unit X11_XImages;

// FIXME DeleteUnderlyingObject
// FIXME public properties for Width, Height. Common base class together with X11_Pixmaps?
{$MODE OBJFPC}
{$M+}

interface
uses X11_Objects, xlib, X11, type_fixes, x, framebuffers;

type
  TXImage = class(system.TObject) // (X11_Objects.TObject, IXImage, X11_Objects.IObject, IInterface)
  private
    fImage : PXImage;
    fBOwnsImage : Boolean;
    fDisplay : PDisplay;
    fFramebufferInfo : TFramebufferInfo;
  protected
    // function GetBytesPerLineCount : TCardinal; // fImage^.bytes_per_line;
    procedure UpdateFramebufferInfo;
  public
    destructor Destroy(); override;
  published
    constructor CreateSHM(aDisplay : PDisplay; const aVisual : IVisual;  const aSHMSegment : ISHMSegment;aData : Pointer; aWidth, aHeight, aDepth : TCardinal; aFormat : Integer = ZPixmap); // SHM:
    constructor Create(aDisplay : PDisplay; const aVisual : IVisual; aWidth, aHeight, aDepth : TCardinal; aBitmapPad : Integer; aBytesPerLine : Integer; aFormat : Integer = ZPixmap; aData : Pointer = nil; aOffset : Integer = 0);
    constructor Reuse(aDisplay : PDisplay; aImage : PXImage; aBOwnsImage : Boolean);
    function FramebufferInfo : TFramebufferInfoP;
  public
    property Display : PDisplay read fDisplay;
    // property BytesPerLineCount : TCardinal read GetBytesPerLineCount;
  end;
  
implementation
uses xutil, xshm;

destructor TXImage.Destroy();
begin
  if fBOwnsImage then
    XDestroyImage(fImage);
    
  inherited Destroy();
end;

constructor TXImage.CreateSHM(aDisplay : PDisplay; const aVisual : IVisual; const aSHMSegment : ISHMSegment; aData : Pointer; aWidth, aHeight, aDepth : TCardinal; aFormat : Integer = ZPixmap); // SHM:
var
  vImage : PXImage;
  VInfo : TXShmSegmentInfo;
begin
  VInfo.shmseg := aSHMSegment.Handle;
  VInfo.shmaddr := aSHMSegment.SharedMemory.Address;
  { TODO? add the other stuff? }
  VInfo.shmid := aSHMSegment.SharedMemory.ID;
  VInfo.readonly := LongInt(aSHMSegment.BReadOnly);
  vImage := XShmCreateImage(aDisplay, aVisual.Handle, aDepth, aFormat, aData, @VInfo, aWidth, aHeight);
  // TODO handle errors.
  Reuse(aDisplay, vImage, True);
end;

constructor TXImage.Create(aDisplay : PDisplay; const aVisual : IVisual; aWidth, aHeight, aDepth : TCardinal; aBitmapPad : Integer; aBytesPerLine : Integer; aFormat : Integer = ZPixmap; aData : Pointer = nil; aOffset : Integer = 0);
var
  vImage : PXImage;
begin
  vImage := XCreateImage(aDisplay, aVisual.Handle, aDepth, aFormat, aOffset, aData, aWidth, aHeight, aBitmapPad, aBytesPerLine);
  // TODO handle errors.
  Reuse(aDisplay, vImage, True);
end;

constructor TXImage.Reuse(aDisplay : PDisplay; aImage : PXImage; aBOwnsImage : Boolean);
begin
  fDisplay := aDisplay;
  fImage := aImage;
  fBOwnsImage := aBOwnsImage;
  UpdateFramebufferInfo();
end;

{function TXImage.GetBytesPerLineCount : TCardinal;
begin
  Result := fImage^.bytes_per_line;
end;}

function TXImage.FramebufferInfo : TFramebufferInfoP;
begin
  Result := @fFramebufferInfo;
end;

// For all formats, bits_per_pixel is less than or equal to 32. For XY formats, bitmap_unit is 8, 16, 24, or 32 bits. For Z format, bits_per_pixel is 4, 8, 12, 16, 20, 24, 28 or 32 bits.

procedure TXImage.UpdateFramebufferInfo;
begin
  // TODO bits_per_pixel,
  // TODO xoffset (FIXME; this is in pixels, added to our X coord. Just move our starting point and decrease size...
  // TODO byte_order LSBFirst|MSBFirst
  // FIXME int bitmap_bit_order;       /* LSBFirst, MSBFirst */
  // FIXME int bitmap_pad;             /* 8, 16, 32 either XY or ZPixmap */
  // FIXME red_mask, green_mask, blue_mask.

  // FIXME PixelComponents PixelBitfield

  with fFramebufferInfo do begin
    assert(fImage^.format = ZPixmap);
    Init(pbR8G8B8{FIXME}, fImage^.width, fImage^.height);
    assert(PixelSize <= fImage^.bitmap_unit);
    PixelSize := fImage^.bitmap_unit;
    RowStride := fImage^.bytes_per_line;
  end;
end;

// TODO bits_per_pixel

end.