TASImage usage/manipulation

I’m trying to directly manipulate a TASImage. (Ultimately to make a waterfall spectrogram display) I’m not quite sure how to force an update.
I have attached some example code to produce a image. After it is drawn and
the macro exits, I issue the command

tas->DrawLine( 1, 1, 500,500, Clr, 5)

tas is a TASImage created in the macro and Clr is also defined in there.
This does not manifest itself on the image until I do a zoom/unzoom type of

I would have thought doing a gPad->Update would have forced this.

Is there a similar call to case a repaint in a TASImage?

TASexample.C (1.08 KB)

It works if you put the DrawLine inside the macro. You really want it out of the macro ?

The macro is just invented for testing. Ultimately, this will be inside.

I am just of the notion to use some setup and then test out my understanding of the calls outside the macro. So it is a non-problem.