BeginVectorLayer()

Syntax

BeginVectorLayer([Alpha])

Begins a new empty layer on top of the current vector drawing output. All future drawing operations will be performed on this layer until EndVectorLayer() is called. This command also saves the current drawing state in the same way as SaveVectorState(). Multiple layers can be created.

Parameters

Alpha (optional)

Specifies the alpha transparency of the new vector layer. Allowed values are from 0 (fully transparent) to 255 (fully opaque). The default is 255 (fully opaque).

Return value

None.

Remarks

The resources needed to create the temporary layer depend on the size of the current clipping path. It is therefore recommended to set a clipping path that covers only the area where the temporary layer will contain any drawing to save resources and improve drawing performance.

Example

  If OpenWindow(0, 0, 0, 400, 200, "VectorDrawing", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
    CanvasGadget(0, 0, 0, 400, 200)

    If StartVectorDrawing(CanvasVectorOutput(0))

      ; Semi-transparent drawing on the base layer
      AddPathCircle(75, 100, 60)      
      VectorSourceColor(RGBA(255, 0, 0, 127))
      FillPath()      
      AddPathCircle(125, 100, 60)
      VectorSourceColor(RGBA(0, 0, 255, 127))
      FillPath()    
      
      ; Opaque drawing on a semi-transparent layer
      BeginVectorLayer(127)
        AddPathCircle(275, 100, 60)    
        VectorSourceColor(RGBA(255, 0, 0, 255))
        FillPath()        
        AddPathCircle(325, 100, 60)
        VectorSourceColor(RGBA(0, 0, 255, 255))
        FillPath()    
      EndVectorLayer()
    
      StopVectorDrawing()
    EndIf
    
    Repeat
      Event = WaitWindowEvent()
    Until Event = #PB_Event_CloseWindow
  EndIf

See Also

EndVectorLayer(), SaveVectorState()

Supported OS

All