Simple Lua function for detecting circle/rectangle collision

CircleRectCollision.lua

local math_abs = math.abs

function circlerect_colliding(cx, cy, cr, rx, ry, rw, rh)
  circleDistance_x = math_abs(cx - rx)
  circleDistance_y = math_abs(cy - ry)

  if circleDistance_x > (rw / 2 + cr) then
  	return false
  end

  if circleDistance_y > (rh / 2 + cr) then 
  	return false
  end

  if circleDistance_x <= (rw / 2) then 
  	return true
  end

  if circleDistance_y <= (rh / 2) then
  	return true
  end

  cornerDistance_sq = (circleDistance_x - rw / 2) ^ 2 + (circleDistance_y - rh / 2) ^ 2

  return (cornerDistance_sq <= (cr ^ 2))
end