Fixed rendering errors in blurpicker with -graphicssystem opengl

1) Need to transfer to brush drawing mode when switching active engine,
to make sure we reset the vertex / texture coordinate pointers for image
drawing.

2) QGLPixmapGLPaintDevice::beginPaint() was changed to use
QGLContext::drawTexture() for blitting the old texture contents to the
render FBO, which means that we also need to set up viewport, modelview,
and projection matrices, and ensure that clipping / stencil testing
is disabled.

3) Make sure stencil testing is disabled when clearing the FBO.

Reviewed-by: Tom

1 files changed, 1 insertions, 0 deletions

diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
index 5e790cf..e41d0b4 100644
--- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
+++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
@@ -1385,6 +1385,7 @@ void QGL2PaintEngineEx::ensureActive()
     d->device->ensureActiveTarget();
 
     if (d->needsSync) {
+        d->transferMode(BrushDrawingMode);
         glViewport(0, 0, d->width, d->height);
         glDepthMask(false);
         glDepthFunc(GL_LESS);