Fix window surface config on OpenGL graphics system.

QtOpenGL uses 16-bit configs by default but on Symbian
it should use 32-bit config.

Task-number: QTBUG-23082
Task-number: ou1cimx1#951223
Reviewed-by: Murray Read

2 files changed, 33 insertions, 8 deletions

diff --git a/src/opengl/qgl_egl.cpp b/src/opengl/qgl_egl.cpp
index 0b96350..21047d7 100644
--- a/src/opengl/qgl_egl.cpp
+++ b/src/opengl/qgl_egl.cpp
@@ -64,6 +64,25 @@ void qt_eglproperties_set_glformat(QEglProperties& eglProperties, const QGLForma
     int stencilSize = glFormat.stencilBufferSize();
     int sampleCount = glFormat.samples();
 
+#ifdef Q_OS_SYMBIAN
+    // on Symbian we prefer 32-bit configs
+    if (glFormat.alpha() && alphaSize <= 0)
+        alphaSize = 8;
+    if (glFormat.depth() && depthSize <= 0)
+        depthSize = 24;
+    if (glFormat.stencil() && stencilSize <= 0)
+        stencilSize = 8;
+    if (glFormat.sampleBuffers() && sampleCount <= 0)
+        sampleCount = 1;
+
+    redSize   = redSize   > 0 ? redSize   : 8;
+    greenSize = greenSize > 0 ? greenSize : 8;
+    blueSize  = blueSize  > 0 ? blueSize  : 8;
+    alphaSize = alphaSize > 0 ? alphaSize : 8;
+    depthSize = depthSize > 0 ? depthSize : 24;
+    stencilSize = stencilSize > 0 ? stencilSize : 8;
+    sampleCount = sampleCount > 0 ? sampleCount : 4;
+#else
     // QGLFormat uses a magic value of -1 to indicate "don't care", even when a buffer of that
     // type has been requested. So we must check QGLFormat's booleans too if size is -1:
     if (glFormat.alpha() && alphaSize <= 0)
@@ -101,6 +120,7 @@ void qt_eglproperties_set_glformat(QEglProperties& eglProperties, const QGLForma
     depthSize = depthSize > 0 ? depthSize : 0;
     stencilSize = stencilSize > 0 ? stencilSize : 0;
     sampleCount = sampleCount > 0 ? sampleCount : 0;
+#endif
 
     eglProperties.setValue(EGL_RED_SIZE,   redSize);
     eglProperties.setValue(EGL_GREEN_SIZE, greenSize);
diff --git a/src/opengl/qgl_symbian.cpp b/src/opengl/qgl_symbian.cpp
index 0148304..7d343f6 100644
--- a/src/opengl/qgl_symbian.cpp
+++ b/src/opengl/qgl_symbian.cpp
@@ -181,14 +181,19 @@ bool QGLContext::chooseContext(const QGLContext* shareContext) // almost same as
         d->ownsEglContext = true;
         d->eglContext->setApi(QEgl::OpenGL);
 
-        // Allow apps to override ability to use multisampling by setting an environment variable. Eg:
-        //   qputenv("QT_SYMBIAN_DISABLE_GL_MULTISAMPLE", "1");
-        // Added to allow camera app to start with limited memory.
-        if (!QSymbianGraphicsSystemEx::hasBCM2727() && !qgetenv("QT_SYMBIAN_DISABLE_GL_MULTISAMPLE").toInt()) {
-            // Most likely we have hw support for multisampling
-            // so let's enable it.
-            d->glFormat.setSampleBuffers(1);
-            d->glFormat.setSamples(4);
+        if (d->glFormat.samples() == EGL_DONT_CARE) {
+            // Allow apps to override ability to use multisampling by setting an environment variable. Eg:
+            //   qputenv("QT_SYMBIAN_DISABLE_GL_MULTISAMPLE", "1");
+            // Added to allow camera app to start with limited memory.
+            if (!QSymbianGraphicsSystemEx::hasBCM2727() && !qgetenv("QT_SYMBIAN_DISABLE_GL_MULTISAMPLE").toInt()) {
+                // Most likely we have hw support for multisampling
+                // so let's enable it.
+                d->glFormat.setSampleBuffers(1);
+                d->glFormat.setSamples(4);
+            } else {
+                d->glFormat.setSampleBuffers(0);
+                d->glFormat.setSamples(1);
+            }
         }
 
 	    // If the device is a widget with WA_TranslucentBackground set, make sure the glFormat