阶段性完成

Assets/OtherPlugins/Le Tai's Asset/TranslucentImage/Script/Utilities/Blitter.cs

@@ -0,0 +1,65 @@
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.Rendering;
+
+namespace LeTai.Asset.TranslucentImage
+{
+public static class Blitter
+{
+    static Mesh fullscreenTriangle;
+
+    /// <summary>
+    /// A fullscreen triangle mesh.
+    /// </summary>
+    static Mesh FullscreenTriangle
+    {
+        get
+        {
+            if (fullscreenTriangle != null)
+                return fullscreenTriangle;
+
+            fullscreenTriangle = new Mesh { name = "Fullscreen Triangle" };
+            fullscreenTriangle.SetVertices(
+                new List<Vector3> {
+                    new Vector3(-1f, -1f, 0f),
+                    new Vector3(-1f, 3f,  0f),
+                    new Vector3(3f,  -1f, 0f)
+                }
+            );
+            fullscreenTriangle.SetIndices(new[] { 0, 1, 2 }, MeshTopology.Triangles, 0, false);
+            fullscreenTriangle.UploadMeshData(false);
+
+            return fullscreenTriangle;
+        }
+    }
+
+    public static void Blit(
+        CommandBuffer          cmd,
+        RenderTargetIdentifier source,
+        RenderTargetIdentifier destination,
+        Material               material,
+        int                    passIndex,
+        MaterialPropertyBlock  propertyBlock = null,
+        Rect                   viewport      = default
+    )
+    {
+        cmd.SetGlobalTexture(ShaderID.MAIN_TEX, source);
+        cmd.SetRenderTarget(new RenderTargetIdentifier(destination, 0, CubemapFace.Unknown, -1),
+                            RenderBufferLoadAction.DontCare,
+                            RenderBufferStoreAction.Store,
+                            RenderBufferLoadAction.DontCare,
+                            RenderBufferStoreAction.DontCare);
+        if (viewport.width != 0)
+            cmd.SetViewport(viewport);
+
+        if (SystemInfo.graphicsShaderLevel >= 30
+#if !UNITY_2023_1_OR_NEWER
+         && SystemInfo.graphicsDeviceType != GraphicsDeviceType.OpenGLES2
+#endif
+           )
+            cmd.DrawProcedural(Matrix4x4.identity, material, passIndex, MeshTopology.Triangles, 3, 1, propertyBlock);
+        else
+            cmd.DrawMesh(FullscreenTriangle, Matrix4x4.identity, material, 0, passIndex, propertyBlock);
+    }
+}
+}