Abstract: A graphics display terminal performs a pan operation with respect to a view motion center to effectuate spherical panning, thereby providing perspective and non-perspective views. Three dimensional instructions stored in terminal memory are re-transformed in accordance with a panned direction. Also a zoom feature is provided so that displayed images may be magnified as desired.

Abstract: The present invention relates to a capability present within a graphics display terminal wherein a zoom operation may be accomplished, the width of each of the lines of the zoomed image being maintained at a one pixel width regardless of the degree or amount of magnification of the zoomed image. This is accomplished by utilizing the firmware stored in the processor to perform the magnification of the image therein, prior to the storage of the appropriate binary data in the video display memory, the binary data being the pixel representation of the displayed image. Since the magnification of the image takes place prior to storage of the binary data in the video display memory, the graphics display terminal of the present invention can use this binary data to display an image, a zoomed image, the width of each line being equal to, approximately, a one pixel width. Therefore, despite the degree of magnification of the zoomed image, a very discernable, clear image will be displayed on the CRT.

Abstract: A method and apparatus is disclosed for independently displaying one of a plurality of images on a display and for superimposing the plurality of images onto one another to produce a composite image. One or more bit planes are selected to constitute a group (defined to be a "surface"), and one or more additional bit planes are selected to constitute another group. The number of groups corresponds to the number of images to be independently displayed. The priority of one group over the other is selected. This ensures that the image from the one group (surface) appears to be "in front of" the images from the other group (surface) on the display. In the case of a color terminal, the colors associated with each group are selected. A color map memory contains a plurality of brightness indices which determines image brightness. Associated with each index is one or more color indices.