TImageEnView.LayersFastDrawing

Declaration

property LayersFastDrawing: TIEFastDrawing;

Description

Improves the performance of layer rendering by delayed or disabling slow operations.

Configure LayerFastDrawingEffects to specify the effect of LayersFastDrawing.

Default: iefDelayed

Note:
◼ LayersFastDrawing only affects what is displayed. It has no effect on the quality of the image when saved
◼ LayersFastDrawing is only used when there are multiple layers, or the background layer is being edited (as a layer)

Layer Performance Properties

To improve the performance in layer applications, consider the following properties:
◼ LayersCaching: Caches the view of each layer. Much faster but uses more memory.
◼ LayersFastDrawing: Display quality of layers (and whether the quality view is delayed).
◼ LayerFastDrawingEffects specifies which features are disabled while fast drawing.
◼ ZoomFilter/DelayZoomFilter: Display quality of images (and whether the quality view is delayed). This option is ignored if LayersFastDrawing is active
◼ LayersRotationUseFilterOnPreview: Whether the quality filter (LayersRotationFilter) is previewed without applying the rotation

Review the Demos\LayerEditing\Layers_AllTypes\ demo for example code.

Examples

// Use best display quality (even when manipulating layers)
ImageEnView1.LayersFastDrawing := iefNormal;

// Use best display quality, except when manipulating layers
ImageEnView1.LayersFastDrawing := iefDelayed;

// Best performance - always display layers at lower quality
ImageEnView1.LayersFastDrawing := iefFast;

// Allow changing of preview quality via a combo-box
procedure Tfmain.cmbPreviewQualityChange(Sender: TObject);
const
 _cmbPreviewQuality_Fast          = 0;
 _cmbPreviewQuality_Delayed_Best  = 1;
 _cmbPreviewQuality_Best          = 2;
begin
  // Separate code to make it easier to understand

  if cmbPreviewQuality.ItemIndex = _cmbPreviewQuality_Fast then
  begin
    // FASTEST DISPLAY

    // Zoom filter
    ImageEnView1.ZoomFilter := rfNone;
    ImageEnView1.DelayZoomFilter := False;

    // Rotation anti-alias
    ImageEnView1.LayersRotationFilter := ierBicubic;
    ImageEnView1.LayersRotationUseFilterOnPreview := False;

    // Fast drawing
    ImageEnView1.LayersFastDrawing := iefFast;
  end
  else
  if cmbPreviewQuality.ItemIndex = _cmbPreviewQuality_Delayed_Best then
  begin
    // DELAYED HIGH QUALITY

    // Zoom filter
    ImageEnView1.ZoomFilter := rfLanczos3;
    ImageEnView1.DelayZoomFilter := True;

    // Rotation anti-alias
    ImageEnView1.LayersRotationFilter := ierBicubic;
    ImageEnView1.LayersRotationUseFilterOnPreview := True;

    // Fast drawing
    ImageEnView1.LayersFastDrawing := iefDelayed;
  end
  else
  begin
    // HIGH QUALITY

    // Zoom filter
    ImageEnView1.ZoomFilter := rfLanczos3;
    ImageEnView1.DelayZoomFilter := False;

    // Rotation anti-alias
    ImageEnView1.LayersRotationFilter := ierBicubic;
    ImageEnView1.LayersRotationUseFilterOnPreview := True;

    // Fast drawing
    ImageEnView1.LayersFastDrawing := iefNormal;
  end;

  ImageEnView1.Update();
end;

See Also

◼ LayersCaching

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