love.graphics.setStencilTest
Configures or disables stencil testing.

When stencil testing is enabled, the geometry of everything that is drawn afterward will be clipped / stencilled out based on a comparison between the arguments of this function and the stencil value of each pixel that the geometry touches. The stencil values of pixels are affected via love.graphics.stencil.
love.graphics.setStencilTest( comparemode, comparevalue )
comparemode CompareMode The type of comparison to make for each pixel.
comparevalue number The value to use when comparing with the stencil value of each pixel. Must be between 0 and 255.
love.graphics.setStencilTest()