Graphics system

• US 6,181,346 B1
• Filed: 03/19/1997
• Issued: 01/30/2001
• Est. Priority Date: 04/05/1996
• Status: Expired due to Term

• Current Assignee: Lenovo PC International Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Ohtani, Munetaka, Ono, Makoto, Moriyama, Takao, Takatsu, Yoshihisa
• Primary Examiner(s): Brier, Jeffery
• Assistant Examiner(s): GOOD JOHNSON, MOTILEWA
• Application Number:
  US08/820,145
• Time in Patent Office: 1,413 Days
• Field of Search: 345/430, 345/503, 345/506
• US Class Current: 345/582
• CPC Class Codes: G06T 11/40 Filling a planar surface by adding surface attributes, e.g. colour or texture

Abstract

This graphics system has a geometric sub-system that does not have to take into consideration memory resources for the raster sub-system of the graphics system. The graphics system sequentially receives from a host computer system data sets that define a graphic object and downloads texture data for graphics from the host computer system, so that geometric processing and rasterization are performed on the graphic object for display on a computer screen.

Claims

1. A graphics system, which sequentially receives from a host computer system data sets that define a graphic object, and which downloads texture data from said host computer system so that geometric processing and rasterization are performed on said graphic object for display on a computer screen, comprising:

(a) a dispatch processor, for receiving data sets from said host computer system and for distributing data sets for geometric processing;

(b) a plurality of geometry node processors, each of said geometry node processors issuing distributing data sets with a texture command including a texture identifier identifying a texture data group and performing geometric processing of said distributed data sets;

(c) a merge processor, for merging geometrically processed data sets output by said geometry node processors and for distributing said data sets for rasterization;

(d) a texture memory, in which one or more texture data groups, including some but not all of said texture data of said host computer system are stored;

(e) a raster processor, for receiving said geometrically processed data sets from said merge processor for rasterizing said geometrically processed data sets and for adding texture to pixels of said data sets obtaining texture data from said texture memory; and

(f) texture memory management means for managing texture data stored in said texture memory placing texture data groups in said texture memory in accordance with said texture commands of each of said geometry node processors so that required texture data is resident in the texture data memory when requested by the raster processor.

2. The graphics system according to claim 1, wherein said texture memory management means includes:

(f-1) a texture list in said merge processor of texture identifiers of said texture data, which specifies a relationship between texture data groups currently stored in said texture memory and corresponding storage areas in said texture memory;

(f-2) first control means in said merge processor for determining whether or not said texture identifier indicated by a received texture command is included on said texture list and for issuing an interrupt request if said texture identifier isn'"'"'t included on said texture list interrupting the transfer of data sets to the raster processor; and

(f-3) second control means for responding to said interrupt request by downloading to said texture memory a texture data group corresponding to said texture identifier from said host computer system, and for updating a result obtained by said downloading in said texture list and upon updating the texture list issuing a resume request to the merge processor.

3. The graphics system according to claim 1, wherein said merge processor includes means for maintaining the order of data sets.

4. The graphics system according to claim 1, wherein said raster processor includes a plurality of raster node processors, each of said raster node processors texturizing and rasterizing pixels in screen regions defined by said data sets.

5. The graphics system according to claim 4 wherein the second control means includes means for replacing texture data resident in the texture memory with said downloaded texture data when the texture memory is full.

6. The graphics system according to claim 5 wherein said second control means replaces texture data in accordance with the least recently used (LRU) algorithm.

7. In a graphics system, which sequentially receives from a host computer system data sets that define a graphic object, and which downloads texture data from said host computer system so that geometric processing and rasterization are performed on said graphic object for display on a computer screen, the method comprising:

(a) receiving data sets from said host computer system and distributing such data sets to a plurality of geometry node processors for geometric processing;

(b) issuing a texture command from each of the geometry node processors including a texture identifier specified in distributed data sets and performing geometric processing of said distributed data sets;

(c) merging geometrically processed data sets outputted by said geometry node processors in a merge processor and distributing said data sets for rasterization;

(d) storing the downloaded texture data in a texture memory;

(e) receiving said geometrically processed data sets from said merge processor and rasterizing said geometrically processed data sets in a plurality of raster processors which each obtain texture data from the texture memory and then add that texture data to the pixels of the data sets; and

(f) managing texture data to be stored in said texture memory in accordance with said texture commands received from each of said geometry node processors having the merge processor assure texture data required for data sets is in the texture data memory prior to providing those data sets to the raster processors.

8. The method according to claim 7, including:

(f-1) maintaining a texture list of texture identifiers of said texture data in the merge processor, which list specifies the relation between currently stored in said texture memory and corresponding storage areas in said texture memory;

(f-2) determining in the merge processor whether or not said texture identifier indicated by a received texture command is included on said texture list and issuing an interrupt request if said texture identifier isn'"'"'t included on said texture list; and

(f-3) in response to said interrupt request, downloading texture data corresponding to said texture identifier from said host computer system to said texture memory, and updating a result obtained by said downloading in said texture list.

9. The method according to claim 8, including maintaining the order of data sets.