| 摘要 |
A method and apparatus for writing a vector of data into a random access memory (14) at high speed wherein the random access memory (RAM) is partitioned into blocks of addressable storage sites and wherein storage sites within each block are individually accessible. A vector generator (38) provides addressing and storage site enabling signals to the RAM (14). Boundary detectors (48, 50) monitor the addressing and storage site selection signals to determine whenever storage sites within a new block of storage sites are sought to be addressed. When a boundary transition is detected, a control signal is provided to the vector generator (38) which slows the operation of the vector generator (38) for a period of time sufficient to permit the RAM (14) to accept a new address. For all other addresses, the vector generator (38) is permitted to operate at a higher speed wherein access to the RAM (14) is made by way of enabling specific storage sites within the block of storage sites being written into. The invention further provides a method and apparatus for generating surface-fill vectors, wherein a vector generator (200) which implements the Bresenhem Algorithm is employed to generate instructions for locating points corresponding to line segments that bound the surface to be filled. The instructions (206) are evaluated such that the X address for a given point is recorded whenever an instruction is issued which indicates a Y address change (206). The recorded X address are corelated to the Y coordinates over which the surface extends. The correlated X and Y addresses then define end points of surface fill vectors which can fill in the surface. |
