From ae290936b9293b9111e0a4a553a4cd3901687235 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20L=C3=BCbe=C3=9F?= <simon.luebess@gmail.com>
Date: Sun, 30 May 2021 19:37:23 +0200
Subject: [PATCH] Added basic support for instanced rendering

---
 .../src/Platform/DX11/Renderer/Dx11RendererAPI.bf        | 7 +++++++
 .../src/Platform/DX11/Renderer/Dx11VertexLayout.bf       | 2 +-
 GlitchyEngine/src/Renderer/GeometryBinding.bf            | 9 +++++++++
 GlitchyEngine/src/Renderer/RenderCommand.bf              | 6 ++++++
 GlitchyEngine/src/Renderer/RendererAPI.bf                | 4 ++++
 GlitchyEngine/src/Renderer/VertexBuffer.bf               | 4 ++--
 6 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/GlitchyEngine/src/Platform/DX11/Renderer/Dx11RendererAPI.bf b/GlitchyEngine/src/Platform/DX11/Renderer/Dx11RendererAPI.bf
index bdaa2cd..0eab23a 100644
--- a/GlitchyEngine/src/Platform/DX11/Renderer/Dx11RendererAPI.bf
+++ b/GlitchyEngine/src/Platform/DX11/Renderer/Dx11RendererAPI.bf
@@ -2,6 +2,8 @@ using GlitchyEngine.Math;
 
 namespace GlitchyEngine.Renderer
 {
+	using internal GlitchyEngine.Renderer;
+
 	extension RendererAPI
 	{
 		private GraphicsContext _context;
@@ -28,5 +30,10 @@ namespace GlitchyEngine.Renderer
 		{
 			_context.DrawIndexed(geometry.IndexCount, geometry.IndexByteOffset, 0);
 		}
+
+		public override void DrawIndexedInstanced(GeometryBinding geometry)
+		{
+			_context.nativeContext.DrawIndexedInstanced(geometry.IndexCount, geometry.InstanceCount, geometry.IndexByteOffset, 0, 0);
+		}
 	}
 }
diff --git a/GlitchyEngine/src/Platform/DX11/Renderer/Dx11VertexLayout.bf b/GlitchyEngine/src/Platform/DX11/Renderer/Dx11VertexLayout.bf
index bcea626..28c3e6c 100644
--- a/GlitchyEngine/src/Platform/DX11/Renderer/Dx11VertexLayout.bf
+++ b/GlitchyEngine/src/Platform/DX11/Renderer/Dx11VertexLayout.bf
@@ -28,7 +28,7 @@ namespace GlitchyEngine.Renderer
 			Debug.Assert(input.Count == output.Count);
 
 			for(int i < input.Count)
-				output[i] = .(input[i].SemanticName, input[i].SemanticIndex, input[i].Format, input[i].InputSlot, input[i].AlignedByteOffset, (.)input[i].InputSlotClass);
+				output[i] = .(input[i].SemanticName, input[i].SemanticIndex, input[i].Format, input[i].InputSlot, input[i].AlignedByteOffset, (.)input[i].InputSlotClass, input[i].InstanceDataStepRate);
 		}
 
 		protected override void CreateNativeLayout()
diff --git a/GlitchyEngine/src/Renderer/GeometryBinding.bf b/GlitchyEngine/src/Renderer/GeometryBinding.bf
index f2be3ed..608be58 100644
--- a/GlitchyEngine/src/Renderer/GeometryBinding.bf
+++ b/GlitchyEngine/src/Renderer/GeometryBinding.bf
@@ -12,6 +12,7 @@ namespace GlitchyEngine.Renderer
 		internal VertexLayout _vertexLayout;
 		internal uint32 _indexByteOffset;
 		internal uint32 _indexCount;
+		internal uint32 _instanceCount;
 		internal PrimitiveTopology _primitiveTopology;
 
 		public this(GraphicsContext context)
@@ -50,6 +51,14 @@ namespace GlitchyEngine.Renderer
 		[Inline]
 		public uint32 IndexCount => _indexCount;
 
+		public uint32 InstanceCount
+		{
+			[Inline]
+			get => _instanceCount;
+			[Inline]
+			set => _instanceCount = value;
+		}
+
 		[Inline]
 		public PrimitiveTopology PrimitiveTopology => _primitiveTopology;
 
diff --git a/GlitchyEngine/src/Renderer/RenderCommand.bf b/GlitchyEngine/src/Renderer/RenderCommand.bf
index f7569fd..be63ac0 100644
--- a/GlitchyEngine/src/Renderer/RenderCommand.bf
+++ b/GlitchyEngine/src/Renderer/RenderCommand.bf
@@ -30,5 +30,11 @@ namespace GlitchyEngine.Renderer
 		{
 			_rendererAPI.DrawIndexed(geometry);
 		}
+
+		[Inline]
+		public static void DrawIndexedInstanced(GeometryBinding geometry)
+		{
+			_rendererAPI.DrawIndexedInstanced(geometry);
+		}
 	}
 }
diff --git a/GlitchyEngine/src/Renderer/RendererAPI.bf b/GlitchyEngine/src/Renderer/RendererAPI.bf
index 8c1a03b..12569cd 100644
--- a/GlitchyEngine/src/Renderer/RendererAPI.bf
+++ b/GlitchyEngine/src/Renderer/RendererAPI.bf
@@ -20,5 +20,9 @@ namespace GlitchyEngine.Renderer
 		public extern void Clear(RenderTarget renderTarget, ColorRGBA clearColor);
 
 		public extern void DrawIndexed(GeometryBinding geometry);
+
+		public extern void DrawInstanced(GeometryBinding geometry);
+
+		public extern void DrawIndexedInstanced(GeometryBinding geometry);
 	}
 }
diff --git a/GlitchyEngine/src/Renderer/VertexBuffer.bf b/GlitchyEngine/src/Renderer/VertexBuffer.bf
index 0107b53..4f7c6e1 100644
--- a/GlitchyEngine/src/Renderer/VertexBuffer.bf
+++ b/GlitchyEngine/src/Renderer/VertexBuffer.bf
@@ -30,14 +30,14 @@ namespace GlitchyEngine.Renderer
 			_vertexType = vertexType;
 
 			_description = .(){
-				Size = ((uint32)_vertexType.Size * vertexCount),
+				Size = ((uint32)_vertexType.Stride * vertexCount),
 				Usage = usage,
 				CPUAccess = cpuAccess,
 				BindFlags = .Vertex,
 				MiscFlags = .None
 			};
 
-			_defaultBinding = .(this, (.)_vertexType.Size, 0);
+			_defaultBinding = .(this, (.)_vertexType.Stride, 0);
 		}
 
 		[Inline]