Car-surface alignment

--vehicle-surface alignment script by CrystalMV

function getEulerAnglesFromMatrix(x1,y1,z1,x2,y2,z2,x3,y3,z3)
        local nz1,nz2,nz3
        nz3 = math.sqrt(x2*x2+y2*y2)
        nz1 = -x2*z2/nz3
        nz2 = -y2*z2/nz3
        local vx = nz1*x1+nz2*y1+nz3*z1
        local vz = nz1*x3+nz2*y3+nz3*z3
        return math.deg(math.asin(z2)),-math.deg(math.atan2(vx,vz)),-math.deg(math.atan2(x2,y2))
end

function getAnglesFromNormalAndAngle(zx,zy,zz,rz)
        rz = math.rad(rz)
        local yx,yy,yz = -math.sin(rz),math.cos(rz),0
        local xx,xy,xz = yy*zz-yz*zy,yz*zx-yx*zz,yz*zy-yy*zx
        yx,yy,yz = zy*xz-zz*xy,zz*xx-xz*zx,zx*xy-zy*xx
        return getEulerAnglesFromMatrix(xx,xy,xz,yx,yy,yz,zx,zy,zz)
end

function putCarOnSurface()
        local car = getPedOccupiedVehicle(localPlayer)
        if not car then return end
        local x,y,z = getElementPosition(car)
        local hit,sx,sy,sz,hitel,nx,ny,nz = processLineOfSight(x,y,z,x,y,z-1000,true,false,false,true)
        if not hit then return end
        local rx,ry,rz = getElementRotation(car)
        rx,ry,rz = getAnglesFromNormalAndAngle(nx,ny,nz,rz)
        setElementRotation(car,rx,ry,rz,"ZXY")
end
addEventHandler("onClientPreRender",root,putCarOnSurface)