Change Symbian to use destroyed swap behaviour in GL

Destroyed swap behaviour is a little bit faster than
preserved swap with heavily animated UIs like QML.

Task-number: QTBUG-18270
Reviewed-by: Samuel Rødal

5 files changed, 51 insertions, 23 deletions

diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
index c8786fb..5c8d2b6 100644
--- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
+++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
@@ -90,10 +90,6 @@
 
 QT_BEGIN_NAMESPACE
 
-#if defined(Q_OS_SYMBIAN)
-#define QT_GL_NO_SCISSOR_TEST
-#endif
-
 #if defined(Q_WS_WIN)
 extern Q_GUI_EXPORT bool qt_cleartype_enabled;
 #endif
diff --git a/src/opengl/opengl.pro b/src/opengl/opengl.pro
index 6bbf99b..6d79584 100644
--- a/src/opengl/opengl.pro
+++ b/src/opengl/opengl.pro
@@ -148,7 +148,7 @@ embedded {
 }
 
 symbian {
-    DEFINES += QGL_USE_TEXTURE_POOL
+    DEFINES += QGL_USE_TEXTURE_POOL QGL_NO_PRESERVED_SWAP
     SOURCES -= qpixmapdata_gl.cpp
     SOURCES += qgl_symbian.cpp \
                qpixmapdata_poolgl.cpp \
diff --git a/src/opengl/qgl_symbian.cpp b/src/opengl/qgl_symbian.cpp
index 78624a2..7caaabd 100644
--- a/src/opengl/qgl_symbian.cpp
+++ b/src/opengl/qgl_symbian.cpp
@@ -228,13 +228,20 @@ bool QGLContext::chooseContext(const QGLContext* shareContext) // almost same as
 
         d->eglSurface = QEgl::createSurface(device(), d->eglContext->config());
 
-#if !defined(QGL_NO_PRESERVED_SWAP)
-        eglGetError();  // Clear error state first.
-        eglSurfaceAttrib(QEgl::display(), d->eglSurface,
-                EGL_SWAP_BEHAVIOR, EGL_BUFFER_PRESERVED);
-        if (eglGetError() != EGL_SUCCESS) {
-            qWarning("QGLContext: could not enable preserved swap");
-        }
+    eglGetError();  // Clear error state first.
+
+#ifdef QGL_NO_PRESERVED_SWAP
+    eglSurfaceAttrib(QEgl::display(), d->eglSurface,
+            EGL_SWAP_BEHAVIOR, EGL_BUFFER_DESTROYED);
+
+    if (eglGetError() != EGL_SUCCESS)
+        qWarning("QGLContext: could not enable destroyed swap behaviour");
+#else
+    eglSurfaceAttrib(QEgl::display(), d->eglSurface,
+            EGL_SWAP_BEHAVIOR, EGL_BUFFER_PRESERVED);
+
+    if (eglGetError() != EGL_SUCCESS)
+        qWarning("QGLContext: could not enable preserved swap behaviour");
 #endif
 
         setWindowCreated(true);
diff --git a/src/opengl/qgltexturepool.cpp b/src/opengl/qgltexturepool.cpp
index 61a88c3..a5472ec 100644
--- a/src/opengl/qgltexturepool.cpp
+++ b/src/opengl/qgltexturepool.cpp
@@ -135,8 +135,11 @@ void QGLTexturePool::releaseTexture(QGLPixmapData *data, GLuint texture)
     if (data)
         removeFromLRU(data);
 
-    QGLShareContextScope ctx(qt_gl_share_widget()->context());
-    glDeleteTextures(1, &texture);
+    QGLWidget *shareWidget = qt_gl_share_widget();
+    if (shareWidget) {
+        QGLShareContextScope ctx(shareWidget->context());
+        glDeleteTextures(1, &texture);
+    }
 }
 
 void QGLTexturePool::useTexture(QGLPixmapData *data)
diff --git a/src/opengl/qwindowsurface_gl.cpp b/src/opengl/qwindowsurface_gl.cpp
index 11a9eb0..ed541ce 100644
--- a/src/opengl/qwindowsurface_gl.cpp
+++ b/src/opengl/qwindowsurface_gl.cpp
@@ -371,6 +371,10 @@ QGLWindowSurface::QGLWindowSurface(QWidget *window)
     d_ptr->q_ptr = this;
     d_ptr->geometry_updated = false;
     d_ptr->did_paint = false;
+
+#ifdef QGL_NO_PRESERVED_SWAP
+    setPartialUpdateSupport(false);
+#endif
 }
 
 QGLWindowSurface::~QGLWindowSurface()
@@ -467,8 +471,16 @@ void QGLWindowSurface::hijackWindow(QWidget *widget)
         if (haveNOKSwapRegion)
             qDebug() << "Found EGL_NOK_swap_region2 extension. Using partial updates.";
     }
-    bool swapBehaviourPreserved = (ctx->d_func()->eglContext->configAttrib(EGL_SWAP_BEHAVIOR)
-                        || (ctx->d_func()->eglContext->configAttrib(EGL_SURFACE_TYPE)&EGL_SWAP_BEHAVIOR_PRESERVED_BIT));
+
+    bool swapBehaviourPreserved = ctx->d_func()->eglContext->configAttrib(EGL_SWAP_BEHAVIOR);
+    if (ctx->d_func()->eglContext->configAttrib(EGL_SURFACE_TYPE)&EGL_SWAP_BEHAVIOR_PRESERVED_BIT) {
+        EGLint swapBehavior;
+        if (eglQuerySurface(ctx->d_func()->eglContext->display(), ctx->d_func()->eglSurface
+                            , EGL_SWAP_BEHAVIOR, &swapBehavior)) {
+            swapBehaviourPreserved = (swapBehavior == EGL_BUFFER_PRESERVED);
+        }
+    }
+
     if (!swapBehaviourPreserved && !haveNOKSwapRegion)
         setPartialUpdateSupport(false); // Force full-screen updates
     else
@@ -514,6 +526,8 @@ static void drawTexture(const QRectF &rect, GLuint tex_id, const QSize &texSize,
 
 void QGLWindowSurface::beginPaint(const QRegion &)
 {
+    updateGeometry();
+
     if (!context())
         return;
 
@@ -874,14 +888,22 @@ void QGLWindowSurface::updateGeometry() {
         ctx->d_func()->eglSurface = QEgl::createSurface(ctx->device(),
                                            ctx->d_func()->eglContext->config());
 
-#if !defined(QGL_NO_PRESERVED_SWAP)
-        eglGetError();  // Clear error state first.
-        eglSurfaceAttrib(QEgl::display(), ctx->d_func()->eglSurface,
-                                    EGL_SWAP_BEHAVIOR, EGL_BUFFER_PRESERVED);
-        if (eglGetError() != EGL_SUCCESS) {
-            qWarning("QGLWindowSurface: could not restore preserved swap behaviour");
+        eglGetError();  // Clear error state.
+        if (hasPartialUpdateSupport()) {
+            eglSurfaceAttrib(ctx->d_func()->eglContext->display(),
+                                            ctx->d_func()->eglSurface,
+                                            EGL_SWAP_BEHAVIOR, EGL_BUFFER_PRESERVED);
+
+            if (eglGetError() != EGL_SUCCESS)
+                qWarning("QGLWindowSurface: could not enable preserved swap behaviour");
+        } else {
+            eglSurfaceAttrib(ctx->d_func()->eglContext->display(),
+                                            ctx->d_func()->eglSurface,
+                                            EGL_SWAP_BEHAVIOR, EGL_BUFFER_DESTROYED);
+
+            if (eglGetError() != EGL_SUCCESS)
+                qWarning("QGLWindowSurface: could not enable destroyed swap behaviour");
         }
-#endif
     }
 #endif