Optimize terrain debug shape drawing by caching lines into a vertex buffer

#2841

Source/Engine/Debug/DebugDraw.cpp

@@ -94,6 +94,13 @@ struct DebugLine
     float TimeLeft;
 };
 
+struct DebugGeometryBuffer
+{
+    GPUBuffer* Buffer;
+    float TimeLeft;
+    Matrix Transform;
+};
+
 struct DebugTriangle
 {
     Float3 V0;
@@ -122,12 +129,9 @@ struct DebugText3D
     float TimeLeft;
 };
 
-PACK_STRUCT(struct Vertex {
-    Float3 Position;
-    Color32 Color;
-    });
+typedef DebugDraw::Vertex Vertex;
 
-GPU_CB_STRUCT(Data {
+GPU_CB_STRUCT(ShaderData {
     Matrix ViewProjection;
     Float2 Padding;
     float ClipPosZBias;
@@ -231,6 +235,7 @@ void TeleportList(const Float3& delta, Array<DebugText3D>& list)
 
 struct DebugDrawData
 {
+    Array<DebugGeometryBuffer> GeometryBuffers;
     Array<DebugLine> DefaultLines;
     Array<Vertex> OneFrameLines;
     Array<DebugTriangle> DefaultTriangles;
@@ -244,7 +249,7 @@ struct DebugDrawData
 
     inline int32 Count() const
     {
-        return LinesCount() + TrianglesCount() + TextCount();
+        return LinesCount() + TrianglesCount() + TextCount() + GeometryBuffers.Count();
     }
 
     inline int32 LinesCount() const
@@ -280,6 +285,7 @@ struct DebugDrawData
 
     inline void Update(float deltaTime)
     {
+        UpdateList(deltaTime, GeometryBuffers);
         UpdateList(deltaTime, DefaultLines);
         UpdateList(deltaTime, DefaultTriangles);
         UpdateList(deltaTime, DefaultWireTriangles);
@@ -784,7 +790,7 @@ void DebugDraw::Draw(RenderContext& renderContext, GPUTextureView* target, GPUTe
 
     // Update constant buffer
     const auto cb = DebugDrawShader->GetShader()->GetCB(0);
-    Data data;
+    ShaderData data;
     Matrix vp;
     Matrix::Multiply(view.View, view.Projection, vp);
     Matrix::Transpose(vp, data.ViewProjection);
@@ -830,6 +836,22 @@ void DebugDraw::Draw(RenderContext& renderContext, GPUTextureView* target, GPUTe
             context->Draw(depthTestTriangles.StartVertex, depthTestTriangles.VertexCount);
         }
 
+        // Geometries
+        for (auto& geometry : Context->DebugDrawDepthTest.GeometryBuffers)
+        {
+            auto tmp = data;
+            Matrix mvp;
+            Matrix::Multiply(geometry.Transform, vp, mvp);
+            Matrix::Transpose(mvp, tmp.ViewProjection);
+            context->UpdateCB(cb, &tmp);
+            auto state = data.EnableDepthTest ? &DebugDrawPsLinesDepthTest : &DebugDrawPsLinesDefault;
+            context->SetState(state->Get(enableDepthWrite, true));
+            context->BindVB(ToSpan(&geometry.Buffer, 1));
+            context->Draw(0, geometry.Buffer->GetElementsCount());
+        }
+        if (Context->DebugDrawDepthTest.GeometryBuffers.HasItems())
+            context->UpdateCB(cb, &data);
+
         if (data.EnableDepthTest)
             context->UnBindSR(0);
     }
@@ -862,6 +884,19 @@ void DebugDraw::Draw(RenderContext& renderContext, GPUTextureView* target, GPUTe
             context->BindVB(ToSpan(&vb, 1));
             context->Draw(defaultTriangles.StartVertex, defaultTriangles.VertexCount);
         }
+
+        // Geometries
+        for (auto& geometry : Context->DebugDrawDefault.GeometryBuffers)
+        {
+            auto tmp = data;
+            Matrix mvp;
+            Matrix::Multiply(geometry.Transform, vp, mvp);
+            Matrix::Transpose(mvp, tmp.ViewProjection);
+            context->UpdateCB(cb, &tmp);
+            context->SetState(DebugDrawPsLinesDefault.Get(false, false));
+            context->BindVB(ToSpan(&geometry.Buffer, 1));
+            context->Draw(0, geometry.Buffer->GetElementsCount());
+        }
     }
 
     // Text
@@ -1088,6 +1123,24 @@ void DebugDraw::DrawLines(const Span<Float3>& lines, const Matrix& transform, co
     }
 }
 
+void DebugDraw::DrawLines(GPUBuffer* lines, const Matrix& transform, float duration, bool depthTest)
+{
+    if (lines == nullptr || lines->GetSize() == 0)
+        return;
+    if (lines->GetSize() % (sizeof(Vertex) * 2) != 0)
+    {
+        DebugLog::ThrowException("Cannot draw debug lines with uneven amount of items in array");
+        return;
+    }
+
+    // Draw lines
+    auto& debugDrawData = depthTest ? Context->DebugDrawDepthTest : Context->DebugDrawDefault;
+    auto& geometry = debugDrawData.GeometryBuffers.AddOne();
+    geometry.Buffer = lines;
+    geometry.TimeLeft = duration;
+    geometry.Transform = transform * Matrix::Translation(-Context->Origin);
+}
+
 void DebugDraw::DrawLines(const Array<Float3>& lines, const Matrix& transform, const Color& color, float duration, bool depthTest)
 {
     DrawLines(Span<Float3>(lines.Get(), lines.Count()), transform, color, duration, depthTest);
@@ -2147,6 +2200,7 @@ void DebugDraw::DrawText(const StringView& text, const Transform& transform, con
 
 void DebugDraw::Clear(void* context)
 {
-    DebugDraw::UpdateContext(context, MAX_float);
+    UpdateContext(context, MAX_float);
 }
+
 #endif

Source/Engine/Debug/DebugDraw.h

@@ -6,6 +6,8 @@
 
 #include "Engine/Scripting/ScriptingType.h"
 #include "Engine/Core/Math/Color.h"
+#include "Engine/Core/Math/Color32.h"
+#include "Engine/Core/Math/Vector3.h"
 #include "Engine/Core/Types/Span.h"
 
 struct RenderView;
@@ -14,6 +16,7 @@ class Light;
 struct RenderContext;
 class GPUTextureView;
 class GPUContext;
+class GPUBuffer;
 class RenderTask;
 class SceneRenderTask;
 class Actor;
@@ -26,6 +29,14 @@ API_CLASS(Static) class FLAXENGINE_API DebugDraw
 {
     DECLARE_SCRIPTING_TYPE_NO_SPAWN(DebugDraw);
 
+    /// <summary>
+    /// Vertex data for debug shapes.
+    /// </summary>
+    PACK_STRUCT(struct Vertex {
+        Float3 Position;
+        Color32 Color;
+        });
+
 #if USE_EDITOR
     /// <summary>
     /// Allocates the context for Debug Drawing. Can be use to redirect debug shapes collecting to a separate container (instead of global state).
@@ -175,6 +186,15 @@ API_CLASS(Static) class FLAXENGINE_API DebugDraw
     /// <param name="depthTest">If set to <c>true</c> depth test will be performed, otherwise depth will be ignored.</param>
     API_FUNCTION() static void DrawLines(const Span<Float3>& lines, const Matrix& transform, const Color& color = Color::White, float duration = 0.0f, bool depthTest = true);
 
+    /// <summary>
+    /// Draws the lines using the provided vertex buffer that contains pairs of Vertex elements. Line positions are located one after another (e.g. l0.start, l0.end, l1.start, l1.end,...).
+    /// </summary>
+    /// <param name="lines">The GPU buffer with vertices for lines (must have multiple of 2 elements).</param>
+    /// <param name="transform">The custom matrix used to transform all line vertices.</param>
+    /// <param name="duration">The duration (in seconds). Use 0 to draw it only once.</param>
+    /// <param name="depthTest">If set to <c>true</c> depth test will be performed, otherwise depth will be ignored.</param>
+    API_FUNCTION() static void DrawLines(GPUBuffer* lines, const Matrix& transform, float duration = 0.0f, bool depthTest = true);
+
     /// <summary>
     /// Draws the lines. Line positions are located one after another (e.g. l0.start, l0.end, l1.start, l1.end,...).
     /// </summary>
@@ -691,9 +711,9 @@ API_CLASS(Static) class FLAXENGINE_API DebugDraw
     API_FUNCTION() static void DrawText(const StringView& text, const Transform& transform, const Color& color = Color::White, int32 size = 32, float duration = 0.0f);
 
     /// <summary>
-    /// Clear all debug draw displayed on sceen.
+    /// Clears all debug shapes displayed on screen.
     /// </summary>
-    /// <returns></returns>
+    /// <param name="context">The context.</param>
     API_FUNCTION() static void Clear(void* context = nullptr);
 };