Commander X16

 

wait... how did you manage that vertical wave effect???   I tried something like that but couldn't get the vera to do what i wanted with the vertical scaling register

4 minutes ago, desertfish said:

wait... how did you manage that vertical wave effect???   I tried something like that but couldn't get the vera to do what i wanted with the vertical scaling register

I believe this kind of effect is done by changing the vertical scroll register on each scanline, rather than vertical scaling.

So, adding to my review  and your reply @CursorKeys...

I'd suggest putting in a hotkey to instantly reveal the text: esc, spacebar, or just any key.  And then another press to continue on.  Forcing your user to read at a fixed rate is just bad juju, thanks ?

On 6/18/2021 at 1:59 AM, desertfish said:

wait... how did you manage that vertical wave effect???   I tried something like that but couldn't get the vera to do what i wanted with the vertical scaling register

 

On 6/18/2021 at 2:06 AM, Elektron72 said:

I believe this kind of effect is done by changing the vertical scroll register on each scanline, rather than vertical scaling.

This is correct. And for double wave effect, I change both H and V registers, and since it's two layers, I am change 4 registers.

Also I found it works pretty well every second line, but I am getting weird effects if I do it every scan-line. Anyway every second scan line is pretty good for the effects I want to do.



The interrupt looks more or less like this.

__interrupt void irq_line() {



*VERA_L1_HSCROLL_L = WAVES[loffset];

*VERA_L0_HSCROLL_L = WAVES[loffset];

loffset+=2;



// Reset the LINE interrupt magic below

 *VERA_IRQLINE_L = (unsigned char)loffset & 0xFF;

 if(loffset > 255) { *VERA_IEN |= 128;  }

 else { *VERA_IEN &= 255-128; }

*VERA_ISR = VERA_LINE;