unit X11_Pixmaps;

interface
uses xlib, X11_Objects, X11_Drawables, X11_Shared_Memory, X11, type_fixes, framebuffers;

// TODO public properties for Width, Height.
// FIXME common base class with X11_XImages.
type  
  TPixmap = class(TDrawable, IPixmap, IDrawable, X11_Objects.IObject, IInterface)
  private
    fFramebufferInfo : TFramebufferInfo;
  protected
    procedure DeleteUnderlyingObject; override;
    procedure UpdateFramebufferInfo(aWidth, aHeight, aDepth : TCardinal);
  published
    constructor Create(aDisplay : PDisplay; aWidth, aHeight, aDepth : TCardinal);
    constructor CreateSHM(aDisplay : PDisplay; const aSHMSegment : ISHMSegment; aWidth, aHeight, aDepth : TCardinal; const aWindow : IWindow);
    function FramebufferInfo : TFramebufferInfoP;
  end;

implementation
uses xshm;

constructor TPixmap.Create(aDisplay : PDisplay; aWidth, aHeight, aDepth : TCardinal);
begin
  inherited Reuse(aDisplay, XCreatePixmap(aDisplay, fHandle, aWidth, aHeight, aDepth), True);
  UpdateFramebufferInfo(aWidth, aHeight, aDepth);
end;

{ for aWindow, use the screen's root window if in doubt. }
constructor TPixmap.CreateSHM(aDisplay : PDisplay; const aSHMSegment : ISHMSegment; aWidth, aHeight, aDepth : TCardinal; const aWindow : IWindow);
var
  VInfo : TXShmSegmentInfo;
  VWindowHandle : THandle;
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);

  if AWindow <> nil then
    VWindowHandle := AWindow.Handle
  else
    VWindowHandle := RootWindowOfScreen(xlib.DefaultScreenOfDisplay(aDisplay));

  // TODO use the root window  
  inherited Reuse(aDisplay, XShmCreatePixmap(aDisplay, VWindowHandle, aSHMSegment.SharedMemory.Address, @VInfo, aWidth, aHeight, aDepth), True);
  UpdateFramebufferInfo(aWidth, aHeight, aDepth);
end;

// FIXME call UpdateFramebufferInfo when reusing.
// TODO a constructor where you can specify the start address?

procedure TPixmap.DeleteUnderlyingObject;
begin
  if fHandle <> 0 then begin
    XFreePixmap(Display, fHandle);
    fHandle := 0;
  end;
end;

procedure TPixmap.UpdateFramebufferInfo(aWidth, aHeight, aDepth : TCardinal);
begin
  with fFramebufferInfo do begin
    Init(pbR8G8B8{FIXME}, aWidth, aHeight);
    assert(PixelSize <= aDepth);
    PixelSize := aDepth;
    // FIXME RowStride := ;
  end;
end;

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

end.