From f5745c8cbfd802c6b9e73b5f5c9c9e303047bc9c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Aleksi=20Gr=C3=B6n?= <aleksi.gron@gmail.com>
Date: Thu, 24 Oct 2024 11:07:34 +0300
Subject: [PATCH] Experimental terrain shadows are enabled with debug setting

---
 editor/src/Views/DebugView.cpp              |  4 +++
 engine/src/Graphics/TerrainSystem.cpp       | 38 +++++++++++++--------
 engine/src/Rendering/RenderDebugFeature.hpp |  3 +-
 3 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/editor/src/Views/DebugView.cpp b/editor/src/Views/DebugView.cpp
index cfdc70d8..4e66c98b 100644
--- a/editor/src/Views/DebugView.cpp
+++ b/editor/src/Views/DebugView.cpp
@@ -58,6 +58,10 @@ void DebugView::Update(EditorContext& context)
 			if (ImGui::Checkbox("Draw terrain tiles", &drawTerrain))
 				features.SetFeatureEnabled(kokko::RenderDebugFeatureFlag::DrawTerrainTiles, drawTerrain);
 
+			bool terrainShadows = features.IsFeatureEnabled(kokko::RenderDebugFeatureFlag::ExperimentalTerrainShadows);
+			if (ImGui::Checkbox("Experimental terrain shadows", &terrainShadows))
+				features.SetFeatureEnabled(kokko::RenderDebugFeatureFlag::ExperimentalTerrainShadows, terrainShadows);
+
 			if (ImGui::Button("Capture profile"))
 			{
 				debug->RequestBeginProfileSession();
diff --git a/engine/src/Graphics/TerrainSystem.cpp b/engine/src/Graphics/TerrainSystem.cpp
index 80c3b76a..560396c1 100644
--- a/engine/src/Graphics/TerrainSystem.cpp
+++ b/engine/src/Graphics/TerrainSystem.cpp
@@ -295,22 +295,23 @@ void TerrainSystem::SetRoughnessValue(TerrainId id, float roughness)
 	instances[id.i].roughnessValue = roughness;
 }
 
-void TerrainSystem::Upload(const UploadParameters& parameters)
+void TerrainSystem::Upload(const UploadParameters& params)
 {
 	uniformBlocksRendered = 0;
+	const bool drawShadows = params.renderDebug.IsFeatureEnabled(RenderDebugFeatureFlag::ExperimentalTerrainShadows);
 
 	for (size_t i = 1, count = instances.GetCount(); i < count; ++i)
 	{
 		// FIXME: Rendering will not be correct if multiple terrain instances exist in the world
 		// All uniform block info needs to be made instance-specific
 
-		const RenderViewport& fullscreenViewport = parameters.viewports[parameters.fullscreenViewportIndex];
+		const RenderViewport& fullscreenViewport = params.viewports[params.fullscreenViewportIndex];
 
 		// Select tiles to render
 
 		TerrainInstance& instance = instances[i];
 		TerrainQuadTree& quadTree = instance.quadTree;
-		quadTree.UpdateTilesToRender(fullscreenViewport.frustum, fullscreenViewport.position, parameters.renderDebug);
+		quadTree.UpdateTilesToRender(fullscreenViewport.frustum, fullscreenViewport.position, params.renderDebug);
 		ArrayView<const TerrainTileDrawInfo> tiles = quadTree.GetTilesToRender();
 		uint32_t tileCount = static_cast<uint32_t>(tiles.GetCount());
 
@@ -330,7 +331,8 @@ void TerrainSystem::Upload(const UploadParameters& parameters)
 		uniforms.metalness = 0.0f;
 		uniforms.roughness = instance.roughnessValue;
 
-		int viewportCount = parameters.shadowViewportsEndIndex - parameters.shadowViewportsBeginIndex + 1;
+		int shadowViewports = drawShadows ? params.shadowViewportsEndIndex - params.shadowViewportsBeginIndex : 0;
+		int viewportCount = shadowViewports + 1;
 		uint32_t uniformBlockCount = tileCount * viewportCount;
 		uniformStagingBuffer.Resize(uniformBlockCount * uniformBlockStride);
 
@@ -371,16 +373,19 @@ void TerrainSystem::Upload(const UploadParameters& parameters)
 			};
 
 			// Shadow viewports
-			uint32_t vpEnd = parameters.shadowViewportsEndIndex;
-			for (uint32_t vpIdx = parameters.shadowViewportsBeginIndex; vpIdx != vpEnd; ++vpIdx)
+			if (drawShadows)
 			{
-				uniforms.MVP = parameters.viewports[vpIdx].viewProjection;
-				uniforms.MV = parameters.viewports[vpIdx].view.inverse;
-
-				for (const auto& tile : tiles)
+				uint32_t vpEnd = params.shadowViewportsEndIndex;
+				for (uint32_t vpIdx = params.shadowViewportsBeginIndex; vpIdx != vpEnd; ++vpIdx)
 				{
-					updateTileInfo(tile);
-					writeToBuffer();
+					uniforms.MVP = params.viewports[vpIdx].viewProjection;
+					uniforms.MV = params.viewports[vpIdx].view.inverse;
+
+					for (const auto& tile : tiles)
+					{
+						updateTileInfo(tile);
+						writeToBuffer();
+					}
 				}
 			}
 
@@ -409,10 +414,13 @@ void TerrainSystem::Submit(const SubmitParameters& params)
 	{
 		params.commandList->AddToViewport(params.fullscreenViewportIndex, RenderPassType::OpaqueGeometry, depth, i);
 
-		const size_t vpEnd = params.shadowViewportsEndIndex;
-		for (size_t vpIdx = params.shadowViewportsBeginIndex; vpIdx != vpEnd; ++vpIdx)
+		if (params.renderDebug.IsFeatureEnabled(RenderDebugFeatureFlag::ExperimentalTerrainShadows))
 		{
-			params.commandList->AddToViewport(vpIdx, RenderPassType::OpaqueGeometry, depth, i);
+			const size_t vpEnd = params.shadowViewportsEndIndex;
+			for (size_t vpIdx = params.shadowViewportsBeginIndex; vpIdx != vpEnd; ++vpIdx)
+			{
+				params.commandList->AddToViewport(vpIdx, RenderPassType::OpaqueGeometry, depth, i);
+			}
 		}
 	}
 }
diff --git a/engine/src/Rendering/RenderDebugFeature.hpp b/engine/src/Rendering/RenderDebugFeature.hpp
index 42976f82..3429a174 100644
--- a/engine/src/Rendering/RenderDebugFeature.hpp
+++ b/engine/src/Rendering/RenderDebugFeature.hpp
@@ -10,7 +10,8 @@ enum class RenderDebugFeatureFlag : uint32_t
 	None = 0,
 	DrawBounds = 1 << 0,
 	DrawNormals = 1 << 1,
-	DrawTerrainTiles = 1 << 2
+	DrawTerrainTiles = 1 << 2,
+	ExperimentalTerrainShadows = 1 << 3
 };
 
 }