Add mipmap support (#36)

* Add mipmap support and better blur controls

* Update package.json

Runtime/BlurConfig.cs

@@ -15,5 +15,7 @@ public struct BlurConfig
 
         public int Width;
         public int Height;
+
+        public bool EnableMipMaps;
     }
 }

Runtime/BlurPasses.cs

@@ -44,7 +44,7 @@ public static void KawaseExecutePass<TPass, T>(TPass data, T cmd) where TPass :
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         private static float CalculateOffset(BlurConfig blurConfig, int iteration)
         {
-            return (blurConfig.Offset + iteration * blurConfig.Scale) / blurConfig.Downsample * blurConfig.Intensity;
+            return (blurConfig.Offset + iteration * blurConfig.Scale) / blurConfig.Downsample;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -55,7 +55,9 @@ private static void BlitTexture<T>(T cmd, Texture sourceHandle, Texture destinat
             mpb.SetVector(Constants.BlurParamsId, new Vector4(blurConfig.Intensity, blurConfig.Scale, blurConfig.Downsample, blurConfig.Offset));
             mpb.SetTexture(Constants.BlitTextureId, sourceHandle);
 
-            // TODO: Implement mipLevel and depthSlice support, if relevant
+            // TODO: add a lookup for getting mipmap level from offset value
+            mpb.SetFloat(Constants.BlitMipLevelId, blurConfig.EnableMipMaps ? Mathf.Log(offset, 2) : 0);
+
             cmd.SetRenderTarget(destinationHandle, 0, CubemapFace.Unknown, 0);
             cmd.DrawProcedural(Matrix4x4.identity, blurConfig.Material, 0, MeshTopology.Quads, 4, 1, mpb);
         }

Runtime/Constants.cs

@@ -10,6 +10,7 @@ public static class Constants
         public static readonly int BlurParamsId = Shader.PropertyToID("_BlurParams");
         public static readonly int BlitTextureId = Shader.PropertyToID("_BlitTexture");
         public static readonly int BlitScaleBiasId = Shader.PropertyToID("_BlitScaleBias");
+        public static readonly int BlitMipLevelId = Shader.PropertyToID("_BlitMipLevel");
         public static readonly int GlobalFullScreenBlurTextureId = Shader.PropertyToID("_GlobalUniversalBlurTexture");
     }
 }

Runtime/UniversalBlurFeature.cs

@@ -7,16 +7,15 @@ namespace Unified.UniversalBlur.Runtime
     public class UniversalBlurFeature : ScriptableRendererFeature
     {
         [Header("Blur Settings")]
-        [Range(1, 8)] [SerializeField] private int iterations = 4;
-
-        [Space]
-
-        [Range(0f, 1f)] [SerializeField] public float intensity = 1.0f;
+        [Range(1, 12)] [SerializeField] private int iterations = 4;
         [Range(1f, 10f)] [SerializeField] private float downsample = 2.0f;
+
+        [Tooltip("Enable mipmaps for more efficient blur")]
+        [SerializeField] private bool enableMipMaps = true;
         // [Range(0f, 10f)] 
         [SerializeField] private float scale = 1f;
         // [Range(0f, 10f)] 
-        [SerializeField] private float offset = 2f;
+        [SerializeField] private float offset = 1f;
 
         [Space]
 
@@ -33,6 +32,8 @@ public class UniversalBlurFeature : ScriptableRendererFeature
                  "\n\nOther: BeforeRenderingTransparents (will hide transparents)")]
         [SerializeField] private RenderPassEvent injectionPoint = RenderPassEvent.AfterRenderingPostProcessing;
 
+        private float _intensity = 1.0f;
+
         [SerializeField]
         [HideInInspector]
         [Reload("Shaders/Blur.shader")]
@@ -41,6 +42,13 @@ public class UniversalBlurFeature : ScriptableRendererFeature
         private Material _material;
         private UniversalBlurPass _blurPass;
         private float _renderScale; 
+
+        // Avoid changing intensity value, but useful for transitions
+        public float Intensity
+        {
+            get => _intensity;
+            set => _intensity = Mathf.Clamp(value, 0f, 1f);
+        }
 
         /// <inheritdoc/>
         public override void Create()
@@ -111,11 +119,13 @@ private BlurConfig GetBlurConfig(in RenderingData renderingData)
                 Height = height,
 
                 Material = _material,
-                Intensity = intensity,
+                Intensity = _intensity,
                 Downsample = downsample,
                 Offset = offset,
                 BlurType = blurType,
                 Iterations = iterations,
+
+                EnableMipMaps = enableMipMaps
             };
         }
 

Runtime/UniversalBlurPass.cs

@@ -47,13 +47,20 @@ public void DrawDefaultTexture()
             Shader.SetGlobalTexture(Constants.GlobalFullScreenBlurTextureId, Texture2D.linearGrayTexture);
         }
 
+        private RenderTextureDescriptor GetDescriptor() =>
+            new(_blurConfig.Width, _blurConfig.Height, GraphicsFormat.B10G11R11_UFloatPack32, 0)
+            {
+                useMipMap = _blurConfig.EnableMipMaps,
+                autoGenerateMips = _blurConfig.EnableMipMaps
+            };
+
         public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
         {
             var cmd = CommandBufferPool.Get();
-            
-            var descriptor = new RenderTextureDescriptor(_blurConfig.Width, _blurConfig.Height, GraphicsFormat.B10G11R11_UFloatPack32, 0);
-            
-            #if UNITY_6000_0_OR_NEWER
+
+            var descriptor = GetDescriptor();
+
+#if UNITY_6000_0_OR_NEWER
             RenderingUtils.ReAllocateHandleIfNeeded(ref _sourceRT, descriptor, FilterMode.Bilinear, TextureWrapMode.Clamp, name: k_BlurTextureSourceName);
             RenderingUtils.ReAllocateHandleIfNeeded(ref _destinationRT, descriptor, FilterMode.Bilinear, TextureWrapMode.Clamp, name: k_BlurTextureDestinationName);
             #else
@@ -96,15 +103,12 @@ public override void RecordRenderGraph(RenderGraph renderGraph, ContextContainer
 
             var cameraColorSource = resourceData.activeColorTexture;
 
-            var rtDescriptor = renderGraph.GetTextureDesc(cameraColorSource);
-            rtDescriptor.width = _blurConfig.Width;
-            rtDescriptor.height = _blurConfig.Height;
-            rtDescriptor.clearBuffer = false;
-
-            rtDescriptor.name = k_BlurTextureSourceName;
-            TextureHandle source = renderGraph.CreateTexture(rtDescriptor);
-            rtDescriptor.name = k_BlurTextureDestinationName;
-            TextureHandle destination = renderGraph.CreateTexture(rtDescriptor);
+            var descriptor = new TextureDesc(GetDescriptor());
+
+            descriptor.name = k_BlurTextureSourceName;
+            TextureHandle source = renderGraph.CreateTexture(descriptor);
+            descriptor.name = k_BlurTextureDestinationName;
+            TextureHandle destination = renderGraph.CreateTexture(descriptor);
 
             using (var builder = renderGraph.AddUnsafePass<RenderGraphPassData>(k_PassName, out var passData, _profilingSampler))
             {

Shaders/Common.hlsl

@@ -10,9 +10,7 @@ SAMPLER(sampler_BlitTexture);
 // Function defines
 #define SAMPLE(textureName, coord2) SAMPLE_TEXTURE2D_LOD(textureName, sampler_LinearClamp, coord2, _BlitMipLevel);
 
-#define SAMPLE_BASEMAP(uv)          half4(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_BlitTexture, UnityStereoTransformScreenSpaceTex(uv)));
-#define SAMPLE_BASEMAP_R(uv)        half(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_BlitTexture, UnityStereoTransformScreenSpaceTex(uv)).r);
-
+#define SAMPLE_BASEMAP(uv) half4(SAMPLE_TEXTURE2D_LOD(_BlitTexture, sampler_LinearClamp, UnityStereoTransformScreenSpaceTex(uv), _BlitMipLevel));
 
 // Constants
 static const half  HALF_POINT_ONE   = half(0.1);
@@ -186,7 +184,7 @@ half4 KawaseBlur(Varyings input) : SV_Target
     half2 uv = input.texcoord;
     half2 texelSize = TEXEL_SIZE.xy * rcp(DOWNSAMPLE);
 
-    half4 col = KawaseBlurFilter(uv, texelSize, ITERATION);
-
+    half4 col = KawaseBlurFilter(uv, texelSize * INTENSITY, ITERATION * OFFSET);
+    
     return col;
 }

package.json

@@ -2,7 +2,7 @@
     "name": "com.unify.unified-universal-blur",
     "displayName": "Unified Blur",
     "description": "Unified Blur enables you to use translucent blur effect on your canvas.",
-    "version": "0.7.1",
+    "version": "0.7.2",
     "unity": "2022.3",
     "license": "MIT",
     "repository": {