PIXEL DELTA INTERPOLATION METHOD AND APPARATUS

A method for rendering an object including receiving a pixel tile representing a portion of a primitive to be rendered, determining attributes of a reference pixel within the pixel tile, and determining the attributes of neighboring pixels within the pixel tile based on barycentric differences relative to the reference pixel is disclosed. A circuit for calculating at least one attribute of an object to be rendered includes an initial calculation circuit providing full precision reference pixel attribute data in response to a pixel tile that defines at least a portion of the object; and a derivative circuit, operatively coupled to the initial calculation circuit, providing reduced precision neighboring pixel attribute data in response to the pixel tile. The derivative circuit includes a plurality of pixel attribute sub-circuits or components, which determine the attribute values of neighboring pixels within the pixel tile at a precision less than that of the precision used to define the reference pixel.