README

dvulkan

Free Pascal Header for Vulkan API, public domain. All in the dvulkan.pas file.

Issues

• Tested only on Windows, no support for other platforms for now
• Declarations for vk_video are incomplete. Should be removed completely I guess

Naming

Almost all names are consistent with those of the C headers:

• Vk* - types
• vk* - functions
• PFN_* - pointers to functions
• VK_* - constants

There are several exceptions, though:

• When a field or a function argument is a Pascal keyword, an underscore prefix is added, e.g. _type instead of type
• When a declaration instoduced which is not part of the Vulkan API, regular pascal conventions are implied (e.g. T prefix for types), e.g. TVkHandleNonDispatchable
• Additionaly, almost each type has corresponding P* and PP* declarations for a "pointer to X" and a "pointer to pointer to X" types respectively. For example, for VkBuffer there are PVkBuffer and PPVkBuffer types.

The loader

The dvulkan unit is provided with a loader. The loader consists of the following:

• Statically loaded vkGetInstanceProcAddr provided by the system.
• A function LoadVulkanGeneralFunctions and a record TVulkanGeneralFunctions for loading general function (i.e. non-instance and non-device functions)
• A function LoadVulkanInstanceFunctions and a record TVulkanInstanceFunctions for loading instance functions
• A function LoadVulkanDeviceFunctions and a record TVulkanDeviceFunctions for loading device functions

Here is an example pseudocode of how to use all of that:

var
  vkg: TVulkanGeneralFunctions;
  vki: TVulkanInstanceFunctions;
  vkd: TVulkanDeviceFunctions;
  instance: VkInstance;
  device: VkDevice;

function InitVulkan: Boolean;
begin
  if not LoadVulkanGeneralFunctions(@vkGetInstanceProcAddr, vkg) then
    Exit(False);

  ...

  if vkg.vkCreateInstance(@instanceCreateInfo, nil, @instance) <> VK_SUCCESS then
    Exit(False);

  if not LoadVulkanInstanceFunctions(instance, vkg.vkGetInstanceProcAddr, vki) then
      Exit(False);

  ...

  if vki.vkCreateDevice(physicalDevice, @deviceCreateInfo, nil, @device) <> VK_SUCCESS then
    Exit(False);

  // Notice the vki.vkGetDeviceProcAddr
  if not LoadVulkanInstanceFunctions(instance, vki.vkGetDeviceProcAddr, vkd) then
      Exit(False);

  // Now all the functions loaded to vkg, vki, vkd and can be used

  ...

  Exit(True);
end;

The dvulkan.pas unit does not provide global functions besides the global vkGetInstanceProcAddr. If you don't want to use prefixes in your code, you can use with operator:

  with vkg, vki, vkd do begin
    ...
  end;

You can disable the loader entirely by commenting out the DVULKAN_LOADER define.