Vertical Blanking

[Miura]

Hi,

 

Is there a function where I can see there the rasterbeam is drawing the picture. If I would change a color, I don't want to do this in a middle of a picture, but when the Rasterbeam is somewhere else.

 

In the Amiga Assembler days this function was called "Vertical Blanking"

 

Thanks,

Miura

[Nerseus]

It's called vertical retrace now. I'm not sure if you can control anything about it with GDI+. With DirectX it's an option (can't remember offhand) so that the page flipping or drawing only occurs on verticle retrace, meaning that you can specify that you want to do the flipping/drawing in between a retrace (between the time the beam has finished drawing is going back to the top to start again).

 

I can look it up later if you're using DirectX and need the help.

 

With it turned on (wait for retrace), you're locked into a max framerate that matches your Hz refresh of the monitor, obviously. In my Ms Pacman clone, it sticks around 75 (close to my 80 Hz refresh at home). When turned off, it jumps to about 500.

 

If you can't find it with vertical retrace, you may look for tearing or screen tearing, another common term when NOT waiting for the vertical retrace.

 

-ner