leissler [Lexaloffle Blog Feed]

Screen memory remapping not working in multiscreen

Tue, 30 May 2023 18:59:53 UTC

When using multiscreen mode, the following function (which should print a scaled text) turned out to render only on the first screen:

function scale_text(str,x,y,c,scale)
    memcpy(0x4300,0x0,0x0200)
    memset(0x0,0,0x0200)

    -- draw to spr mem at 0x0000
    poke(0x5f55,0x00)
    print(str,0,0,7)
    -- draw to screen mem again
    poke(0x5f55,0x60)

    local w,h = #str*4,5
    pal(7,c)
    palt(0,true)
    sspr(0,0,w,h,x,y,w*scale,h*scale)
    pal()

    memcpy(0x0,0x4300,0x0200)
end

Just like normal printing, I expected this to work in multiscreen with the following calling code:

poke(0x5f36,1)
scrs_w, scrs_h = 3,1;
scr_ix = 0;

_camera = camera
function camera(x,y)
  x = x or 0
  y = y or 0
  local dx=flr(scr_ix % scrs_w)
  local dy=flr(scr_ix / scrs_w)
  _camera(x+128*dx, y+128*dy)
end

function _draw()
  scr_ix = stat(3)
  camera(0,0)
  cls(scr_ix+5)

  sspr(0,0,24,24,200,30,48,48)

  print("hello",120,80,8)
  scale_text("hello",110,60,12,1.5)

  return scr_ix < stat(11)-1
end

But the result is a cut-off scaled text, while the normal text and the other sspr() call work just fine.

I think this is a bug in PICO-8, with remapping gfx memory not properly working in multiscreen mode.

0.2.2 crashes when drawing lines

Tue, 23 Feb 2021 23:35:12 UTC

Hi,

on a Mac (Big Sur) I did some experiments with drawing a 3D starfield using lines.

starfield_test

by leissler

[Click to Play]

However, PICO-8 regularly crashes completely (play around with the 6 buttons for the star speed in all 3 directions) and a debug with lldb on the Mac terminal uncovered the following:

So there seems to be a problem in 0.2.2 with line drawing somewhere.

I hope this can be fixed for the upcoming 0.2.2b

Martin

Can't INSTALL_GAMES on 0.2.1

Sat, 04 Jul 2020 12:48:52 UTC

On 0.2.1, trying to INSTALL_GAMES with 0.2.1 gives me this error.

INSTALL_DEMOS seems to work fine, though.

Might this be connected to the 0.2.1 release notes saying:
"Fixed: Crash when INSTALL_GAMES / INSTALL_DEMOS without a writeable disk"?

Platform: macOS Catalina, 10.15.5