Examples: DirectX10/11/12, Allegro, Marmalade: Render functions early out when display size is zero (minimized). (#2496)

examples/imgui_impl_marmalade.cpp

@@ -40,6 +40,10 @@ static ImVec2       g_RenderScale = ImVec2(1.0f,1.0f);
 // (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
 void ImGui_Marmalade_RenderDrawData(ImDrawData* draw_data)
 {
+    // Avoid rendering when minimized
+    if (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f)
+        return;
+
     // Render command lists
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {