icuSources/samples/layout/GnomeFontInstance.cpp

   1 /*
   2  *******************************************************************************
   3  *
   4  *   © 2016 and later: Unicode, Inc. and others.
   5  *   License & terms of use: http://www.unicode.org/copyright.html#License
   6  *
   7  *******************************************************************************
   8  *******************************************************************************
   9  *
  10  *   Copyright (C) 1999-2007, International Business Machines
  11  *   Corporation and others.  All Rights Reserved.
  12  *
  13  *******************************************************************************
  14  *   file name:  GnomeFontInstance.cpp
  15  *
  16  *   created on: 08/30/2001
  17  *   created by: Eric R. Mader
  18  */
  19
  20 #include <gnome.h>
  21 #include <ft2build.h>
  22 #include FT_FREETYPE_H
  23 #include FT_GLYPH_H
  24 #include FT_RENDER_H
  25 #include FT_TRUETYPE_TABLES_H
  26 #include <cairo.h>
  27 #include <cairo-ft.h>
  28
  29 #include "layout/LETypes.h"
  30 #include "layout/LESwaps.h"
  31
  32 #include "GnomeFontInstance.h"
  33 #include "sfnt.h"
  34 #include "cmaps.h"
  35
  36 GnomeSurface::GnomeSurface(GtkWidget *theWidget)
  37     : fWidget(theWidget)
  38 {
  39     fCairo = gdk_cairo_create(fWidget->window);
  40 }
  41
  42 GnomeSurface::~GnomeSurface()
  43 {
  44     cairo_destroy(fCairo);
  45 }
  46
  47 void GnomeSurface::drawGlyphs(const LEFontInstance *font, const LEGlyphID *glyphs, le_int32 count,
  48                               const float *positions, le_int32 x, le_int32 y, le_int32 /*width*/, le_int32 /*height*/)
  49 {
  50     GnomeFontInstance *gFont = (GnomeFontInstance *) font;
  51
  52     gFont->rasterizeGlyphs(fCairo, glyphs, count, positions, x, y);
  53 }
  54
  55 GnomeFontInstance::GnomeFontInstance(FT_Library engine, const char *fontPathName, le_int16 pointSize, LEErrorCode &status)
  56     : FontTableCache(), fPointSize(pointSize), fUnitsPerEM(0), fAscent(0), fDescent(0), fLeading(0),
  57       fDeviceScaleX(1), fDeviceScaleY(1), fMapper(NULL)
  58 {
  59     FT_Error error;
  60
  61     fFace      = NULL;
  62     fCairoFace = NULL;
  63
  64     error = FT_New_Face(engine, fontPathName, 0, &fFace);
  65
  66     if (error != 0) {
  67         printf("OOPS! Got error code %d\n", error);
  68         status = LE_FONT_FILE_NOT_FOUND_ERROR;
  69         return;
  70     }
  71
  72     // FIXME: what about the display resolution?
  73     fDeviceScaleX = ((float) 96) / 72;
  74     fDeviceScaleY = ((float) 96) / 72;
  75
  76     error = FT_Set_Char_Size(fFace, 0, pointSize << 6, 92, 92);
  77
  78     fCairoFace = cairo_ft_font_face_create_for_ft_face(fFace, 0);
  79
  80     fUnitsPerEM = fFace->units_per_EM;
  81
  82     fAscent  = (le_int32) (yUnitsToPoints(fFace->ascender) * fDeviceScaleY);
  83     fDescent = (le_int32) -(yUnitsToPoints(fFace->descender) * fDeviceScaleY);
  84     fLeading = (le_int32) (yUnitsToPoints(fFace->height) * fDeviceScaleY) - fAscent - fDescent;
  85
  86     // printf("Face = %s, unitsPerEM = %d, ascent = %d, descent = %d\n", fontPathName, fUnitsPerEM, fAscent, fDescent);
  87
  88     if (error != 0) {
  89         status = LE_MEMORY_ALLOCATION_ERROR;
  90         return;
  91     }
  92
  93     status = initMapper();
  94 }
  95
  96 GnomeFontInstance::~GnomeFontInstance()
  97 {
  98     cairo_font_face_destroy(fCairoFace);
  99
 100     if (fFace != NULL) {
 101         FT_Done_Face(fFace);
 102     }
 103 }
 104
 105 LEErrorCode GnomeFontInstance::initMapper()
 106 {
 107     LETag cmapTag = LE_CMAP_TABLE_TAG;
 108     const CMAPTable *cmap = (const CMAPTable *) readFontTable(cmapTag);
 109
 110     if (cmap == NULL) {
 111         return LE_MISSING_FONT_TABLE_ERROR;
 112     }
 113
 114     fMapper = CMAPMapper::createUnicodeMapper(cmap);
 115
 116     if (fMapper == NULL) {
 117         return LE_MISSING_FONT_TABLE_ERROR;
 118     }
 119
 120     return LE_NO_ERROR;
 121 }
 122
 123 const void *GnomeFontInstance::getFontTable(LETag tableTag) const
 124 {
 125     return FontTableCache::find(tableTag);
 126 }
 127
 128 const void *GnomeFontInstance::readFontTable(LETag tableTag) const
 129 {
 130     FT_ULong len = 0;
 131     FT_Byte *result = NULL;
 132
 133     FT_Load_Sfnt_Table(fFace, tableTag, 0, NULL, &len);
 134
 135     if (len > 0) {
 136         result = LE_NEW_ARRAY(FT_Byte, len);
 137         FT_Load_Sfnt_Table(fFace, tableTag, 0, result, &len);
 138     }
 139
 140     return result;
 141 }
 142
 143 void GnomeFontInstance::getGlyphAdvance(LEGlyphID glyph, LEPoint &advance) const
 144 {
 145     advance.fX = 0;
 146     advance.fY = 0;
 147
 148     if (glyph >= 0xFFFE) {
 149         return;
 150     }
 151
 152     FT_Error error;
 153
 154     error = FT_Load_Glyph(fFace, glyph, FT_LOAD_DEFAULT);
 155
 156     if (error != 0) {
 157         return;
 158     }
 159
 160     advance.fX = fFace->glyph->metrics.horiAdvance >> 6;
 161     return;
 162 }
 163
 164 le_bool GnomeFontInstance::getGlyphPoint(LEGlyphID glyph, le_int32 pointNumber, LEPoint &point) const
 165 {
 166     FT_Error error;
 167
 168     error = FT_Load_Glyph(fFace, glyph, FT_LOAD_DEFAULT);
 169
 170     if (error != 0) {
 171         return FALSE;
 172     }
 173
 174     if (pointNumber >= fFace->glyph->outline.n_points) {
 175         return FALSE;
 176     }
 177
 178     point.fX = fFace->glyph->outline.points[pointNumber].x >> 6;
 179     point.fY = fFace->glyph->outline.points[pointNumber].y >> 6;
 180
 181     return TRUE;
 182 }
 183
 184 void GnomeFontInstance::rasterizeGlyphs(cairo_t *cairo, const LEGlyphID *glyphs, le_int32 glyphCount, const float *positions,
 185                                         le_int32 x, le_int32 y) const
 186 {
 187     cairo_glyph_t *glyph_t = LE_NEW_ARRAY(cairo_glyph_t, glyphCount);
 188     le_int32 in, out;
 189
 190     for (in = 0, out = 0; in < glyphCount; in += 1) {
 191         TTGlyphID glyph = LE_GET_GLYPH(glyphs[in]);
 192
 193         if (glyph < 0xFFFE) {
 194             glyph_t[out].index = glyph;
 195             glyph_t[out].x     = x + positions[in*2];
 196             glyph_t[out].y     = y + positions[in*2 + 1];
 197
 198             out += 1;
 199         }
 200     }
 201
 202     cairo_set_font_face(cairo, fCairoFace);
 203     cairo_set_font_size(cairo, getXPixelsPerEm() * getScaleFactorX());
 204     cairo_show_glyphs(cairo, glyph_t, out);
 205
 206     LE_DELETE_ARRAY(glyph_t);
 207 }