From 144a91ea9797674db8f4d2ecd5c5eeeaf574979e Mon Sep 17 00:00:00 2001
From: baldurk <baldurk@baldurk.org>
Date: Thu, 18 Feb 2016 17:32:51 +0100
Subject: [PATCH] Correctly handle sparsely-defined descriptor set layouts
 (Refs #176)

---
 renderdoc/driver/vulkan/vk_info.cpp | 30 ++++++++++++++++++++---------
 renderdoc/driver/vulkan/vk_info.h   |  7 ++++++-
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/renderdoc/driver/vulkan/vk_info.cpp b/renderdoc/driver/vulkan/vk_info.cpp
index 00ca20ec9..eaca156d7 100644
--- a/renderdoc/driver/vulkan/vk_info.cpp
+++ b/renderdoc/driver/vulkan/vk_info.cpp
@@ -29,29 +29,41 @@ void DescSetLayout::Init(VulkanResourceManager *resourceMan, VulkanCreationInfo
 {
 	dynamicCount = 0;
 
+	// descriptor set layouts can be sparse, such that only three bindings exist
+	// but they are at 0, 5 and 10.
+	// We assume here that while the layouts may be sparse that's mostly to allow
+	// multiple layouts to co-exist nicely, and that we can allocate our bindings
+	// array to cover the whole size, and leave some elements unused.
+
+	// will be at least this size.
 	bindings.resize(pCreateInfo->bindingCount);
 	for(uint32_t i=0; i < pCreateInfo->bindingCount; i++)
 	{
-		bindings[i].descriptorCount = pCreateInfo->pBindings[i].descriptorCount;
-		bindings[i].descriptorType = pCreateInfo->pBindings[i].descriptorType;
-		bindings[i].stageFlags = pCreateInfo->pBindings[i].stageFlags;
+		uint32_t b = pCreateInfo->pBindings[i].binding;
+		// expand to fit the binding
+		if(b >= bindings.size())
+			bindings.resize(b+1);
 
-		if(bindings[i].descriptorType == VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC ||
-			 bindings[i].descriptorType == VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC)
+		bindings[b].descriptorCount = pCreateInfo->pBindings[i].descriptorCount;
+		bindings[b].descriptorType = pCreateInfo->pBindings[i].descriptorType;
+		bindings[b].stageFlags = pCreateInfo->pBindings[i].stageFlags;
+
+		if(bindings[b].descriptorType == VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC ||
+			 bindings[b].descriptorType == VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC)
 			dynamicCount++;
 
 		if(pCreateInfo->pBindings[i].pImmutableSamplers)
 		{
-			bindings[i].immutableSampler = new ResourceId[bindings[i].descriptorCount];
+			bindings[b].immutableSampler = new ResourceId[bindings[i].descriptorCount];
 
-			for(uint32_t s=0; s < bindings[i].descriptorCount; s++)
+			for(uint32_t s=0; s < bindings[b].descriptorCount; s++)
 			{
 				// during writing, the create info contains the *wrapped* objects.
 				// on replay, we have the wrapper map so we can look it up
 				if(resourceMan->IsWriting())
-					bindings[i].immutableSampler[s] = GetResID(pCreateInfo->pBindings[i].pImmutableSamplers[s]);
+					bindings[b].immutableSampler[s] = GetResID(pCreateInfo->pBindings[i].pImmutableSamplers[s]);
 				else
-					bindings[i].immutableSampler[s] = resourceMan->GetNonDispWrapper(pCreateInfo->pBindings[i].pImmutableSamplers[s])->id;
+					bindings[b].immutableSampler[s] = resourceMan->GetNonDispWrapper(pCreateInfo->pBindings[i].pImmutableSamplers[s])->id;
 			}
 		}
 	}
diff --git a/renderdoc/driver/vulkan/vk_info.h b/renderdoc/driver/vulkan/vk_info.h
index 3c23278fb..e5f1bc982 100644
--- a/renderdoc/driver/vulkan/vk_info.h
+++ b/renderdoc/driver/vulkan/vk_info.h
@@ -39,7 +39,12 @@ struct DescSetLayout
 
 	struct Binding
 	{
-		Binding() : immutableSampler(NULL) {}
+		// set reasonable defaults in the constructor as with sparse descriptor set layouts
+		// some elements could be untouched. We set stageFlags to 0 so the UI ignores these
+		// elements
+		Binding()
+			: descriptorType(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER), descriptorCount(1)
+			, stageFlags(0), immutableSampler(NULL) {}
 		~Binding() { SAFE_DELETE_ARRAY(immutableSampler); }
 
 		VkDescriptorType descriptorType;