold_start=ge->request_char;
  79     c_start=ge->request_char;
  80     c_stop=ge->request_char2;
  81     if(c_start>c_stop)
  82     {
  83         /* just in case */
  84         c_start=ge->request_char2;
  85         c_stop=ge->request_char;
  86     }
  87     D(bug("GetWidthList - from %ld to %ld\n",c_start,c_stop));
  88
  89     for(i=c_start;i<=c_stop;i++)
  90     {
  91         ge->request_char=i;
  92         j=UnicodeToGlyphIndex(ge);
  93
  94         if(j==0)
  95         {
  96             D(bug("GetWidthList - no glyph %ld i=%ld p=%ld e=%ld\n"
  97                   ,i, ge->cmap_index,ge->platform, ge->encoding));
  98             continue;
  99         }
 100
 101         if(FT_Load_Glyph(ge->face,j,FT_LOAD_DEFAULT))
 102         {
 103             D(bug("Error loading glyph %ld.\n",(LONG)j));
 104             howwide=0;
 105         }
 106         else
 107         {
 108             //FT_Get_Glyph_Metrics( ge->glyph, &ge->metrics );
 109             metrics = &ge->face->glyph->metrics;
 110
 111         #if 0
 112             howwide=((metrics->horiAdvance)<<16)/units_per_em;
 113         #else
 114             howwide = (metrics->horiAdvance << 10) /
 115                       (( ge->face->size->metrics.x_ppem * units_per_em) / ge->face->units_per_EM);
 116         #endif
 117         }
 118
 119         node = AllocMem(sizeof(struct GlyphWidthEntry), MEMF_CLEAR);
 120         if(node==NULL)
 121         {
 122             D(bug("GetWidthList - AllocMem for %ld failed\n",i));
 123             FreeWidthList(ge,gw);
 124             set_last_error(ge,OTERR_NoMemory);
 125             ge->request_char=hold_start;
 126             return NULL;
 127         }
 128
 129         node->gwe_Code = i;     /* amiga char */
 130         /* character advance, as fraction of em width */
 131         node->gwe_Width = howwide;
 132
 133         //              D(bug("GetWidthList - glyph %ld width %lx\n",
 134         //                      node->gwe_Code, node->gwe_Width ));
 135
 136         AddTail( (struct List *)gw, (struct Node *)node );
 137     }
 138
 139     ge->request_char=hold_start;
 140     return gw;
 141 }
 142
 143
 144 int get_kerning_dir(FT_GlyphEngine *ge)
 145 {
 146     //FT_Kern_Subtable *k;
 147     //FT_Kern_0_Pair   *p;      /* a table of nPairs 'pairs' */
 148
 149     //int i,kern_value;
 150     FT_Vector kerning;
 151     FT_UShort l,r;              /* left and right indexes */
 152
 153     /* instance change may be irrelevant, but just in case */
 154     if (ge->instance_changed)
 155     {
 156         /* reset everything first */
 157         if(SetInstance(ge)!=OTERR_Success)
 158             return 0;
 159     }
 160
 161     /* get left and right glyph indexes */
 162     l=char_to_glyph(ge,ge->request_char);
 163     r=char_to_glyph(ge,ge->request_char2);
 164     if(l==0 || r==0) return(0); /* no chance */
 165
 166     if (FT_Get_Kerning(ge->face, l, r, ft_kerning_unscaled, &kerning))
 167         return 0;
 168
 169     return (-kerning.x << 16) / ge->corrected_upem;
 170 }