A method is described for improving the responsiveness and accuracy of a graphics system to user-initiated picking actions. In this method, the visual cueing and pick window positioning components of the graphics system tracking/picking function are temporarily separated at the time the user attempts to pick. By handling these two components of the tracking/picking function independently, both type 1 (failure to pick the desired item) and type 2 (picking an undesired item) errors are prevented. This translates into greater productivity for the graphics system user.
A method is described that gives local control to an application program during the drawing process when a "pickable" primitive intersects the pick window. This control is provided in such a way that the state of graphics workstation remains unaltered. Thus the application program is permitted to make "picking" or visualization decisions at the moment the pick occurs, and then resume execution of the display program wherever desired (typically, at the graphic instruction following the one that caused the pick). This capability enables application programs to provide greater functionality, usability and productivity to their users.
A cursor positioning system for use with computer systems employing relative-pointing devices (e.g., trackballs or mice) for cursor positioning functions. The cursor positioning system employs a cursor driver, stored in a memory of the computer system and responsive to cursor positioning signals from the relative-pointing device, to enable fast and accurate cursor positioning to specific, predefined locations. The cursor driver responds to user-actuated signals, such as "clicks" or keystrokes to record cursor position objects at particular cursor locations. Thereafter, during cursor position selection mode, initiated by a keystroke or relative-pointing device signal, the cursor's position is moved from position object to position object. The preferred embodiment also provides for recording of bias objects, typically the same as the position objects, to attract the cursor's location towards them. This attraction reduces undershoot and overshoot of the cursor. Additionally, autoconfiguration of the cursor position/bias objects results from monitoring for prespecified actions from the user, such as "click"-events, and recording that position when the number of clicks at that location exceed a particular threshold. Subsequent use or non-use of that position can increase that objects weighting for bias influence effects. The cursor positioning system provides consistent cursor positioning tools, for all applications, and permits addition of new cursor tools to applications and the operating without modification of the applications.
A display screen is divided into a plurality of split screens and a mouse equipped with a switch moves a cursor among the plurality of split screens. A first position of the mouse is memorized when the switch is depressed. A cursor is moved to a predetermined position in the split screen belonging to a predetermined scope of the distance of movement if the mouse is moved from the first position to a second position when the switch is released.
A graphic display processing system is disclosed, in which a two-dimensional pattern or an image of a three-dimensional pattern can be displayed on the display screen of a display device, and moreover it can be rapidly judged whether or not each graphic data on a display list formed in a graphic data buffer corresponds to a pattern in a pattern pick region (namely, pick aperture) set on the display screen. In more detail, display color data in the pick aperture is first read out of a frame memory for storing image data. In a case where an image of a three-dimensional pattern is displayed, depth values in the pick aperture are read out of a Z-buffer for storing depth values with respect to a displayed pattern. Next, the read-out display color data is compared with display color commands on the display list, or the read-out depth values are compared with depth values obtained from geometrical form commands on the display list, to check whether or not each graphic data on the display list indicates the same display color or depth value as that of a pattern to be picked, thereby selecting only graphic data which is judged to indicate the same display color or depth value as that of the to-be-picked pattern. Then, it is checked whether or not the selected graphic data indicates a pattern intersecting with the pick aperture. Thus, desired graphic data can be rapidly picked out of the display list.
A method and apparatus for analysing the motion of an object in an motion video in which the frame of a video image (suitably converted to graphics format) is displayed on a video display unit and overlaid by a graphics image including a mouse pointer. The mouse is manipulated by the user to capture the pixel coordinates of the desired object in successive frames of the video thereby providing data which represents the variation in position of the object with time.
