Added function for getting best-fit depth format to device

Refs #607

base/VulkanDevice.hpp

@@ -567,5 +567,36 @@ namespace vks
 			return (std::find(supportedExtensions.begin(), supportedExtensions.end(), extension) != supportedExtensions.end());
 		}
 
+		/**
+		* Select the best-fit depth format for this device from a list of possible depth (and stencil) formats
+		*
+		* @param checkSamplingSupport Check if the format can be sampled from (e.g. for shader reads)
+		*
+		* @return The depth format that best fits for the current device
+		*
+		* @throw Throws an exception if no depth format fits the requirements
+		*/
+		VkFormat getSupportedDepthFormat(bool checkSamplingSupport)
+		{
+			// All depth formats may be optional, so we need to find a suitable depth format to use
+			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 formatProperties;
+				vkGetPhysicalDeviceFormatProperties(physicalDevice, format, &formatProperties);
+				// Format must support depth stencil attachment for optimal tiling
+				if (formatProperties.optimalTilingFeatures & VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT)
+				{
+					if (checkSamplingSupport) {
+						if (!(formatProperties.optimalTilingFeatures & VK_FORMAT_FEATURE_SAMPLED_IMAGE_BIT)) {
+							continue;
+						}
+					}
+					return format;
+				}
+			}
+			throw std::runtime_error("Could not find a matching depth format");
+		}
+
 	};
 }

examples/shadowmappingcascade/shadowmappingcascade.cpp

@@ -262,8 +262,7 @@ public:
 	*/
 	void prepareDepthPass()
 	{
-		VkFormat depthFormat;
+		VkFormat depthFormat = vulkanDevice->getSupportedDepthFormat(true);
-		vks::tools::getSupportedDepthFormat(physicalDevice, &depthFormat);
 
 		/*
 			Depth map renderpass