make sure "structure" pass is culled when not needed

the structure (depth path) wasn't culled even if both ssao and
contact-shadows were disabled.

filament/src/PostProcessManager.cpp

@@ -602,10 +602,11 @@ FrameGraphId<FrameGraphTexture> PostProcessManager::screenSpaceAmbientOclusion(
 FrameGraphId<FrameGraphTexture> PostProcessManager::structure(FrameGraph& fg,
         const RenderPass& pass, uint32_t width, uint32_t height, float scale) noexcept {
 
-    // structure pass -- automatically culled if not used
-    // used for SSAO currently. It consists of a mipmapped depth path
-    // mipmapping is tunned for SSAO
-    struct DepthPassData {
+    // structure pass -- automatically culled if not used, currently used by:
+    //    - ssao
+    //     - contact shadows
+    // It consists of a mipmapped depth pass, tuned for SSAO
+    struct StructurePassData {
         FrameGraphId<FrameGraphTexture> depth;
         FrameGraphRenderTargetHandle rt;
     };
@@ -618,8 +619,8 @@ FrameGraphId<FrameGraphTexture> PostProcessManager::structure(FrameGraph& fg,
     const size_t levelCount = FTexture::maxLevelCount(width, height) - 5;
     assert(levelCount >= 1);
 
-    // SSAO generates its own depth pass at the requested resolution
-    auto& ssaoDepthPass = fg.addPass<DepthPassData>("SSAO Depth Pass",
+    // generate depth pass at the requested resolution
+    auto& structurePass = fg.addPass<StructurePassData>("Structure Pass",
             [&](FrameGraph::Builder& builder, auto& data) {
                 data.depth = builder.createTexture("Depth Buffer", {
                         .width = width, .height = height,
@@ -628,7 +629,7 @@ FrameGraphId<FrameGraphTexture> PostProcessManager::structure(FrameGraph& fg,
 
                 data.depth = builder.write(builder.read(data.depth));
 
-                data.rt = builder.createRenderTarget("SSAO Depth Target", {
+                data.rt = builder.createRenderTarget("Structure Target", {
                         .attachments = {{}, data.depth },
                         .clearFlags = TargetBufferFlags::DEPTH
                 });
@@ -638,7 +639,7 @@ FrameGraphId<FrameGraphTexture> PostProcessManager::structure(FrameGraph& fg,
                 pass.execute(resources.getPassName(), out.target, out.params);
             });
 
-    auto depth = ssaoDepthPass.getData().depth;
+    auto depth = structurePass.getData().depth;
 
     /*
      * create depth mipmap chain

filament/src/Renderer.cpp

@@ -315,7 +315,7 @@ void FRenderer::renderJob(ArenaScope& arena, FView& view) {
     // --------------------------------------------------------------------------------------------
     // structure pass -- automatically culled if not used
     // Currently it consists of a simple depth pass.
-    // This is normally used by SSAO
+    // This is normally used by SSAO and contact-shadows
 
     // TODO: this should be a FrameGraph pass to participate to automatic culling
     pass.newCommandBuffer();
@@ -348,7 +348,8 @@ void FRenderer::renderJob(ArenaScope& arena, FView& view) {
             .hdrFormat = hdrFormat,
             .msaa = msaa,
             .clearFlags = clearFlags,
-            .clearColor = clearColor
+            .clearColor = clearColor,
+            .hasContactShadows = scene.hasContactShadows()
     };
 
     // We use a framegraph pass to wait for froxelization to finish (so it can be done
@@ -576,7 +577,8 @@ FrameGraphId<FrameGraphTexture> FRenderer::colorPass(FrameGraph& fg, const char*
                 data.color = blackboard.get<FrameGraphTexture>("color");
                 data.structure = blackboard.get<FrameGraphTexture>("structure");
 
-                if (data.structure.isValid()) {
+                if (config.hasContactShadows) {
+                    assert(data.structure.isValid());
                     data.structure = builder.sample(data.structure);
                 }
 

filament/src/Scene.cpp

@@ -178,6 +178,7 @@ void FScene::updateUBOs(utils::Range<uint32_t> visibleRenderables, backend::Hand
     // allocate space into the command stream directly
     void* const buffer = driver.allocate(size);
 
+    bool hasContactShadows = false;
     auto& sceneData = mRenderableData;
     for (uint32_t i : visibleRenderables) {
         mat4f const& model = sceneData.elementAt<WORLD_TRANSFORM>(i);
@@ -206,20 +207,27 @@ void FScene::updateUBOs(utils::Range<uint32_t> visibleRenderables, backend::Hand
         // Note that we cast bools to uint32. Booleans are byte-sized in C++, but we need to
         // initialize all 32 bits in the UBO field.
 
-        UniformBuffer::setUniform(buffer, offset + offsetof(PerRenderableUib, skinningEnabled),
-                uint32_t(sceneData.elementAt<VISIBILITY_STATE>(i).skinning));
-
-        UniformBuffer::setUniform(buffer, offset + offsetof(PerRenderableUib, morphingEnabled),
-                uint32_t(sceneData.elementAt<VISIBILITY_STATE>(i).morphing));
-
-        UniformBuffer::setUniform(buffer, offset + offsetof(PerRenderableUib, screenSpaceContactShadows),
-                uint32_t(sceneData.elementAt<VISIBILITY_STATE>(i).screenSpaceContactShadows));
+        FRenderableManager::Visibility visibility = sceneData.elementAt<VISIBILITY_STATE>(i);
+        hasContactShadows = hasContactShadows || visibility.screenSpaceContactShadows;
+        UniformBuffer::setUniform(buffer,
+                offset + offsetof(PerRenderableUib, skinningEnabled),
+                uint32_t(visibility.skinning));
 
         UniformBuffer::setUniform(buffer,
-                offset + offsetof(PerRenderableUib, morphWeights), sceneData.elementAt<MORPH_WEIGHTS>(i));
+                offset + offsetof(PerRenderableUib, morphingEnabled),
+                uint32_t(visibility.morphing));
+
+        UniformBuffer::setUniform(buffer,
+                offset + offsetof(PerRenderableUib, screenSpaceContactShadows),
+                uint32_t(visibility.screenSpaceContactShadows));
+
+        UniformBuffer::setUniform(buffer,
+                offset + offsetof(PerRenderableUib, morphWeights),
+                sceneData.elementAt<MORPH_WEIGHTS>(i));
     }
 
     // TODO: handle static objects separately
+    mHasContactShadows = hasContactShadows;
     mRenderableViewUbh = renderableUbh;
     driver.loadUniformBuffer(renderableUbh, { buffer, size });
 }
@@ -390,6 +398,17 @@ void FScene::setSkybox(FSkybox const* skybox) noexcept {
     }
 }
 
+bool FScene::hasContactShadows() const noexcept {
+    bool hasContactShadows = mHasContactShadows;
+    auto& lcm = mEngine.getLightManager();
+    FLightManager::Instance directionalLight = mLightData.elementAt<LIGHT_INSTANCE>(0);
+    if (directionalLight.isValid()) {
+        auto const& shadowOoptions = lcm.getShadowOptions(directionalLight);
+        hasContactShadows = hasContactShadows && shadowOoptions.screenSpaceContactShadows;
+    }
+    return hasContactShadows;
+}
+
 } // namespace details
 
 // ------------------------------------------------------------------------------------------------

filament/src/details/Renderer.h

@@ -109,6 +109,7 @@ private:
         backend::TargetBufferFlags clearFlags;
         math::float4 clearColor = {};
         float refractionLodOffset;
+        bool hasContactShadows;
     };
 
     FrameGraphId<FrameGraphTexture> colorPass(FrameGraph& fg, const char* name,

filament/src/details/Scene.h

@@ -194,6 +194,8 @@ public:
 
     void updateUBOs(utils::Range<uint32_t> visibleRenderables, backend::Handle<backend::HwUniformBuffer> renderableUbh) noexcept;
 
+    bool hasContactShadows() const noexcept;
+
 private:
     static inline void computeLightRanges(math::float2* zrange,
             CameraInfo const& camera, const math::float4* spheres, size_t count) noexcept;
@@ -215,13 +217,14 @@ private:
 
     /*
      * The data below is valid only during a view pass. i.e. if a scene is used in multiple
-     * views, the data below is update for each view.
+     * views, the data below is updated for each view.
      * In essence, this data should be owned by View, but it's so scene-specific, that for now
      * we store it here.
      */
     RenderableSoa mRenderableData;
     LightSoa mLightData;
     backend::Handle<backend::HwUniformBuffer> mRenderableViewUbh; // This is actually owned by the view.
+    bool mHasContactShadows = false;
 };
 
 FILAMENT_UPCAST(Scene)