Vulkan Support

[selimanac]

Since all of Defold’s default targets are moving to Vulkan, it would be nice to have Vulkan support.
P.S. I’m going to try adding Vulkan support, but I have no idea if it’s even possible.

[britzl]

It should be possible yes. Dear-ImGUI has a vulkan implementation here:

https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_vulkan.cpp

You need to update imconfig.h and set a different define if vulkan is present:

https://github.com/britzl/extension-imgui/blob/master/imgui/src/imgui/imconfig.h

The question is how to answer "if vulkan is present?". There might be a define we can check.

[selimanac]

It should be possible yes. Dera-ImGUI has a vulkan implementation here:

I know, but you are using additional GL libs. Something similar might be required for Vulkan?

You need to update imconfig.h and set a different define if vulkan is present:

https://github.com/britzl/extension-imgui/blob/master/imgui/src/imgui/imconfig.h

The question is how to answer "if vulkan is present?". There might be a define we can check.

If I manage to come this far, I’ll let you know :)

[selimanac]

If I manage to come this far, I’ll let you know :)

I guess it is not possible without accessing the built-in(Defold's) Vulkan context’s surface, render pass, etc. (at least for me).
I tried to initialize Vulkan (device, pool, swapchain, framebuffer, etc.) separately, but couldn’t manage properly. I also think this is not the proper way (creating a separate Vulkan context + might require MoltenVK for mac); it’s way beyond my knowledge.
There might be a simpler way that I can’t figure out...

[Jhonnyg]

If you can figure out what you need from the context we can expose those things in the vulkan DMSDK header:
https://github.com/defold/defold/blob/dev/engine/graphics/src/dmsdk/graphics/graphics_vulkan.h

Perhaps a way forward would be to take some other implementation and then figure out what you need from defold and then we can provide those mechanisms via the sdk.

[selimanac]

If you can figure out what you need from the context we can expose those things in the vulkan DMSDK header:

I will try...

Perhaps a way forward would be to take some other implementation and then figure out what you need from defold and then we can provide those mechanisms via the sdk.

There is actually a vulkan + glfw example: https://github.com/ocornut/imgui/blob/master/examples/example_glfw_vulkan/main.cpp. We need to pass the init_info for start:

static VkAllocationCallbacks*   g_Allocator = nullptr;
static VkInstance               g_Instance = VK_NULL_HANDLE;
static VkPhysicalDevice         g_PhysicalDevice = VK_NULL_HANDLE;
static VkDevice                 g_Device = VK_NULL_HANDLE;
static uint32_t                 g_QueueFamily = (uint32_t)-1;
static VkQueue                  g_Queue = VK_NULL_HANDLE;
static VkDebugReportCallbackEXT g_DebugReport = VK_NULL_HANDLE;
static VkPipelineCache          g_PipelineCache = VK_NULL_HANDLE;
static VkDescriptorPool         g_DescriptorPool = VK_NULL_HANDLE;

static ImGui_ImplVulkanH_Window g_MainWindowData;
static uint32_t                 g_MinImageCount = 2;
static bool                     g_SwapChainRebuild = false;


.... 


ImGui_ImplVulkan_InitInfo init_info = {};
    //init_info.ApiVersion = VK_API_VERSION_1_3;              // Pass in your value of VkApplicationInfo::apiVersion, otherwise will default to header version.
    init_info.Instance = g_Instance;
    init_info.PhysicalDevice = g_PhysicalDevice;
    init_info.Device = g_Device;
    init_info.QueueFamily = g_QueueFamily;
    init_info.Queue = g_Queue;
    init_info.PipelineCache = g_PipelineCache;
    init_info.DescriptorPool = g_DescriptorPool;
    init_info.RenderPass = wd->RenderPass;
    init_info.Subpass = 0;
    init_info.MinImageCount = g_MinImageCount;
    init_info.ImageCount = wd->ImageCount;
    init_info.MSAASamples = VK_SAMPLE_COUNT_1_BIT;
    init_info.Allocator = g_Allocator;
    init_info.CheckVkResultFn = check_vk_result;
    ImGui_ImplVulkan_Init(&init_info);

[britzl]

https://github.com/ocornut/imgui/wiki/Integrating-with-Vulkan#vulkan-components-that-are-needed-for-dear-imgui

• VkInstance
• VkPhysicalDevice
• VkDevice
• VkQueueFamily
• VkQueue
• VkDescriptorPool
• VkCommandPool
• VkCommandBuffer
• VkRenderPass
• VkFramebuffer

We have everything in VulkanContext in graphics_vulkan_private.h:

https://github.com/defold/defold/blob/dev/engine/graphics/src/vulkan/graphics_vulkan_private.h#L362

[selimanac]

We have everything in VulkanContext in graphics_vulkan_private.h:

Great news, thank you.
Looks like this is a step toward the public API, unless you’d rather I take my chances with the private one?

[britzl]

Looks like this is a step toward the public API, unless you’d rather I take my chances with the private one?

I will add functions to graphics_vulkan.h in dmSDK!

[britzl]

Looks like this is a step toward the public API, unless you’d rather I take my chances with the private one?

I will add functions to graphics_vulkan.h in dmSDK!

Task has been taken over by @ekharkunov