From 63eae1bd15ea8aa1e4fc460194e34ecb5fc55b3a Mon Sep 17 00:00:00 2001 From: Jiang Jiang Date: Fri, 4 Nov 2011 14:47:31 +0100 Subject: Fix subpixel positioning support Move subpixelPositionForX from QTextureGlyphCache to QFontEngine, since some font engines like QFontEngineFT may need a custom implementation or tweak it a little bit. In QRasterPaintEngine::drawCachedGlyphs, do not add aliasedCoodinate to x offset as that will break subpixel positioning. Change-Id: Idbcec617509459b80965220ceb07b17737649bbf Reviewed-by: Eskil Abrahamsen Blomfeldt --- src/gui/opengl/qopenglpaintengine.cpp | 13 ++++++----- src/gui/painting/qpaintengine_raster.cpp | 4 ++-- src/gui/painting/qtextureglyphcache.cpp | 27 ++++------------------ src/gui/painting/qtextureglyphcache_p.h | 5 +--- src/gui/text/qfontengine.cpp | 13 +++++++---- src/gui/text/qfontengine_ft.cpp | 1 + src/gui/text/qfontengine_ft_p.h | 1 - src/gui/text/qfontengine_p.h | 3 ++- .../gl2paintengineex/qpaintengineex_opengl2.cpp | 2 +- 9 files changed, 27 insertions(+), 42 deletions(-) diff --git a/src/gui/opengl/qopenglpaintengine.cpp b/src/gui/opengl/qopenglpaintengine.cpp index a87c3548de..c1bde757a2 100644 --- a/src/gui/opengl/qopenglpaintengine.cpp +++ b/src/gui/opengl/qopenglpaintengine.cpp @@ -1536,12 +1536,13 @@ void QOpenGL2PaintEngineExPrivate::drawCachedGlyphs(QFontEngineGlyphCache::Type void *cacheKey = ctx->shareGroup(); bool recreateVertexArrays = false; + QFontEngine *fe = staticTextItem->fontEngine(); QOpenGLTextureGlyphCache *cache = - (QOpenGLTextureGlyphCache *) staticTextItem->fontEngine()->glyphCache(cacheKey, glyphType, QTransform()); + (QOpenGLTextureGlyphCache *) fe->glyphCache(cacheKey, glyphType, QTransform()); if (!cache || cache->cacheType() != glyphType || cache->contextGroup() == 0) { cache = new QOpenGLTextureGlyphCache(glyphType, QTransform()); - staticTextItem->fontEngine()->setGlyphCache(cacheKey, cache); + fe->setGlyphCache(cacheKey, cache); recreateVertexArrays = true; } @@ -1565,11 +1566,11 @@ void QOpenGL2PaintEngineExPrivate::drawCachedGlyphs(QFontEngineGlyphCache::Type // cache so this text is performed before we test if the cache size has changed. if (recreateVertexArrays) { cache->setPaintEnginePrivate(this); - if (!cache->populate(staticTextItem->fontEngine(), staticTextItem->numGlyphs, + if (!cache->populate(fe, staticTextItem->numGlyphs, staticTextItem->glyphs, staticTextItem->glyphPositions)) { // No space for glyphs in cache. We need to reset it and try again. cache->clear(); - cache->populate(staticTextItem->fontEngine(), staticTextItem->numGlyphs, + cache->populate(fe, staticTextItem->numGlyphs, staticTextItem->glyphs, staticTextItem->glyphPositions); } cache->fillInPendingGlyphs(); @@ -1620,11 +1621,11 @@ void QOpenGL2PaintEngineExPrivate::drawCachedGlyphs(QFontEngineGlyphCache::Type vertexCoordinates->clear(); textureCoordinates->clear(); - bool supportsSubPixelPositions = staticTextItem->fontEngine()->supportsSubPixelPositions(); + bool supportsSubPixelPositions = fe->supportsSubPixelPositions(); for (int i=0; inumGlyphs; ++i) { QFixed subPixelPosition; if (supportsSubPixelPositions) - subPixelPosition = cache->subPixelPositionForX(staticTextItem->glyphPositions[i].x); + subPixelPosition = fe->subPixelPositionForX(staticTextItem->glyphPositions[i].x); QTextureGlyphCache::GlyphAndSubPixelPosition glyph(staticTextItem->glyphs[i], subPixelPosition); diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp index e49bd229e7..d5449a7eb5 100644 --- a/src/gui/painting/qpaintengine_raster.cpp +++ b/src/gui/painting/qpaintengine_raster.cpp @@ -2752,13 +2752,13 @@ bool QRasterPaintEngine::drawCachedGlyphs(int numGlyphs, const glyph_t *glyphs, const uchar *bits = image.bits(); for (int i=0; isubPixelPositionForX(positions[i].x); + QFixed subPixelPosition = fontEngine->subPixelPositionForX(positions[i].x); QTextureGlyphCache::GlyphAndSubPixelPosition glyph(glyphs[i], subPixelPosition); const QTextureGlyphCache::Coord &c = cache->coords[glyph]; if (c.isNull()) continue; - int x = qFloor(positions[i].x + offs) + c.baseLineX - margin; + int x = qFloor(positions[i].x) + c.baseLineX - margin; int y = qFloor(positions[i].y + offs) - c.baseLineY - margin; // printf("drawing [%d %d %d %d] baseline [%d %d], glyph: %d, to: %d %d, pos: %d %d\n", diff --git a/src/gui/painting/qtextureglyphcache.cpp b/src/gui/painting/qtextureglyphcache.cpp index 5876f3bf93..1e0ed0f798 100644 --- a/src/gui/painting/qtextureglyphcache.cpp +++ b/src/gui/painting/qtextureglyphcache.cpp @@ -99,23 +99,6 @@ int QTextureGlyphCache::calculateSubPixelPositionCount(glyph_t glyph) const return images.size(); } -QFixed QTextureGlyphCache::subPixelPositionForX(QFixed x) const -{ - if (m_subPixelPositionCount <= 1) - return QFixed(); - - QFixed subPixelPosition; - if (x != 0) { - subPixelPosition = x - x.floor(); - QFixed fraction = (subPixelPosition / QFixed::fromReal(1.0 / m_subPixelPositionCount)).floor(); - - // Compensate for precision loss in fixed point to make sure we are always drawing at a subpixel position over - // the lower boundary for the selected rasterization by adding 1/64. - subPixelPosition = fraction / QFixed(m_subPixelPositionCount) + QFixed::fromReal(0.015625); - } - return subPixelPosition; -} - bool QTextureGlyphCache::populate(QFontEngine *fontEngine, int numGlyphs, const glyph_t *glyphs, const QFixedPoint *positions) { @@ -129,13 +112,13 @@ bool QTextureGlyphCache::populate(QFontEngine *fontEngine, int numGlyphs, const const int paddingDoubled = glyphPadding() * 2; bool supportsSubPixelPositions = fontEngine->supportsSubPixelPositions(); - if (m_subPixelPositionCount == 0) { + if (fontEngine->m_subPixelPositionCount == 0) { if (!supportsSubPixelPositions) { - m_subPixelPositionCount = 1; + fontEngine->m_subPixelPositionCount = 1; } else { int i = 0; - while (m_subPixelPositionCount == 0 && i < numGlyphs) - m_subPixelPositionCount = calculateSubPixelPositionCount(glyphs[i++]); + while (fontEngine->m_subPixelPositionCount == 0 && i < numGlyphs) + fontEngine->m_subPixelPositionCount = calculateSubPixelPositionCount(glyphs[i++]); } } @@ -156,7 +139,7 @@ bool QTextureGlyphCache::populate(QFontEngine *fontEngine, int numGlyphs, const QFixed subPixelPosition; if (supportsSubPixelPositions) { QFixed x = positions != 0 ? positions[i].x : QFixed(); - subPixelPosition = subPixelPositionForX(x); + subPixelPosition = fontEngine->subPixelPositionForX(x); } if (coords.contains(GlyphAndSubPixelPosition(glyph, subPixelPosition))) diff --git a/src/gui/painting/qtextureglyphcache_p.h b/src/gui/painting/qtextureglyphcache_p.h index bc5eebbecb..d9d57f41ab 100644 --- a/src/gui/painting/qtextureglyphcache_p.h +++ b/src/gui/painting/qtextureglyphcache_p.h @@ -81,7 +81,7 @@ class Q_GUI_EXPORT QTextureGlyphCache : public QFontEngineGlyphCache public: QTextureGlyphCache(QFontEngineGlyphCache::Type type, const QTransform &matrix) : QFontEngineGlyphCache(matrix, type), m_current_fontengine(0), - m_w(0), m_h(0), m_cx(0), m_cy(0), m_currentRowHeight(0), m_subPixelPositionCount(0) + m_w(0), m_h(0), m_cx(0), m_cy(0), m_currentRowHeight(0) { } virtual ~QTextureGlyphCache() { } @@ -146,8 +146,6 @@ public: QImage textureMapForGlyph(glyph_t g, QFixed subPixelPosition) const; - QFixed subPixelPositionForX(QFixed x) const; - protected: int calculateSubPixelPositionCount(glyph_t) const; @@ -159,7 +157,6 @@ protected: int m_cx; // current x int m_cy; // current y int m_currentRowHeight; // Height of last row - int m_subPixelPositionCount; // Number of positions within a single pixel for this cache }; inline uint qHash(const QTextureGlyphCache::GlyphAndSubPixelPosition &g) diff --git a/src/gui/text/qfontengine.cpp b/src/gui/text/qfontengine.cpp index 067a630d4d..5c6c8d186a 100644 --- a/src/gui/text/qfontengine.cpp +++ b/src/gui/text/qfontengine.cpp @@ -179,6 +179,7 @@ QFontEngine::QFontEngine() hbFace = 0; glyphFormat = -1; + m_subPixelPositionCount = 0; } QFontEngine::~QFontEngine() @@ -635,17 +636,19 @@ QImage QFontEngine::alphaRGBMapForGlyph(glyph_t glyph, QFixed /*subPixelPosition return rgbMask; } -QFixed QFontEngine::subPixelPositionForX(QFixed x) +QFixed QFontEngine::subPixelPositionForX(QFixed x) const { - int m_subPixelPositionCount = 4; - if (!supportsSubPixelPositions()) - return 0; + if (m_subPixelPositionCount <= 1 || !supportsSubPixelPositions()) + return QFixed(); QFixed subPixelPosition; if (x != 0) { subPixelPosition = x - x.floor(); QFixed fraction = (subPixelPosition / QFixed::fromReal(1.0 / m_subPixelPositionCount)).floor(); - subPixelPosition = fraction / QFixed(m_subPixelPositionCount); + + // Compensate for precision loss in fixed point to make sure we are always drawing at a subpixel position over + // the lower boundary for the selected rasterization by adding 1/64. + subPixelPosition = fraction / QFixed(m_subPixelPositionCount) + QFixed::fromReal(0.015625); } return subPixelPosition; } diff --git a/src/gui/text/qfontengine_ft.cpp b/src/gui/text/qfontengine_ft.cpp index eb7415ae8e..6845c67463 100644 --- a/src/gui/text/qfontengine_ft.cpp +++ b/src/gui/text/qfontengine_ft.cpp @@ -657,6 +657,7 @@ QFontEngineFT::QFontEngineFT(const QFontDef &fd) defaultFormat = Format_None; embeddedbitmap = false; cacheEnabled = qgetenv("QT_NO_FT_CACHE").isEmpty() || qgetenv("QT_NO_FT_CACHE").toInt() == 0; + m_subPixelPositionCount = 4; } QFontEngineFT::~QFontEngineFT() diff --git a/src/gui/text/qfontengine_ft_p.h b/src/gui/text/qfontengine_ft_p.h index d4a6def286..fd0be4f1c8 100644 --- a/src/gui/text/qfontengine_ft_p.h +++ b/src/gui/text/qfontengine_ft_p.h @@ -315,7 +315,6 @@ private: bool initFromFontEngine(const QFontEngineFT *fontEngine); HintStyle defaultHintStyle() const { return default_hint_style; } - protected: QFreetypeFace *freetype; diff --git a/src/gui/text/qfontengine_p.h b/src/gui/text/qfontengine_p.h index ec1f22b6e1..4caf91e735 100644 --- a/src/gui/text/qfontengine_p.h +++ b/src/gui/text/qfontengine_p.h @@ -158,7 +158,7 @@ public: }; virtual int synthesized() const { return 0; } virtual bool supportsSubPixelPositions() const { return false; } - QFixed subPixelPositionForX(QFixed x); + virtual QFixed subPixelPositionForX(QFixed x) const; virtual QFixed emSquareSize() const { return ascent(); } @@ -277,6 +277,7 @@ public: int glyphFormat; QImage currentlyLockedAlphaMap; + int m_subPixelPositionCount; // Number of positions within a single pixel for this cache protected: static const QVector &grayPalette(); diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp index 947abf81ff..45ac639286 100644 --- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp +++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp @@ -1654,7 +1654,7 @@ void QGL2PaintEngineExPrivate::drawCachedGlyphs(QFontEngineGlyphCache::Type glyp for (int i=0; inumGlyphs; ++i) { QFixed subPixelPosition; if (supportsSubPixelPositions) - subPixelPosition = cache->subPixelPositionForX(staticTextItem->glyphPositions[i].x); + subPixelPosition = staticTextItem->fontEngine()->subPixelPositionForX(staticTextItem->glyphPositions[i].x); QTextureGlyphCache::GlyphAndSubPixelPosition glyph(staticTextItem->glyphs[i], subPixelPosition); -- cgit v1.2.3