[VK] Move some ImGui stuff

src/core/engine/backends/vulkan_backend.cpp

@@ -31,20 +31,6 @@
 namespace gravel {
 namespace {
 
-inline constexpr VkDescriptorPoolSize kImGuiDescriptorPoolSizes[] = {
-    {VK_DESCRIPTOR_TYPE_SAMPLER, 8},
-    {VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 32},
-    {VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE, 8},
-    {VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, 8},
-    {VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER, 8},
-    {VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER, 8},
-    {VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 32},
-    {VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 8},
-    {VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, 8},
-    {VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, 8},
-    {VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT, 8},
-};
-
 [[nodiscard]] auto select_gpu() -> VkPhysicalDevice
 {
   GRAVEL_ASSERT(vk::get_instance() != VK_NULL_HANDLE);
@@ -70,11 +56,7 @@ VulkanBackend::VulkanBackend()
       mRenderPass {mSwapchain.get_image_format()},
       mSampler {vk::create_sampler()},
       mPipelineCache {vk::create_pipeline_cache()},
-      mImGuiPipelineCache {vk::create_pipeline_cache()},
-      mImGuiDescriptorPool {1'000,
-                            kImGuiDescriptorPoolSizes,
-                            array_length(kImGuiDescriptorPoolSizes),
-                            VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT},
+      mImGuiData {},
       mPipelineBuilder {mPipelineCache.get()}
 {
   create_shading_pipeline();
@@ -133,7 +115,7 @@ void VulkanBackend::stop()
 
 void VulkanBackend::on_init(Scene& scene)
 {
-  prepare_imgui_for_vulkan();
+  vk::init_imgui(mImGuiData, mRenderPass.get(), mSwapchain.get_image_count());
 
   scene.add<vk::ImageCache>();
 
@@ -154,36 +136,6 @@ void VulkanBackend::on_init(Scene& scene)
   camera_context.active_camera = camera_entity;
 }
 
-void VulkanBackend::prepare_imgui_for_vulkan()
-{
-  const auto graphics_queue_family_index =
-      vk::get_queue_family_indices(vk::get_gpu(), vk::get_surface())
-          .graphics_family.value();
-
-  ImGui_ImplVulkan_InitInfo info {};
-  info.Instance = mInstance.get();
-  info.PhysicalDevice = mGPU;
-  info.Device = mDevice.get();
-  info.QueueFamily = graphics_queue_family_index;
-  info.Queue = vk::get_graphics_queue();
-  info.PipelineCache = mImGuiPipelineCache.get();
-  info.DescriptorPool = mImGuiDescriptorPool.get();
-  info.Subpass = 0;
-  info.MinImageCount = vk::kMaxFramesInFlight;
-  info.ImageCount = vk::kMaxFramesInFlight;
-  info.MSAASamples = VK_SAMPLE_COUNT_1_BIT;
-  info.Allocator = nullptr;
-  info.CheckVkResultFn = [](const VkResult result) {
-    GRAVEL_VK_CALL(result, "[VK] ImGui Vulkan backend error");
-  };
-
-  if (!ImGui_ImplVulkan_Init(&info, mRenderPass.get())) {
-    throw Error {"[VK] Could not initialize ImGui Vulkan backend"};
-  }
-
-  DearImGuiVulkan::recreate_font_textures();
-}
-
 void VulkanBackend::on_quit()
 {
   vkDeviceWaitIdle(mDevice.get());

src/core/engine/backends/vulkan_backend.hpp

@@ -14,6 +14,7 @@
 #include "graphics/vulkan/device.hpp"
 #include "graphics/vulkan/frame.hpp"
 #include "graphics/vulkan/image/sampler.hpp"
+#include "graphics/vulkan/imgui.hpp"
 #include "graphics/vulkan/instance.hpp"
 #include "graphics/vulkan/model.hpp"
 #include "graphics/vulkan/pipeline/descriptor_pool.hpp"
@@ -78,8 +79,7 @@ class VulkanBackend final : public Backend {
   vk::RenderPass mRenderPass;
   vk::Sampler mSampler;
   vk::PipelineCache mPipelineCache;
-  vk::PipelineCache mImGuiPipelineCache;
-  vk::DescriptorPool mImGuiDescriptorPool;
+  vk::ImGuiData mImGuiData;
   vk::CommandPool mCommandPool;
   vk::DescriptorSetLayoutBuilder mDescriptorSetLayoutBuilder;
   vk::PipelineLayoutBuilder mPipelineLayoutBuilder;
@@ -96,7 +96,6 @@ class VulkanBackend final : public Backend {
 
   void create_shading_pipeline();
   void create_frame_data();
-  void prepare_imgui_for_vulkan();
 
   void update_static_matrix_buffer(const Camera& camera,
                                    const Transform& camera_transform);

src/core/graphics/vulkan/imgui.cpp

@@ -0,0 +1,43 @@
+#include "imgui.hpp"
+
+#include <imgui_impl_vulkan.h>
+
+#include "common/debug/error.hpp"
+#include "graphics/vulkan/context.hpp"
+#include "graphics/vulkan/physical_device.hpp"
+#include "graphics/vulkan/util/constants.hpp"
+#include "graphics/vulkan/util/vk_call.hpp"
+#include "init/dear_imgui_vulkan.hpp"
+
+namespace gravel::vk {
+
+void init_imgui(ImGuiData& data, VkRenderPass render_pass, const uint32 swapchain_images)
+{
+  const auto graphics_queue_family_index =
+      get_queue_family_indices(get_gpu(), get_surface()).graphics_family.value();
+
+  ImGui_ImplVulkan_InitInfo info {};
+  info.Instance = get_instance();
+  info.PhysicalDevice = get_gpu();
+  info.Device = get_device();
+  info.QueueFamily = graphics_queue_family_index;
+  info.Queue = get_graphics_queue();
+  info.PipelineCache = data.pipeline_cache.get();
+  info.DescriptorPool = data.descriptor_pool.get();
+  info.Subpass = 0;
+  info.MinImageCount = kMaxFramesInFlight;
+  info.ImageCount = swapchain_images;
+  info.MSAASamples = VK_SAMPLE_COUNT_1_BIT;
+  info.Allocator = nullptr;
+  info.CheckVkResultFn = [](const VkResult result) {
+    GRAVEL_VK_CALL(result, "[VK] ImGui Vulkan backend error");
+  };
+
+  if (!ImGui_ImplVulkan_Init(&info, render_pass)) {
+    throw Error {"[VK] Could not initialize ImGui Vulkan backend"};
+  }
+
+  DearImGuiVulkan::recreate_font_textures();
+}
+
+}  // namespace gravel::vk

src/core/graphics/vulkan/imgui.hpp

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <array>  // size
+
+#include <vulkan/vulkan.h>
+
+#include "common/primitives.hpp"
+#include "graphics/vulkan/pipeline/descriptor_pool.hpp"
+#include "graphics/vulkan/pipeline/pipeline_cache.hpp"
+
+namespace gravel::vk {
+
+inline constexpr VkDescriptorPoolSize kImGuiDescriptorPoolSizes[] = {
+    {VK_DESCRIPTOR_TYPE_SAMPLER, 8},
+    {VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 32},
+    {VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE, 8},
+    {VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, 8},
+    {VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER, 8},
+    {VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER, 8},
+    {VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 32},
+    {VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 8},
+    {VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, 8},
+    {VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, 8},
+    {VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT, 8},
+};
+
+struct ImGuiData final {
+  PipelineCache pipeline_cache {create_pipeline_cache()};
+  DescriptorPool descriptor_pool {1'000,
+                                  kImGuiDescriptorPoolSizes,
+                                  std::size(kImGuiDescriptorPoolSizes),
+                                  VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT};
+};
+
+/// Initializes the ImGui Vulkan backend.
+void init_imgui(ImGuiData& data, VkRenderPass render_pass, uint32 swapchain_images);
+
+}  // namespace gravel::vk