From 1b34feacef7a2d3ac005449a7cfbcb08a6bbf947 Mon Sep 17 00:00:00 2001 From: Kim Motoyoshi Kalland Date: Tue, 8 Sep 2009 14:30:19 +0200 Subject: Resubmit support for subpixel antialiasing on text in the GL2 engine. The antialiasing is currently not gamma corrected and is disabled on OpenGL ES 2.0. Reviewed-by: Samuel --- src/gui/kernel/qapplication_win.cpp | 2 +- .../gl2paintengineex/qglengineshadermanager.cpp | 12 +- .../gl2paintengineex/qglengineshadermanager_p.h | 8 +- .../gl2paintengineex/qglengineshadersource_p.h | 33 +++++ .../gl2paintengineex/qpaintengineex_opengl2.cpp | 142 ++++++++++++++++++--- .../gl2paintengineex/qpaintengineex_opengl2_p.h | 2 + src/opengl/qglextensions.cpp | 3 +- src/opengl/qglextensions_p.h | 9 ++ 8 files changed, 186 insertions(+), 25 deletions(-) diff --git a/src/gui/kernel/qapplication_win.cpp b/src/gui/kernel/qapplication_win.cpp index 2b1aaf5..6ecd535 100644 --- a/src/gui/kernel/qapplication_win.cpp +++ b/src/gui/kernel/qapplication_win.cpp @@ -220,7 +220,7 @@ static void resolveAygLibs() # define FE_FONTSMOOTHINGCLEARTYPE 0x0002 #endif -bool qt_cleartype_enabled; +Q_GUI_EXPORT bool qt_cleartype_enabled; Q_GUI_EXPORT bool qt_win_owndc_required; // CS_OWNDC is required if we use the GL graphicssystem as default typedef HCTX (API *PtrWTOpen)(HWND, LPLOGCONTEXT, BOOL); diff --git a/src/opengl/gl2paintengineex/qglengineshadermanager.cpp b/src/opengl/gl2paintengineex/qglengineshadermanager.cpp index b3458af..eceed06 100644 --- a/src/opengl/gl2paintengineex/qglengineshadermanager.cpp +++ b/src/opengl/gl2paintengineex/qglengineshadermanager.cpp @@ -134,7 +134,8 @@ QGLEngineSharedShaders::QGLEngineSharedShaders(const QGLContext* context) code[ShockingPinkSrcFragmentShader] = qglslShockingPinkSrcFragmentShader; code[MaskFragmentShader] = qglslMaskFragmentShader; - code[RgbMaskFragmentShader] = ""; //### + code[RgbMaskFragmentShaderPass1] = qglslRgbMaskFragmentShaderPass1; + code[RgbMaskFragmentShaderPass2] = qglslRgbMaskFragmentShaderPass2; code[RgbMaskWithGammaFragmentShader] = ""; //### code[MultiplyCompositionModeFragmentShader] = ""; //### @@ -587,10 +588,15 @@ bool QGLEngineShaderManager::useCorrectShaderProg() if (maskType == PixelMask) { maskShaderName = QGLEngineSharedShaders::MaskFragmentShader; texCoords = true; - } else if (maskType == SubPixelMask) { - maskShaderName = QGLEngineSharedShaders::RgbMaskFragmentShader; + } else if (maskType == SubPixelMaskPass1) { + maskShaderName = QGLEngineSharedShaders::RgbMaskFragmentShaderPass1; + texCoords = true; + } else if (maskType == SubPixelMaskPass2) { + maskShaderName = QGLEngineSharedShaders::RgbMaskFragmentShaderPass2; + texCoords = true; } else if (maskType == SubPixelWithGammaMask) { maskShaderName = QGLEngineSharedShaders::RgbMaskWithGammaFragmentShader; + texCoords = true; } else { qCritical("QGLEngineShaderManager::useCorrectShaderProg() - Unknown mask type"); } diff --git a/src/opengl/gl2paintengineex/qglengineshadermanager_p.h b/src/opengl/gl2paintengineex/qglengineshadermanager_p.h index 3c5a5f5..47d9a2a 100644 --- a/src/opengl/gl2paintengineex/qglengineshadermanager_p.h +++ b/src/opengl/gl2paintengineex/qglengineshadermanager_p.h @@ -142,7 +142,8 @@ Masks are implementations of "qcolorp vec4 applyMask(qcolorp vec4 src)": qglslMaskFragmentShader - qglslRgbMaskFragmentShader + qglslRgbMaskFragmentShaderPass1 + qglslRgbMaskFragmentShaderPass2 qglslRgbMaskWithGammaFragmentShader Composition modes are "qcolorp vec4 compose(qcolorp vec4 src)": @@ -321,7 +322,8 @@ public: ShockingPinkSrcFragmentShader, MaskFragmentShader, - RgbMaskFragmentShader, + RgbMaskFragmentShaderPass1, + RgbMaskFragmentShaderPass2, RgbMaskWithGammaFragmentShader, MultiplyCompositionModeFragmentShader, @@ -376,7 +378,7 @@ public: QGLEngineShaderManager(QGLContext* context); ~QGLEngineShaderManager(); - enum MaskType {NoMask, PixelMask, SubPixelMask, SubPixelWithGammaMask}; + enum MaskType {NoMask, PixelMask, SubPixelMaskPass1, SubPixelMaskPass2, SubPixelWithGammaMask}; enum PixelSrcType { ImageSrc = Qt::TexturePattern+1, NonPremultipliedImageSrc = Qt::TexturePattern+2, diff --git a/src/opengl/gl2paintengineex/qglengineshadersource_p.h b/src/opengl/gl2paintengineex/qglengineshadersource_p.h index 6bcf010..8ae86d3 100644 --- a/src/opengl/gl2paintengineex/qglengineshadersource_p.h +++ b/src/opengl/gl2paintengineex/qglengineshadersource_p.h @@ -401,6 +401,39 @@ static const char* const qglslMaskFragmentShader = "\ return src * mask.a; \ }"; +// For source over with subpixel antialiasing, the final color is calculated per component as follows +// (.a is alpha component, .c is red, green or blue component): +// alpha = src.a * mask.c * opacity +// dest.c = dest.c * (1 - alpha) + src.c * alpha +// +// In the first pass, calculate: dest.c = dest.c * (1 - alpha) with blend funcs: zero, 1 - source color +// In the second pass, calculate: dest.c = dest.c + src.c * alpha with blend funcs: one, one +// +// If source is a solid color (src is constant), only the first pass is needed, with blend funcs: constant, 1 - source color + +// For source composition with subpixel antialiasing, the final color is calculated per component as follows: +// alpha = src.a * mask.c * opacity +// dest.c = dest.c * (1 - mask.c) + src.c * alpha +// + +static const char* const qglslRgbMaskFragmentShaderPass1 = "\ + varying highp vec2 textureCoords;\ + uniform lowp sampler2D maskTexture;\ + lowp vec4 applyMask(lowp vec4 src) \ + {\ + lowp vec4 mask = texture2D(maskTexture, textureCoords); \ + return src.a * mask; \ + }"; + +static const char* const qglslRgbMaskFragmentShaderPass2 = "\ + varying highp vec2 textureCoords;\ + uniform lowp sampler2D maskTexture;\ + lowp vec4 applyMask(lowp vec4 src) \ + {\ + lowp vec4 mask = texture2D(maskTexture, textureCoords); \ + return src * mask; \ + }"; + /* Left to implement: RgbMaskFragmentShader, diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp index 930d181..ba2a0ea 100644 --- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp +++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp @@ -90,6 +90,10 @@ static const GLuint QT_IMAGE_TEXTURE_UNIT = 0; //Can be the same as brush static const GLuint QT_MASK_TEXTURE_UNIT = 1; static const GLuint QT_BACKGROUND_TEXTURE_UNIT = 2; +#ifdef Q_WS_WIN +extern Q_GUI_EXPORT bool qt_cleartype_enabled; +#endif + class QGLTextureGlyphCache : public QObject, public QTextureGlyphCache { Q_OBJECT @@ -100,6 +104,7 @@ public: virtual void createTextureData(int width, int height); virtual void resizeTextureData(int width, int height); virtual void fillTexture(const Coord &c, glyph_t glyph); + virtual int glyphMargin() const; inline GLuint texture() const { return m_texture; } @@ -290,7 +295,7 @@ void QGLTextureGlyphCache::fillTexture(const Coord &c, glyph_t glyph) glBindTexture(GL_TEXTURE_2D, m_texture); if (mask.format() == QImage::Format_RGB32) { - glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, m_height - c.y, maskWidth, maskHeight, GL_BGRA, GL_UNSIGNED_BYTE, mask.bits()); + glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth, maskHeight, GL_BGRA, GL_UNSIGNED_BYTE, mask.bits()); } else { #ifdef QT_OPENGL_ES2 glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth, maskHeight, GL_ALPHA, GL_UNSIGNED_BYTE, mask.bits()); @@ -310,6 +315,17 @@ void QGLTextureGlyphCache::fillTexture(const Coord &c, glyph_t glyph) } } +int QGLTextureGlyphCache::glyphMargin() const +{ +#if defined(Q_WS_MAC) + return 2; +#elif defined (Q_WS_X11) + return 0; +#else + return m_type == QFontEngineGlyphCache::Raster_RGBMask ? 2 : 0; +#endif +} + extern QImage qt_imageForBrush(int brushStyle, bool invert); ////////////////////////////////// Private Methods ////////////////////////////////////////// @@ -1209,6 +1225,12 @@ void QGL2PaintEngineEx::drawTextItem(const QPointF &p, const QTextItem &textItem if (ti.fontEngine->fontDef.pixelSize * qSqrt(s->matrix.determinant()) >= 64) drawCached = false; + if (d->glyphCacheType == QFontEngineGlyphCache::Raster_RGBMask + && state()->composition_mode != QPainter::CompositionMode_Source + && state()->composition_mode != QPainter::CompositionMode_SourceOver) { + drawCached = false; + } + if (drawCached) { d->drawCachedGlyphs(p, ti); return; @@ -1229,11 +1251,12 @@ void QGL2PaintEngineExPrivate::drawCachedGlyphs(const QPointF &p, const QTextIte QFontEngineGlyphCache::Type glyphType = ti.fontEngine->glyphFormat >= 0 ? QFontEngineGlyphCache::Type(ti.fontEngine->glyphFormat) - : QFontEngineGlyphCache::Raster_A8; + : glyphCacheType; QGLTextureGlyphCache *cache = (QGLTextureGlyphCache *) ti.fontEngine->glyphCache(ctx, s->matrix); - if (!cache) { + + if (!cache || cache->cacheType() != glyphType) { cache = new QGLTextureGlyphCache(ctx, glyphType, s->matrix); ti.fontEngine->setGlyphCache(ctx, cache); } @@ -1248,12 +1271,6 @@ void QGL2PaintEngineExPrivate::drawCachedGlyphs(const QPointF &p, const QTextIte transferMode(BrushDrawingMode); transferMode(TextDrawingMode); - if (glyphType == QFontEngineGlyphCache::Raster_A8) - shaderManager->setMaskType(QGLEngineShaderManager::PixelMask); - else if (glyphType == QFontEngineGlyphCache::Raster_RGBMask) - shaderManager->setMaskType(QGLEngineShaderManager::SubPixelMask); - //### TODO: Gamma correction - int margin = cache->glyphMargin(); GLfloat dx = 1.0 / cache->width(); @@ -1274,10 +1291,96 @@ void QGL2PaintEngineExPrivate::drawCachedGlyphs(const QPointF &p, const QTextIte textureCoordinateArray.addRect(QRectF(c.x*dx, c.y*dy, c.w * dx, c.h * dy)); } + if (vertexCoordinateArray.data() != oldVertexCoordinateDataPtr) + glVertexAttribPointer(QT_VERTEX_COORDS_ATTR, 2, GL_FLOAT, GL_FALSE, 0, vertexCoordinateArray.data()); + if (textureCoordinateArray.data() != oldTextureCoordinateDataPtr) + glVertexAttribPointer(QT_TEXTURE_COORDS_ATTR, 2, GL_FLOAT, GL_FALSE, 0, textureCoordinateArray.data()); + QBrush pensBrush = q->state()->pen.brush(); setBrush(&pensBrush); - prepareForDraw(false); // Text always causes src pixels to be transparent + if (glyphType == QFontEngineGlyphCache::Raster_A8) { + + // Greyscale antialiasing + + shaderManager->setMaskType(QGLEngineShaderManager::PixelMask); + prepareForDraw(false); // Text always causes src pixels to be transparent + } else if (glyphType == QFontEngineGlyphCache::Raster_RGBMask) { + + // Subpixel antialiasing without gamma correction + + QPainter::CompositionMode compMode = q->state()->composition_mode; + Q_ASSERT(compMode == QPainter::CompositionMode_Source + || compMode == QPainter::CompositionMode_SourceOver); + + shaderManager->setMaskType(QGLEngineShaderManager::SubPixelMaskPass1); + + if (pensBrush.style() == Qt::SolidPattern) { + // Solid patterns can get away with only one pass. + QColor c = pensBrush.color(); + qreal oldOpacity = q->state()->opacity; + if (compMode == QPainter::CompositionMode_Source) { + c = premultiplyColor(c, q->state()->opacity); + q->state()->opacity = 1; + opacityUniformDirty = true; + } + + compositionModeDirty = false; // I can handle this myself, thank you very much + prepareForDraw(false); // Text always causes src pixels to be transparent + + // prepareForDraw() have set the opacity on the current shader, so the opacity state can now be reset. + if (compMode == QPainter::CompositionMode_Source) { + q->state()->opacity = oldOpacity; + opacityUniformDirty = true; + } + + glEnable(GL_BLEND); + glBlendFunc(GL_CONSTANT_COLOR, GL_ONE_MINUS_SRC_COLOR); + glBlendColor(c.redF(), c.greenF(), c.blueF(), c.alphaF()); + } else { + // Other brush styles need two passes. + + qreal oldOpacity = q->state()->opacity; + if (compMode == QPainter::CompositionMode_Source) { + q->state()->opacity = 1; + opacityUniformDirty = true; + pensBrush = Qt::white; + setBrush(&pensBrush); + } + + compositionModeDirty = false; // I can handle this myself, thank you very much + prepareForDraw(false); // Text always causes src pixels to be transparent + glEnable(GL_BLEND); + glBlendFunc(GL_ZERO, GL_ONE_MINUS_SRC_COLOR); + + glActiveTexture(GL_TEXTURE0 + QT_MASK_TEXTURE_UNIT); + glBindTexture(GL_TEXTURE_2D, cache->texture()); + updateTextureFilter(GL_TEXTURE_2D, GL_REPEAT, false); + +#ifndef QT_OPENGL_ES_2 + if (inRenderText) + shaderManager->currentProgram()->setUniformValue(location(QGLEngineShaderManager::Depth), zValueForRenderText()); +#endif + shaderManager->currentProgram()->setUniformValue(location(QGLEngineShaderManager::MaskTexture), QT_MASK_TEXTURE_UNIT); + glDrawArrays(GL_TRIANGLES, 0, 6 * glyphs.size()); + + shaderManager->setMaskType(QGLEngineShaderManager::SubPixelMaskPass2); + + if (compMode == QPainter::CompositionMode_Source) { + q->state()->opacity = oldOpacity; + opacityUniformDirty = true; + pensBrush = q->state()->pen.brush(); + setBrush(&pensBrush); + } + + compositionModeDirty = false; + prepareForDraw(false); // Text always causes src pixels to be transparent + glEnable(GL_BLEND); + glBlendFunc(GL_ONE, GL_ONE); + } + compositionModeDirty = true; + } + //### TODO: Gamma correction glActiveTexture(GL_TEXTURE0 + QT_MASK_TEXTURE_UNIT); glBindTexture(GL_TEXTURE_2D, cache->texture()); @@ -1287,14 +1390,7 @@ void QGL2PaintEngineExPrivate::drawCachedGlyphs(const QPointF &p, const QTextIte if (inRenderText) shaderManager->currentProgram()->setUniformValue(location(QGLEngineShaderManager::Depth), zValueForRenderText()); #endif - shaderManager->currentProgram()->setUniformValue(location(QGLEngineShaderManager::MaskTexture), QT_MASK_TEXTURE_UNIT); - - if (vertexCoordinateArray.data() != oldVertexCoordinateDataPtr) - glVertexAttribPointer(QT_VERTEX_COORDS_ATTR, 2, GL_FLOAT, GL_FALSE, 0, vertexCoordinateArray.data()); - if (textureCoordinateArray.data() != oldTextureCoordinateDataPtr) - glVertexAttribPointer(QT_TEXTURE_COORDS_ATTR, 2, GL_FLOAT, GL_FALSE, 0, textureCoordinateArray.data()); - glDrawArrays(GL_TRIANGLES, 0, 6 * glyphs.size()); } @@ -1353,6 +1449,18 @@ bool QGL2PaintEngineEx::begin(QPaintDevice *pdev) glDisable(GL_MULTISAMPLE); #endif + d->glyphCacheType = QFontEngineGlyphCache::Raster_A8; + +#if !defined(QT_OPENGL_ES_2) + if (!d->device->format().alpha() +#if defined(Q_WS_WIN) + && qt_cleartype_enabled +#endif + ) { + d->glyphCacheType = QFontEngineGlyphCache::Raster_RGBMask; + } +#endif + return true; } diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h b/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h index a44be90..8b09f41 100644 --- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h +++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h @@ -60,6 +60,7 @@ #include #include #include +#include enum EngineMode { ImageDrawingMode, @@ -205,6 +206,7 @@ public: int width, height; QGLContext *ctx; EngineMode mode; + QFontEngineGlyphCache::Type glyphCacheType; mutable QOpenGL2PaintEngineState *last_created_state; diff --git a/src/opengl/qglextensions.cpp b/src/opengl/qglextensions.cpp index 3699d62..c785d8a 100644 --- a/src/opengl/qglextensions.cpp +++ b/src/opengl/qglextensions.cpp @@ -391,8 +391,9 @@ bool qt_resolve_version_2_0_functions(QGLContext *ctx) if (glStencilOpSeparate) return gl2supported; + glBlendColor = (_glBlendColor) ctx->getProcAddress(QLatin1String("glBlendColor")); glStencilOpSeparate = (_glStencilOpSeparate) ctx->getProcAddress(QLatin1String("glStencilOpSeparate")); - if (!glStencilOpSeparate) + if (!glBlendColor || !glStencilOpSeparate) gl2supported = false; return gl2supported; diff --git a/src/opengl/qglextensions_p.h b/src/opengl/qglextensions_p.h index 40840b5..3510765 100644 --- a/src/opengl/qglextensions_p.h +++ b/src/opengl/qglextensions_p.h @@ -152,6 +152,7 @@ typedef void (APIENTRY *_glActiveStencilFaceEXT) (GLenum ); // Needed for GL2 engine: typedef void (APIENTRY *_glStencilOpSeparate) (GLenum face, GLenum sfail, GLenum dpfail, GLenum dppass); typedef void (APIENTRY *_glActiveTexture) (GLenum); +typedef void (APIENTRY *_glBlendColor) (GLclampf, GLclampf, GLclampf, GLclampf); // EXT_GL_framebuffer_object @@ -247,6 +248,7 @@ struct QGLExtensionFuncs // Extras for GL2 engine: qt_glActiveTexture = 0; qt_glStencilOpSeparate = 0; + qt_glBlendColor = 0; qt_glActiveStencilFaceEXT = 0; qt_glMultiTexCoord4f = 0; @@ -360,6 +362,8 @@ struct QGLExtensionFuncs // Extras needed for GL2 engine: _glActiveTexture qt_glActiveTexture; _glStencilOpSeparate qt_glStencilOpSeparate; + _glBlendColor qt_glBlendColor; + #endif // FBOs @@ -574,6 +578,10 @@ struct QGLExtensionFuncs #endif #ifndef GL_VERSION_1_4 +#define GL_CONSTANT_COLOR 0x8001 +#define GL_ONE_MINUS_CONSTANT_COLOR 0x8002 +#define GL_CONSTANT_ALPHA 0x8003 +#define GL_ONE_MINUS_CONSTANT_ALPHA 0x8004 #define GL_INCR_WRAP 0x8507 #define GL_DECR_WRAP 0x8508 #endif @@ -717,6 +725,7 @@ struct QGLExtensionFuncs #if !defined(QT_OPENGL_ES_2) #define glStencilOpSeparate QGLContextPrivate::extensionFuncs(ctx).qt_glStencilOpSeparate +#define glBlendColor QGLContextPrivate::extensionFuncs(ctx).qt_glBlendColor #endif #if defined(QT_OPENGL_ES_2) -- cgit v0.12