Add warnings to readFramebuffer

This allows detecting problems with the render capture if the capture
fails.

Change-Id: I20f630eb9a1adb677513ff225d21c7e338c57809
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/src/render/graphicshelpers/graphicscontext.cpp b/src/render/graphicshelpers/graphicscontext.cpp
index c5440e45e..3bd5cdb4a 100644
--- a/src/render/graphicshelpers/graphicscontext.cpp
+++ b/src/render/graphicshelpers/graphicscontext.cpp
@@ -1812,8 +1812,11 @@ QImage GraphicsContext::readFramebuffer(QSize size)
 
     GLint samples = 0;
     m_gl->functions()->glGetIntegerv(GL_SAMPLES, &samples);
-    if (samples > 0 && !m_glHelper->supportsFeature(GraphicsHelperInterface::BlitFramebuffer))
+    if (samples > 0 && !m_glHelper->supportsFeature(GraphicsHelperInterface::BlitFramebuffer)) {
+        qWarning () << Q_FUNC_INFO << "Unable to capture multisampled framebuffer; "
+                       "Required feature BlitFramebuffer is missing.";
         return img;
+    }
 
     img = QImage(size.width(), size.height(), imageFormat);
 
@@ -1834,6 +1837,7 @@ QImage GraphicsContext::readFramebuffer(QSize size)
         if (status != GL_FRAMEBUFFER_COMPLETE) {
             gl->glDeleteRenderbuffers(1, &rb);
             gl->glDeleteFramebuffers(1, &fbo);
+            qWarning () << Q_FUNC_INFO << "Copy-framebuffer not complete: " << status;
             return img;
         }