Add test for the "overrideLightColour" registry key

Confirm that a light wireframe is rendered with a default shader (based on the
entity class) if the registry key is set, then reverts to using the _color key
once the registry key is cleared.

libs/registry/CachedKey.h

@@ -6,8 +6,7 @@ namespace registry
 {
 
 /**
- * \brief
- * Simple value caching class for a registry key.
+ * \brief Simple value caching class for a registry key.
  *
  * This can be used when a registry key needs to be read frequently but only
  * written rarely. It stores a copy of the value converted to its given type,

radiantcore/entity/light/LightNode.cpp

@@ -26,7 +26,8 @@ LightNode::LightNode(const IEntityClassPtr& eclass) :
 	_lightEndInstance(_light.endTransformed(), std::bind(&LightNode::selectedChangedComponent, this, std::placeholders::_1)),
 	_dragPlanes(std::bind(&LightNode::selectedChangedComponent, this, std::placeholders::_1)),
     _renderableRadius(_light._lightBox.origin),
-    _renderableFrustum(_light._lightBox.origin, _light._lightStartTransformed, _light._frustum)
+    _renderableFrustum(_light._lightBox.origin, _light._lightStartTransformed, _light._frustum),
+    _overrideColKey(colours::RKEY_OVERRIDE_LIGHTCOL)
 {}
 
 LightNode::LightNode(const LightNode& other) :
@@ -46,7 +47,8 @@ LightNode::LightNode(const LightNode& other) :
 	_lightEndInstance(_light.endTransformed(), std::bind(&LightNode::selectedChangedComponent, this,std::placeholders:: _1)),
 	_dragPlanes(std::bind(&LightNode::selectedChangedComponent, this, std::placeholders::_1)),
     _renderableRadius(_light._lightBox.origin),
-    _renderableFrustum(_light._lightBox.origin, _light._lightStartTransformed, _light._frustum)
+    _renderableFrustum(_light._lightBox.origin, _light._lightStartTransformed, _light._frustum),
+    _overrideColKey(colours::RKEY_OVERRIDE_LIGHTCOL)
 {}
 
 LightNodePtr LightNode::Create(const IEntityClassPtr& eclass)
@@ -303,9 +305,6 @@ void LightNode::renderLightVolume(RenderableCollector& collector,
                                   bool selected) const
 {
     // Obtain the appropriate Shader for the light volume colour
-    static registry::CachedKey<bool> _overrideColKey(
-        colours::RKEY_OVERRIDE_LIGHTCOL
-    );
     Shader* colourShader = _overrideColKey.get() ? EntityNode::_wireShader.get()
                                                  : _colourKey.getWireShader();
     if (!colourShader)

radiantcore/entity/light/LightNode.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "ilightnode.h"
+#include "registry/CachedKey.h"
 
 #include "Light.h"
 #include "dragplanes.h"
@@ -45,6 +46,9 @@ class LightNode :
 	// a temporary variable for calculating the AABB of all (selected) components
 	mutable AABB m_aabb_component;
 
+    // Cached rkey to override light volume colour
+    registry::CachedKey<bool> _overrideColKey;
+
 public:
 	LightNode(const IEntityClassPtr& eclass);
 

test/Entity.cpp

@@ -6,10 +6,12 @@
 #include "iselectable.h"
 #include "iselection.h"
 #include "ishaders.h"
+#include "icolourscheme.h"
 
 #include "render/NopVolumeTest.h"
 #include "string/convert.h"
 #include "transformlib.h"
+#include "registry/registry.h"
 
 namespace test
 {
@@ -465,6 +467,46 @@ TEST_F(EntityTest, LightVolumeColorFromColorKey)
     }
 }
 
+TEST_F(EntityTest, OverrideLightVolumeColour)
+{
+    // Create a light with an arbitrary colour
+    auto light = createByClassName("light");
+    light->getEntity().setKeyValue("_color", "0.25 0.55 0.9");
+
+    // Set the "override light volume colour" key
+    registry::setValue(colours::RKEY_OVERRIDE_LIGHTCOL, true);
+
+    {
+        RenderFixture rf;
+        rf.renderSubGraph(light);
+
+        // The shader should ignore the _color key and render based on the entity
+        // class colour
+        EXPECT_EQ(rf.collector.renderables, 1);
+        const Shader* shader = rf.collector.renderablePtrs.at(0).first;
+        EXPECT_EQ(shader->getMaterial()->getName(), "<0.000000 1.000000 0.000000>");
+    }
+
+    // Unset the override key
+    registry::setValue(colours::RKEY_OVERRIDE_LIGHTCOL, false);
+
+    {
+        RenderFixture rf;
+        rf.renderSubGraph(light);
+
+        // Light should be rendered with its original _color key again
+        EXPECT_EQ(rf.collector.renderables, 1);
+        const Shader* shader = rf.collector.renderablePtrs.at(0).first;
+        EXPECT_EQ(shader->getMaterial()->getName(), "<0.250000 0.550000 0.900000>");
+    }
+
+    // Changing the override key after deleting the light must not crash
+    // (because the LightNode's CachedKey is sigc::trackable)
+    light.reset();
+    registry::setValue(colours::RKEY_OVERRIDE_LIGHTCOL, true);
+    registry::setValue(colours::RKEY_OVERRIDE_LIGHTCOL, false);
+}
+
 TEST_F(EntityTest, FuncStaticLocalToWorld)
 {
     auto funcStatic = createByClassName("func_static");