Add a simple test for rendering a light entity

Render the light entity in wireframe mode and confirm we receive the expected
number of renderables (origin diamond, radius and light_center depending on
selection status).

include/irenderable.h

@@ -16,8 +16,7 @@ class RendererLight;
 class LitObject;
 
 /**
- * \brief
- * Class which accepts OpenGLRenderable objects during the first pass of
+ * \brief Class which accepts OpenGLRenderable objects during the first pass of
  * rendering.
  *
  * Each Renderable in the scenegraph is passed a reference to a
@@ -33,8 +32,7 @@ class RenderableCollector
     virtual ~RenderableCollector() {}
 
     /**
-     * \brief
-     * Submit a renderable object
+     * \brief Submit a renderable object.
      *
      * This method allows renderable geometry to be submitted under the control
      * of a LitObject which will determine whether and how the renderable is
@@ -74,8 +72,7 @@ class RenderableCollector
                                const IRenderEntity* entity = nullptr) = 0;
 
     /**
-     * \brief
-     * Submit a light source for the render operation.
+     * \brief Submit a light source for the render operation.
      *
      * This is the entry point for lights into the render front-end. Each light
      * in the scene graph must be submitted through this method in order to
@@ -85,9 +82,8 @@ class RenderableCollector
     virtual void addLight(const RendererLight& light) = 0;
 
     /**
-     * \brief
-     * Determine if this RenderableCollector can accept renderables for full
-     * materials rendering, or just wireframe rendering.
+     * \brief Determine if this RenderableCollector can accept renderables for
+     * full materials rendering, or just wireframe rendering.
      *
      * \return
      * true if full materials are supported, false if only wireframe rendering

test/Entity.cpp

@@ -2,6 +2,10 @@
 
 #include "ieclass.h"
 #include "ientity.h"
+#include "irendersystemfactory.h"
+#include "iselectable.h"
+
+#include "render/NopVolumeTest.h"
 
 namespace test
 {
@@ -244,6 +248,64 @@ TEST_F(EntityTest, CopySpawnargs)
     EXPECT_EQ(overlap.size(), 0);
 }
 
+namespace
+{
+    // A simple RenderableCollector which just logs the number of renderables
+    // and lights submitted
+    struct TestRenderableCollector: public RenderableCollector
+    {
+        int renderables = 0;
+        int lights = 0;
+
+        void addRenderable(Shader& shader, const OpenGLRenderable& renderable,
+                           const Matrix4& localToWorld,
+                           const LitObject* litObject = nullptr,
+                           const IRenderEntity* entity = nullptr) override
+        {
+            ++renderables;
+        }
+
+        void addLight(const RendererLight& light)
+        {
+            ++lights;
+        }
+
+        bool supportsFullMaterials() const override { return true; }
+        void setHighlightFlag(Highlight::Flags flags, bool enabled) override
+        {}
+    };
+}
+
+TEST_F(EntityTest, RenderLightEntity)
+{
+    auto light = createByClassName("light");
+    auto& spawnArgs = light->getEntity();
+
+    // Rendering requires a backend and a volume test
+    auto backend = GlobalRenderSystemFactory().createRenderSystem();
+    render::NopVolumeTest volumeTest;
+
+    // Render the light in wireframe mode. This should render just the origin
+    // diamond.
+    {
+        TestRenderableCollector wireframeRenderer;
+        light->setRenderSystem(backend);
+        light->renderWireframe(wireframeRenderer, volumeTest);
+        EXPECT_EQ(wireframeRenderer.renderables, 1);
+    }
+
+    // With the light selected, we should get the origin diamond, the radius and
+    // the center vertex.
+    {
+        TestRenderableCollector wireframeRenderer;
+        Node_getSelectable(light)->setSelected(true);
+        light->setRenderSystem(backend);
+        light->renderWireframe(wireframeRenderer, volumeTest);
+        EXPECT_EQ(wireframeRenderer.renderables, 3);
+        Node_getSelectable(light)->setSelected(false);
+    }
+}
+
 TEST_F(EntityTest, CreateAttachedLightEntity)
 {
     // Create the torch entity which has an attached light