rom/graphics/textextent.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Calculate the size a text needs in a specific rastport.
   6     Lang: english
   7 */
   8 #include "graphics_intern.h"
   9 #include <graphics/rastport.h>
  10
  11 /*****************************************************************************
  12
  13     NAME */
  14 #include <graphics/rastport.h>
  15 #include <graphics/text.h>
  16 #include <proto/graphics.h>
  17
  18         AROS_LH4(void, TextExtent,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(struct RastPort   *, rp, A1),
  22         AROS_LHA(CONST_STRPTR       , string, A0),
  23         AROS_LHA(ULONG              , count, D0),
  24         AROS_LHA(struct TextExtent *, textExtent, A2),
  25
  26 /*  LOCATION */
  27         struct GfxBase *, GfxBase, 115, Graphics)
  28
  29 /*  FUNCTION
  30
  31     INPUTS
  32
  33     RESULT
  34
  35     NOTES
  36
  37     EXAMPLE
  38
  39     BUGS
  40
  41     SEE ALSO
  42
  43     INTERNALS
  44
  45     HISTORY
  46         29-10-95    digulla automatically created from
  47                             graphics_lib.fd and clib/graphics_protos.h
  48
  49 *****************************************************************************/
  50 {
  51     AROS_LIBFUNC_INIT
  52     AROS_LIBBASE_EXT_DECL(struct GfxBase *,GfxBase)
  53
  54     struct TextFont *tf = rp->Font;
  55
  56     textExtent->te_Width = TextLength(rp, string, count);
  57     textExtent->te_Height = tf->tf_YSize;
  58     textExtent->te_Extent.MinY = -tf->tf_Baseline;
  59     textExtent->te_Extent.MaxY = textExtent->te_Height - 1 - tf->tf_Baseline;
  60
  61     /* MinX/MaxX can be a bit more complicated if there are kerning/space tables */
  62
  63     if ((tf->tf_Flags & FPF_PROPORTIONAL) || tf->tf_CharKern || tf->tf_CharSpace)
  64     {
  65         WORD  idx;
  66         WORD  defaultidx = NUMCHARS(tf) - 1; /* Last glyph is the default glyph */
  67         WORD  x, x2;
  68         UBYTE c;
  69
  70         textExtent->te_Extent.MinX = 0;
  71         textExtent->te_Extent.MaxX = 0;
  72         x = 0;
  73
  74         if (count)
  75         {
  76             while(count--)
  77             {
  78                 c = *string++;
  79
  80                 if ( c < tf->tf_LoChar || c > tf->tf_HiChar)
  81                 {
  82                     idx = defaultidx;
  83                 }
  84                 else
  85                 {
  86                     idx = c - tf->tf_LoChar;
  87                 }
  88
  89                 #define CHECK_MINMAX(x) \
  90                     if ((x) < textExtent->te_Extent.MinX) textExtent->te_Extent.MinX = (x); \
  91                     if ((x) > textExtent->te_Extent.MaxX) textExtent->te_Extent.MaxX = (x);
  92
  93                 x += ((WORD *)tf->tf_CharKern)[idx];
  94                 CHECK_MINMAX(x);
  95
  96                 x2 = x + ( ( ((ULONG *)tf->tf_CharLoc)[idx] ) & 0xFFFF);
  97                 CHECK_MINMAX(x2);
  98
  99                 x += ((WORD *)tf->tf_CharSpace)[idx];
 100                 CHECK_MINMAX(x);
 101
 102                 x += rp->TxSpacing;
 103                 CHECK_MINMAX(x);
 104
 105             } /* while(count--) */
 106
 107             textExtent->te_Extent.MaxX--;
 108
 109         } /* if (count) */
 110
 111     } /* if ((tf->tf_Flags & FPF_PROPORTIONAL) || tf->tf_CharKern || tf->tf_CharSpace) */
 112     else
 113     {
 114         /* Normal non-proportional Font */
 115         textExtent->te_Extent.MinX = 0;
 116         textExtent->te_Extent.MaxX = textExtent->te_Width - 1;
 117     }
 118
 119     if (rp->AlgoStyle & FSF_BOLD)
 120     {
 121         textExtent->te_Extent.MaxX += tf->tf_BoldSmear;
 122     }
 123
 124     if (rp->AlgoStyle & FSF_ITALIC)
 125     {
 126         /*  ######            ######
 127         **  ##  ##            ##  ##
 128         **  ##  ##           ##  ##
 129         **  ##  ##  ===>     ##  ##
 130         **  ##  ##          ##  ##
 131         **..##..##..      ..##..##..
 132         **  ##  ##         ##  ##
 133         **  ######         ######
 134         */
 135
 136         textExtent->te_Extent.MaxX += tf->tf_Baseline / 2;
 137         textExtent->te_Extent.MinX -= (tf->tf_YSize - tf->tf_Baseline) / 2;
 138     }
 139
 140     AROS_LIBFUNC_EXIT
 141
 142 } /* TextExtent */