142 lines
2.8 KiB
Lua
142 lines
2.8 KiB
Lua
pico-8 cartridge // http://www.pico-8.com
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version 42
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__lua__
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bx0=0
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by0=0
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bx1=127
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by1=127
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lx0=0
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ly0=0
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lx1=127
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ly1=127
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-->8
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function collides()
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local tmin=0
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local tmax=1
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local ldx=lx1-lx0
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local ldy=ly1-ly0
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-- x
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if ldx==0 then
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if (lx0<bx0 or lx0>bx1) return
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else
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local tx0=(bx0-lx0)/ldx
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local tx1=(bx1-lx0)/ldx
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if (tx0 > tx1) tx0,tx1=tx1,tx0
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if (tmin < tx0) tmin=tx0
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if (tmax > tx1) tmax=tx1
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end
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if ldy==0 then
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if (ly0<by0 or ly0>by1) return
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else
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local ty0=(by0-ly0)/ldy
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local ty1=(by1-ly0)/ldy
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if (ty0 > ty1) ty0,ty1=ty1,ty0
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if (tmin < ty0) tmin=ty0
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if (tmax > ty1) tmax=ty1
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end
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if (tmax < tmin) return
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return tmin,tmax
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end
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-->8
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function _init()
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poke(0x5f2d,1) -- enable mouse
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end
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function _bounce_screen(x)
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return _bounce(x*128,128)
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end
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function _bounce(x,mx)
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x=x%(mx * 2)
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if (x>=mx)return mx-(x-mx)
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return x
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end
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function _to_halfopen(x0,x1)
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-- turn two numbers into a
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-- half-open integer range
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x0=flr(x0)
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x1=flr(x1)
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local lo=min(x0,x1)
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local hi=max(x0,x1)
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if (hi==lo) return lo,hi
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return lo,hi-1
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end
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function _update60()
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local t=time()/16
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local bx0_=_bounce_screen(t*1)
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local by0_=_bounce_screen(t*2)
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local bx1_=_bounce_screen(t*3)
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local by1_=_bounce_screen(t*4)
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bx0,bx1=_to_halfopen(bx0_,bx1_)
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by0,by1=_to_halfopen(by0_,by1_)
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update_line()
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--[[
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local lx0_=_bounce_screen(t*1.5)
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local ly0_=_bounce_screen(t*2.5)
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local lx1_=_bounce_screen(t*3.5)
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local ly1_=_bounce_screen(t*4.5)
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lx0,lx1=lx0_,lx1_
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ly0,ly1=ly0_,ly1_
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]]--
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end
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was_down=false
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last_mx,last_my=nil,nil
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function update_line()
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local mx,my=stat(32),stat(33)
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local is_down=stat(34)!=0
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if is_down then
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if was_down then
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lx1,ly1=mx,my
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else
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lx0,ly0=mx,my
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end
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end
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was_down=is_down
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last_mx,last_my=mx,my
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end
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-->8
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function _draw()
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cls(0)
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rect(bx0,by0,bx1,by1,6)
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line(lx0,ly0,lx1,ly1,2)
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local cmin, cmax = collides()
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if cmin then
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local dx,dy=lx1-lx0,ly1-ly0
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line(lx0 + dx*cmin,
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ly0 + dy*cmin,
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lx0 + dx*cmax,
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ly0 + dy*cmax,
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8)
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pset(lx0 + dx*cmin,
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ly0 + dy*cmin,
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12)
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end
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pset(last_mx,last_my,7)
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end
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__gfx__
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00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
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00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
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00700700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
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00077000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
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00077000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
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00700700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
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