src/quick/scenegraph/qsgdefaultdistancefieldglyphcache.cpp

   1 /****************************************************************************
   2 **
   3 ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
   4 ** Contact: http://www.qt-project.org/
   5 **
   6 ** This file is part of the QtDeclarative module of the Qt Toolkit.
   7 **
   8 ** $QT_BEGIN_LICENSE:LGPL$
   9 ** GNU Lesser General Public License Usage
  10 ** This file may be used under the terms of the GNU Lesser General Public
  11 ** License version 2.1 as published by the Free Software Foundation and
  12 ** appearing in the file LICENSE.LGPL included in the packaging of this
  13 ** file. Please review the following information to ensure the GNU Lesser
  14 ** General Public License version 2.1 requirements will be met:
  15 ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
  16 **
  17 ** In addition, as a special exception, Nokia gives you certain additional
  18 ** rights. These rights are described in the Nokia Qt LGPL Exception
  19 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
  20 **
  21 ** GNU General Public License Usage
  22 ** Alternatively, this file may be used under the terms of the GNU General
  23 ** Public License version 3.0 as published by the Free Software Foundation
  24 ** and appearing in the file LICENSE.GPL included in the packaging of this
  25 ** file. Please review the following information to ensure the GNU General
  26 ** Public License version 3.0 requirements will be met:
  27 ** http://www.gnu.org/copyleft/gpl.html.
  28 **
  29 ** Other Usage
  30 ** Alternatively, this file may be used in accordance with the terms and
  31 ** conditions contained in a signed written agreement between you and Nokia.
  32 **
  33 **
  34 **
  35 **
  36 **
  37 **
  38 ** $QT_END_LICENSE$
  39 **
  40 ****************************************************************************/
  41
  42 #include "qsgdefaultdistancefieldglyphcache_p.h"
  43
  44 #include <QtQuick/private/qsgdistancefieldutil_p.h>
  45 #include <qopenglfunctions.h>
  46
  47 QT_BEGIN_NAMESPACE
  48
  49 QHash<QString, QOpenGLMultiGroupSharedResource> QSGDefaultDistanceFieldGlyphCache::m_textures_data;
  50
  51 QSGDefaultDistanceFieldGlyphCache::DistanceFieldTextureData *QSGDefaultDistanceFieldGlyphCache::textureData(QOpenGLContext *c)
  52 {
  53     QString key = QString::fromLatin1("%1_%2_%3_%4")
  54             .arg(font().familyName())
  55             .arg(font().styleName())
  56             .arg(font().weight())
  57             .arg(font().style());
  58     return m_textures_data[key].value<QSGDefaultDistanceFieldGlyphCache::DistanceFieldTextureData>(c);
  59 }
  60
  61 QSGDefaultDistanceFieldGlyphCache::QSGDefaultDistanceFieldGlyphCache(QSGDistanceFieldGlyphCacheManager *man, QOpenGLContext *c, const QRawFont &font)
  62     : QSGDistanceFieldGlyphCache(man, c, font)
  63     , m_maxTextureSize(0)
  64 {
  65     m_textureData = textureData(c);
  66 }
  67
  68 void QSGDefaultDistanceFieldGlyphCache::requestGlyphs(const QSet<glyph_t> &glyphs)
  69 {
  70     QList<GlyphPosition> glyphPositions;
  71     QVector<glyph_t> glyphsToRender;
  72
  73     for (QSet<glyph_t>::const_iterator it = glyphs.constBegin(); it != glyphs.constEnd() ; ++it) {
  74         glyph_t glyphIndex = *it;
  75
  76         if (cacheIsFull() && m_textureData->unusedGlyphs.isEmpty())
  77             continue;
  78
  79         m_textureData->unusedGlyphs.remove(glyphIndex);
  80
  81         GlyphPosition p;
  82         p.glyph = glyphIndex;
  83         p.position = QPointF(m_textureData->currX, m_textureData->currY);
  84
  85         if (!cacheIsFull()) {
  86             m_textureData->currX += QT_DISTANCEFIELD_TILESIZE(doubleGlyphResolution());
  87             if (m_textureData->currX >= maxTextureSize()) {
  88                 m_textureData->currX = 0;
  89                 m_textureData->currY += QT_DISTANCEFIELD_TILESIZE(doubleGlyphResolution());
  90             }
  91         } else {
  92             // Recycle glyphs
  93             if (!m_textureData->unusedGlyphs.isEmpty()) {
  94                 glyph_t unusedGlyph = *m_textureData->unusedGlyphs.constBegin();
  95                 TexCoord unusedCoord = glyphTexCoord(unusedGlyph);
  96                 p.position = QPointF(unusedCoord.x, unusedCoord.y);
  97                 m_textureData->unusedGlyphs.remove(unusedGlyph);
  98                 removeGlyph(unusedGlyph);
  99             }
 100         }
 101
 102         if (p.position.y() < maxTextureSize()) {
 103             glyphPositions.append(p);
 104             glyphsToRender.append(glyphIndex);
 105         }
 106     }
 107
 108     setGlyphsPosition(glyphPositions);
 109     markGlyphsToRender(glyphsToRender);
 110 }
 111
 112 void QSGDefaultDistanceFieldGlyphCache::storeGlyphs(const QHash<glyph_t, QImage> &glyphs)
 113 {
 114     int requiredWidth = maxTextureSize();
 115     int rows = 128 / (requiredWidth / QT_DISTANCEFIELD_TILESIZE(doubleGlyphResolution())); // Enough rows to fill the latin1 set by default..
 116     int requiredHeight = qMin(maxTextureSize(),
 117                               qMax(m_textureData->currY + QT_DISTANCEFIELD_TILESIZE(doubleGlyphResolution()),
 118                                    QT_DISTANCEFIELD_TILESIZE(doubleGlyphResolution()) * rows));
 119
 120     resizeTexture((requiredWidth), (requiredHeight));
 121     glBindTexture(GL_TEXTURE_2D, m_textureData->texture);
 122
 123     QVector<glyph_t> glyphTextures;
 124
 125     QHash<glyph_t, QImage>::const_iterator it;
 126     for (it = glyphs.constBegin(); it != glyphs.constEnd(); ++it) {
 127         glyph_t glyphIndex = it.key();
 128         TexCoord c = glyphTexCoord(glyphIndex);
 129
 130         glyphTextures.append(glyphIndex);
 131
 132         QImage glyph = it.value();
 133
 134         if (useWorkaroundBrokenFBOReadback()) {
 135             uchar *inBits = glyph.scanLine(0);
 136             uchar *outBits = m_textureData->image.scanLine(int(c.y)) + int(c.x);
 137             for (int y = 0; y < glyph.height(); ++y) {
 138                 qMemCopy(outBits, inBits, glyph.width());
 139                 inBits += glyph.bytesPerLine();
 140                 outBits += m_textureData->image.bytesPerLine();
 141             }
 142         }
 143
 144         glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, glyph.width(), glyph.height(), GL_ALPHA, GL_UNSIGNED_BYTE, glyph.constBits());
 145     }
 146
 147     Texture t;
 148     t.textureId = m_textureData->texture;
 149     t.size = m_textureData->size;
 150     setGlyphsTexture(glyphTextures, t);
 151 }
 152
 153 void QSGDefaultDistanceFieldGlyphCache::referenceGlyphs(const QSet<glyph_t> &glyphs)
 154 {
 155     m_textureData->unusedGlyphs -= glyphs;
 156 }
 157
 158 void QSGDefaultDistanceFieldGlyphCache::releaseGlyphs(const QSet<glyph_t> &glyphs)
 159 {
 160     m_textureData->unusedGlyphs += glyphs;
 161 }
 162
 163 void QSGDefaultDistanceFieldGlyphCache::createTexture(int width, int height)
 164 {
 165     if (useWorkaroundBrokenFBOReadback() && m_textureData->image.isNull())
 166         m_textureData->image = QImage(width, height, QImage::Format_Indexed8);
 167
 168     while (glGetError() != GL_NO_ERROR) { }
 169
 170     glGenTextures(1, &m_textureData->texture);
 171     glBindTexture(GL_TEXTURE_2D, m_textureData->texture);
 172
 173     glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, 0);
 174     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 175     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 176     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 177     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 178
 179     m_textureData->size = QSize(width, height);
 180
 181     GLuint error = glGetError();
 182     if (error != GL_NO_ERROR) {
 183         glBindTexture(GL_TEXTURE_2D, 0);
 184         glDeleteTextures(1, &m_textureData->texture);
 185         m_textureData->texture = 0;
 186     }
 187
 188 }
 189
 190 void QSGDefaultDistanceFieldGlyphCache::resizeTexture(int width, int height)
 191 {
 192     int oldWidth = m_textureData->size.width();
 193     int oldHeight = m_textureData->size.height();
 194     if (width == oldWidth && height == oldHeight)
 195         return;
 196
 197     GLuint oldTexture = m_textureData->texture;
 198     createTexture(width, height);
 199
 200     if (!oldTexture)
 201         return;
 202
 203     updateTexture(oldTexture, m_textureData->texture, m_textureData->size);
 204
 205     if (useWorkaroundBrokenFBOReadback()) {
 206         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, oldWidth, oldHeight, GL_ALPHA, GL_UNSIGNED_BYTE, m_textureData->image.constBits());
 207         m_textureData->image = m_textureData->image.copy(0, 0, width, height);
 208         glDeleteTextures(1, &oldTexture);
 209         return;
 210     }
 211
 212     if (!m_textureData->blitProgram)
 213         m_textureData->createBlitProgram();
 214
 215     Q_ASSERT(m_textureData->blitProgram);
 216
 217     if (!m_textureData->fbo)
 218         ctx->functions()->glGenFramebuffers(1, &m_textureData->fbo);
 219     ctx->functions()->glBindFramebuffer(GL_FRAMEBUFFER, m_textureData->fbo);
 220
 221     GLuint tmp_texture;
 222     glGenTextures(1, &tmp_texture);
 223     glBindTexture(GL_TEXTURE_2D, tmp_texture);
 224     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, oldWidth, oldHeight, 0,
 225                  GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 226     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 227     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 228     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 229     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 230     glBindTexture(GL_TEXTURE_2D, 0);
 231     ctx->functions()->glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
 232                                              GL_TEXTURE_2D, tmp_texture, 0);
 233
 234     ctx->functions()->glActiveTexture(GL_TEXTURE0);
 235     glBindTexture(GL_TEXTURE_2D, oldTexture);
 236
 237     // save current render states
 238     GLboolean stencilTestEnabled;
 239     GLboolean depthTestEnabled;
 240     GLboolean scissorTestEnabled;
 241     GLboolean blendEnabled;
 242     GLint viewport[4];
 243     GLint oldProgram;
 244     glGetBooleanv(GL_STENCIL_TEST, &stencilTestEnabled);
 245     glGetBooleanv(GL_DEPTH_TEST, &depthTestEnabled);
 246     glGetBooleanv(GL_SCISSOR_TEST, &scissorTestEnabled);
 247     glGetBooleanv(GL_BLEND, &blendEnabled);
 248     glGetIntegerv(GL_VIEWPORT, &viewport[0]);
 249     glGetIntegerv(GL_CURRENT_PROGRAM, &oldProgram);
 250
 251     glDisable(GL_STENCIL_TEST);
 252     glDisable(GL_DEPTH_TEST);
 253     glDisable(GL_SCISSOR_TEST);
 254     glDisable(GL_BLEND);
 255
 256     glViewport(0, 0, oldWidth, oldHeight);
 257
 258     ctx->functions()->glVertexAttribPointer(QT_VERTEX_COORDS_ATTR, 2, GL_FLOAT, GL_FALSE, 0, m_textureData->blitVertexCoordinateArray);
 259     ctx->functions()->glVertexAttribPointer(QT_TEXTURE_COORDS_ATTR, 2, GL_FLOAT, GL_FALSE, 0, m_textureData->blitTextureCoordinateArray);
 260
 261     m_textureData->blitProgram->bind();
 262     m_textureData->blitProgram->enableAttributeArray(int(QT_VERTEX_COORDS_ATTR));
 263     m_textureData->blitProgram->enableAttributeArray(int(QT_TEXTURE_COORDS_ATTR));
 264     m_textureData->blitProgram->disableAttributeArray(int(QT_OPACITY_ATTR));
 265     m_textureData->blitProgram->setUniformValue("imageTexture", GLuint(0));
 266
 267     glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
 268
 269     glBindTexture(GL_TEXTURE_2D, m_textureData->texture);
 270
 271     glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, oldWidth, oldHeight);
 272
 273     ctx->functions()->glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
 274                                                 GL_RENDERBUFFER, 0);
 275     glDeleteTextures(1, &tmp_texture);
 276     glDeleteTextures(1, &oldTexture);
 277
 278     ctx->functions()->glBindFramebuffer(GL_FRAMEBUFFER, 0);
 279
 280     // restore render states
 281     if (stencilTestEnabled)
 282         glEnable(GL_STENCIL_TEST);
 283     if (depthTestEnabled)
 284         glEnable(GL_DEPTH_TEST);
 285     if (scissorTestEnabled)
 286         glEnable(GL_SCISSOR_TEST);
 287     if (blendEnabled)
 288         glEnable(GL_BLEND);
 289     glViewport(viewport[0], viewport[1], viewport[2], viewport[3]);
 290     ctx->functions()->glUseProgram(oldProgram);
 291
 292     m_textureData->blitProgram->disableAttributeArray(int(QT_VERTEX_COORDS_ATTR));
 293     m_textureData->blitProgram->disableAttributeArray(int(QT_TEXTURE_COORDS_ATTR));
 294 }
 295
 296 bool QSGDefaultDistanceFieldGlyphCache::useWorkaroundBrokenFBOReadback() const
 297 {
 298     static bool set = false;
 299     static bool useWorkaround = false;
 300     if (!set) {
 301         QOpenGLContextPrivate *ctx_p = static_cast<QOpenGLContextPrivate *>(QOpenGLContextPrivate::get(ctx));
 302         useWorkaround = ctx_p->workaround_brokenFBOReadBack;
 303         set = true;
 304     }
 305     return useWorkaround;
 306 }
 307
 308 int QSGDefaultDistanceFieldGlyphCache::maxTextureSize() const
 309 {
 310     if (!m_maxTextureSize)
 311         glGetIntegerv(GL_MAX_TEXTURE_SIZE, &m_maxTextureSize);
 312     return m_maxTextureSize;
 313 }
 314
 315 QT_END_NAMESPACE