Added possibility to disable the litbase pass optimization in RenderPath, if an ambient-only pass is needed.

Docs/Reference.dox

@@ -713,7 +713,7 @@ The render path XML definition looks like this:
         <texture unit="unit" name="viewport|RTName|TextureName" />
         <shaderparameter name="ParameterName" value="x y z w" />
     </command>
-    <command type="forwardlights" output="viewport|RTName" />
+    <command type="forwardlights" uselitbase="true|false" output="viewport|RTName" />
     <command type="lightvolumes"  vs="VertexShaderName" ps="PixelShaderName" output="viewport|RTName" />
         <texture unit="unit" name="viewport|RTName|TextureName" />
     </command>
@@ -728,6 +728,7 @@ Otherwise fully customized scene render passes can be specified, but there are a
 
 - The "light" and "litbase" passes will be automatically rendered by the forwardlights command, interleaved with shadow map rendering as necessary.
 - The "litalpha" pass for transparent objects is automatically merged with the "alpha" pass, if it exists in the render path definition. The idea is that all transparent objects are sorted back to front, and their base passes (the actual "alpha" pass) are rendered first, followed by their additive pixel-lit passes. The "usescissor" flag in the scenepass command should be set to true, so that scissor rectangles limit the effect of lights on transparent objects.
+- The forwardlights command can optionally disable the "litbase" pass optimization without having to touch the material techniques, if a separate opaque ambient-only base pass is needed. By default the optimization is enabled.
 
 
 \page Lights Lights and shadows

Docs/ScriptAPI.dox

@@ -1668,6 +1668,7 @@ Properties:<br>
 - bool useFogColor
 - bool markToStencil
 - bool vertexLights
+- bool useLitBase
 - bool useScissor
 - String vertexShaderName
 - String pixelShaderName

Engine/Engine/GraphicsAPI.cpp

@@ -318,6 +318,7 @@ static void RegisterRenderPath(asIScriptEngine* engine)
     engine->RegisterObjectProperty("RenderPathCommand", "bool useFogColor", offsetof(RenderPathCommand, useFogColor_));
     engine->RegisterObjectProperty("RenderPathCommand", "bool markToStencil", offsetof(RenderPathCommand, markToStencil_));
     engine->RegisterObjectProperty("RenderPathCommand", "bool vertexLights", offsetof(RenderPathCommand, vertexLights_));
+    engine->RegisterObjectProperty("RenderPathCommand", "bool useLitBase", offsetof(RenderPathCommand, useLitBase_));
     engine->RegisterObjectProperty("RenderPathCommand", "bool useScissor", offsetof(RenderPathCommand, useScissor_));
     engine->RegisterObjectProperty("RenderPathCommand", "String vertexShaderName", offsetof(RenderPathCommand, vertexShaderName_));
     engine->RegisterObjectProperty("RenderPathCommand", "String pixelShaderName", offsetof(RenderPathCommand, pixelShaderName_));

Engine/Graphics/RenderPath.cpp

@@ -125,6 +125,11 @@ void RenderPathCommand::LoadParameters(const XMLElement& element)
             useScissor_ = element.GetBool("usescissor");
         break;
         
+    case CMD_FORWARDLIGHTS:
+        if (element.HasAttribute("uselitbase"))
+            useLitBase_ = element.GetBool("uselitbase");
+        break;
+        
     case CMD_LIGHTVOLUMES:
     case CMD_QUAD:
         vertexShaderName_ = element.GetAttribute("vs");

Engine/Graphics/RenderPath.h

@@ -97,6 +97,7 @@ struct RenderPathCommand
         active_(true),
         useFogColor_(false),
         markToStencil_(false),
+        useLitBase_(true),
         useScissor_(false),
         vertexLights_(false)
     {
@@ -148,6 +149,8 @@ struct RenderPathCommand
     bool markToStencil_;
     /// Vertex lights flag.
     bool vertexLights_;
+    /// Use lit base pass optimization for forward per-pixel lights.
+    bool useLitBase_;
     /// Scissor optimization flag.
     bool useScissor_;
     /// Vertex shader name.

Engine/Graphics/View.cpp

@@ -687,6 +687,15 @@ void View::GetBatches()
     PODVector<Light*> vertexLights;
     BatchQueue* alphaQueue = batchQueues_.Contains(PASS_ALPHA) ? &batchQueues_[PASS_ALPHA] : (BatchQueue*)0;
     
+    // Check whether to use the lit base pass optimization
+    bool useLitBase = true;
+    for (unsigned i = 0; i < renderPath_->commands_.Size(); ++i)
+    {
+        const RenderPathCommand& command = renderPath_->commands_[i];
+        if (command.type_ == CMD_FORWARDLIGHTS)
+            useLitBase = command.useLitBase_;
+    }
+    
     // Process lit geometries and shadow casters for each light
     {
         PROFILE(ProcessLights);
@@ -820,7 +829,7 @@ void View::GetBatches()
                     
                     // If drawable limits maximum lights, only record the light, and check maximum count / build batches later
                     if (!drawable->GetMaxLights())
-                        GetLitBatches(drawable, lightQueue, alphaQueue);
+                        GetLitBatches(drawable, lightQueue, alphaQueue, useLitBase);
                     else
                         maxLightsDrawables_.Insert(drawable);
                 }
@@ -872,7 +881,7 @@ void View::GetBatches()
                 // Find the correct light queue again
                 LightBatchQueue* queue = light->GetLightQueue();
                 if (queue)
-                    GetLitBatches(drawable, *queue, alphaQueue);
+                    GetLitBatches(drawable, *queue, alphaQueue, useLitBase);
             }
         }
     }
@@ -1059,7 +1068,7 @@ void View::UpdateGeometries()
     queue->Complete();
 }
 
-void View::GetLitBatches(Drawable* drawable, LightBatchQueue& lightQueue, BatchQueue* alphaQueue)
+void View::GetLitBatches(Drawable* drawable, LightBatchQueue& lightQueue, BatchQueue* alphaQueue, bool useLitBase)
 {
     Light* light = lightQueue.light_;
     Zone* zone = GetZone(drawable);
@@ -1068,7 +1077,7 @@ void View::GetLitBatches(Drawable* drawable, LightBatchQueue& lightQueue, BatchQ
     bool hasAmbientGradient = zone->GetAmbientGradient() && zone->GetAmbientStartColor() != zone->GetAmbientEndColor();
     // Shadows on transparencies can only be rendered if shadow maps are not reused
     bool allowTransparentShadows = !renderer_->GetReuseShadowMaps();
-    bool allowLitBase = light == drawable->GetFirstLight() && drawable->GetVertexLights().Empty() && !hasAmbientGradient;
+    bool allowLitBase = useLitBase && light == drawable->GetFirstLight() && drawable->GetVertexLights().Empty() && !hasAmbientGradient;
     
     for (unsigned i = 0; i < batches.Size(); ++i)
     {

Engine/Graphics/View.h

@@ -138,7 +138,7 @@ private:
     /// Update geometries and sort batches.
     void UpdateGeometries();
     /// Get pixel lit batches for a certain light and drawable.
-    void GetLitBatches(Drawable* drawable, LightBatchQueue& lightQueue, BatchQueue* alphaQueue);
+    void GetLitBatches(Drawable* drawable, LightBatchQueue& lightQueue, BatchQueue* alphaQueue, bool useLitBase);
     /// Execute render commands.
     void ExecuteRenderPathCommands();
     /// Set rendertargets for current render command.