From 43430e73a2f44c8e89190adc6f89a4562741f6bd Mon Sep 17 00:00:00 2001
From: dnesov <contact.dnesov@gmail.com>
Date: Sun, 18 Aug 2024 20:46:32 +0200
Subject: [PATCH] Initialize WebGPU render pass, Implement ClearBackground in
 StandardRenderer

---
 TestGame/TestGame.cs                       |  3 +-
 Voile/Source/Rendering/StandardRenderer.cs | 74 ++++++++++++++++++----
 2 files changed, 65 insertions(+), 12 deletions(-)

diff --git a/TestGame/TestGame.cs b/TestGame/TestGame.cs
index dace329..51163cc 100644
--- a/TestGame/TestGame.cs
+++ b/TestGame/TestGame.cs
@@ -98,7 +98,8 @@ public class TestGame : Game
             // _scene.BeginDraw();
             // _scene.EndDraw();
             _renderer.BeginFrame();
-            // _renderer.ClearBackground(Color.White);
+            _renderer.ClearBackground(Color.Red);
+            _renderer.ClearBackground(Color.Blue);
             _renderer.EndFrame();
         }
     }
diff --git a/Voile/Source/Rendering/StandardRenderer.cs b/Voile/Source/Rendering/StandardRenderer.cs
index d9de609..875e1b8 100644
--- a/Voile/Source/Rendering/StandardRenderer.cs
+++ b/Voile/Source/Rendering/StandardRenderer.cs
@@ -5,6 +5,7 @@ using Silk.NET.WebGPU;
 using Silk.NET.Maths;
 using Voile.Utils;
 using System.Runtime.InteropServices;
+using System.Runtime.CompilerServices;
 
 namespace Voile.Rendering
 {
@@ -67,12 +68,14 @@ namespace Voile.Rendering
             _window!.DoEvents();
             _window.DoUpdate();
             _window.DoRender();
+
+            WgpuBeginFrame();
         }
 
         /// <inheritdoc />
         public override void ClearBackground(Color color)
         {
-            throw new NotImplementedException();
+            _clearColor = color;
         }
 
         public override void DrawText(Font font, string text, Color color)
@@ -120,10 +123,7 @@ namespace Voile.Rendering
         }
 
         /// <inheritdoc />
-        public override void EndFrame()
-        {
-
-        }
+        public override void EndFrame() => WgpuEndFrame();
 
         /// <inheritdoc />
         public override void Shutdown()
@@ -258,12 +258,15 @@ namespace Voile.Rendering
 
         private unsafe void ConfigureSurface()
         {
-            SurfaceConfiguration configuration = new SurfaceConfiguration();
-            configuration.Device = _device;
-            configuration.Width = (uint)_window!.Size.X;
-            configuration.Height = (uint)_window.Size.Y;
-            configuration.Format = Silk.NET.WebGPU.TextureFormat.Bgra8Unorm;
-            configuration.PresentMode = PresentMode.Fifo;
+            SurfaceConfiguration configuration = new SurfaceConfiguration
+            {
+                Device = _device,
+                Width = (uint)_window!.Size.X,
+                Height = (uint)_window.Size.Y,
+                Format = Silk.NET.WebGPU.TextureFormat.Bgra8Unorm,
+                PresentMode = PresentMode.Immediate,
+                Usage = TextureUsage.RenderAttachment
+            };
 
             _wgpu!.SurfaceConfigure(_surface, configuration);
         }
@@ -280,6 +283,42 @@ namespace Voile.Rendering
             _logger.Info("WGPU Debug Callback Configured.");
         }
 
+        private unsafe void WgpuBeginFrame()
+        {
+            _queue = _wgpu.DeviceGetQueue(_device);
+
+            _commandEncoder = _wgpu.DeviceCreateCommandEncoder(_device, null);
+
+            _wgpu.SurfaceGetCurrentTexture(_surface, ref _surfaceTexture);
+            _surfaceTextureView = _wgpu.TextureCreateView(_surfaceTexture.Texture, null);
+
+            RenderPassColorAttachment* colorAttachments = stackalloc RenderPassColorAttachment[1];
+            colorAttachments[0].View = _surfaceTextureView;
+            colorAttachments[0].LoadOp = LoadOp.Clear;
+            colorAttachments[0].ClearValue = VoileColorToWebGPUColor(_clearColor);
+            colorAttachments[0].StoreOp = StoreOp.Store;
+
+            _renderPassDescriptor.ColorAttachments = colorAttachments;
+            _renderPassDescriptor.ColorAttachmentCount = 1;
+
+            _renderPassEncoder = _wgpu.CommandEncoderBeginRenderPass(_commandEncoder, _renderPassDescriptor);
+        }
+
+        private unsafe void WgpuEndFrame()
+        {
+            _wgpu.RenderPassEncoderEnd(_renderPassEncoder);
+            var commandBuffer = _wgpu.CommandEncoderFinish(_commandEncoder, null);
+
+            _wgpu.QueueSubmit(_queue, 1, &commandBuffer);
+            _wgpu.SurfacePresent(_surface);
+
+            _wgpu.TextureViewRelease(_surfaceTextureView);
+            _wgpu.TextureRelease(_surfaceTexture.Texture);
+            _wgpu.RenderPassEncoderRelease(_renderPassEncoder);
+            _wgpu.CommandBufferRelease(commandBuffer);
+            _wgpu.CommandEncoderRelease(_commandEncoder);
+        }
+
         private unsafe void ShutdownUnsafe()
         {
             _wgpu.DeviceDestroy(_device);
@@ -288,14 +327,27 @@ namespace Voile.Rendering
             _wgpu.AdapterRelease(_adapter);
         }
 
+        private Silk.NET.WebGPU.Color VoileColorToWebGPUColor(Color color)
+        {
+            return new Silk.NET.WebGPU.Color(color.R, color.G, color.B, color.A);
+        }
+
         private Vector2 _windowSize;
         private IWindow? _window;
 
+        private Color _clearColor = Color.Black;
+
         private WebGPU? _wgpu;
         private unsafe Instance* _instance;
         private unsafe Surface* _surface;
         private unsafe Adapter* _adapter;
         private unsafe Device* _device;
+        private unsafe Queue* _queue;
+        private SurfaceTexture _surfaceTexture;
+        private unsafe TextureView* _surfaceTextureView;
+        private unsafe CommandEncoder* _commandEncoder;
+        private RenderPassDescriptor _renderPassDescriptor;
+        private unsafe RenderPassEncoder* _renderPassEncoder;
 
         private Logger _logger = new(nameof(StandardRenderer));
     }