Abstract: An apparatus and method for processing graphics primitives for display is disclosed. The apparatus comprises in sequence: rasterization circuitry, depth testing circuitry and rendering circuitry. The depth testing circuitry determines if a selected graphics fragment would be obscured when displayed by comparing a depth comparison function and a depth value associated with the selected graphics fragment with a stored depth value. The depth testing circuitry is configured to suppress rendering operations with respect to the selected graphics fragment if the depth testing indicates that the selected graphics fragment would be obscured. The depth testing circuitry is configured to store an update indication in dependence on a received depth comparison function, wherein the update indication shows a possible change direction due to the updating for a stored depth value which depends on that received depth comparison function.