Add ColorTargetSettings.Load to match the render pass docs

docs/render-pass-flow.md

@@ -106,7 +106,7 @@ new RenderPassBuilder(commandBuffer)
 **ColorTargetSettings options:**
 - `Clear` - Clear the target before rendering
 - `Load` - Keep existing contents
-- Others may exist for different load/store operations
+- Other combinations: `new ColorTargetSettings { LoadOperation = ..., StoreOperation = ..., ClearColorValue = ... }`
 
 Add multiple color targets for deferred rendering (G-buffer). A pass takes at most 8 color targets, SDL's limit.
 

src/Pixely.Ui/UiRenderer.cs

@@ -22,8 +22,6 @@ internal sealed class UiRenderer<TRenderContext> : IRenderer<TRenderContext>, ID
         ClearColorValue = LinearColors.Transparent
     };
 
-    private static readonly ColorTargetSettings _loadColorTargetSettings = new() { LoadOperation = LoadOperation.Load };
-
     private static readonly Matrix4x4 _presentViewProjection =
         Matrix4x4.CreateOrthographicOffCenterLeftHanded(0, 1, 1, 0, 0, 1);
 
@@ -287,7 +285,7 @@ private static void ClearTarget(CommandBuffer commandBuffer, Texture target)
 
     private void Present(CommandBuffer commandBuffer, Texture target, Texture retainedTexture, Matrix4x4 world)
     {
-        ColorTargetSettings settings = _clearTarget ? ColorTargetSettings.Clear : _loadColorTargetSettings;
+        ColorTargetSettings settings = _clearTarget ? ColorTargetSettings.Clear : ColorTargetSettings.Load;
 
         using RenderPass presentPass = new RenderPassBuilder(commandBuffer)
             .AddColorTarget(target, settings)

src/Pixely/Gpu/ColorTargetSettings.cs

@@ -6,4 +6,5 @@ public class ColorTargetSettings
     public LoadOperation LoadOperation { get; init; } = LoadOperation.Clear;
     public StoreOperation StoreOperation { get; init; } = StoreOperation.Store;
     public static readonly ColorTargetSettings Clear = new();
+    public static readonly ColorTargetSettings Load = new() { LoadOperation = LoadOperation.Load };
 }