Depth format selection function in vkTools namespace. #11 #13

base/vulkanexamplebase.cpp

@@ -522,24 +522,8 @@ void VulkanExampleBase::initVulkan(bool enableValidation)
 	// Get the graphics queue
 	vkGetDeviceQueue(device, graphicsQueueIndex, 0, &queue);
 
-	// Find supported depth format
+	VkBool32 validDepthFormat = vkTools::getSupportedDepthFormat(physicalDevice, &depthFormat);
-	// We prefer 24 bits of depth and 8 bits of stencil, but that may not be supported by all implementations
+	assert(validDepthFormat);
-	std::vector<VkFormat> depthFormats = { VK_FORMAT_D24_UNORM_S8_UINT, VK_FORMAT_D16_UNORM_S8_UINT, VK_FORMAT_D16_UNORM };
-	bool depthFormatFound = false;
-	for (auto& format : depthFormats)
-	{
-		VkFormatProperties formatProps;
-		vkGetPhysicalDeviceFormatProperties(physicalDevice, format, &formatProps);
-		// Format must support depth stencil attachment for optimal tiling
-		if (formatProps.optimalTilingFeatures && VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT)
-		{
-			depthFormat = format;
-			depthFormatFound = true;
-			break;
-		}		
-	}
-
-	assert(depthFormatFound);
 
 	swapChain.init(instance, physicalDevice, device);
 }

base/vulkantools.cpp

@@ -74,6 +74,33 @@ namespace vkTools
 		}
 	}
 
+	VkBool32 getSupportedDepthFormat(VkPhysicalDevice physicalDevice, VkFormat *depthFormat)
+	{
+		// Since all depth formats may be optional, we need to find a suitable depth format to use
+		// Start with the highest precision packed format
+		std::vector<VkFormat> depthFormats = { 
+			VK_FORMAT_D32_SFLOAT_S8_UINT, 
+			VK_FORMAT_D32_SFLOAT,
+			VK_FORMAT_D24_UNORM_S8_UINT, 
+			VK_FORMAT_D16_UNORM_S8_UINT, 
+			VK_FORMAT_D16_UNORM 
+		};
+
+		for (auto& format : depthFormats)
+		{
+			VkFormatProperties formatProps;
+			vkGetPhysicalDeviceFormatProperties(physicalDevice, format, &formatProps);
+			// Format must support depth stencil attachment for optimal tiling
+			if (formatProps.optimalTilingFeatures & VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT)
+			{
+				*depthFormat = format;
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 	// Create an image memory barrier for changing the layout of
 	// an image and put it into an active command buffer
 	// See chapter 11.4 "Image Layout" for details

base/vulkantools.h

@@ -38,6 +38,10 @@ namespace vkTools
 	// Return string representation of a vulkan error string
 	std::string errorString(VkResult errorCode);
 	
+	// Selected a suitable supported depth format starting with 32 bit down to 16 bit
+	// Returns false if none of the depth formats in the list is supported by the device
+	VkBool32 getSupportedDepthFormat(VkPhysicalDevice physicalDevice, VkFormat *depthFormat);
+
 	// Put an image memory barrier for setting an image layout into the given command buffer
 	void setImageLayout(
 		VkCommandBuffer cmdbuffer,