[Port] [6000.3] RenderGraph - Fix a crash on old IOS devices due to attachments exceeding the maximum Pixel Storage size

Author: Evergreen

Packages/com.unity.render-pipelines.core/Runtime/RenderGraph/Compiler/PassesData.cs

@@ -5,6 +5,7 @@
 using UnityEngine.Rendering;
 using System.Collections.Generic;
 using Unity.Collections;
+using UnityEngine.Experimental.Rendering;
 
 namespace UnityEngine.Rendering.RenderGraphModule.NativeRenderPassCompiler
 {
@@ -1013,6 +1014,12 @@ public static PassBreakAudit CanMerge(CompilerContextData contextData, int activ
                 }
             }
 
+            // Determines if the pixel storage limit is reached after adding the new 'pass to merge' attachments to the current native render pass.
+            if (TotalAttachmentsSizeExceedPixelStorageLimit(contextData, ref nativePass, ref attachmentsToTryAdding))
+            {
+                return new PassBreakAudit(PassBreakReason.AttachmentLimitReached, passIdToMerge);
+            }
+
             // We check first if we are at risk of having too many subpasses,
             // only then we do the costlier subpass merging check, short circuiting it whenever possible
             bool canAddAnExtraSubpass = (nativePass.numGraphPasses < NativePassCompiler.k_MaxSubpass);
@@ -1025,6 +1032,34 @@ public static PassBreakAudit CanMerge(CompilerContextData contextData, int activ
             return new PassBreakAudit(PassBreakReason.Merged, passIdToMerge);
         }
 
+        static bool TotalAttachmentsSizeExceedPixelStorageLimit(CompilerContextData contextData, ref NativePassData nativePass, ref FixedAttachmentArray<PassFragmentData> attachmentsToTryAdding)
+        {
+            // TODO: We are currently only checking for iOS GPU Family 1 to 3 since the storage size is much more restricted (16 bytes for Family 1 and 32 for Family 2 & 3).
+            // This is temporary. Later on, we should check all iOS GPU Families but also Android (Vulkan) to avoid the same potential restrictions.
+            if (Application.platform == RuntimePlatform.IPhonePlayer && SystemInfo.maxTiledPixelStorageSize <= 32)
+            {
+                int totalSize = 0;
+
+                // Iterate over current attachments
+                for (int i = 0; i < nativePass.fragments.size; ++i)
+                {
+                    ref readonly var unvResource = ref contextData.UnversionedResourceData(nativePass.fragments[i].resource);
+                    totalSize += SystemInfo.GetTiledRenderTargetStorageSize(unvResource.graphicsFormat, unvResource.msaaSamples);
+                }
+
+                // Iterate over new attachments to add
+                for (int i = 0; i < attachmentsToTryAdding.size; ++i)
+                {
+                    ref readonly var unvResource = ref contextData.UnversionedResourceData(attachmentsToTryAdding[i].resource);
+                    totalSize += SystemInfo.GetTiledRenderTargetStorageSize(unvResource.graphicsFormat, unvResource.msaaSamples);
+                }
+
+                return totalSize > SystemInfo.maxTiledPixelStorageSize;
+            }
+            
+            return false;
+        }
+
         // This function follows the structure of TryMergeNativeSubPass but only tests if the new native subpass can be
         // merged with the last one, allowing for early returns. It does not modify the state
         // ref for nativePass is used for performance reasons. The method should not modify nativePass.

Packages/com.unity.render-pipelines.core/Runtime/RenderGraph/Compiler/ResourcesData.cs

@@ -2,6 +2,7 @@
 using System.Runtime.CompilerServices;
 using Unity.Collections;
 using UnityEngine.Rendering;
+using UnityEngine.Experimental.Rendering;
 
 namespace UnityEngine.Rendering.RenderGraphModule.NativeRenderPassCompiler
 {
@@ -29,6 +30,7 @@ internal struct ResourceUnversionedData
         public readonly int height;
         public readonly int volumeDepth;
         public readonly int msaaSamples;
+        public readonly GraphicsFormat graphicsFormat;
 
         public int latestVersionNumber; // mostly readonly, can be decremented only if all passes using the last version are culled
 
@@ -62,6 +64,7 @@ public ResourceUnversionedData(TextureResource rll, ref RenderTargetInfo info, r
             discard = desc.discardBuffer;
             bindMS = info.bindMS;
             textureUVOrigin = rll.textureUVOrigin;
+            graphicsFormat = desc.format;
         }
 
         public ResourceUnversionedData(IRenderGraphResource rll, ref BufferDesc _, bool isResourceShared)
@@ -87,6 +90,7 @@ public ResourceUnversionedData(IRenderGraphResource rll, ref BufferDesc _, bool
             discard = false;
             bindMS = false;
             textureUVOrigin = TextureUVOriginSelection.Unknown;
+            graphicsFormat = GraphicsFormat.None;
         }
 
         public ResourceUnversionedData(IRenderGraphResource rll, ref RayTracingAccelerationStructureDesc _, bool isResourceShared)
@@ -112,6 +116,7 @@ public ResourceUnversionedData(IRenderGraphResource rll, ref RayTracingAccelerat
             discard = false;
             bindMS = false;
             textureUVOrigin = TextureUVOriginSelection.Unknown;
+            graphicsFormat = GraphicsFormat.None;
         }
 
         public void InitializeNullResource()