33 lines
878 B
Lua
33 lines
878 B
Lua
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--This is a basic raycast function.
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--It checks whether two points on a map can "see" each other based on the map data. It assumes flag 0 to be the collision layer.
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--It returns TRUE if they can see each other or FALSE if they can't.
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function can_see(x1,y1,x2,y2,length)
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--x1 and y1 are the point of view,length is the max distance of the two points
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local max_length=length or 1000
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local xvec=0
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local yvec=0
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local len=0
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local ret=true
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local tx=x1
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local ty=y1
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xvec=x2-x1
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yvec=y2-y1
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len=sqrt(xvec^2+yvec^2)
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if len==0 or len>max_length then
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ret=false
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end
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xvec=(xvec/len)
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yvec=(yvec/len)
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if ret then
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for i=1,len do
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tx+=xvec
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ty+=yvec
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if fget(mget(flr(tx/8),flr(ty/8)),0) then
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ret=false
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break
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end
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end
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end
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return ret
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end
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