Computer graphics system and method employing frame buffer having subpixel field, display fields and a control field for relating display fields to the subpixel field

• US 5,757,375 A
• Filed: 07/25/1995
• Issued: 05/26/1998
• Est. Priority Date: 08/11/1994
• Status: Expired due to Term

• Current Assignee: NVIDIA Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kawase, Kei
• Primary Examiner(s): Feild, Joseph H.
• Assistant Examiner(s): BUCHEL JR, RUDOLPH JOHN
• Application Number:
  US08/506,704
• Time in Patent Office: 1,036 Days
• Field of Search: 395/119, 395/122, 395/127, 395/131, 395/142-3, 395/508-516, 395/520-1, 345/419, 345/422, 345/427, 345/431, 345/501, 345/136, 345/189-90
• US Class Current: 345/613
• CPC Class Codes: G09G 5/393 Arrangements for updating the contents of the bit-mapped memory

Abstract

A computer graphics system is disclosed for generating pixel data corresponding to a plurality of pixels to be displayed. The computer graphics system includes a frame buffer having entries associated with each of the pixels. Each of the entries includes a subpixel data field, a plurality of display data fields, and a control field. For each entry the sub-pixel data field stores data corresponding to a set of sub-pixels, at least one of the plurality of display data fields stores data determined by filtering of the data of the sub-pixel data field of the entry, and the control field stores data representing a relationship between the sub-pixel data field of the entry and each of the plurality of display data fields of the entry.

Claims

1. A computer graphics system for generating pixel data corresponding to a plurality of pixels to be displayed, comprising:

a frame buffer including entries associated with each of said pixels, each of said entries including a sub-pixel data field, a plurality of display data fields, and a control field,

wherein for each entry,

said sub-pixel data field stores data corresponding to a set of sub-pixels,

at least one of said plurality of display data fields stores data determined by filtering of said data of said sub-pixel data field of said entry, and

said control field stores data representing relationship between said sub-pixel data field of said entry and each of said plurality of display data fields of said entry.

2. The computer graphics system of claim 1, wherein said control field of said entry includes a plurality of bits, each bit associated with one of said plurality of display data fields, and each bit indicating whether the associated one display data field has been determined by filtering of said data of said sub-pixel data field of said entry.

3. The computer graphics system of claim 1, further comprising:

drawing means for generating said data stored in said sub-pixel data field for each entry, and for generating said control field for each entry.

4. The computer graphics system of claim 3, wherein said drawing means generates said data stored in said sub-pixel data field for a particular entry as a function of said control field of said particular entry.

5. The computer graphics system of claim 4, wherein said drawing means generates said data stored in said sub-pixel field for a particular entry as a function of data previously stored in said sub-pixel field of said particular entry.

6. The computer graphics system of claim 1, further comprising:

filtering means for generating said plurality of display data fields of each entry as a function of said data stored in said sub-pixel data field of said entry, and for writing said plurality of display data fields to each entry.

7. In a computer graphics system that generates pixel data corresponding to a plurality of pixels to be displayed, the system including a frame buffer comprising entries associated with each of said pixels, each entry including a sub-pixel data field, a plurality of display data fields, and a control field, a method for generating said pixel data comprising the steps of:

for each entry of said frame buffer,

(a) generating sub-pixel data corresponding to a set of sub-pixels, and writing said sub-pixel data to said sub-pixel data field of said entry;

(b) filtering said sub-pixel data stored in said sub-pixel data field of said entry, and writing a result of said filtering to at least one of said plurality of display data fields of said entry; and

(c) generating condition data representing relationship between said sub-pixel data field of said entry and each of said plurality of display data fields of said entry, and writing said condition data to said control field of said entry.

8. The method of claim 7, wherein said control field of said entry includes a plurality of bits, each bit associated with one of said plurality of display data fields, and each bit indicating whether the associated one display data field has been determined by filtering of said sub-pixel data of said sub-pixel data field of said entry.

9. The method of claim 7, wherein the sub-pixel data generated in step (a) is generated as a function of data stored in said control field of said entry.

10. The method of claim 7, wherein the sub-pixel data generated in step (a) is generated as a function of data previously stored in said sub-pixel field of said entry.

11. A computer graphics system for generating pixel data corresponding to a plurality of pixels to be displayed, comprising:

a frame buffer including entries associated with each of said pixels, each of said entries including a sub-pixel data field, a plurality of display data fields, and a control field,

wherein for each entry,

said sub-pixel data field stores data corresponding to a set of sub-pixels,

at least one of said plurality of display data fields stores data determined by filtering of said data of said sub-pixel data field of said entry, and

said control field stores data representing relationship between said sub-pixel data field of said entry and each of said plurality of display data fields of said entry;

drawing means for generating said data stored in said sub-pixel field for each entry, and for generating said control field for each entry; and

filtering means for generating said plurality of display data fields of each entry as a function of said data stored in said sub-pixel data field of said entry, and for writing said plurality of display data fields to each entry.

12. The computer graphics system of claim 11, wherein said control field of said entry includes a plurality of bits, each bit associated with one of said plurality of display data fields, and each bit indicating whether the associated one display data field has been determined by filtering of said data of said sub-pixel data field of said entry.

13. The computer graphics system of claim 11, wherein said drawing means generates said data stored in said sub-pixel field for a particular entry as a function of data stored in said control field of said particular entry.

14. The computer graphics system of claim 11, wherein said drawing means generates said data stored in said sub-pixel field for a particular entry as a function of data previously stored in said sub-pixel field of said particular entry.