Sync with vblank on PTP (v1)? Attn Rayman

avsa242

Ray,

Can you tell me if this is the proper way to wait for vblank on the original PTP?

PUB meter|i,j,k,l
  
fs.SetPrecision(2)
i:=f.FFloat(0)
gr.textmode(2,2,6,5)
repeat
 repeat until lcd_status == 1 ' Sync with VBlank
 gr.clear

 i:=f.FAdd(i,0.10)
 j:=fs.FloatToFormat(i,9,0)
 gr.text(-90,50,j)

I don't have enough RAM for a double-buffered display, so I'm trying to wait until the display is ready before clearing it for the next frame, instead. It does seem to work; the flicker is reduced to pretty much nothing, however, the refresh rate of my outer repeat loop is at or slightly less than 10 per second (without waiting it is 20-30/sec), so I just want to be sure this is the right way to sync before trying to change the rest of my program (I'm sure a lot of time is eaten up by f.Fadd and fs.FloatToFormat - F32 and FloatString objects, respectively).

Thanks!

Cheers,
Jesse

Rayman

I think that is the right way. That driver is just a modified version of the Parallax VGA driver.
I think that part of it works the same may.

Double buffering that way will probably be a challenge though...

avsa242

Ray, thanks. It seemed to work, I just wanted to be sure I wasn't missing something.
Yeah, with the float objects, I just don't have enough RAM left to double-buffer - so I'm going with a single buffer and syncing with the vblank signal to reduce flicker, instead.

Cheers,
Jesse

Rayman

Sounds like you're doing a meter of some sort... One thing you can do is do graphics over a smaller portion of the screen and text elsewhere...
You can actually have multiple independent graphics areas around the screen.

avsa242

See I don't have the instincts that that would've occurred to me Thanks, I'll look into it. Tile-based graphics are alien to me...I'm still hung up on my old BASIC days of just setting a screen resolution, and drawing text, lines, pixels and circles

Cheers,
Jesse