Graphic display system having analog interpolators

摘要

In a graphic display system a plurality of sets of first, second and third geometrical digital signals and a pictorial signal are stored in a memory and read therefrom at the raster speed of a display unit into plural latches with which plural interpolators are respectively associated. The first and second signals represent the gradients of the planes of a solid object with respect to the two axes of a coordinate system respectively, and the third signal represents the depth of a point lying on each edge of the object. Each interpolator converts the first gradient signal from the associated latch to a corresponding voltage and includes a proportioning circuit that scales the voltage as a function of the second gradient signal and as a function of a fourth signal representing the location of a scan point. Proportioned signals from the interpolators are summed respectively with the associated third signals to indicate the instantaneous values of the depths of the planes as a function of the raster scan. The summed signals are compared with each other to detect the one having a smallest magnitude to enable the pictorial signal of the desired plane.