Changeset 561 for trunk/src/opengl/qwindowsurface_gl.cpp

Timestamp:

Feb 11, 2010, 11:19:06 PM (15 years ago)

Author:

Dmitry A. Kuminov

Message:

trunk: Merged in qt 4.6.1 sources.

Location:

trunk

Files:

• . (modified) (1 prop)
• src/opengl/qwindowsurface_gl.cpp (modified) (34 diffs)

trunk/src/opengl/qwindowsurface_gl.cpp

@@ -2 +2 @@
 **
 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
-** Contact: Qt Software Information (qt-info@nokia.com)
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
 **
 ** This file is part of the QtOpenGL module of the Qt Toolkit.
@@ -21 +22 @@
 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
 **
-** In addition, as a special exception, Nokia gives you certain
-** additional rights. These rights are described in the Nokia Qt LGPL
-** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
-** package.
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
 **
 ** GNU General Public License Usage
@@ -34 +34 @@
 ** met: http://www.gnu.org/copyleft/gpl.html.
 **
-** If you are unsure which license is appropriate for your use, please
-** contact the sales department at qt-sales@nokia.com.
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
 ** $QT_END_LICENSE$
 **
@@ -50 +50 @@
 #include <qcolormap.h>
 #include <qdesktopwidget.h>
+#include <private/qwidget_p.h>
 #include "qdebug.h"
 
@@ -55 +56 @@
 #include <private/qt_x11_p.h>
 #include <qx11info_x11.h>
-#include <private/qwidget_p.h>
 
 #ifndef QT_OPENGL_ES
@@ -70 +70 @@
 #include <private/qglpixelbuffer_p.h>
 #include <private/qgraphicssystem_gl_p.h>
+
+#include <private/qpaintengineex_opengl2_p.h>
+#include <private/qpixmapdata_gl_p.h>
+
+#ifndef QT_OPENGL_ES_2
 #include <private/qpaintengine_opengl_p.h>
+#endif
 
 #ifndef GLX_ARB_multisample
 #define GLX_SAMPLE_BUFFERS_ARB  100000
 #define GLX_SAMPLES_ARB         100001
+#endif
+
+#ifdef QT_OPENGL_ES_1_CL
+#include "qgl_cl_p.h"
+#endif
+
+#ifdef QT_OPENGL_ES
+#include <private/qegl_p.h>
 #endif
 
@@ -83 +97 @@
 //
 #ifdef Q_WS_WIN
-Q_GUI_EXPORT bool qt_win_owndc_required;
+extern Q_GUI_EXPORT bool qt_win_owndc_required;
 #endif
 QGLGraphicsSystem::QGLGraphicsSystem()
@@ -97 +111 @@
         int spec[16];
         spec[i++] = GLX_RGBA;
-#if 0
         spec[i++] = GLX_DOUBLEBUFFER;
-        spec[i++] = GLX_DEPTH_SIZE;
-        spec[i++] = 8;
-        spec[i++] = GLX_STENCIL_SIZE;
-        spec[i++] = 8;
-        spec[i++] = GLX_SAMPLE_BUFFERS_ARB;
-        spec[i++] = 1;
-        spec[i++] = GLX_SAMPLES_ARB;
-        spec[i++] = 4;
-#endif
+
+        if (!qgetenv("QT_GL_SWAPBUFFER_PRESERVE").isNull()) {
+            spec[i++] = GLX_DEPTH_SIZE;
+            spec[i++] = 8;
+            spec[i++] = GLX_STENCIL_SIZE;
+            spec[i++] = 8;
+            spec[i++] = GLX_SAMPLE_BUFFERS_ARB;
+            spec[i++] = 1;
+            spec[i++] = GLX_SAMPLES_ARB;
+            spec[i++] = 4;
+        }
+
         spec[i++] = XNone;
 
@@ -161 +177 @@
     }
 #elif defined(Q_WS_WIN)
-    QGLWindowSurface::surfaceFormat.setDoubleBuffer(false);
+    QGLWindowSurface::surfaceFormat.setDoubleBuffer(true);
 
     qt_win_owndc_required = true;
@@ -174 +190 @@
 {
 public:
-    QGLGlobalShareWidget() : widget(0) {}
+    QGLGlobalShareWidget() : widget(0), initializing(false) {}
 
     QGLWidget *shareWidget() {
-        if (!widget && !cleanedUp) {
+        if (!initializing && !widget && !cleanedUp) {
+            initializing = true;
             widget = new QGLWidget;
+            // We dont need this internal widget to appear in QApplication::topLevelWidgets()
+            if (QWidgetPrivate::allWidgets)
+                QWidgetPrivate::allWidgets->remove(widget);
+            initializing = false;
         }
         return widget;
@@ -184 +205 @@
 
     void cleanup() {
-        delete widget;
+        QGLWidget *w = widget;
+        cleanedUp = true;
         widget = 0;
-        cleanedUp = true;
+        delete w;
     }
 
@@ -193 +215 @@
 private:
     QGLWidget *widget;
+    bool initializing;
 };
 
@@ -215 +238 @@
 }
 
+
 struct QGLWindowSurfacePrivate
 {
@@ -224 +248 @@
     int tried_fbo : 1;
     int tried_pb : 1;
+    int destructive_swap_buffers : 1;
+    int geometry_updated : 1;
 
     QGLContext *ctx;
@@ -233 +259 @@
 
     QList<QImage> buffers;
+    QGLWindowSurfaceGLPaintDevice glDevice;
+    QGLWindowSurface* q_ptr;
 };
 
 QGLFormat QGLWindowSurface::surfaceFormat;
+
+void QGLWindowSurfaceGLPaintDevice::endPaint()
+{
+    glFlush();
+    QGLPaintDevice::endPaint();
+}
+
+QSize QGLWindowSurfaceGLPaintDevice::size() const
+{
+    return d->size;
+}
+
+QGLContext* QGLWindowSurfaceGLPaintDevice::context() const
+{
+    return d->ctx;
+}
+
+
+int QGLWindowSurfaceGLPaintDevice::metric(PaintDeviceMetric m) const
+{
+    return qt_paint_device_metric(d->q_ptr->window(), m);
+}
+
+QPaintEngine *QGLWindowSurfaceGLPaintDevice::paintEngine() const
+{
+    return qt_qgl_paint_engine();
+}
 
 QGLWindowSurface::QGLWindowSurface(QWidget *window)
@@ -245 +300 @@
     d_ptr->fbo = 0;
     d_ptr->ctx = 0;
+#if defined (QT_OPENGL_ES_2)
+    d_ptr->tried_fbo = true;
+    d_ptr->tried_pb = true;
+#else
     d_ptr->tried_fbo = false;
     d_ptr->tried_pb = false;
+#endif
+    d_ptr->destructive_swap_buffers = qgetenv("QT_GL_SWAPBUFFER_PRESERVE").isNull();
+    d_ptr->glDevice.d = d_ptr;
+    d_ptr->q_ptr = this;
+    d_ptr->geometry_updated = false;
 }
 
@@ -263 +327 @@
 }
 
+void QGLWindowSurface::deleted(QObject *object)
+{
+    // Make sure that the fbo is destroyed before destroying its context.
+    delete d_ptr->fbo;
+    d_ptr->fbo = 0;
+
+    QWidget *widget = qobject_cast<QWidget *>(object);
+    if (widget) {
+        QWidgetPrivate *widgetPrivate = widget->d_func();
+        if (widgetPrivate->extraData()) {
+            union { QGLContext **ctxPtr; void **voidPtr; };
+            voidPtr = &widgetPrivate->extraData()->glContext;
+            int index = d_ptr->contexts.indexOf(ctxPtr);
+            if (index != -1) {
+                delete *ctxPtr;
+                *ctxPtr = 0;
+                d_ptr->contexts.removeAt(index);
+            }
+        }
+    }
+}
+
 void QGLWindowSurface::hijackWindow(QWidget *widget)
 {
@@ -272 +358 @@
     QGLContext *ctx = new QGLContext(surfaceFormat, widget);
     ctx->create(qt_gl_share_widget()->context());
-#ifdef Q_WS_MAC
-    ctx->updatePaintDevice();
-#endif
+
+#if defined(Q_WS_X11) && defined(QT_OPENGL_ES)
+    // Create the EGL surface to draw into.  QGLContext::chooseContext()
+    // does not do this for X11/EGL, but does do it for other platforms.
+    // This probably belongs in qgl_x11egl.cpp.
+    QGLContextPrivate *ctxpriv = ctx->d_func();
+    ctxpriv->eglSurface = ctxpriv->eglContext->createSurface(widget);
+    if (ctxpriv->eglSurface == EGL_NO_SURFACE) {
+        qWarning() << "hijackWindow() could not create EGL surface";
+    }
+    qDebug("QGLWindowSurface - using EGLConfig %d", reinterpret_cast<int>(ctxpriv->eglContext->config()));
+#endif
+
     widgetPrivate->extraData()->glContext = ctx;
 
     union { QGLContext **ctxPtr; void **voidPtr; };
+
+    connect(widget, SIGNAL(destroyed(QObject*)), this, SLOT(deleted(QObject*)));
 
     voidPtr = &widgetPrivate->extraData()->glContext;
@@ -284 +382 @@
 }
 
-#if !defined(QT_OPENGL_ES_2)
-Q_GLOBAL_STATIC(QOpenGLPaintEngine, qt_gl_window_surface_paintengine)
-#endif
-
-/*! \reimp */
-QPaintEngine *QGLWindowSurface::paintEngine() const
-{
-#if !defined(QT_OPENGL_ES_2)
-    return qt_gl_window_surface_paintengine();
-#else
-    return 0;
-#endif
-}
-
-int QGLWindowSurface::metric(PaintDeviceMetric m) const
-{
-    return window()->metric(m);
-}
-
 QGLContext *QGLWindowSurface::context() const
 {
@@ -310 +389 @@
 QPaintDevice *QGLWindowSurface::paintDevice()
 {
+    updateGeometry();
+
     if (d_ptr->pb)
         return d_ptr->pb;
 
     if (d_ptr->ctx)
-        return this;
+        return &d_ptr->glDevice;
 
     QGLContext *ctx = reinterpret_cast<QGLContext *>(window()->d_func()->extraData()->glContext);
@@ -337 +418 @@
 void QGLWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoint &offset)
 {
+    if (context() && widget != window()) {
+        qWarning("No native child widget support in GL window surface without FBOs or pixel buffers");
+        return;
+    }
+
+    //### Find out why d_ptr->geometry_updated isn't always false.
+    // flush() should not be called when d_ptr->geometry_updated is true. It assumes that either
+    // d_ptr->fbo or d_ptr->pb is allocated and has the correct size.
+    if (d_ptr->geometry_updated)
+        return;
+
     QWidget *parent = widget->internalWinId() ? widget : widget->nativeParentWidget();
     Q_ASSERT(parent);
 
+    if (!geometry().isValid())
+        return;
+
+    // Needed to support native child-widgets...
     hijackWindow(parent);
 
@@ -347 +443 @@
     QRect rect = br.translated(-offset - wOffset);
 
-    const GLenum target = qt_gl_preferredTextureTarget();
+    const GLenum target = GL_TEXTURE_2D;
+    Q_UNUSED(target);
 
     if (context()) {
@@ -353 +450 @@
 
         if (context()->format().doubleBuffer()) {
-            glBindTexture(target, d_ptr->tex_id);
-
-            QVector<QRect> rects = d_ptr->paintedRegion.rects();
-            for (int i = 0; i < rects.size(); ++i) {
-                QRect br = rects.at(i);
-                if (br.isEmpty())
-                    continue;
-
-                const uint bottom = window()->height() - (br.y() + br.height());
-                glCopyTexSubImage2D(target, 0, br.x(), bottom, br.x(), bottom, br.width(), br.height());
-            }
-
-            glBindTexture(target, 0);
-
-            QRegion dirtyRegion = QRegion(window()->rect()) - d_ptr->paintedRegion;
-
-            if (!dirtyRegion.isEmpty()) {
-                context()->makeCurrent();
-
-                glMatrixMode(GL_MODELVIEW);
-                glLoadIdentity();
-
-                glMatrixMode(GL_PROJECTION);
-                glLoadIdentity();
+#if !defined(QT_OPENGL_ES_2)
+            if (d_ptr->destructive_swap_buffers) {
+                glBindTexture(target, d_ptr->tex_id);
+
+                QVector<QRect> rects = d_ptr->paintedRegion.rects();
+                for (int i = 0; i < rects.size(); ++i) {
+                    QRect br = rects.at(i);
+                    if (br.isEmpty())
+                        continue;
+
+                    const uint bottom = window()->height() - (br.y() + br.height());
+                    glCopyTexSubImage2D(target, 0, br.x(), bottom, br.x(), bottom, br.width(), br.height());
+                }
+
+                glBindTexture(target, 0);
+
+                QRegion dirtyRegion = QRegion(window()->rect()) - d_ptr->paintedRegion;
+
+                if (!dirtyRegion.isEmpty()) {
+                    glMatrixMode(GL_MODELVIEW);
+                    glLoadIdentity();
+
+                    glMatrixMode(GL_PROJECTION);
+                    glLoadIdentity();
 #ifndef QT_OPENGL_ES
-                glOrtho(0, window()->width(), window()->height(), 0, -999999, 999999);
+                    glOrtho(0, window()->width(), window()->height(), 0, -999999, 999999);
 #else
-                glOrthof(0, window()->width(), window()->height(), 0, -999999, 999999);
-#endif
-                glViewport(0, 0, window()->width(), window()->height());
-
-                QVector<QRect> rects = dirtyRegion.rects();
-                glColor4f(1, 1, 1, 1);
-                for (int i = 0; i < rects.size(); ++i) {
-                    QRect rect = rects.at(i);
-                    if (rect.isEmpty())
-                        continue;
-
-                    drawTexture(rect, d_ptr->tex_id, window()->size(), rect);
+                    glOrthof(0, window()->width(), window()->height(), 0, -999999, 999999);
+#endif
+                    glViewport(0, 0, window()->width(), window()->height());
+
+                    QVector<QRect> rects = dirtyRegion.rects();
+                    glColor4f(1, 1, 1, 1);
+                    for (int i = 0; i < rects.size(); ++i) {
+                        QRect rect = rects.at(i);
+                        if (rect.isEmpty())
+                            continue;
+
+                        drawTexture(rect, d_ptr->tex_id, window()->size(), rect);
+                    }
                 }
             }
+#endif
             d_ptr->paintedRegion = QRegion();
-
             context()->swapBuffers();
         } else {
@@ -404 +502 @@
     }
 
+    QGLContext *previous_ctx = const_cast<QGLContext *>(QGLContext::currentContext());
     QGLContext *ctx = reinterpret_cast<QGLContext *>(parent->d_func()->extraData()->glContext);
-    GLuint texture;
+
+    // QPainter::end() should have unbound the fbo, otherwise something is very wrong...
+    Q_ASSERT(!d_ptr->fbo || !d_ptr->fbo->isBound());
+
+    if (ctx != previous_ctx) {
+        ctx->makeCurrent();
+    }
+
+    QSize size = widget->rect().size();
+    if (d_ptr->destructive_swap_buffers && ctx->format().doubleBuffer()) {
+        rect = parent->rect();
+        br = rect.translated(wOffset + offset);
+        size = parent->size();
+    }
+
+    glDisable(GL_SCISSOR_TEST);
+
+    if (d_ptr->fbo && (QGLExtensions::glExtensions & QGLExtensions::FramebufferBlit)) {
+        const int h = d_ptr->fbo->height();
+
+        const int sx0 = br.left();
+        const int sx1 = br.left() + br.width();
+        const int sy0 = h - (br.top() + br.height());
+        const int sy1 = h - br.top();
+
+        const int tx0 = rect.left();
+        const int tx1 = rect.left() + rect.width();
+        const int ty0 = parent->height() - (rect.top() + rect.height());
+        const int ty1 = parent->height() - rect.top();
+
+        if (window() == parent || d_ptr->fbo->format().samples() <= 1) {
+            // glBindFramebuffer(GL_DRAW_FRAMEBUFFER_EXT, 0);
+            glBindFramebuffer(GL_READ_FRAMEBUFFER_EXT, d_ptr->fbo->handle());
+
+            glBlitFramebufferEXT(sx0, sy0, sx1, sy1,
+                    tx0, ty0, tx1, ty1,
+                    GL_COLOR_BUFFER_BIT,
+                    GL_NEAREST);
+
+            glBindFramebuffer(GL_READ_FRAMEBUFFER_EXT, 0);
+        } else {
+            // can't do sub-region blits with multisample FBOs
+            QGLFramebufferObject *temp = qgl_fbo_pool()->acquire(d_ptr->fbo->size(), QGLFramebufferObjectFormat());
+
+            glBindFramebuffer(GL_DRAW_FRAMEBUFFER_EXT, temp->handle());
+            glBindFramebuffer(GL_READ_FRAMEBUFFER_EXT, d_ptr->fbo->handle());
+
+            glBlitFramebufferEXT(0, 0, d_ptr->fbo->width(), d_ptr->fbo->height(),
+                    0, 0, d_ptr->fbo->width(), d_ptr->fbo->height(),
+                    GL_COLOR_BUFFER_BIT,
+                    GL_NEAREST);
+
+            glBindFramebuffer(GL_READ_FRAMEBUFFER_EXT, temp->handle());
+            glBindFramebuffer(GL_DRAW_FRAMEBUFFER_EXT, 0);
+
+            glBlitFramebufferEXT(sx0, sy0, sx1, sy1,
+                    tx0, ty0, tx1, ty1,
+                    GL_COLOR_BUFFER_BIT,
+                    GL_NEAREST);
+
+            glBindFramebuffer(GL_READ_FRAMEBUFFER_EXT, 0);
+
+            qgl_fbo_pool()->release(temp);
+        }
+    }
+#if !defined(QT_OPENGL_ES_2)
+    else {
+        GLuint texture;
     if (d_ptr->fbo) {
         texture = d_ptr->fbo->texture();
@@ -417 +583 @@
     }
 
-    QSize size = widget->rect().size();
-    if (ctx->format().doubleBuffer()) {
-        rect = parent->rect();
-        br = rect.translated(wOffset);
-        size = parent->size();
-    }
-
-    ctx->makeCurrent();
-#ifdef Q_WS_MAC
-    ctx->updatePaintDevice();
-#endif
-    if (d_ptr->fbo)
-        d_ptr->fbo->release();
-
-    glMatrixMode(GL_MODELVIEW);
-    glLoadIdentity();
-
-    glMatrixMode(GL_PROJECTION);
-    glLoadIdentity();
+        glDisable(GL_DEPTH_TEST);
+
+        if (d_ptr->fbo) {
+            d_ptr->fbo->release();
+        } else {
+            ctx->makeCurrent();
+        }
+
+        glMatrixMode(GL_MODELVIEW);
+        glLoadIdentity();
+
+        glMatrixMode(GL_PROJECTION);
+        glLoadIdentity();
 #ifndef QT_OPENGL_ES
-    glOrtho(0, size.width(), size.height(), 0, -999999, 999999);
+        glOrtho(0, size.width(), size.height(), 0, -999999, 999999);
 #else
-    glOrthof(0, size.width(), size.height(), 0, -999999, 999999);
-#endif
-    glViewport(0, 0, size.width(), size.height());
-
-    glColor4f(1, 1, 1, 1);
-    drawTexture(rect, texture, window()->size(), br);
+        glOrthof(0, size.width(), size.height(), 0, -999999, 999999);
+#endif
+        glViewport(0, 0, size.width(), size.height());
+
+        glColor4f(1, 1, 1, 1);
+        drawTexture(rect, texture, window()->size(), br);
+
+        if (d_ptr->fbo)
+            d_ptr->fbo->bind();
+    }
+#else
+    // OpenGL/ES 2.0 version of the fbo blit.
+    else if (d_ptr->fbo) {
+        Q_UNUSED(target);
+
+        GLuint texture = d_ptr->fbo->texture();
+
+        glDisable(GL_DEPTH_TEST);
+
+        if (d_ptr->fbo->isBound())
+            d_ptr->fbo->release();
+
+        glViewport(0, 0, size.width(), size.height());
+
+        QGLShaderProgram *blitProgram =
+            QGLEngineSharedShaders::shadersForContext(ctx)->blitProgram();
+        blitProgram->bind();
+        blitProgram->setUniformValue("imageTexture", 0 /*QT_IMAGE_TEXTURE_UNIT*/);
+
+        // The shader manager's blit program does not multiply the
+        // vertices by the pmv matrix, so we need to do the effect
+        // of the orthographic projection here ourselves.
+        QRectF r;
+        qreal w = size.width() ? size.width() : 1.0f;
+        qreal h = size.height() ? size.height() : 1.0f;
+        r.setLeft((rect.left() / w) * 2.0f - 1.0f);
+        if (rect.right() == (size.width() - 1))
+            r.setRight(1.0f);
+        else
+            r.setRight((rect.right() / w) * 2.0f - 1.0f);
+        r.setBottom((rect.top() / h) * 2.0f - 1.0f);
+        if (rect.bottom() == (size.height() - 1))
+            r.setTop(1.0f);
+        else
+            r.setTop((rect.bottom() / w) * 2.0f - 1.0f);
+
+        drawTexture(r, texture, window()->size(), br);
+    }
+#endif
 
     if (ctx->format().doubleBuffer())
@@ -450 +653 @@
     else
         glFlush();
-
-    if (d_ptr->fbo)
-        d_ptr->fbo->bind();
-}
+}
+
 
 void QGLWindowSurface::setGeometry(const QRect &rect)
 {
     QWindowSurface::setGeometry(rect);
-
-    const GLenum target = qt_gl_preferredTextureTarget();
+    d_ptr->geometry_updated = true;
+}
+
+
+void QGLWindowSurface::updateGeometry() {
+    if (!d_ptr->geometry_updated)
+        return;
+    d_ptr->geometry_updated = false;
+
+
+    QRect rect = geometry();
+    hijackWindow(window());
+    QGLContext *ctx = reinterpret_cast<QGLContext *>(window()->d_func()->extraData()->glContext);
+
+#ifdef Q_WS_MAC
+    ctx->updatePaintDevice();
+#endif
+
+    const GLenum target = GL_TEXTURE_2D;
 
     if (rect.width() <= 0 || rect.height() <= 0)
@@ -470 +688 @@
 
     if (d_ptr->ctx) {
-        glBindTexture(target, d_ptr->tex_id);
-        glTexImage2D(target, 0, GL_RGBA, rect.width(), rect.height(), 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
-        glBindTexture(target, 0);
+#ifndef QT_OPENGL_ES_2
+        if (d_ptr->destructive_swap_buffers) {
+            glBindTexture(target, d_ptr->tex_id);
+            glTexImage2D(target, 0, GL_RGBA, rect.width(), rect.height(), 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
+            glBindTexture(target, 0);
+        }
+#endif
         return;
     }
 
-    if (d_ptr->pb || !d_ptr->tried_pb) {
+    if (d_ptr->destructive_swap_buffers
+        && (QGLExtensions::glExtensions & QGLExtensions::FramebufferObject)
+        && (d_ptr->fbo || !d_ptr->tried_fbo)
+        && qt_gl_preferGL2Engine())
+    {
+        d_ptr->tried_fbo = true;
+        ctx->d_ptr->internal_context = true;
+        ctx->makeCurrent();
+        delete d_ptr->fbo;
+
+        QGLFramebufferObjectFormat format;
+        format.setAttachment(QGLFramebufferObject::CombinedDepthStencil);
+        format.setInternalTextureFormat(GLenum(GL_RGBA));
+        format.setTextureTarget(target);
+
+        if (QGLExtensions::glExtensions & QGLExtensions::FramebufferBlit)
+            format.setSamples(8);
+
+        d_ptr->fbo = new QGLFramebufferObject(rect.size(), format);
+
+        if (d_ptr->fbo->isValid()) {
+            qDebug() << "Created Window Surface FBO" << rect.size()
+                     << "with samples" << d_ptr->fbo->format().samples();
+            return;
+        } else {
+            qDebug() << "QGLWindowSurface: Failed to create valid FBO, falling back";
+            delete d_ptr->fbo;
+            d_ptr->fbo = 0;
+        }
+    }
+
+#if !defined(QT_OPENGL_ES_2)
+    if (d_ptr->destructive_swap_buffers && (d_ptr->pb || !d_ptr->tried_pb)) {
         d_ptr->tried_pb = true;
 
@@ -491 +745 @@
 
         if (d_ptr->pb->isValid()) {
-            qDebug() << "PB Sample buffers:" << d_ptr->pb->format().sampleBuffers();
+            qDebug() << "Created Window Surface Pixelbuffer, Sample buffers:" << d_ptr->pb->format().sampleBuffers();
             d_ptr->pb->makeCurrent();
 
@@ -504 +758 @@
             glMatrixMode(GL_PROJECTION);
             glLoadIdentity();
-#ifndef QT_OPENGL_ES
             glOrtho(0, d_ptr->pb->width(), d_ptr->pb->height(), 0, -999999, 999999);
-#else
-            glOrthof(0, d_ptr->pb->width(), d_ptr->pb->height(), 0, -999999, 999999);
-#endif
 
             d_ptr->pb->d_ptr->qctx->d_func()->internal_context = true;
@@ -518 +768 @@
         }
     }
-
-    if ((QGLExtensions::glExtensions & QGLExtensions::FramebufferObject) && (d_ptr->fbo || !d_ptr->tried_fbo)) {
-        d_ptr->tried_fbo = true;
-        hijackWindow(window());
-        QGLContext *ctx = reinterpret_cast<QGLContext *>(window()->d_func()->extraData()->glContext);
-        ctx->d_ptr->internal_context = true;
-        ctx->makeCurrent();
-        delete d_ptr->fbo;
-        d_ptr->fbo = new QGLFramebufferObject(rect.size(), QGLFramebufferObject::CombinedDepthStencil,
-                                              GLenum(target), GLenum(GL_RGBA));
-
-        d_ptr->fbo->bind();
-        if (d_ptr->fbo->isValid()) {
-            return;
-        } else {
-            qDebug() << "QGLWindowSurface: Failed to create valid FBO, falling back";
-            delete d_ptr->fbo;
-            d_ptr->fbo = 0;
-        }
-    }
-
-    hijackWindow(window());
-    QGLContext *ctx = reinterpret_cast<QGLContext *>(window()->d_func()->extraData()->glContext);
+#endif // !defined(QT_OPENGL_ES_2)
+
     ctx->makeCurrent();
 
-    glGenTextures(1, &d_ptr->tex_id);
-    glBindTexture(target, d_ptr->tex_id);
-    glTexImage2D(target, 0, GL_RGBA, rect.width(), rect.height(), 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
-
-    glTexParameterf(target, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glTexParameterf(target, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glBindTexture(target, 0);
+#ifndef QT_OPENGL_ES_2
+    if (d_ptr->destructive_swap_buffers) {
+        glGenTextures(1, &d_ptr->tex_id);
+        glBindTexture(target, d_ptr->tex_id);
+        glTexImage2D(target, 0, GL_RGBA, rect.width(), rect.height(), 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
+
+        glTexParameterf(target, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+        glTexParameterf(target, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+        glBindTexture(target, 0);
+    }
+#endif
 
     qDebug() << "QGLWindowSurface: Using plain widget as window surface" << this;;
@@ -579 +812 @@
 #endif
 
-    const GLenum target = qt_gl_preferredTextureTarget();
+    const GLenum target = GL_TEXTURE_2D;
 
     glBindTexture(target, d_ptr->tex_id);
@@ -592 +825 @@
 static void drawTexture(const QRectF &rect, GLuint tex_id, const QSize &texSize, const QRectF &br)
 {
-    const GLenum target = qt_gl_preferredTextureTarget();
+    const GLenum target = GL_TEXTURE_2D;
     QRectF src = br.isEmpty()
         ? QRectF(QPointF(), texSize)
@@ -620 +853 @@
     qt_add_rect_to_array(rect, vertexArray);
 
+#if !defined(QT_OPENGL_ES_2)
     glVertexPointer(2, q_vertexTypeEnum, 0, vertexArray);
     glTexCoordPointer(2, q_vertexTypeEnum, 0, texCoordArray);
@@ -634 +868 @@
     glDisable(target);
     glBindTexture(target, 0);
+#else
+    glVertexAttribPointer(QT_VERTEX_COORDS_ATTR, 2, GL_FLOAT, GL_FALSE, 0, vertexArray);
+    glVertexAttribPointer(QT_TEXTURE_COORDS_ATTR, 2, GL_FLOAT, GL_FALSE, 0, texCoordArray);
+
+    glBindTexture(target, tex_id);
+
+    glEnableVertexAttribArray(QT_VERTEX_COORDS_ATTR);
+    glEnableVertexAttribArray(QT_TEXTURE_COORDS_ATTR);
+    glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+    glDisableVertexAttribArray(QT_VERTEX_COORDS_ATTR);
+    glDisableVertexAttribArray(QT_TEXTURE_COORDS_ATTR);
+
+    glBindTexture(target, 0);
+#endif
 }