The SDL Component Suite is an industry leading collection of components supporting scientific and engineering computing. Please visit the SDL Web site for more information....



OnDataRendered


Unit:SDL_rot3d
Class: TRot3D
Declaration: OnDataRendered: TRenderEvent;
{ TRenderEvent = procedure (Sender: TObject; Canvas: TCanvas) of object; }

The events OnDataRendered and OnBeforeRenderData provide a hook for adding user defined graphics to the 3D data display. The event OnDataRendered occurs after the data has been drawn. The variable parameter Canvas provides access to the canvas of the data area. Please note that the state of the canvas (e.g. the color of its pen, or the fill mode of the brush) depends on the graphics elements drawn before.

Hint 1: The declaration of this event has been changed with the introduction of release 10.1 of the SDL Suite. Please see the corresponding type declaration and the section How to Deal with a Canvas Reference Change for details.

Hint 2: In order to avoid unwanted size effects regarding characters displayed on canvases of different resolution (i.e. the screen and a printer) you should never directly assign the font size within the event. Use SetCanvasFontSizeScaled instead. So, for example, the statement Canvas.Font.Size := 12; should be replaced by SetCanvasFontSizeScaled (Canvas, 12);

Example: Following is an example on how to implement user defined graphics on top of the Rot3D data. It displays the text HALLO in the middle of the 3D surface.

procedure TForm1.Rot3D1DataRendered(Sender: TObject; Canvas: TCanvas);
begin
Canvas.Brush.Style := bsClear;
Canvas.Font.Color := clRed;
Canvas.TextOut(Rot3D1.CentX, Rot3D1.CentY, 'HALLO');
end;



Last Update: 2023-Dec-14