Computer graphics priority system with antialiasing

Claim 2

A process for resolving priority at specific locations of designated coordinate values of x and y for a graphics display between a first primitive P 1 defined in conventional three-dimensional space in a plane a 1 x+b 1 y+c 1 z+d 1 =0 and a second primitive P 2 similarly defined in a plane a 2 x+b 2 y+c 2 z+d 2 =0, said planes potentially although not necessarily intersecting along a projected line of intersection in said display, comprising the steps of: defining said projected line of intersection by determining the values of (c 2 a 1 -c 1 a 2 ), (c 2 b 1 -c 1 b 2 ) and (c 2 d 1 -c 1 d 2 ); storing the determined values (c 2 a 1 -c 1 a 2 ), (c 2 b 1 -c 1 b 2 ) and (c 2 d 1 -c 1 d 2 ); storing picture element data to define elemental areas of said graphics display; resolving priority for said elemental areas in sequence as between said primitives for said display to determine precedence in favor of one of said primitives P 1 or P 2 under control of c 1 , c 2 , and one or more of (c 2 a 1 -c 1 a 2 ), (c 2 b 1 -c 1 b 2 ) and (c 2 d 1 -c 1 d 2 ); and storing display data of said one primitive for said elemental areas to provide electrical signals for the graphics display.

Claim 3

A process according to claim 1 including the further step of resolving said line of intersection existing between said primitives as more horizontal or more vertical as by determining the relative magnitudes of (c 2 a 1 -c 1 a 2 ) and (c 2 b 1 -c 1 b 2 ), and further resolving said priority under control of whether said line is either more horizontal or more vertical.

Claim 4

A process according to claim 2 wherein priority is resolved in favor of said first primitive to one side of said more vertical line, and priority is resolved in favor of said second primitive to the other side of said more vertical line, under control of c 1 , c 2 and (c 2 a 1 -c 1 a 2 ).

Claim 5

A process according to claim 2 wherein priority is resolved in favor of said first primitive to one side of said more vertical line, and priority is resolved in favor of said second primitive to the other side of said more vertical line, under control of the signs of c 1 , c 2 and (c 2 a 1 -c 1 a 2 ).

Claim 6

A process according to claim 2 wherein priority is resolved in favor of said first primitive to one side of said more horizontal line, and priority is resolved in favor of said second primitive to the other side of said more horizontal line, under control of c 1 , c 2 and (c 2 b 1 -c 1 b 2 ).

Claim 7

A process according to claim 2 wherein priority is resolved in favor of said first primitive to one side of said more horizontal line, and priority is resolved in favor of said second primitive to the other side of said more horizontal line, under control of the signs of c 1 , c 2 and (c 2 b 1 -c 1 b 2 ).

Claim 8

A process according to claim 1 wherein said priority is further resolved by determining the absence of an intersecting line between said planes.

Claim 9

A process according to claim 7 wherein said priority is resolved in favor of one of said primitives under control of c 1 , c 2 and (c 2 d 1 -c 1 d 2 ).

Claim 10

A process according to claim 7 wherein said priority is resolved in favor of one of said primitives under control of the signs of c 1 , c 2 and (c 2 d 1 -c 1 d 2 ).

Claim 11

A process according to claim 7 wherein determination of said absence of an intersecting line between planes is controlled by the determined magnitudes of (c 2 a 1 -c 1 a 2 ) and (c 2 b 1 -c 1 b 2 ).

Claim 12

A process according to claim 1 wherein said designated x and y values indicate subpixels for said display and said process further includes a step of computing composites for pixels in accordance with priorities determined for said subpixels.

Claim 13

A hidden surface elimination system for resolving priority as between primitives for a computer graphics image display with respect to picture element areas, the primitives P 1 , P 2 and so on being defined in planes, a 1 x+b 1 y+c 1 z+d 1 =0; a 2 x+b 2 y+c 2 z+d 2 =0 and so on, the hidden surface elimination system comprising: means for receiving primitive data to specify components for a computer graphics display in the form of said primitives P 1 and P 2 and so on; structure for sequencing said picture element areas to be occupied by said primitives P 1 and P 2 as specified by the received primitive data to identify primitives contending for a picture element area; structure for resolving priority between primitives P 1 and P 2 contending for a pixel area, by determining the values (c 2 a 1 -c 1 a 2 ), (c 2 b 1 -c 1 b 2 ) and (c 2 d 1 -c 1 d 2 ) and logically analyzing the signs of certain of the values to select one of said contending primitives P1 or P2 for the picture element area; and cache memory means for receiving the determined values (c 2 a 1 -c 1 a 2 ), (c 2 b 1 -c 1 b 2 ) and (c 2 d 1 -c 1 d 2 ) and means for identifying said values for use on occurrence of another pixel with contention between the primitives P 1 and P 2 .

Claim 14

A hidden surface elimination system for resolving priority as between primitives for a computer graphics image display with respect to picture element areas, the primitives P 1 , P 2 and so on being defined in planes, a 1 x+b 1 y+c 1 z+d 1 =0; a 2 x+b 2 y+c 2 z+d 2 =0 and so on, the hidden surface elimination system comprising: means for receiving primitive data to specify components for a computer graphics display in the form of said primitives P 1 and P 2 and so on; structure for sequencing said picture element areas to be occupied by said primitives P 1 and P 2 as specified by the received primitive data to identify primitives contending for a picture element area; structure for resolving priority between primitives P 1 and P 2 contending for a pixel area, by determining the values (c 2 a 1 -c 1 a 2 ), (c 2 b 1 -c 1 b 2 ) and (c 2 d 1 -c 1 d 2 ) and logically analyzing the signs of certain of the values to select one of said contending primitives P1 or P2 for the picture element area; and cache memory means for receiving the determined values (c 2 a 1 -c 1 a 2 ), (c 2 b 1 -c 1 b 2 ) and (c 2 d 1 -c 1 d 2 ) and means for identifying said values for use on occurrence of another pixel with contention between the primitives P 1 and P 2 .

Claim 15

A hidden surface elimination system for resolving priority as between primitives for a computer graphics image display with respect to picture element areas, the primitives P 1 , P 2 and so on being defined in planes, a 1 x+b 1 y+c 1 z+d 1 =0; a 2 x+b 2 y+c 2 z+d 2 =0 and so on, the hidden surface elimination system comprising: means for receiving primitive data to specify components for a computer graphics display in the form of said primitives P 1 and P 2 and so on; structure for sequencing said picture element areas to be occupied by said primitives P 1 and P 2 as specified by the received primitive data to identify primitives contending for a picture element area, said structure for sequencing comprising a raster converter for scan converting said primitives; and memory means for receiving the determined values (c 2 a 1 -c 1 a 2 ), (c 2 b 1 -c 1 b 2 ) and (c 2 d 1 -c 1 d 2 ) and means for identifying said values for use on occurrence of another pixel with contention between the primitives P 1 and P 2 .

Claim 16

A hidden surface elimination system for resolving priority as between primitives for a computer graphics image display with respect to picture element areas, the primitives P 1 , P 2 and so on being defined in planes, a 1 x+b 1 y+c 1 z+d 1 =0; a 2 x+b 2 y+c 2 z+d 2 =0 and so on, the hidden surface elimination system comprising: means for receiving primitive data to specify components for a computer graphics display in the form of said primitives P 1 and P 2 and so on; structure for sequencing said picture element areas to be occupied by said primitives P 1 and P 2 as specified by the received primitive data to identify primitives contending for a picture element area, said structure for sequencing comprising a raster converter for scan converting said primitives; and memory means for receiving the determined values (c 2 a 1 -c 1 a 2 ), (c 2 b 1 -c 1 b 2 ) and (c 2 d 1 -c 1 d 2 ) and means for identifying said values for use on occurrence of another pixel with contention between the primitives P 1 and P 2 .

Claim 17

A system according to claim 13 comprising a plurality of said structures for resolving priority and further including means for coupling said plurality of structures to process said received primitive data and further including means for accessing said memory means by each of said structures.

Claim 18

A system according to claim 13 wherein said memory means further includes a polygon memory for storing primitive data and a mask memory for storing picture element data.

Claim 19

A system according to claim 15 wherein said mask memory stores subpixel data.

Claim 20

A hidden surface elimination system for resolving priority as between primitives for a computer graphics image display with respect to picture element areas, the primitives P 1 , P 2 and so on being defined in planes, a 1 x+b 1 y+c 1 z+d 1 =0; a 2 x+b 2 y+c 2 z+d 2 =0 and so on, the hidden surface elimination system comprising: means for receiving primitive data to specify components for a computer graphics display in the form of said primitives P 1 and P 2 and so on; structure for sequencing said picture element areas to be occupied by said primitives P 1 and P 2 as specified by the received primitive data to identify primitives contending for a picture element area; a polygon memory for storing data on said polygons; a mask memory for storing data on said picture element areas; structure for resolving priority between primitives P 1 and P 2 contending for a pixel area, by determining the values (c 2 a 1 -c 1 a 2 ), (c 2 b 1 -c 1 b 2 ) and (c 2 d 1 -c 1 d 2 ) and logically analyzing the signs of certain of the values to select one of said contending primitives P1 or P2 for the picture element area; and means for storing signal indications of said one contending primitive in said mask memory.

Claim 21

A hidden surface elimination system for resolving priority as between primitives for a computer graphics image display with respect to picture element areas, the primitives P 1 , P 2 and so on being defined in planes, a 1 x+b 1 y+c 1 z+d 1 =0; a 2 x+b 2 y+c 2 z+d 2 =0 and so on, the hidden surface elimination system comprising: means for receiving primitive data to specify components for a computer graphics display in the form of said primitives P 1 and P 2 and so on; structure for sequencing said picture element areas to be occupied by said primitives P 1 and P 2 as specified by the received primitive data to identify primitives contending for a picture element area; a polygon memory for storing data on said polygons; a mask memory for storing data on said picture element areas; structure for resolving priority between primitives P 1 and P 2 contending for a pixel area, by determining the values (c 2 a 1 -c 1 a 2 ), (c 2 b 1 -c 1 b 2 ) and (c 2 d 1 -c 1 d 2 ) and logically analyzing the signs of certain of the values to select one of said contending primitives P1 or P2 for the picture element area; and means for storing signal indications of said one contending primitive in said mask memory.

Claim 22

A system according to claim 17 wherein said mask memory stores designations for polygons in said polygon memory to indicate data for said picture element areas.

Claim 23

A system according to claim 17 further including a frame buffer storage for said image display and means for storing data from said mask memory and said polygon memory in said frame buffer storage.

Claim 24

A system according to claim 19 wherein said means for storing further includes means for processing said data from said mask memory and said polygon memory for shading.