Math engine for generating font gradients

DETAILED DESCRIPTION The present invention overcomes the disadvantages and limitations of the prior art by providing a interpolation engine that is capable of generating gradient signals on a real time basis so that a pulse density modulated signal can be generated that has a pulse-density gradient that varies at the proper rate as the electron beam moves down the page.
The present invention, therefore, comprises a method for generating a gradient of pulse-density modulated correction signals for a video monitor that comprises the steps of, loading a gradient counter with a starting count number for the gradient to be generated, loading an increment rate counter with an increment rate number, generating an increment signal from the increment rate counter that has an increment rate corresponding to the increment rate number, and generating the gradient of pulse density modulated correction signals from the gradient counter by applying the increment signal to the gradient counter to increment the starting count number at the increment rate so as to produce a series of output signals having a gradient that changes at a rate corresponding to the increment rate number.
The present invention also comprises a method of generating a plurality of pulse density modulation signals for a first predetermined vertical segment of a video monitor comprising the steps of generating a first start count number for a first predetermined vertical segment that is representative of a first predetermined number of pulses in a first horizontal line of the first predetermined vertical segment, generating a second start count number for a second predetermined vertical segment located vertically adjacent to the first vertical segment, the second start count number representative of a second predetermined number of pulses in a first horizontal line of the second predetermined vertical segment, generating a difference signal that is representative of a difference between the first and second predetermined number of pulses, generating a gradient signal that is representative of a rate of change of the predetermined number of pulses for each horizontal line of the first predetermined vertical segment, and generating the plurality of pulse density modulation signals for the first vertical segment by modifying the first starting count number by the gradient signal to determine the predetermined number of pulses for each horizontal line of the first vertical segment