Yet another spiral demo :)

pik33

Yet another spiral demo. This time in Spin, using my HDMI driver

A demo code is now simple but compiles only with Flexprop. Propeller Tool doesn't like accessing another object's variables.

 CON
 _clkfreq        = 200000000
 hdmipin         = 8

 obj               v: "hng023"

 pub demo() |x,y,px,py,d

 v.start(512+256+192+48,hdmipin)

 repeat y from -248 to 247
   repeat x from -448 to 447
     px,py:=xypol(x,y)            
     v.putpixel(x+448,y+248,(py+px<<20)>>24)

 repeat
   d:=long[v.palette_ptr+4*255]
   longmove(v.palette_ptr+4,v.palette_ptr,255)
   long[v.palette_ptr]:=d
   v.waitvbl(1)

evanh

Palette cheat! :P

pik33

Yes, good, old, vblank synchronized palette trick Setq2 allows reading all 256 color palette every frame in every vblank

Now, how to do this using a Propeller Tool? It also doesn't like to call putpixel, which is a variable (a method pointer) in the driver.

evanh

Huh, TV is telling me 896x496 resolution.

Can't help with anything Spin, sorry. I'm enjoying Pasm too much.

pik33

Yes, it is 896x496x60Hz, the maximum resolution at which the driver (or rather P2 memory) allows 8 bpp - 446400 bytes used by fb and display list, less than 100 kB left
A lot of pasm is used in the driver

---

You can also rotate a display list

_clkfreq        = 200000000
hdmipin         = 8

obj               v: "hng023"

pub demo() |x,y,px,py,d

v.start(512+256+192+48,hdmipin)

repeat y from -248 to 247
  repeat x from -448 to 447
    px,py:=xypol(x,y)            
    v.putpixel(x+448,y+248,(py+px<<21)>>24)

repeat
  d:=long[v.palette_ptr+4*255]
  longmove(v.palette_ptr+4,v.palette_ptr,255)
  long[v.palette_ptr]:=d
  d:=long[v.dl_ptr]
  longmove(v.dl_ptr,v.dl_ptr+4,495)
  long[v.dl_ptr+4*495]:=d
  v.waitvbl(1)

cgracey

Good idea to use the palette.