erupted ~dub_sdl

ErupteD

Automatically-generated D bindings for Vulkan based on D-Vulkan. Acquiring Vulkan functions is based on Intel API without Secrets

Usage

The bindings have several configurations. The easiest to use is the "with-derelict-loader" configuration. The DerelictUtil mechanism will be used to dynamically load vkGetInstanceProcAddr from vulkan-1.dll or libvulkan.so.1. Otherwise you need to load vkGetInstanceProcAddr with either platform specific means or through some mechanism like glfw3 as shown here. Additional configurations enable the usage of platform specific vulkan functionality (see Platform surface extensions).

To use without configuration:

1. Import via import erupted;.
2. Get a pointer to the vkGetInstanceProcAddr, through platform-specific means (e.g. loading the Vulkan shared library manually, or glfwGetInstanceProcAddress if using GLFW3 >= v3.2 with DerelictGLFW3 >= v3.1.0).
3. Call loadGlobalLevelFunctions(getProcAddr), where getProcAddr is the address of the loaded vkGetInstanceProcAddr function, to load the following functions:
   • vkGetInstanceProcAddr (sets the global variable from the passed value)
   • vkCreateInstance
   • vkEnumerateInstanceExtensionProperties
   • vkEnumerateInstanceLayerProperties
4. Create a VkInstance using the above functions.
5. Call loadInstanceLevelFunctions(VkInstance) to load additional VkInstance related functions. Get information about available physical devices (e.g. GPU(s), APU(s), etc.) and physical device related resources (e.g. Queue Families, Queues per Family, etc. )
6. Now three options are available to acquire a logical device and device resource related functions (functions with first param of VkDevice, VkQueue or VkCommandBuffer):
   • Call loadDeviceLevelFunctions(VkInstance), the acquired functions call indirectly through the VkInstance and will be internally dispatched by the implementation
   • Call loadDeviceLevelFunctions(VkDevice), the acquired functions call directly the VkDevice and related resources. This path is faster, skips one indirection, but (in theory, not tested yet!) is useful only in a single physical device environment. Calling the same function with another VkDevice should overwrite (this is the not tested theory) all the previously fetched __gshared function
   • Call createDispatchDeviceLevelFunctions(VkDevice) and capture the result, which is a struct with all the device level function pointers kind of namespaced in that struct. This should avoid collisions.

To use with the with-derelict-loader configuration, follow the above steps, but call EruptedDerelict.load() instead of performing steps two and three.

Available configurations:

• with-derelict-loader fetches derelictUtil, gets a pointer to vkGetInstanceProcAddr and loads few additional global functions (see above)
• dub-platform-xcb, dub-platform-xlib, dub-platform-wayland fetches corresponding dub packages xcb-d, xlib-d, wayland-client-d, see Platform surface extensions
• dub-platform-???-derelict-loader combines the platforms above with the derelict loader

The API is similar to the C Vulkan API, but with some differences:

• VK_NULL_HANDLE is defined as 0 and can be used as uint64_t type and pointer type argument in C world. D's null can be used only as a pointer argument. This is an issue when compiling for 32 bit, as dispatchable handles (VkInstance, VkPhysicalDevice, VkDevice, VkQueue) are pointer types while non dispatchable handles (e.g. VkSemaphore) are uint64_t types. Hence erupted VK_NULL_HANDLE can only be used as dispatchable null handle (on 32 Bit!). For non dispatchable handles another ErupteD symbol exist VK_NULL_ND_HANDLE. On 64 bit all handles are pointer types and VK_NULL_HANDLE can be used at any place. However VK_NULL_ND_HANDLE is still defined for sake of completeness and ease of use. The issue might be solved when multiple alias this is released, hence I recomend building 64 Bit apps and ignore VK_NULL_ND_HANDLE.
  • If exclusively building a 32 Bit app or switching forth and back between 32 and 64 Bit use VK_NULL_ND_HANDLE for non dispatchable handles
  • If exclusively building a 64 Bit app VK_NULL_HANDLE can be used as any of the two vk handle types
• Named enums in D are not global but they are forwarded into global scope. Hence e.g. VkResult.VK_SUCCESS and VK_SUCCESS can both be used.
• All structures have their sType field set to the appropriate value upon initialization; explicit initialization is not needed.
• VkPipelineShaderStageCreateInfo.module has been renamed to VkPipelineShaderStageCreateInfo._module, since module is a D keyword.

Examples can be found in the examples directory, and run with dub run erupted:examplename

Platform surface extensions

The usage of a third party library like glfw3 is highly recommended instead of vulkan platforms. Dlang has only one official platform binding in phobos which is for windows found in module core.sys.windows.windows. Other bindings to XCB, XLIB and Wayland can be found in the dub registry and are supported experimentally. However, if you wish to create vulkan surface(s) yourself you have three choices:

1. The dub way, this is experimental, currently only three bindings are listed in the registry. Dub fetches them and adds them to erupted build dependency when you specify any of these sub configurations in your projects dub.json (add -derelict-loader to the config name if you want to be able to laod vkGetInstanceProcAddr from derelict):

   • XCB specify "subConfigurations" : { "erupted" : "dub-platform-xcb" }
   • XLIB specify "subConfigurations" : { "erupted" : "dub-platform-xlib" }
   • Wayland specify "subConfigurations" : { "erupted" : "dub-platform-wayland" }

2. The symlink (or copy/move) way. If you like to play with bindings yourself this might be the way for you. Drawback is that you need to add the symlink into any erupted version you use and that your binding is not automatically tracked by dub.

   • Create a directory/module-path similar to those in erupted/types.d (I myself have these paths from the C header vk_platform.h) and symlink it under ErupeD/sources as sibling to ErupeD/sources/erupted.
   • You also need to specify the corresponding vulkan version in your projects dub.json versions block. E.g. to use XCB you need to specify "versions" : [ "VK_USE_PLATFORM_XCB_KHR" ].

3. The source- and importPaths way. This is if you don't want to add stuff to the ErupteD project structure. Drawback here is that neither erupted nor the binding are automatically tracked by dub, you need to check yourself for any updates. In your project REMOVE the erupted dependency and add:

   • "sourcePaths" : [ "path/to/ErupteD/source", "path/to/binding/source" ]
   • "importPaths" : [ "path/to/ErupteD/source", "path/to/binding/source" ]

Additional info:

• there is no need for platform extensions if glfw3 (or similar technique) is used, as shown here.
• for windows platform, in your project specify: "versions" : [ "VK_USE_PLATFORM_WIN32_KHR" ]. The phobos windows modules will be used in that case.
• wayland-client.h cannot exist as module name. The maintainer of wayland-client-d choose wayland.client as module name and the name is used in erupted/types as well.
• for android platform, I have not a single clue how this is supposed to work. If you are interested in android an have an idea how it should work feel free to open up an issue.

Generating Bindings

To erupt the vulkan-docs yourself (Requires Python 3 and lxml.etree) download the Vulkan-Docs repo and call erupt.py passing path/to/vulkan-docs as first argument and an output folder for the D files as second argument.

Diferences to D-Vulkan

• Platform surface extensions
• ErupteD follows API without Secrets in terms of function loading naming and stages (three stages contrary to d-vulkan two stages)

Known Issues

Dub error: Could not find a valid dependency tree configuration:

Solution: Confirm that in YOUR projects dub.selections the xcb-d version is at least 2.1.0+1.11.1 or 2.1.0

Explanation: This is a dub issue with fetching dependencies, in particular with xcb-d and xlib-d. It happens on windows systems as well, even though these dependencies will never be used. Problem is that xlib-d depends on xcb-d ~>1.11.1 while erupted depends on the newer xcb-d ~>2.1.0+1.11.1. This should be O.K. as both xcb-d dependencies can coexist BUT dub.selections of YOUR project has only one entry for the xcb-d dependency. If these dependencies are fetched for the first time dub.selections is created in YOUR project and xcb-d version might have been set to version 1.11.1.