fix frame background if a texture is present

Sofa/GL/Component/Rendering3D/src/sofa/gl/component/rendering3d/OglSceneFrame.cpp

@@ -42,6 +42,7 @@ OglSceneFrame::OglSceneFrame()
     , d_style(initData(&d_style, defaultStyle, "style", ("Style of the frame\n" + Style::dataDescription()).c_str()))
     , d_alignment(initData(&d_alignment, defaultAlignment, "alignment", ("Alignment of the frame in the view\n" + Alignment::dataDescription()).c_str()))
     , d_viewportSize(initData(&d_viewportSize, 150, "viewportSize", "Size of the viewport where the frame is rendered"))
+    , d_solidBackground(initData(&d_solidBackground, false, "solidBackground", "If true, an opaque bkacground will be rendered; otherwise the frame is rendered on top on the normal viewport."))
 {}
 
 void OglSceneFrame::drawArrows(const core::visual::VisualParams* vparams)
@@ -129,12 +130,19 @@ void OglSceneFrame::doDrawVisual(const core::visual::VisualParams* vparams)
             glScissor(0,viewport[3]-viewportSize,viewportSize,viewportSize);
             break;
     }
-
-
+
     glEnable(GL_SCISSOR_TEST);
-    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
-    glClearColor (1.0f, 1.0f, 1.0f, 0.0f);
-
+    if(d_solidBackground.getValue())
+    {
+        // reset color and depth for the mini viewport (setting a background and making render on front)
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
+    }
+    else
+    {
+        // only reset depth to appear on front
+        glClear(GL_DEPTH_BUFFER_BIT );
+    }
+
     glMatrixMode(GL_PROJECTION);
     vparams->drawTool()->pushMatrix();
     glLoadIdentity();

Sofa/GL/Component/Rendering3D/src/sofa/gl/component/rendering3d/OglSceneFrame.h

@@ -58,6 +58,7 @@ class SOFA_GL_COMPONENT_RENDERING3D_API OglSceneFrame : public core::visual::Vis
 
     Data<Alignment> d_alignment; ///< Alignment of the frame in the view
     Data<int> d_viewportSize; ///< Size of the viewport where the frame is rendered
+    Data<bool> d_solidBackground;
 
     OglSceneFrame();