Removing Lines from TCanvas

[Brollo]

Hi, I am developing an application which draws lines between certain points. I am using the MoveTo and LineTo functions of the TCanvas property to do this.
Is there a way to remove the last drawn line from the canvas without affecting the previous drawn lines ?
I've tried drawing a line over the existing line with the Pen.Style property set to psClear but this does not seem to work.

Any ideas ?

 

[VintageWine]

I'm pretty sure not. The canvas is a bitmap, i.e. collection of pixels. Each pixel remembers what its current colour is and that's it. The canvas has no concept that a line exists on it, only that certain pixels are a different colour.

You would have to re-draw the line in white, not clear. but it would cut any other lines that cross it.

Anyone know how Microsoft implement undo in Paint?

Have fun
Simon

 

[TonHu]

Shouldn't you XOR the same LineTo in the same color with the same coordinates?

HTH
TonHu