Add stencil format require toggle

Fixes #1031

base/VulkanTools.cpp

@@ -82,7 +82,7 @@ namespace vks
 		{
 			// 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 = {
+			std::vector<VkFormat> formatList = {
 				VK_FORMAT_D32_SFLOAT_S8_UINT,
 				VK_FORMAT_D32_SFLOAT,
 				VK_FORMAT_D24_UNORM_S8_UINT,
@@ -90,11 +90,10 @@ namespace vks
 				VK_FORMAT_D16_UNORM
 			};
 
-			for (auto& format : depthFormats)
+			for (auto& format : formatList)
 			{
 				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;
@@ -105,6 +104,29 @@ namespace vks
 			return false;
 		}
 
+		VkBool32 getSupportedDepthStencilFormat(VkPhysicalDevice physicalDevice, VkFormat* depthStencilFormat)
+		{
+			std::vector<VkFormat> formatList = {
+				VK_FORMAT_D32_SFLOAT_S8_UINT,
+				VK_FORMAT_D24_UNORM_S8_UINT,
+				VK_FORMAT_D16_UNORM_S8_UINT,
+			};
+
+			for (auto& format : formatList)
+			{
+				VkFormatProperties formatProps;
+				vkGetPhysicalDeviceFormatProperties(physicalDevice, format, &formatProps);
+				if (formatProps.optimalTilingFeatures & VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT)
+				{
+					*depthStencilFormat = format;
+					return true;
+				}
+			}
+
+			return false;
+		}
+
+
 		VkBool32 formatHasStencil(VkFormat format)
 		{
 			std::vector<VkFormat> stencilFormats = {

base/VulkanTools.h

@@ -1,7 +1,7 @@
 /*
  * Assorted Vulkan helper functions
  *
-* Copyright (C) 2016 by Sascha Willems - www.saschawillems.de
+ * Copyright (C) 2016-2023 by Sascha Willems - www.saschawillems.de
  *
  * This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
  */
@@ -78,6 +78,8 @@ namespace vks
 		// 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);
+		// Same as getSupportedDepthFormat but will only select formats that also have stencil
+		VkBool32 getSupportedDepthStencilFormat(VkPhysicalDevice physicalDevice, VkFormat* depthStencilFormat);
 
 		// Returns tru a given format support LINEAR filtering
 		VkBool32 formatIsFilterable(VkPhysicalDevice physicalDevice, VkFormat format, VkImageTiling tiling);

base/vulkanexamplebase.cpp

@@ -1,7 +1,7 @@
 /*
 * Vulkan Example base class
 *
-* Copyright (C) by Sascha Willems - www.saschawillems.de
+* Copyright (C) 2016-2023 by Sascha Willems - www.saschawillems.de
 *
 * This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
 */
@@ -1043,9 +1043,15 @@ bool VulkanExampleBase::initVulkan()
 	// Get a graphics queue from the device
 	vkGetDeviceQueue(device, vulkanDevice->queueFamilyIndices.graphics, 0, &queue);
 
-	// Find a suitable depth format
+	// Find a suitable depth and/or stencil format
-	VkBool32 validDepthFormat = vks::tools::getSupportedDepthFormat(physicalDevice, &depthFormat);
+	VkBool32 validFormat{ false };
-	assert(validDepthFormat);
+	// Sample that make use of stencil will require a depth + stencil format, so we select from a different list
+	if (requiresStencil) {
+		validFormat = vks::tools::getSupportedDepthStencilFormat(physicalDevice, &depthFormat);
+	} else {
+		validFormat = vks::tools::getSupportedDepthFormat(physicalDevice, &depthFormat);
+	}
+	assert(validFormat);
 
 	swapChain.connect(instance, physicalDevice, device);
 

base/vulkanexamplebase.h

@@ -1,7 +1,7 @@
 /*
 * Vulkan Example base class
 *
-* Copyright (C) by Sascha Willems - www.saschawillems.de
+* Copyright (C) 2016-2023 by Sascha Willems - www.saschawillems.de
 *
 * This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
 */
@@ -154,6 +154,7 @@ protected:
 		VkSemaphore renderComplete;
 	} semaphores;
 	std::vector<VkFence> waitFences;
+	bool requiresStencil{ false };
 public:
 	bool prepared = false;
 	bool resized = false;

examples/stencilbuffer/stencilbuffer.cpp

@@ -1,7 +1,7 @@
 /*
 * Vulkan Example - Rendering outlines using the stencil buffer
 *
-* Copyright (C) 2016-2017 by Sascha Willems - www.saschawillems.de
+* Copyright (C) 2016-2023 by Sascha Willems - www.saschawillems.de
 *
 * This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
 */
@@ -43,6 +43,8 @@ public:
 		camera.setPerspective(60.0f, (float)width / (float)height, 0.1f, 512.0f);
 		camera.setRotation(glm::vec3(2.5f, -35.0f, 0.0f));
 		camera.setTranslation(glm::vec3(0.0f, 0.0f, -2.0f));
+		// This samples requires a format that supports depth AND stencil, which will be handled by the base class
+		requiresStencil = true;
 	}
 
 	~VulkanExample()