diff options
author | Tor Arne Vestbø <tor.arne.vestbo@digia.com> | 2014-12-08 15:31:37 +0100 |
---|---|---|
committer | Tor Arne Vestbø <tor.arne.vestbo@theqtcompany.com> | 2014-12-12 22:37:00 +0100 |
commit | 37490d465b203ac109f422b482eda9704f4e8593 (patch) | |
tree | 6c6b150e68f184e87631e983b4be3cf016ff3f1b /src/gui/opengl/qopenglpaintengine.cpp | |
parent | adfeb9e44479c16945409bb9d45d5720524a8c98 (diff) |
GL: Make updateTexture invalidate texture on change of texture unit
Switching texture units means the value of lastTextureUsed could be
invalid, meaning we need to unconditionally re-bind and update parameters.
A future optimization would be to keep a per-texture-unit cache, so
that we wouldn't have to re-bind and set parameters when switching
units back and forth, but this complicates the current code somewhat,
so it's left for another patch.
Change-Id: Icb2a5d03457a907f3c25bbb437feeb7c5f155716
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@theqtcompany.com>
Diffstat (limited to 'src/gui/opengl/qopenglpaintengine.cpp')
-rw-r--r-- | src/gui/opengl/qopenglpaintengine.cpp | 52 |
1 files changed, 48 insertions, 4 deletions
diff --git a/src/gui/opengl/qopenglpaintengine.cpp b/src/gui/opengl/qopenglpaintengine.cpp index 6570d49279..48a2ceaa55 100644 --- a/src/gui/opengl/qopenglpaintengine.cpp +++ b/src/gui/opengl/qopenglpaintengine.cpp @@ -153,12 +153,26 @@ void QOpenGL2PaintEngineExPrivate::useSimpleShader() updateMatrix(); } +/* + Single entry-point for activating, binding, and setting properties. + + Allows keeping track of (caching) the latest texture unit and bound + texture in a central place, so that we can skip re-binding unless + needed. + + \note Any code or Qt API that internally activates or binds will + not affect the cache used by this function, which means they will + lead to inconsisent state. QPainter::beginNativePainting() takes + care of resetting the cache, so for user–code this is fine, but + internally in the paint engine care must be taken to not call + functions that may activate or bind under our feet. +*/ template<typename T> void QOpenGL2PaintEngineExPrivate::updateTexture(GLenum textureUnit, const T &texture, GLenum wrapMode, GLenum filterMode, TextureUpdateMode updateMode) { static const GLenum target = GL_TEXTURE_2D; - funcs.glActiveTexture(GL_TEXTURE0 + textureUnit); + activateTextureUnit(textureUnit); GLuint textureId = bindTexture(texture); @@ -174,6 +188,20 @@ void QOpenGL2PaintEngineExPrivate::updateTexture(GLenum textureUnit, const T &te funcs.glTexParameteri(target, GL_TEXTURE_MIN_FILTER, filterMode); } +void QOpenGL2PaintEngineExPrivate::activateTextureUnit(GLenum textureUnit) +{ + if (textureUnit != lastTextureUnitUsed) { + funcs.glActiveTexture(GL_TEXTURE0 + textureUnit); + lastTextureUnitUsed = textureUnit; + + // We simplify things by keeping a single cached value of the last + // texture that was bound, instead of one per texture unit. This + // means that switching texture units could potentially mean we + // need a re-bind and corresponding parameter updates. + lastTextureUsed = GLuint(-1); + } +} + template<> GLuint QOpenGL2PaintEngineExPrivate::bindTexture(const GLuint &textureId) { @@ -597,9 +625,15 @@ void QOpenGL2PaintEngineEx::beginNativePainting() } #endif // QT_OPENGL_ES_2 + d->resetGLState(); + + // We don't know what texture units and textures the native painting + // will activate and bind, so we can't assume anything when we return + // from the native painting. + d->lastTextureUnitUsed = QT_UNKNOWN_TEXTURE_UNIT; d->lastTextureUsed = GLuint(-1); + d->dirtyStencilRegion = QRect(0, 0, d->width, d->height); - d->resetGLState(); d->shaderManager->setDirty(); @@ -608,8 +642,9 @@ void QOpenGL2PaintEngineEx::beginNativePainting() void QOpenGL2PaintEngineExPrivate::resetGLState() { + activateTextureUnit(QT_DEFAULT_TEXTURE_UNIT); + funcs.glDisable(GL_BLEND); - funcs.glActiveTexture(GL_TEXTURE0); funcs.glDisable(GL_STENCIL_TEST); funcs.glDisable(GL_DEPTH_TEST); funcs.glDisable(GL_SCISSOR_TEST); @@ -1368,7 +1403,12 @@ void QOpenGL2PaintEngineEx::renderHintsChanged() #endif // QT_OPENGL_ES_2 Q_D(QOpenGL2PaintEngineEx); + + // This is a somewhat sneaky way of conceptually making the next call to + // updateTexture() use FoceUpdate for the TextureUpdateMode. We need this + // as new render hints may require updating the filter mode. d->lastTextureUsed = GLuint(-1); + d->brushTextureDirty = true; // qDebug("QOpenGL2PaintEngineEx::renderHintsChanged() not implemented!"); } @@ -1673,7 +1713,7 @@ void QOpenGL2PaintEngineExPrivate::drawCachedGlyphs(QFontEngine::GlyphFormat gly // uses the image texture unit for blitting to the cache, while // we switch between image and mask units when drawing. static const GLenum glypchCacheTextureUnit = QT_IMAGE_TEXTURE_UNIT; - funcs.glActiveTexture(GL_TEXTURE0 + glypchCacheTextureUnit); + activateTextureUnit(glypchCacheTextureUnit); cache->fillInPendingGlyphs(); @@ -1892,6 +1932,10 @@ void QOpenGL2PaintEngineExPrivate::drawCachedGlyphs(QFontEngine::GlyphFormat gly else funcs.glActiveTexture(GL_TEXTURE0 + QT_MASK_TEXTURE_UNIT); + // Need to reset the unit here, until we've made drawCachedGlyphs + // use the shared code-path for activating and binding. + lastTextureUnitUsed = QT_UNKNOWN_TEXTURE_UNIT; + if (lastMaskTextureUsed != cache->texture()) { funcs.glBindTexture(GL_TEXTURE_2D, cache->texture()); lastMaskTextureUsed = cache->texture(); |