added texture2d atlas

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Decal/DecalSystem.cs

 
         static public int m_DecalsVisibleThisFrame = 0;
 
+        private Texture2DAtlas m_Atlas = null;
+
+        public Texture2DAtlas Atlas
+        {
+            get
+            {
+                if (m_Atlas == null)
+                {
+                    m_Atlas = new Texture2DAtlas(4096, 4096, RenderTextureFormat.ARGB32);
+                }
+                return m_Atlas;
+            }
+        }
+
         private class DecalSet
         {
             private void InitializeMaterialValues()
             {
                 m_DiffuseTexIndex = (m_DiffuseTexture != null) ? instance.TextureAtlas.FetchSlice(cmd, m_DiffuseTexture) : -1;
                 m_NormalTexIndex = (m_NormalTexture != null) ? instance.TextureAtlas.FetchSlice(cmd, m_NormalTexture) : -1;
-                m_MaskTexIndex = (m_MaskTexture != null) ? instance.TextureAtlas.FetchSlice(cmd, m_MaskTexture) : -1;             
+                m_MaskTexIndex = (m_MaskTexture != null) ? instance.TextureAtlas.FetchSlice(cmd, m_MaskTexture) : -1;
+
+                if (m_DiffuseTexture != null)
+                {
+                    instance.Atlas.AddTexture(cmd, m_DiffuseTexture);
+                }
             }
 
             public void RemoveFromTextureCache()
         {
             if (m_DecalAtlas != null)
                 m_DecalAtlas.Release();
+            if (m_Atlas != null)
+                m_Atlas.Release();
+            m_Atlas = null;
         }
     }
 }

ScriptableRenderPipeline/HDRenderPipeline/HDRP/HDUtils.cs

             }
         }
 
-        public static void BlitTexture(CommandBuffer cmd, RTHandle source, RTHandle destination, Vector4 scaleBiasSrc, Vector4 scaleBiasDst, float srcMipLevel, int dstMipLevel, bool bilinear)
+        public static void BlitTexture(CommandBuffer cmd, Texture source, RTHandle destination, Vector4 scaleBiasSrc, Vector4 scaleBiasDst, float srcMipLevel, int dstMipLevel, bool bilinear)
         {
             s_PropertyBlock.SetTexture(HDShaderIDs._BlitTexture, source);
             s_PropertyBlock.SetVector(HDShaderIDs._BlitScaleBiasSrc, scaleBiasSrc);

ScriptableRenderPipeline/HDRenderPipeline/HDRP/RenderPipelineResources/Blit.shader

         {
             Varyings output;
             output.positionCS = GetFullScreenTriangleVertexPosition(input.vertexID) * float4(_BlitScaleBiasDst.xy, 1, 1) + float4(_BlitScaleBiasDst.zw, 0, 0);
-            output.texcoord   = GetFullScreenTriangleTexCoord(input.vertexID) * float4(_BlitScaleBiasSrc.xy, 1, 1) + float4(_BlitScaleBiasSrc.zw, 0, 0);
+            output.texcoord   = GetFullScreenTriangleTexCoord(input.vertexID) * _BlitScaleBiasSrc.xy + _BlitScaleBiasSrc.zw;
             return output;
         }
 

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Texture2DAtlas.cs

+using System.Collections.Generic;
+using UnityEngine.Rendering;
+using UnityEngine.Experimental.Rendering.HDPipeline;
+
+
+#if UNITY_EDITOR
+using UnityEditor;
+#endif
+
+namespace UnityEngine.Experimental.Rendering
+{
+    public class Texture2DAtlas
+    {
+        private RTHandle m_AtlasTexture = null;
+        private int m_Width;
+        private int m_Height;
+        private RenderTextureFormat m_Format;
+
+        public Texture2DAtlas(int width, int height, RenderTextureFormat format)
+        {
+            m_Width = width;
+            m_Height = height;
+            m_Format = format;
+            m_AtlasTexture = RTHandle.Alloc(m_Width,
+                m_Height,
+                1,
+                DepthBits.None,
+                RenderTextureFormat.ARGB32,
+                FilterMode.Point,
+                TextureWrapMode.Clamp,
+                TextureDimension.Tex2D,
+                false,
+                false,
+                true,
+                false);
+        }
+
+        public void Release()
+        {
+            RTHandle.Release(m_AtlasTexture);
+        }
+
+        public void AddTexture(CommandBuffer cmd, Texture texture)
+        {
+            float scaleW = (float)texture.width / m_Width;
+            float scaleH = (float) texture.height / m_Height;
+            HDUtils.BlitTexture(cmd, texture, m_AtlasTexture, new Vector4(1,1,0,0), new Vector4(scaleW, scaleH, 0, 0), 0, 0, false);
+        }
+    }
+}

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Texture2DAtlas.cs.meta

+fileFormatVersion: 2
+guid: 081cfbdef2e1c014aa1d1c9aa16fb952
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: