icuSources/layout/LEFontInstance.cpp

   1 /*
   2  *******************************************************************************
   3  *
   4  *   Copyright (C) 1999-2007, International Business Machines
   5  *   Corporation and others.  All Rights Reserved.
   6  *
   7  *******************************************************************************
   8  *   file name:  LEFontInstance.cpp
   9  *
  10  *   created on: 02/06/2003
  11  *   created by: Eric R. Mader
  12  */
  13
  14 #include "LETypes.h"
  15 #include "LEScripts.h"
  16 #include "LEFontInstance.h"
  17 #include "LEGlyphStorage.h"
  18
  19 U_NAMESPACE_BEGIN
  20
  21 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(LEFontInstance)
  22
  23 LECharMapper::~LECharMapper()
  24 {
  25     // nothing to do.
  26 }
  27
  28 LEFontInstance::~LEFontInstance()
  29 {
  30     // nothing to do
  31 }
  32
  33 const LEFontInstance *LEFontInstance::getSubFont(const LEUnicode chars[], le_int32 *offset, le_int32 limit,
  34                                                        le_int32 script, LEErrorCode &success) const
  35 {
  36     if (LE_FAILURE(success)) {
  37         return NULL;
  38     }
  39
  40     if (chars == NULL || *offset < 0 || limit < 0 || *offset >= limit || script < 0 || script >= scriptCodeCount) {
  41         success = LE_ILLEGAL_ARGUMENT_ERROR;
  42         return NULL;
  43     }
  44
  45     *offset = limit;
  46     return this;
  47 }
  48
  49 void LEFontInstance::mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count,
  50                                       le_bool reverse, const LECharMapper *mapper, le_bool filterZeroWidth, LEGlyphStorage &glyphStorage) const
  51 {
  52     le_int32 i, out = 0, dir = 1;
  53
  54     if (reverse) {
  55         out = count - 1;
  56         dir = -1;
  57     }
  58
  59     for (i = offset; i < offset + count; i += 1, out += dir) {
  60         LEUnicode16 high = chars[i];
  61         LEUnicode32 code = high;
  62
  63         if (i < offset + count - 1 && high >= 0xD800 && high <= 0xDBFF) {
  64             LEUnicode16 low = chars[i + 1];
  65
  66             if (low >= 0xDC00 && low <= 0xDFFF) {
  67                 code = (high - 0xD800) * 0x400 + low - 0xDC00 + 0x10000;
  68             }
  69         }
  70
  71         glyphStorage[out] = mapCharToGlyph(code, mapper, filterZeroWidth);
  72
  73         if (code >= 0x10000) {
  74             i += 1;
  75             glyphStorage[out += dir] = 0xFFFF;
  76         }
  77     }
  78 }
  79
  80 LEGlyphID LEFontInstance::mapCharToGlyph(LEUnicode32 ch, const LECharMapper *mapper) const
  81 {
  82     return mapCharToGlyph(ch, mapper, TRUE);
  83 }
  84
  85 LEGlyphID LEFontInstance::mapCharToGlyph(LEUnicode32 ch, const LECharMapper *mapper, le_bool filterZeroWidth) const
  86 {
  87     LEUnicode32 mappedChar = mapper->mapChar(ch);
  88
  89     if (mappedChar == 0xFFFE || mappedChar == 0xFFFF) {
  90         return 0xFFFF;
  91     }
  92
  93     if (filterZeroWidth && (mappedChar == 0x200C || mappedChar == 0x200D)) {
  94         return canDisplay(mappedChar)? 0x0001 : 0xFFFF;
  95     }
  96
  97     return mapCharToGlyph(mappedChar);
  98 }
  99
 100 le_bool LEFontInstance::canDisplay(LEUnicode32 ch) const
 101 {
 102     return LE_GET_GLYPH(mapCharToGlyph(ch)) != 0;
 103 }
 104
 105 float LEFontInstance::xUnitsToPoints(float xUnits) const
 106 {
 107     return (xUnits * getXPixelsPerEm()) / (float) getUnitsPerEM();
 108 }
 109
 110 float LEFontInstance::yUnitsToPoints(float yUnits) const
 111 {
 112     return (yUnits * getYPixelsPerEm()) / (float) getUnitsPerEM();
 113 }
 114
 115 void LEFontInstance::unitsToPoints(LEPoint &units, LEPoint &points) const
 116 {
 117     points.fX = xUnitsToPoints(units.fX);
 118     points.fY = yUnitsToPoints(units.fY);
 119 }
 120
 121 float LEFontInstance::xPixelsToUnits(float xPixels) const
 122 {
 123     return (xPixels * getUnitsPerEM()) / (float) getXPixelsPerEm();
 124 }
 125
 126 float LEFontInstance::yPixelsToUnits(float yPixels) const
 127 {
 128     return (yPixels * getUnitsPerEM()) / (float) getYPixelsPerEm();
 129 }
 130
 131 void LEFontInstance::pixelsToUnits(LEPoint &pixels, LEPoint &units) const
 132 {
 133     units.fX = xPixelsToUnits(pixels.fX);
 134     units.fY = yPixelsToUnits(pixels.fY);
 135 }
 136
 137 void LEFontInstance::transformFunits(float xFunits, float yFunits, LEPoint &pixels) const
 138 {
 139     pixels.fX = xUnitsToPoints(xFunits) * getScaleFactorX();
 140     pixels.fY = yUnitsToPoints(yFunits) * getScaleFactorY();
 141 }
 142
 143 le_int32 LEFontInstance::getLineHeight() const
 144 {
 145     return getAscent() + getDescent() + getLeading();
 146 }
 147
 148 U_NAMESPACE_END
 149