icuSources/samples/layout/GnomeFontInstance.cpp

   1 /*
   2  *******************************************************************************
   3  *
   4  *   Copyright (C) 1999-2007, International Business Machines
   5  *   Corporation and others.  All Rights Reserved.
   6  *
   7  *******************************************************************************
   8  *   file name:  GnomeFontInstance.cpp
   9  *
  10  *   created on: 08/30/2001
  11  *   created by: Eric R. Mader
  12  */
  13
  14 #include <gnome.h>
  15 #include <ft2build.h>
  16 #include FT_FREETYPE_H
  17 #include FT_GLYPH_H
  18 #include FT_RENDER_H
  19 #include FT_TRUETYPE_TABLES_H
  20 #include <cairo.h>
  21 #include <cairo-ft.h>
  22
  23 #include "layout/LETypes.h"
  24 #include "layout/LESwaps.h"
  25
  26 #include "GnomeFontInstance.h"
  27 #include "sfnt.h"
  28 #include "cmaps.h"
  29
  30 GnomeSurface::GnomeSurface(GtkWidget *theWidget)
  31     : fWidget(theWidget)
  32 {
  33     fCairo = gdk_cairo_create(fWidget->window);
  34 }
  35
  36 GnomeSurface::~GnomeSurface()
  37 {
  38     cairo_destroy(fCairo);
  39 }
  40
  41 void GnomeSurface::drawGlyphs(const LEFontInstance *font, const LEGlyphID *glyphs, le_int32 count,
  42                               const float *positions, le_int32 x, le_int32 y, le_int32 /*width*/, le_int32 /*height*/)
  43 {
  44     GnomeFontInstance *gFont = (GnomeFontInstance *) font;
  45
  46     gFont->rasterizeGlyphs(fCairo, glyphs, count, positions, x, y);
  47 }
  48
  49 GnomeFontInstance::GnomeFontInstance(FT_Library engine, const char *fontPathName, le_int16 pointSize, LEErrorCode &status)
  50     : FontTableCache(), fPointSize(pointSize), fUnitsPerEM(0), fAscent(0), fDescent(0), fLeading(0),
  51       fDeviceScaleX(1), fDeviceScaleY(1), fMapper(NULL)
  52 {
  53     FT_Error error;
  54
  55     fFace      = NULL;
  56     fCairoFace = NULL;
  57
  58     error = FT_New_Face(engine, fontPathName, 0, &fFace);
  59
  60     if (error != 0) {
  61         printf("OOPS! Got error code %d\n", error);
  62         status = LE_FONT_FILE_NOT_FOUND_ERROR;
  63         return;
  64     }
  65
  66     // FIXME: what about the display resolution?
  67     fDeviceScaleX = ((float) 96) / 72;
  68     fDeviceScaleY = ((float) 96) / 72;
  69
  70     error = FT_Set_Char_Size(fFace, 0, pointSize << 6, 92, 92);
  71
  72     fCairoFace = cairo_ft_font_face_create_for_ft_face(fFace, 0);
  73
  74     fUnitsPerEM = fFace->units_per_EM;
  75
  76     fAscent  = (le_int32) (yUnitsToPoints(fFace->ascender) * fDeviceScaleY);
  77     fDescent = (le_int32) -(yUnitsToPoints(fFace->descender) * fDeviceScaleY);
  78     fLeading = (le_int32) (yUnitsToPoints(fFace->height) * fDeviceScaleY) - fAscent - fDescent;
  79
  80     // printf("Face = %s, unitsPerEM = %d, ascent = %d, descent = %d\n", fontPathName, fUnitsPerEM, fAscent, fDescent);
  81
  82     if (error != 0) {
  83         status = LE_MEMORY_ALLOCATION_ERROR;
  84         return;
  85     }
  86
  87     status = initMapper();
  88 }
  89
  90 GnomeFontInstance::~GnomeFontInstance()
  91 {
  92     cairo_font_face_destroy(fCairoFace);
  93
  94     if (fFace != NULL) {
  95         FT_Done_Face(fFace);
  96     }
  97 }
  98
  99 LEErrorCode GnomeFontInstance::initMapper()
 100 {
 101     LETag cmapTag = LE_CMAP_TABLE_TAG;
 102     const CMAPTable *cmap = (const CMAPTable *) readFontTable(cmapTag);
 103
 104     if (cmap == NULL) {
 105         return LE_MISSING_FONT_TABLE_ERROR;
 106     }
 107
 108     fMapper = CMAPMapper::createUnicodeMapper(cmap);
 109
 110     if (fMapper == NULL) {
 111         return LE_MISSING_FONT_TABLE_ERROR;
 112     }
 113
 114     return LE_NO_ERROR;
 115 }
 116
 117 const void *GnomeFontInstance::getFontTable(LETag tableTag) const
 118 {
 119     return FontTableCache::find(tableTag);
 120 }
 121
 122 const void *GnomeFontInstance::readFontTable(LETag tableTag) const
 123 {
 124     FT_ULong len = 0;
 125     FT_Byte *result = NULL;
 126
 127     FT_Load_Sfnt_Table(fFace, tableTag, 0, NULL, &len);
 128
 129     if (len > 0) {
 130         result = LE_NEW_ARRAY(FT_Byte, len);
 131         FT_Load_Sfnt_Table(fFace, tableTag, 0, result, &len);
 132     }
 133
 134     return result;
 135 }
 136
 137 void GnomeFontInstance::getGlyphAdvance(LEGlyphID glyph, LEPoint &advance) const
 138 {
 139     advance.fX = 0;
 140     advance.fY = 0;
 141
 142     if (glyph >= 0xFFFE) {
 143         return;
 144     }
 145
 146     FT_Error error;
 147
 148     error = FT_Load_Glyph(fFace, glyph, FT_LOAD_DEFAULT);
 149
 150     if (error != 0) {
 151         return;
 152     }
 153
 154     advance.fX = fFace->glyph->metrics.horiAdvance >> 6;
 155     return;
 156 }
 157
 158 le_bool GnomeFontInstance::getGlyphPoint(LEGlyphID glyph, le_int32 pointNumber, LEPoint &point) const
 159 {
 160     FT_Error error;
 161
 162     error = FT_Load_Glyph(fFace, glyph, FT_LOAD_DEFAULT);
 163
 164     if (error != 0) {
 165         return FALSE;
 166     }
 167
 168     if (pointNumber >= fFace->glyph->outline.n_points) {
 169         return FALSE;
 170     }
 171
 172     point.fX = fFace->glyph->outline.points[pointNumber].x >> 6;
 173     point.fY = fFace->glyph->outline.points[pointNumber].y >> 6;
 174
 175     return TRUE;
 176 }
 177
 178 void GnomeFontInstance::rasterizeGlyphs(cairo_t *cairo, const LEGlyphID *glyphs, le_int32 glyphCount, const float *positions,
 179                                         le_int32 x, le_int32 y) const
 180 {
 181     cairo_glyph_t *glyph_t = LE_NEW_ARRAY(cairo_glyph_t, glyphCount);
 182     le_int32 in, out;
 183
 184     for (in = 0, out = 0; in < glyphCount; in += 1) {
 185         TTGlyphID glyph = LE_GET_GLYPH(glyphs[in]);
 186
 187         if (glyph < 0xFFFE) {
 188             glyph_t[out].index = glyph;
 189             glyph_t[out].x     = x + positions[in*2];
 190             glyph_t[out].y     = y + positions[in*2 + 1];
 191
 192             out += 1;
 193         }
 194     }
 195
 196     cairo_set_font_face(cairo, fCairoFace);
 197     cairo_set_font_size(cairo, getXPixelsPerEm() * getScaleFactorX());
 198     cairo_show_glyphs(cairo, glyph_t, out);
 199
 200     LE_DELETE_ARRAY(glyph_t);
 201 }