Abstract: A high performance method for the compression of floating point format surface normals and the inverse method for the decompression of those compressed surface normals. Each of the three vector components of the surface normal is compressed by subtracting a constant from the floating point format value, then extracting a predefined field, and finally storing the extracted field. Decompression of the compressed surface normal requires first converting the three stored vector components into floating-point format and then adding a predefined constant to each. Typically the surface normals are of unit length.

Abstract: Enhanced capability design-rule halos for use in Computer Aided Design (CAD) software programs are described. Such enhanced halos, created around a design feature at the design rule distance from that feature, have the following characteristics: beveled corners for closer placement of adjacent non-parallel and/or non-perpendicular design features, level-to-level design rule halos, following a bend or turn in a design feature, the design rule halo automatically adapts to bends or turns in the design feature and associated changes in the design feature following the bend, following a bend or turn in a design feature, the design feature and the design rule halo automatically snap back, as required, to avoid a design rule violation with respect to an adjacent design feature, and the design-rule halo is prevented from extending closer to an adjacent design feature than the design rule distance. These actions are performed real-time and interactively.

Abstract: Enhanced capability design-rule halos for use in Computer Aided Design (CAD) software programs are described. Such enhanced halos, created around a design feature at the design rule distance from that feature, have the following characteristics: beveled corners for closer placement of adjacent non-parallel and/or non-perpendicular design features, level-to-level design rule halos, following a bend or turn in a design feature, the design rule halo automatically adapts to bends or turns in the design feature and associated changes in the design feature following the bend, following a bend or turn in a design feature, the design feature and the design rule halo automatically snap back, as required, to avoid a design rule violation with respect to an adjacent design feature, and the design-rule halo is prevented from extending closer to an adjacent design feature than the design rule distance. These actions are performed real-time and interactively.