Method, Display Adapter and Computer Program Product for Improved Graphics Performance by Using a Replaceable Culling Program

Abstract

It is presented a method for improving performance of generation of digitally represented graphics. Said method comprises the steps of: selecting (440) a tile comprising fragments to process; executing (452) a culling program for the tile, the culling program being replaceable; and executing a set of instructions, selected from a plurality of sets of instructions based on an output value of the culling program, for each of a plurality of subsets of the fragments. A corresponding display adapter and computer program product are also presented.

What is claimed is: 
     
         1 . A method comprising:
 selecting fragments to process;   executing a culling program for said fragments, said culling program being replaceable; and   executing a set of instructions, selected from a plurality of sets of instructions based on an output value of said culling program, for each of a plurality of subsets of said fragments.   
     
     
         2 . The method according to  claim 1 , including representing a whole tile of fragments for at least part of instructions of said culling program. 
     
     
         3 . The method according to  claim 1 , including using interval arithmetic for at least part of instructions of said culling program. 
     
     
         4 . The method according to  claim 1 , including using affine arithmetic for at least part of instructions of said culling program. 
     
     
         5 . The method according to  claim 1 , including providing values representing at least one attribute of a plurality of said fragments to said culling program. 
     
     
         6 . The method according to  claim 1 , wherein executing said subsets of fragments using subsets comprising only one fragment. 
     
     
         7 . The method according to  claim 1 , wherein said step of executing a set of instructions involves, when said output value satisfies a culling condition, executing a first set of instructions for each of a plurality of subsets of said fragments, and when said output value fails said culling condition, executing a second set of instructions for each of said plurality of subsets of fragments. 
     
     
         8 . The method according to  claim 7 , wherein said first set of instructions comprise fewer instructions than said second set of instructions. 
     
     
         9 . The method according to  claim 7 , wherein said first set of instructions comprises zero instructions. 
     
     
         10 . The method according to  claim 7 , wherein in said step of executing a set of instructions, said culling condition corresponds to said fragments of said tile making no contribution to a finally rendered image. 
     
     
         11 . The method according to  claim 7 , wherein in said step of executing a set of instructions, said culling condition corresponds to said fragments of said tile making a contribution less than a threshold value to a finally rendered image. 
     
     
         12 . The method according to  claim 5 , wherein providing values includes using interval arithmetic and using a plurality of fragments of said tile as input. 
     
     
         13 . The method according to  claim 5 , wherein providing values includes using affine arithmetic and using a plurality of fragments of said tile as input. 
     
     
         14 . The method according to  claim 5 , wherein providing values includes calculating values as a result of said culling program requesting access to said values. 
     
     
         15 . The method according to  claim 5 , wherein in said step of providing values, said values are calculated prior to executing said culling program. 
     
     
         16 . The method according to  claim 1 , wherein selecting a tile involves selecting a tile which is at least partly overlapped by a polygon being processed. 
     
     
         17 . The method according to  claim 16 , wherein said fragments are fragments associated with said polygon. 
     
     
         18 . The method according to  claim 16 , including selecting a tile, executing a culling program, providing values, and executing a set of instructions repeatedly until all tiles which are at least partly overlapped by said specified polygon have been processed. 
     
     
         19 . The method according to  claim 18 , wherein at least one of values calculated by said culling program is used in said selected set of instructions or in processing by subsequently used processing units. 
     
     
         20 . A processor-based device comprising a display adapter to:
 select a tile comprising fragments to process;   execute a culling program for said tile, said culling program being replaceable;   execute a set of instructions, selected from a plurality of sets of instructions based on an output value of said culling program, for each of a plurality of subsets of said fragments; and   a storage storing said instructions.   
     
     
         21 . The device of  claim 20  further including a display adapter to represent a whole tile of fragments for at least part of the instructions of said culling program. 
     
     
         22 . The device of  claim 20 , said display adapter to use interval arithmetic for at least part of the instructions of said culling program. 
     
     
         23 . The device of  claim 20 , said display adapter to use affine arithmetic for at least part of the instructions of said culling program. 
     
     
         24 . A computer readable medium storing instructions for execution by a computer to:
 select a tile comprising fragments to process;   execute a culling program for said fragments, said culling program being replaceable; and   select from a plurality of sets of instructions based on an output value of said culling program for each of a plurality of subsets of said fragments.   
     
     
         25 . The medium according to  claim 25 , including representing a whole tile of fragments for at least part of instructions of said culling program. 
     
     
         26 . The medium according to  claim 25 , including using interval arithmetic for at least part of instructions of said culling program. 
     
     
         27 . The medium according to  claim 25 , including using affine arithmetic for at least part of instructions of said culling program. 
     
     
         28 . The medium according to  claim 25 , including providing values representing at least one attribute of a plurality of said fragments to said culling program.