From 9964a1f5ad379b274a216ab5a745e8fa00b3de3d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20L=C3=BCbe=C3=9F?= <simon.luebess@gmail.com>
Date: Sun, 6 Dec 2020 00:08:55 +0100
Subject: [PATCH] Added generic Buffer

---
 GlitchyEngine/src/Application.bf              | 10 ++++--
 .../Platform/DX11/Renderer/Dx11PixelShader.bf |  3 +-
 GlitchyEngine/src/Renderer/Buffer.bf          | 31 +++++++++++++++++++
 Sandbox/content/basicShader.hlsl              |  7 ++++-
 4 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/GlitchyEngine/src/Application.bf b/GlitchyEngine/src/Application.bf
index cb0a648..c7d25df 100644
--- a/GlitchyEngine/src/Application.bf
+++ b/GlitchyEngine/src/Application.bf
@@ -70,6 +70,7 @@ namespace GlitchyEngine
 
 		VertexBuffer<VertexColor> _vertexBuffer ~ delete _;
 		IndexBuffer _indexBuffer ~ delete _;
+		Buffer<ColorRGBA> _cBuffer ~ delete _;
 
 		RasterizerState _rasterizerState ~ delete _;
 
@@ -94,7 +95,6 @@ namespace GlitchyEngine
 			if(result.Failed || errorBlob != null)
 			{
 				Debug.Write("ERROR: Failed to compile Vertex Shader: {}", result);
-				//ErrorPrinter.PrintErrorBlob(errorBlob);
 				Runtime.FatalError("Failed to compile Vertex Shader");
 			}
 
@@ -126,7 +126,12 @@ namespace GlitchyEngine
 			//
 
 			_pixelShader = Shader.FromFile!<PixelShader>(_window.Context, "content\\basicShader.hlsl", "PS");
-			
+			_pixelShader.[Friend]_buffers = new .[1];
+
+			_cBuffer = new Buffer<ColorRGBA>(_window.Context, .(0, .Constant, .Immutable, .None));
+			_cBuffer.Data = .White;
+			_cBuffer.Update();
+
 			float pO3 = Math.PI_f / 3.0f;
 			VertexColor[?] vertices = .(
 				VertexColor(.Zero, Color(255,255,255)),
@@ -206,6 +211,7 @@ namespace GlitchyEngine
 
 					_window.Context.SetViewport(Window.Context.SwapChain.BackbufferViewport);
 
+					_immediateContext.PixelShader.SetConstantBuffers(0, 1, &_cBuffer.[Friend]nativeBuffer);
 					_window.Context.SetPixelShader(_pixelShader);
 
 					_window.Context.DrawIndexed(3 * 6);
diff --git a/GlitchyEngine/src/Platform/DX11/Renderer/Dx11PixelShader.bf b/GlitchyEngine/src/Platform/DX11/Renderer/Dx11PixelShader.bf
index 65f6b51..ad6a168 100644
--- a/GlitchyEngine/src/Platform/DX11/Renderer/Dx11PixelShader.bf
+++ b/GlitchyEngine/src/Platform/DX11/Renderer/Dx11PixelShader.bf
@@ -56,7 +56,7 @@ namespace GlitchyEngine.Renderer
 				Log.EngineLogger.Error($"Failed to create pixel shader: Message ({(int)result}): {result}");
 			}
 
-			Reflect(shaderBlob);
+			//Reflect(shaderBlob);
 			
 			shaderBlob?.Release();
 		}
@@ -78,6 +78,7 @@ namespace GlitchyEngine.Renderer
 				var bufferReflection = reflection.GetConstantBufferByIndex(i);
 				bufferReflection.GetDescription(let bufferDesc);
 			}
+			reflection.Release();
 		}
 	}
 }
diff --git a/GlitchyEngine/src/Renderer/Buffer.bf b/GlitchyEngine/src/Renderer/Buffer.bf
index 53f03fd..5520046 100644
--- a/GlitchyEngine/src/Renderer/Buffer.bf
+++ b/GlitchyEngine/src/Renderer/Buffer.bf
@@ -179,4 +179,35 @@ namespace GlitchyEngine.Renderer
 		 */
 		protected extern Result<void> PlatformSetData(void* data, uint32 byteLength, uint32 dstByteOffset, MapType mapType);
 	}
+	
+	/**
+	 * A buffer containing an array of a struct on the GPU.
+	 * @param T The type of the struct represented by this buffer.
+	 */
+	public class Buffer<T> : Buffer where T : struct
+	{
+		public T Data;
+
+		/**
+		 * Creates a new instance of a Buffer<T>
+		 * @param context The graphics context.
+		 * @param description Describes the Buffer. Note: description.Size is ignored, as it will always be sizeof(T).
+		 */
+		public this(GraphicsContext context, BufferDescription description) : base(context)
+		{
+			_description = description;
+			_description.Size = (uint32)sizeof(T);
+		}
+
+		// Todo: perhaps add a constructor that takes all parameters from description except Size
+
+		/**
+		 * Uploads the date from @see Data to the GPU.
+		 */
+		[Inline]
+		public void Update()
+		{
+			PlatformSetData(&Data, (uint32)sizeof(T), 0, .WriteDiscard);
+		}
+	}
 }
diff --git a/Sandbox/content/basicShader.hlsl b/Sandbox/content/basicShader.hlsl
index 72c8200..5ece317 100644
--- a/Sandbox/content/basicShader.hlsl
+++ b/Sandbox/content/basicShader.hlsl
@@ -1,3 +1,8 @@
+cbuffer Constants
+{
+    float4 BaseColor;
+}
+
 struct VS_IN
 {
     float3 Position : POSITION;
@@ -21,5 +26,5 @@ PS_IN VS(VS_IN input)
 
 float4 PS(PS_IN input) : SV_TARGET
 {
-    return input.Color;
+    return input.Color * BaseColor;
 }
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