unit uvkuSwapChain;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils,
  Vulkan, uvkuBase, uvkuTypes;

type
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
  TvkuSwapChain = class(TvkuAllocHandle)
  private
    fHandle: VkSwapchainKHR;
    fDeviceCommands: TVkDeviceCommands;

    procedure CreateHandle(const aCreateInfo: PVkSwapchainCreateInfoKHR);
  public
    property Handle:          VkSwapchainKHR    read fHandle;
    property DeviceCommands:  TVkDeviceCommands read fDeviceCommands;

    function GetImages: TVkImageArr;
    function AcquireNextImage(const aTimeout: VkUint64; const aSemaphore: VkSemaphore; const aFence: VkFence): VkUint32;

    constructor Create(
      const aCreateInfo: TVkSwapchainCreateInfoKHR;
      const aDeviceCommands: TVkDeviceCommands;
      const aAllocCallbacks: PVkAllocationCallbacks = nil); overload;
    constructor Create(
      const aHandle: VkSwapchainKHR;
      const aOwnsHandle: Boolean;
      const aDeviceCommands: TVkDeviceCommands;
      const aAllocCallbacks: PVkAllocationCallbacks = nil); overload;
    destructor Destroy; override;
  end;

implementation

uses
  uvkuUtils;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//TvkuSwapChain//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
procedure TvkuSwapChain.CreateHandle(const aCreateInfo: PVkSwapchainCreateInfoKHR);
var err: TVkResult;
begin
  if not Assigned(fDeviceCommands.vkCreateSwapchainKHR) then
    raise TvkuException.Create('invalid function pointer: vkCreateSwapchainKHR; did you enabled the VK_KHR_swapchain extension?');
  err := fDeviceCommands.vkCreateSwapchainKHR(fDeviceCommands.Device, aCreateInfo, AllocCallbacks, @fHandle);
  if (err < VK_SUCCESS) then
    raise TvkuErrorException.Create('unable to create swap chain', err);
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function TvkuSwapChain.GetImages: TVkImageArr;
var
  c: VkUint32;
  err: TVkResult;
begin
  if not Assigned(fDeviceCommands.vkGetSwapchainImagesKHR) then
    raise TvkuInvalidFuncPtrException.Create('vkGetSwapchainImagesKHR', 'VK_KHR_swapchain');
  err := fDeviceCommands.vkGetSwapchainImagesKHR(fDeviceCommands.Device, fHandle, @c, nil);
  if (err < VK_SUCCESS) then
    raise TvkuErrorException.Create('unable to get swap chain image count', err);
  SetLength(result, c);
  err := fDeviceCommands.vkGetSwapchainImagesKHR(fDeviceCommands.Device, fHandle, @c, @result[0]);
  if (err < VK_SUCCESS) then
    raise TvkuErrorException.Create('unable to get swap chain images', err);
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function TvkuSwapChain.AcquireNextImage(const aTimeout: VkUint64; const aSemaphore: VkSemaphore; const aFence: VkFence): VkUint32;
var
  err: TVkResult;
begin
  if not Assigned(fDeviceCommands.vkAcquireNextImageKHR) then
    raise TvkuInvalidFuncPtrException.Create('vkAcquireNextImageKHR', 'VK_KHR_swapchain');
  err := fDeviceCommands.vkAcquireNextImageKHR(fDeviceCommands.Device, fHandle, aTimeout, aSemaphore, aFence, @result);
  if (err < VK_SUCCESS) then
    raise TvkuErrorException.Create('unable to aquire next image', err);
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
constructor TvkuSwapChain.Create(const aCreateInfo: TVkSwapchainCreateInfoKHR; const aDeviceCommands: TVkDeviceCommands;
  const aAllocCallbacks: PVkAllocationCallbacks);
begin
  inherited Create;
  fDeviceCommands := aDeviceCommands;
  SetAllocCallbacks(aAllocCallbacks);
  CreateHandle(@aCreateInfo);
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
constructor TvkuSwapChain.Create(const aHandle: VkSwapchainKHR; const aOwnsHandle: Boolean;
  const aDeviceCommands: TVkDeviceCommands; const aAllocCallbacks: PVkAllocationCallbacks);
begin
  inherited Create;
  fHandle         := aHandle;
  fDeviceCommands := aDeviceCommands;
  OwnsHandle      := aOwnsHandle;
  SetAllocCallbacks(aAllocCallbacks);
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
destructor TvkuSwapChain.Destroy;
begin
  if OwnsHandle and (fHandle <> VK_INVALID_NDP_HANDLE) then
    fDeviceCommands.vkDestroySwapchainKHR(fDeviceCommands.Device, fHandle, AllocCallbacks);
  fHandle := VK_INVALID_NDP_HANDLE;
  inherited Destroy;
end;

end.