unit uvkuInstanceFactory;

{$mode objfpc}{$H+}
{$I Vulkan.inc}

interface

uses
  Classes, SysUtils,
  Vulkan, uvkuInstance, uvkuAllocationHandler, uvkuTypes;

type
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
  TvkuInstanceEx = class(TvkuInstance)
  private
    fAllocHandler: TvkuAllocationHandler;
    fOwnsHandler: Boolean;
  public
    destructor Destroy; override;
  end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
  TvkuInstanceFactory = class(TObject)
  private
    fFlags:           VkInstanceCreateFlags;
    fApplicationInfo: TvkuApplicationInfo;

    fLayers:     TStringList;
    fExtensions: TStringList;

    function GetLayers: TStrings;
    function GetExtensions: TStrings;
  public
    property Flags:           VkInstanceCreateFlags read fFlags;
    property ApplicationInfo: TvkuApplicationInfo   read fApplicationInfo;
    property Layers:          TStrings              read GetLayers;
    property Extensions:      TStrings              read GetExtensions;

    function CreateInstance: TvkuInstanceEx;
    function CreateInstance(
      const aAllocHandler: TvkuAllocationHandler;
      const aOwnsHandler: Boolean): TvkuInstanceEx;

    constructor Create;
    destructor Destroy; override;
  end;

function vkuApplicationInfo: TvkuApplicationInfo;
function vkuApplicationInfo(
    aAppName:        String;
    aAppVersion:     VkVersion;
    aEngineName:     String;
    aEngineVersion:  VkVersion;
    aApiVersion:     VkVersion = VK_API_VERSION): TvkuApplicationInfo;

implementation

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function vkuApplicationInfo: TvkuApplicationInfo;
begin
  result.AppName        := ExtractFileName(ParamStr(0));
  result.AppVersion     := 0;
  result.EngineName     := ExtractFileName(ParamStr(0));
  result.EngineVersion  := 0;
  result.ApiVersion     := VK_API_VERSION;
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function vkuApplicationInfo(aAppName: String; aAppVersion: VkVersion; aEngineName: String; aEngineVersion: VkVersion; aApiVersion: VkVersion): TvkuApplicationInfo;
begin
  result := vkuApplicationInfo();
  result.AppName       := aAppName;
  result.AppVersion    := aAppVersion;
  result.EngineName    := aEngineName;
  result.EngineVersion := aEngineVersion;
  result.ApiVersion    := aApiVersion;
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//TvkuInstanceEx/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
destructor TvkuInstanceEx.Destroy;
begin
  inherited Destroy;
  if fOwnsHandler then
    FreeAndNil(fAllocHandler);
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//TvkuInstanceFactory///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function TvkuInstanceFactory.GetLayers: TStrings;
begin
  result := fLayers;
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function TvkuInstanceFactory.GetExtensions: TStrings;
begin
  result := fExtensions;
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function TvkuInstanceFactory.CreateInstance: TvkuInstanceEx;
begin
  result := CreateInstance(nil, false);
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function TvkuInstanceFactory.CreateInstance(const aAllocHandler: TvkuAllocationHandler; const aOwnsHandler: Boolean): TvkuInstanceEx;
var
  CreateInfo: TVkInstanceCreateInfo;
  AppInfo: TVkApplicationInfo;
  i: Integer;
  lay: array of PVkChar;
  ext: array of PVkChar;
begin
  FillByte(AppInfo{%H-}, SizeOf(AppInfo), 0);
  AppInfo.sType              := VK_STRUCTURE_TYPE_APPLICATION_INFO;
  AppInfo.pNext              := nil;
  AppInfo.pApplicationName   := PVkChar(fApplicationInfo.AppName);
  AppInfo.applicationVersion := fApplicationInfo.AppVersion;
  AppInfo.pEngineName        := PVkChar(fApplicationInfo.EngineName);
  AppInfo.engineVersion      := fApplicationInfo.EngineVersion;
  AppInfo.apiVersion         := fApplicationInfo.ApiVersion;

  SetLength(lay, fLayers.Count);
  for i := 0 to fLayers.Count-1 do
    lay[i] := PVkChar(fLayers[i]);

  SetLength(ext, fExtensions.Count);
  for i := 0 to fExtensions.Count-1 do
    ext[i] := PVkChar(fExtensions[i]);

  FillByte(CreateInfo{%H-}, SizeOf(CreateInfo), 0);
  CreateInfo.sType                    := VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
  CreateInfo.pNext                    := nil;
  CreateInfo.flags                    := fFlags;
  CreateInfo.pApplicationInfo         := @AppInfo;
  CreateInfo.enabledLayerCount        := Length(lay);
  CreateInfo.ppEnabledLayerNames      := @lay[0];
  CreateInfo.enabledExtensionCount    := Length(ext);
  CreateInfo.ppEnabledExtensionNames  := @ext[0];

  if Assigned(aAllocHandler)
    then result := TvkuInstanceEx.Create(CreateInfo, aAllocHandler.GetAllocationCallbacksPtr)
    else result := TvkuInstanceEx.Create(CreateInfo);
  try
    TvkuInstanceEx(result).fAllocHandler := aAllocHandler;
    TvkuInstanceEx(result).fOwnsHandler  := aOwnsHandler;
  except
    FreeAndNil(result);
    raise;
  end;
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
constructor TvkuInstanceFactory.Create;
begin
  inherited Create;
  fLayers          := TStringList.Create;
  fExtensions      := TStringList.Create;
  fApplicationInfo := vkuApplicationInfo;
  fFlags           := 0;
end;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
destructor TvkuInstanceFactory.Destroy;
begin
  FreeAndNil(fLayers);
  FreeAndNil(fExtensions);
  inherited Destroy;
end;

end.