Abstract: A method, apparatus, article of manufacture for defining a precision drawing point is disclosed. The method permits the definition of temporary interesting points anywhere in the drawing space. Each temporary interesting point allows the definition of a set of candidate alignment lines, all intersecting at the temporary interesting point. When the user moves a cursor within a snap distance of one of the set of candidate alignment lines, an alignment line is displayed. The precision drawing point is then defined on the alignment line. The drawing point can be defined when the cursor is within a snap distance of one of a set of pre-settable snap distances from the temporary interesting point. Alternatively, the drawing point can be defined by selecting a second temporary interesting point associated with a second set of candidate alignment lines, and positioning the cursor within a snap distance of one of the second set of candidate alignment lines.

Abstract: The present invention comprises a method and apparatus for manipulating screen objects utilizing multiband regions of influence. Positioning a reference point of an object within a particular band invokes a particular functionality or operation related to that band. In one embodiment, three types of functionality are provided. Moving a reference datum (for example, a line representing an edge or a user defined reference point) of an object A into a first band of an object B places object A under the influence of object B's gravity, causing object A to be pulled into precise alignment with object B. Moving the reference point of object A from the first band into a second band turns off object B's gravity, allowing object A to be freely moved to any arbitrary position near the object B. Moving the reference point of the object A to a position outside all bands causes object B's gravity function to be turned back on.

Abstract: A graphic form correction apparatus and method for a CAD system wherein a display position of a dimension-relating symbol such as a dimension line, an extension line or a dimension value entered on a two-dimensional graphic form is automatically corrected in response to a correction of the two-dimensional graphic form. The graphic form correction apparatus includes an additional symbol arrangement section for arranging an additional symbol such as a finish symbol or a surface roughness in the proximity of the dimension-relating symbol, and an additional symbol position storage section for storing a display position of the additional symbol and a display position of the dimension-relating symbol in a coordinated relationship.