Fix SPIRV parsing for SpvOpTypeImage

OpTypeImage can be used for sampled or storage images, which is
indicated by an extra word we haven't parsed until now. This is not
necessary right now but might be if we decide to get rid of combined
image/samplers.

Author: zeux

src/shaders.cpp

@@ -32,6 +32,7 @@ struct Id
 	uint32_t storageClass;
 	uint32_t binding;
 	uint32_t set;
+	uint32_t imageSampled;
 	uint32_t constant;
 };
 
@@ -58,14 +59,14 @@ static VkShaderStageFlagBits getShaderStage(SpvExecutionModel executionModel)
 	}
 }
 
-static VkDescriptorType getDescriptorType(SpvOp op)
+static VkDescriptorType getDescriptorType(SpvOp op, uint32_t imageSampled = 0)
 {
 	switch (op)
 	{
 	case SpvOpTypeStruct:
 		return VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;
 	case SpvOpTypeImage:
-		return VK_DESCRIPTOR_TYPE_STORAGE_IMAGE;
+		return imageSampled == 1 ? VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE : VK_DESCRIPTOR_TYPE_STORAGE_IMAGE;
 	case SpvOpTypeSampler:
 		return VK_DESCRIPTOR_TYPE_SAMPLER;
 	case SpvOpTypeSampledImage:
@@ -158,7 +159,6 @@ static void parseShader(Shader& shader, const uint32_t* code, uint32_t codeSize)
 		}
 		break;
 		case SpvOpTypeStruct:
-		case SpvOpTypeImage:
 		case SpvOpTypeSampler:
 		case SpvOpTypeSampledImage:
 		case SpvOpTypeAccelerationStructureKHR:
@@ -172,6 +172,18 @@ static void parseShader(Shader& shader, const uint32_t* code, uint32_t codeSize)
 			ids[id].opcode = opcode;
 		}
 		break;
+		case SpvOpTypeImage:
+		{
+			assert(wordCount >= 9);
+
+			uint32_t id = insn[1];
+			assert(id < idBound);
+
+			assert(ids[id].opcode == 0);
+			ids[id].opcode = opcode;
+			ids[id].imageSampled = insn[7];
+		}
+		break;
 		case SpvOpTypePointer:
 		{
 			assert(wordCount == 4);
@@ -225,8 +237,8 @@ static void parseShader(Shader& shader, const uint32_t* code, uint32_t codeSize)
 			assert(id.binding < 32);
 			assert(ids[id.typeId].opcode == SpvOpTypePointer);
 
-			uint32_t typeKind = ids[ids[id.typeId].typeId].opcode;
-			VkDescriptorType resourceType = getDescriptorType(SpvOp(typeKind));
+			const Id& type = ids[ids[id.typeId].typeId];
+			VkDescriptorType resourceType = getDescriptorType(SpvOp(type.opcode), type.imageSampled);
 
 			assert((shader.resourceMask & (1 << id.binding)) == 0 || shader.resourceTypes[id.binding] == resourceType);