vcl/unx/generic/gdi/cairotextrender.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <unx/cairotextrender.hxx>
  21
  22 #include <unx/fc_fontoptions.hxx>
  23 #include <unx/freetype_glyphcache.hxx>
  24 #include <vcl/svapp.hxx>
  25 #include <sallayout.hxx>
  26
  27 #include <cairo.h>
  28 #include <cairo-ft.h>
  29
  30 namespace {
  31
  32 typedef struct FT_FaceRec_* FT_Face;
  33
  34 class CairoFontsCache
  35 {
  36 public:
  37     struct CacheId
  38     {
  39         FT_Face maFace;
  40         const FontConfigFontOptions *mpOptions;
  41         bool mbEmbolden;
  42         bool mbVerticalMetrics;
  43         bool operator ==(const CacheId& rOther) const
  44         {
  45             return maFace == rOther.maFace &&
  46                 mpOptions == rOther.mpOptions &&
  47                 mbEmbolden == rOther.mbEmbolden &&
  48                 mbVerticalMetrics == rOther.mbVerticalMetrics;
  49         }
  50     };
  51
  52 private:
  53     typedef         std::deque< std::pair<void *, CacheId> > LRUFonts;
  54     static LRUFonts maLRUFonts;
  55 public:
  56                                 CairoFontsCache() = delete;
  57
  58     static void                 CacheFont(void *pFont, const CacheId &rId);
  59     static void*                FindCachedFont(const CacheId &rId);
  60 };
  61
  62 CairoFontsCache::LRUFonts CairoFontsCache::maLRUFonts;
  63
  64 void CairoFontsCache::CacheFont(void *pFont, const CairoFontsCache::CacheId &rId)
  65 {
  66     maLRUFonts.push_front( std::pair<void*, CairoFontsCache::CacheId>(pFont, rId) );
  67     if (maLRUFonts.size() > 8)
  68     {
  69         cairo_font_face_destroy(static_cast<cairo_font_face_t*>(maLRUFonts.back().first));
  70         maLRUFonts.pop_back();
  71     }
  72 }
  73
  74 void* CairoFontsCache::FindCachedFont(const CairoFontsCache::CacheId &rId)
  75 {
  76     auto aI = std::find_if(maLRUFonts.begin(), maLRUFonts.end(),
  77         [&rId](const LRUFonts::value_type& rFont) { return rFont.second == rId; });
  78     if (aI != maLRUFonts.end())
  79         return aI->first;
  80     return nullptr;
  81 }
  82
  83 }
  84
  85 namespace
  86 {
  87     bool hasRotation(int nRotation)
  88     {
  89       return nRotation != 0;
  90     }
  91
  92     double toRadian(Degree10 nDegree10th)
  93     {
  94         return (Degree10(3600) - nDegree10th).get() * M_PI / 1800.0;
  95     }
  96
  97     cairo_t* syncCairoContext(cairo_t* cr)
  98     {
  99         //rhbz#1283420 tdf#117413 bodge to force a read from the underlying surface which has
 100         //the side effect of making the mysterious xrender related problem go away
 101         cairo_surface_t *target = cairo_get_target(cr);
 102         if (cairo_surface_get_type(target) == CAIRO_SURFACE_TYPE_XLIB)
 103         {
 104             cairo_surface_t *throw_away = cairo_surface_create_similar(target, cairo_surface_get_content(target), 1, 1);
 105             cairo_t *force_read_cr = cairo_create(throw_away);
 106             cairo_set_source_surface(force_read_cr, target, 0, 0);
 107             cairo_paint(force_read_cr);
 108             cairo_destroy(force_read_cr);
 109             cairo_surface_destroy(throw_away);
 110         }
 111         return cr;
 112     }
 113 }
 114
 115 void CairoTextRender::DrawTextLayout(const GenericSalLayout& rLayout, const SalGraphics& rGraphics)
 116 {
 117     const FreetypeFontInstance& rInstance = static_cast<FreetypeFontInstance&>(rLayout.GetFont());
 118     const FreetypeFont& rFont = rInstance.GetFreetypeFont();
 119
 120     std::vector<cairo_glyph_t> cairo_glyphs;
 121     std::vector<int> glyph_extrarotation;
 122     cairo_glyphs.reserve( 256 );
 123
 124     Point aPos;
 125     const GlyphItem* pGlyph;
 126     int nStart = 0;
 127     while (rLayout.GetNextGlyph(&pGlyph, aPos, nStart))
 128     {
 129         cairo_glyph_t aGlyph;
 130         aGlyph.index = pGlyph->glyphId();
 131         aGlyph.x = aPos.X();
 132         aGlyph.y = aPos.Y();
 133         cairo_glyphs.push_back(aGlyph);
 134
 135         if (pGlyph->IsVertical())
 136             glyph_extrarotation.push_back(1);
 137         else
 138             glyph_extrarotation.push_back(0);
 139     }
 140
 141     if (cairo_glyphs.empty())
 142         return;
 143
 144     const FontSelectPattern& rFSD = rInstance.GetFontSelectPattern();
 145     int nHeight = rFSD.mnHeight;
 146     int nWidth = rFSD.mnWidth ? rFSD.mnWidth : nHeight;
 147     if (nWidth == 0 || nHeight == 0)
 148         return;
 149
 150     int nRatio = nWidth * 10 / nHeight;
 151     if (FreetypeFont::AlmostHorizontalDrainsRenderingPool(nRatio, rFSD))
 152         return;
 153
 154     /*
 155      * It might be ideal to cache surface and cairo context between calls and
 156      * only destroy it when the drawable changes, but to do that we need to at
 157      * least change the SalFrame etc impls to dtor the SalGraphics *before* the
 158      * destruction of the windows they reference
 159     */
 160     cairo_t *cr = syncCairoContext(getCairoContext());
 161     if (!cr)
 162     {
 163         SAL_WARN("vcl", "no cairo context for text");
 164         return;
 165     }
 166
 167     ImplSVData* pSVData = ImplGetSVData();
 168     if (const cairo_font_options_t* pFontOptions = pSVData->mpDefInst->GetCairoFontOptions())
 169     {
 170         const StyleSettings& rStyleSettings = Application::GetSettings().GetStyleSettings();
 171         if (!rStyleSettings.GetUseFontAAFromSystem() && !rGraphics.getAntiAlias())
 172         {
 173             // Disable font AA in case global AA setting is supposed to affect
 174             // font rendering (not the default) and AA is disabled.
 175             cairo_font_options_t* pOptions = cairo_font_options_copy(pFontOptions);
 176             cairo_font_options_set_antialias(pOptions, CAIRO_ANTIALIAS_NONE);
 177             cairo_set_font_options(cr, pOptions);
 178             cairo_font_options_destroy(pOptions);
 179         }
 180         else
 181             cairo_set_font_options(cr, pFontOptions);
 182     }
 183
 184     double nDX, nDY;
 185     getSurfaceOffset(nDX, nDY);
 186     cairo_translate(cr, nDX, nDY);
 187
 188     clipRegion(cr);
 189
 190     cairo_set_source_rgb(cr,
 191         mnTextColor.GetRed()/255.0,
 192         mnTextColor.GetGreen()/255.0,
 193         mnTextColor.GetBlue()/255.0);
 194
 195     FT_Face aFace = rFont.GetFtFace();
 196     CairoFontsCache::CacheId aId;
 197     aId.maFace = aFace;
 198     aId.mpOptions = rFont.GetFontOptions();
 199     aId.mbEmbolden = rFont.NeedsArtificialBold();
 200
 201     cairo_matrix_t m;
 202
 203     std::vector<int>::const_iterator aEnd = glyph_extrarotation.end();
 204     std::vector<int>::const_iterator aStart = glyph_extrarotation.begin();
 205     std::vector<int>::const_iterator aI = aStart;
 206     while (aI != aEnd)
 207     {
 208         int nGlyphRotation = *aI;
 209
 210         std::vector<int>::const_iterator aNext = nGlyphRotation?(aI+1):std::find_if(aI+1, aEnd, hasRotation);
 211
 212         size_t nStartIndex = std::distance(aStart, aI);
 213         size_t nLen = std::distance(aI, aNext);
 214
 215         aId.mbVerticalMetrics = nGlyphRotation != 0.0;
 216         cairo_font_face_t* font_face = static_cast<cairo_font_face_t*>(CairoFontsCache::FindCachedFont(aId));
 217         if (!font_face)
 218         {
 219             const FontConfigFontOptions *pOptions = aId.mpOptions;
 220             FcPattern *pPattern = pOptions->GetPattern();
 221             font_face = cairo_ft_font_face_create_for_pattern(pPattern);
 222             CairoFontsCache::CacheFont(font_face, aId);
 223         }
 224         cairo_set_font_face(cr, font_face);
 225
 226         cairo_set_font_size(cr, nHeight);
 227
 228         cairo_matrix_init_identity(&m);
 229
 230         if (rLayout.GetOrientation())
 231             cairo_matrix_rotate(&m, toRadian(rLayout.GetOrientation()));
 232
 233         cairo_matrix_scale(&m, nWidth, nHeight);
 234
 235         if (nGlyphRotation)
 236         {
 237             cairo_matrix_rotate(&m, toRadian(Degree10(nGlyphRotation * 900)));
 238
 239             cairo_matrix_t em_square;
 240             cairo_matrix_init_identity(&em_square);
 241             cairo_get_matrix(cr, &em_square);
 242
 243             cairo_matrix_scale(&em_square, aFace->units_per_EM,
 244                 aFace->units_per_EM);
 245             cairo_set_matrix(cr, &em_square);
 246
 247             cairo_font_extents_t font_extents;
 248             cairo_font_extents(cr, &font_extents);
 249
 250             cairo_matrix_init_identity(&em_square);
 251             cairo_set_matrix(cr, &em_square);
 252
 253             //gives the same positions as pre-cairo conversion, but I don't
 254             //like them
 255             double xdiff = 0.0;
 256             double ydiff = 0.0;
 257
 258             // The y is the origin point position, but Cairo will draw
 259             // the glyph *above* that point, we need to move it down to
 260             // the glyph’s baseline.
 261             cairo_text_extents_t aExt;
 262             cairo_glyph_extents(cr, &cairo_glyphs[nStartIndex], nLen, &aExt);
 263             double nDescender = std::fmax(aExt.height + aExt.y_bearing, 0);
 264             ydiff = (aExt.x_advance - nDescender) / nHeight;
 265             xdiff = -font_extents.descent/nHeight;
 266
 267             cairo_matrix_translate(&m, xdiff, ydiff);
 268         }
 269
 270         if (rFont.NeedsArtificialItalic())
 271         {
 272             cairo_matrix_t shear;
 273             cairo_matrix_init_identity(&shear);
 274             shear.xy = -shear.xx * 0x6000L / 0x10000L;
 275             cairo_matrix_multiply(&m, &shear, &m);
 276         }
 277
 278         cairo_set_font_matrix(cr, &m);
 279         cairo_show_glyphs(cr, &cairo_glyphs[nStartIndex], nLen);
 280         if (cairo_status(cr) != CAIRO_STATUS_SUCCESS)
 281         {
 282             SAL_WARN("vcl", "rendering text failed with stretch ratio of: " << nRatio << ", " << cairo_status_to_string(cairo_status(cr)));
 283         }
 284
 285 #if OSL_DEBUG_LEVEL > 2
 286         //draw origin
 287         cairo_save (cr);
 288         cairo_rectangle (cr, cairo_glyphs[nStartIndex].x, cairo_glyphs[nStartIndex].y, 5, 5);
 289         cairo_set_source_rgba (cr, 1, 0, 0, 0.80);
 290         cairo_fill (cr);
 291         cairo_restore (cr);
 292 #endif
 293
 294         aI = aNext;
 295     }
 296
 297     releaseCairoContext(cr);
 298 }
 299
 300 void FontConfigFontOptions::cairo_font_options_substitute(FcPattern* pPattern)
 301 {
 302     ImplSVData* pSVData = ImplGetSVData();
 303     const cairo_font_options_t* pFontOptions = pSVData->mpDefInst->GetCairoFontOptions();
 304     if( !pFontOptions )
 305         return;
 306     cairo_ft_font_options_substitute(pFontOptions, pPattern);
 307 }
 308
 309 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */