learn-vulkan/vk_gui.cpp

#include "vk_gui.h"
#include "vk_initializers.h"
#include <SDL.h>
#include <SDL_vulkan.h>
#include <imgui.h>
#include <imgui_impl_sdl2.h>
#include <imgui_impl_vulkan.h>
#include "vk_engine.h"

struct SDL_Window* VkGUI::init_window(VkExtent2D windowExtent)
{
  SDL_Init(SDL_INIT_VIDEO);

  SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_VULKAN);

  return SDL_CreateWindow(
      "Vulkan Engine",
      SDL_WINDOWPOS_UNDEFINED,
      SDL_WINDOWPOS_UNDEFINED,
      int(windowExtent.width),
      int(windowExtent.height),
      window_flags);
}

void VkGUI::init_imgui(VulkanEngine& engine)
{
  // 1. create descriptor pool for IMGUI
  //  the size of the pool is very oversize, but it's copied from imgui demo
  //  itself.
  VkDescriptorPoolSize pool_sizes[] = {
    { VK_DESCRIPTOR_TYPE_SAMPLER, 1000 },
    { VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1000 },
    { VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE, 1000 },
    { VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, 1000 },
    { VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER, 1000 },
    { VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER, 1000 },
    { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1000 },
    { VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 1000 },
    { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, 1000 },
    { VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, 1000 },
    { VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT, 1000 }
  };

  VkDescriptorPoolCreateInfo pool_info{
    .sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO,
      .flags = VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT,
      .maxSets = 1000,
      .poolSizeCount = (uint32_t)std::size(pool_sizes),
      .pPoolSizes = pool_sizes,
  };

  VkDescriptorPool imguiPool;
  VK_CHECK(vkCreateDescriptorPool(engine._device, &pool_info, nullptr, &imguiPool));

  // 2: initialize the imgui library
  ImGui::CreateContext();

  ImGui_ImplSDL2_InitForVulkan(engine._window);

  ImGui_ImplVulkan_InitInfo init_info{
    .Instance = engine._instance,
      .PhysicalDevice = engine._chosenGPU,
      .Device = engine._device,
      .Queue = engine._graphicsQueue,
      .DescriptorPool = imguiPool,
      .MinImageCount = 3,
      .ImageCount = 3,
      .MSAASamples = VK_SAMPLE_COUNT_1_BIT,
      .UseDynamicRendering = true,
      .PipelineRenderingCreateInfo = {
        .sType = VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO,
        .colorAttachmentCount = 1,
        .pColorAttachmentFormats = &engine._swapchainImageFormat,
      },
  };

  ImGui_ImplVulkan_Init(&init_info);
  ImGui_ImplVulkan_CreateFontsTexture();

  engine._mainDeletionQueue.push_function([=,this]() {
      ImGui_ImplVulkan_Shutdown();
      vkDestroyDescriptorPool(engine._device, imguiPool, nullptr);
      });
}

void VkGUI::draw_imgui(VkExtent2D& swapchainExtent, VkCommandBuffer cmd, VkImageView targetImageView)
{
  VkRenderingAttachmentInfo colorAttachment = vkinit::attachment_info(targetImageView, nullptr, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);

  VkRenderingInfo renderInfo = vkinit::rendering_info(swapchainExtent, &colorAttachment, nullptr);

  vkCmdBeginRendering(cmd, &renderInfo);

  ImGui_ImplVulkan_RenderDrawData(ImGui::GetDrawData(), cmd);

  vkCmdEndRendering(cmd);
}

void VkGUI::render_imgui(std::vector<ComputeEffect>& backgroundEffects, int* currentBackgroundEffect)
{
  ImGui_ImplVulkan_NewFrame();
  ImGui_ImplSDL2_NewFrame();

  ImGui::NewFrame();

  if (ImGui::Begin("background")) {

    ComputeEffect& selected = backgroundEffects[*currentBackgroundEffect];

    ImGui::Text("Selected effect: %s", selected.name);

    ImGui::SliderInt("Effect Index", currentBackgroundEffect,0, backgroundEffects.size() - 1);

    ImGui::InputFloat4("data1",(float*)& selected.data.data1);
    ImGui::InputFloat4("data2",(float*)& selected.data.data2);
    ImGui::InputFloat4("data3",(float*)& selected.data.data3);
    ImGui::InputFloat4("data4",(float*)& selected.data.data4);
  }
  ImGui::End();

  ImGui::Render();
}

void VkGUI::destroy(struct SDL_Window* _window)
{
  SDL_DestroyWindow(_window);
}


void VkGUI::poll_event() {
  SDL_Event event;

  while(SDL_PollEvent(&event) != 0) {
    //close the window when user alt-f4s or clicks the X button
    if(event.type == SDL_QUIT) {
      should_quit = true;
    }

    if(event.type == SDL_WINDOWEVENT) {
      if(event.window.event == SDL_WINDOWEVENT_MINIMIZED) {
        stop_rendering = true;
      }

      if(event.window.event == SDL_WINDOWEVENT_RESTORED) {
        stop_rendering = false;
      }
    }

    ImGui_ImplSDL2_ProcessEvent(&event);
  }
}