Force software renderer to using ES2

Task-number: QTRD-3410
Change-Id: I86b240b6548ec4c94f6be0dc352ed112965926f3
Change-Id: I86b240b6548ec4c94f6be0dc352ed112965926f3
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@theqtcompany.com>

README

@@ -88,4 +88,5 @@ Known Issues
   "QT += datavisualization" in the pro file. This is because Qt Data Visualization QML plugin has
   a dependency to Qt Data Visualization C++ library, which Qt Creator doesn't automatically add
   to the deployment package.
-
+- Only OpenGL ES2 emulation is available for software renderer (that is, when using
+  QCoreApplication::setAttribute(Qt::AA_UseSoftwareOpenGL))

src/datavisualization/doc/src/qtdatavisualization.qdoc

@@ -338,6 +338,8 @@
             "QT += datavisualization" in the pro file. This is because Qt Data Visualization
             QML plugin has a dependency to Qt Data Visualization C++ library, which Qt Creator
             doesn't automatically add to the deployment package.
+        \li Only OpenGL ES2 emulation is available for software renderer (that is, when using
+            QCoreApplication::setAttribute(Qt::AA_UseSoftwareOpenGL))
     \endlist
 */
 

src/datavisualization/utils/qutils.h

@@ -20,29 +20,68 @@
 #define QUTILS_H
 
 #include <QtGui/QSurfaceFormat>
+#include <QtGui/QOpenGLContext>
+#include <QtGui/QOffscreenSurface>
+#include <QtCore/QCoreApplication>
 
 namespace QtDataVisualization {
 
 inline static QSurfaceFormat qDefaultSurfaceFormat(bool antialias = true)
 {
+    bool isES = false;
+
     QSurfaceFormat surfaceFormat;
 
+    // Common attributes
     surfaceFormat.setDepthBufferSize(24);
     surfaceFormat.setStencilBufferSize(8);
     surfaceFormat.setSwapBehavior(QSurfaceFormat::DoubleBuffer);
     surfaceFormat.setRenderableType(QSurfaceFormat::DefaultRenderableType);
+
+    QOpenGLContext *ctx = QOpenGLContext::currentContext();
+    QOffscreenSurface *dummySurface = 0;
+    if (!ctx) {
+        dummySurface = new QOffscreenSurface();
+        dummySurface->setFormat(surfaceFormat);
+        dummySurface->create();
+        ctx = new QOpenGLContext;
+        ctx->setFormat(surfaceFormat);
+        ctx->create();
+        ctx->makeCurrent(dummySurface);
+    }
+
 #if defined(QT_OPENGL_ES_2)
-    // Antialias not supported for ES
+    isES = true;
-    antialias = false;
+#elif (QT_VERSION < QT_VERSION_CHECK(5, 3, 0))
-    surfaceFormat.setRedBufferSize(8);
+    isES = false;
-    surfaceFormat.setBlueBufferSize(8);
+#else
-    surfaceFormat.setGreenBufferSize(8);
+    isES = ctx->isOpenGLES();
 #endif
 
-    if (antialias)
+    if (dummySurface) {
-        surfaceFormat.setSamples(8);
+        ctx->doneCurrent();
-    else
+        delete ctx;
-        surfaceFormat.setSamples(0);
+        delete dummySurface;
+    }
+
+    // We support only ES2 emulation with software renderer for now
+    if (QCoreApplication::testAttribute(Qt::AA_UseSoftwareOpenGL)) {
+        qWarning("Only OpenGL ES2 emulation is available for software rendering.");
+        isES = true;
+    }
+
+    if (isES) {
+        // For ES2 only attributes
+        surfaceFormat.setRedBufferSize(8);
+        surfaceFormat.setBlueBufferSize(8);
+        surfaceFormat.setGreenBufferSize(8);
+    } else {
+        // For OpenGL only attributes
+        if (antialias)
+            surfaceFormat.setSamples(8);
+        else
+            surfaceFormat.setSamples(0);
+    }
 
     return surfaceFormat;
 }

src/datavisualization/utils/utils.cpp

@@ -329,7 +329,7 @@ void Utils::resolveStatics()
     QOpenGLContext *ctx = QOpenGLContext::currentContext();
     QOffscreenSurface *dummySurface = 0;
     if (!ctx) {
-        QSurfaceFormat surfaceFormat = qDefaultSurfaceFormat();
+        QSurfaceFormat surfaceFormat;
         dummySurface = new QOffscreenSurface();
         dummySurface->setFormat(surfaceFormat);
         dummySurface->create();
@@ -355,6 +355,12 @@ void Utils::resolveStatics()
         delete dummySurface;
     }
 
+    // We support only ES2 emulation with software renderer for now
+    if (QCoreApplication::testAttribute(Qt::AA_UseSoftwareOpenGL)) {
+        qWarning("Only OpenGL ES2 emulation is available for software rendering.");
+        isES = true;
+    }
+
     staticsResolved = true;
 }