Expand pre-warming

README.md

@@ -2,6 +2,8 @@
 
 Enables loading (and uploading to GPU) textures asynchronously using compute shaders.
 
+This package has yet to be tested thoroughly.
+
 ## Quickstart
 
 Here's how you could create a texture:
@@ -16,6 +18,12 @@ var texture = await AsyncTextureLoader.Instance.LoadTextureAsync(image);
 
 See [Quickstart](#quickstart) for basic usage. The platform has to support compute shaders for this to work.
 
+
+### Pre-Warming
+
+The first time the compute shader is used, a hiccup can occur in some cases. To prevent this,
+call `AsyncTextureLoader.Prewarm()` somewhere you don't care about hiccups.
+
 ### Advanced Usage
 
 Take a look at the implementation of `LoadTextureAsync()` to get a good overview of the inner workings:
@@ -77,16 +85,8 @@ Naturally, this step is superfluous if you use `AsyncTextureLoader.UploadDataAsy
 
 ### Mips
 
-Currently, mipmaps are generated by default using `RenderTexture.GenerateMips()`.
-
-If you don't need mips or want to customize the amount of them, you have the option to do so
-in `AsyncTextureLoader.AcquireTextureAsync()` like so:
-
-```c#
-var image = await DecodeImageAsync(input);
-var texture = await AcquireTextureAsync(image.Width, image.Height, mipCount: 0);
-await UploadDataAsync(texture, image);
-```
+Currently, mipmaps are generated by default using `RenderTexture.GenerateMips()`, possibly causing a hiccup. The methods
+of `AsyncTextureLoader` have options to control the number of mips to be generated.
 
 ## Background
 

Runtime/AsyncTextureLoader.cs

@@ -112,13 +112,23 @@ public void Prewarm()
         /// </summary>
         /// <param name="width"></param>
         /// <param name="height"></param>
-        public void Prewarm(int width, int height)
+        public async void Prewarm(int width, int height)
         {
             if (_computeShader == null)
             {
                 InitialComputeBufferSize = width * height;
                 Init();
                 CreateComputeBuffer(InitialComputeBufferSize);
+
+                var rt = await AcquireTextureAsync(1, 1, 0, true);
+                try
+                {
+                    await UploadDataAsync(rt, 1, 1, new byte[4]);
+                }
+                finally
+                {
+                    RenderTexture.ReleaseTemporary(rt);
+                }
             }
         }
 
@@ -395,13 +405,14 @@ public async Task UploadDataAsync(RenderTexture texture, int xOffset, int yOffse
         /// Asynchronously loads a texture. Will automatically fall back to the blocking approach if compute shaders are not supported.
         /// </summary>
         /// <param name="input"></param>
+        /// <param name="mipCount"></param>
         /// <returns></returns>
-        public async Task<Texture> LoadTextureAsync(Stream input)
+        public async Task<Texture> LoadTextureAsync(Stream input, int mipCount = -1)
         {
             if (SystemInfo.supportsComputeShaders)
             {
                 var image = await DecodeImageAsync(input);
-                var texture = await AcquireTextureAsync(image.Width, image.Height);
+                var texture = await AcquireTextureAsync(image.Width, image.Height, mipCount);
                 await UploadDataAsync(texture, 0, 0, image.Width, image.Height, 0, image.Data);
                 return texture;
             }
@@ -420,10 +431,11 @@ public async Task<Texture> LoadTextureAsync(Stream input)
         /// Asynchronously loads a texture. Will automatically fall back to the blocking approach if compute shaders are not supported.
         /// </summary>
         /// <param name="bytes"></param>
+        /// <param name="mipCount"></param>
         /// <returns></returns>
-        public Task<Texture> LoadTextureAsync(byte[] bytes)
+        public Task<Texture> LoadTextureAsync(byte[] bytes, int mipCount = -1)
         {
-            return LoadTextureAsync(new MemoryStream(bytes));
+            return LoadTextureAsync(new MemoryStream(bytes), mipCount);
         }
 
         #endregion