Backends: Vulkan: Support for dynamic_rendering (#5446, #5037)

Co-authored-by: Caio Oliveira <cmarcelo@gmail.com>
Simplified for master branch.

# Conflicts:
#	backends/imgui_impl_vulkan.cpp

backends/imgui_impl_vulkan.cpp

@@ -212,6 +212,11 @@ IMGUI_VULKAN_FUNC_MAP(IMGUI_VULKAN_FUNC_DEF)
 #undef IMGUI_VULKAN_FUNC_DEF
 #endif // VK_NO_PROTOTYPES
 
+#if defined(VK_VERSION_1_3) || defined(VK_KHR_dynamic_rendering)
+static PFN_vkCmdBeginRenderingKHR imgui_vkCmdBeginRenderingKHR;
+static PFN_vkCmdEndRenderingKHR imgui_vkCmdEndRenderingKHR;
+#endif
+
 //-----------------------------------------------------------------------------
 // SHADERS
 //-----------------------------------------------------------------------------
@@ -840,6 +845,19 @@ static void ImGui_ImplVulkan_CreatePipeline(VkDevice device, const VkAllocationC
     info.layout = bd->PipelineLayout;
     info.renderPass = renderPass;
     info.subpass = subpass;
+
+#if defined(VK_VERSION_1_3) || defined(VK_KHR_dynamic_rendering)
+    VkPipelineRenderingCreateInfoKHR pipelineRenderingCreateInfo = {};
+    pipelineRenderingCreateInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO_KHR;
+    pipelineRenderingCreateInfo.colorAttachmentCount = 1;
+    pipelineRenderingCreateInfo.pColorAttachmentFormats = &bd->VulkanInitInfo.ColorAttachmentFormat;
+
+    if (bd->VulkanInitInfo.UseDynamicRendering) {
+        info.pNext = &pipelineRenderingCreateInfo;
+        info.renderPass = VK_NULL_HANDLE; // Just make sure it's actually nullptr.
+    }
+#endif
+
     VkResult err = vkCreateGraphicsPipelines(device, pipelineCache, 1, &info, allocator, pipeline);
     check_vk_result(err);
 }
@@ -952,10 +970,16 @@ bool    ImGui_ImplVulkan_LoadFunctions(PFN_vkVoidFunction(*loader_func)(const ch
         return false;
     IMGUI_VULKAN_FUNC_MAP(IMGUI_VULKAN_FUNC_LOAD)
 #undef IMGUI_VULKAN_FUNC_LOAD
+
+#if defined(VK_VERSION_1_3) || defined(VK_KHR_dynamic_rendering)
+    imgui_vkCmdBeginRenderingKHR = reinterpret_cast<PFN_vkCmdBeginRenderingKHR>(loader_func("vkCmdBeginRenderingKHR", user_data));
+    imgui_vkCmdEndRenderingKHR = reinterpret_cast<PFN_vkCmdEndRenderingKHR>(loader_func("vkCmdEndRenderingKHR", user_data));
+#endif
 #else
     IM_UNUSED(loader_func);
     IM_UNUSED(user_data);
 #endif
+
     g_FunctionsLoaded = true;
     return true;
 }
@@ -964,6 +988,20 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass rend
 {
     IM_ASSERT(g_FunctionsLoaded && "Need to call ImGui_ImplVulkan_LoadFunctions() if IMGUI_IMPL_VULKAN_NO_PROTOTYPES or VK_NO_PROTOTYPES are set!");
 
+    if (info->UseDynamicRendering) {
+#if defined(VK_VERSION_1_3) || defined(VK_KHR_dynamic_rendering)
+#ifndef VK_NO_PROTOTYPES
+        imgui_vkCmdBeginRenderingKHR = reinterpret_cast<PFN_vkCmdBeginRenderingKHR>(vkGetInstanceProcAddr(info->Instance, "vkCmdBeginRenderingKHR"));
+        imgui_vkCmdEndRenderingKHR = reinterpret_cast<PFN_vkCmdEndRenderingKHR>(vkGetInstanceProcAddr(info->Instance, "vkCmdEndRenderingKHR"));
+#endif
+
+        IM_ASSERT(imgui_vkCmdBeginRenderingKHR != nullptr);
+        IM_ASSERT(imgui_vkCmdEndRenderingKHR != nullptr);
+#else
+        IM_ASSERT(!"Can't use dynamic rendering when neither VK_VERSION_1_3 or VK_KHR_dynamic_rendering is defined.");
+#endif
+    }
+
     ImGuiIO& io = ImGui::GetIO();
     IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
 
@@ -980,7 +1018,8 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass rend
     IM_ASSERT(info->DescriptorPool != VK_NULL_HANDLE);
     IM_ASSERT(info->MinImageCount >= 2);
     IM_ASSERT(info->ImageCount >= info->MinImageCount);
-    IM_ASSERT(render_pass != VK_NULL_HANDLE);
+    if (!info->UseDynamicRendering)
+        IM_ASSERT(render_pass != VK_NULL_HANDLE);
 
     bd->VulkanInitInfo = *info;
     bd->RenderPass = render_pass;
@@ -1297,7 +1336,7 @@ void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, V
         vkDestroySwapchainKHR(device, old_swapchain, allocator);
 
     // Create the Render Pass
-    {
+    if (!wd->UseDynamicRendering) {
         VkAttachmentDescription attachment = {};
         attachment.format = wd->SurfaceFormat.format;
         attachment.samples = VK_SAMPLE_COUNT_1_BIT;
@@ -1359,7 +1398,7 @@ void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, V
     }
 
     // Create Framebuffer
-    {
+    if (!wd->UseDynamicRendering) {
         VkImageView attachment[1];
         VkFramebufferCreateInfo info = {};
         info.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;

backends/imgui_impl_vulkan.h

@@ -61,6 +61,8 @@ struct ImGui_ImplVulkan_InitInfo
     VkSampleCountFlagBits           MSAASamples;            // >= VK_SAMPLE_COUNT_1_BIT (0 -> default to VK_SAMPLE_COUNT_1_BIT)
     const VkAllocationCallbacks*    Allocator;
     void                            (*CheckVkResultFn)(VkResult err);
+    bool                            UseDynamicRendering;    // Need to explicitly enable VK_KHR_dynamic_rendering extension to use this, even for Vulkan 1.3.
+    VkFormat                        ColorAttachmentFormat;
 };
 
 // Called by user code
@@ -139,6 +141,7 @@ struct ImGui_ImplVulkanH_Window
     VkPresentModeKHR    PresentMode;
     VkRenderPass        RenderPass;
     VkPipeline          Pipeline;               // The window pipeline may uses a different VkRenderPass than the one passed in ImGui_ImplVulkan_InitInfo
+    bool                UseDynamicRendering;
     bool                ClearEnable;
     VkClearValue        ClearValue;
     uint32_t            FrameIndex;             // Current frame being rendered to (0 <= FrameIndex < FrameInFlightCount)