-- Simple Square Brush by Pinkbat5 / pocl.v
function main(x, y, p)
    bs_setmode (1)
    local w = bs_width ()
    local opacity = 255 * bs_opaque() * ( 1 - (1 - p) * bs_param1() )
    local r, g, b = 0, 0, 0
    bs_polygon (x+w/2, y+w/2)
    bs_polygon (x-w/2, y+w/2)
    bs_polygon (x-w/2, y-w/2)
    bs_polygon (x+w/2, y-w/2)
    bs_fill (r,g,b,opacity)
    return 1
end

function param1()
	local s = "Opacity by Pressure"
	return s, 0, 1, 0
end