System and method for graphical rendering of point primitives

• US 8,466,874 B1
• Filed: 02/10/2009
• Issued: 06/18/2013
• Est. Priority Date: 02/10/2009
• Status: Active Grant

• Current Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Gardiner, Harold Dee
• Primary Examiner(s): Lao, Lun-Yi
• Assistant Examiner(s): Sadio, Insa
• Application Number:
  US12/368,866
• Time in Patent Office: 1,589 Days
• Field of Search: 345/156, 345/157, 345 7- 8, 315/9, 315/13.1, 701/1, 701/3, 701/4, 701/33.9, 701/120, 701/400, 701/528
• US Class Current: 345/157
• CPC Class Codes: G09G 2340/0457 Improvement of perceived resolution by subpixel rendering
• CPC Class Codes: G09G 2380/10 Automotive applications
• CPC Class Codes: G09G 2380/12 Avionics applications
• CPC Class Codes: G09G 5/06 using colour palettes, e.g. look-up tables

Abstract

A system for rendering point primitives for output to an electronic display includes electronics configured to determine a position of a point primitive within a sub-pixel grid. The electronics configured to determine a size of the point primitive and to determine a positional relationship between a pixel and the sub-pixel grid. The system includes a storage circuit configured to determine a first sample bit mask based on the size and based on the position of the point primitive. The system includes at least one set of selector circuits configured to select a second sample bit mask the size of the pixel based on the first sample bit mask and based on the positional relationship between the pixel and the sub-pixel grid. The second sample bit mask indicates which sub-pixels are to be illuminated on the electronic display to represent the point primitive.

Claims

1. A system for rendering point primitives for output to an electronic display, comprising:

processing electronics configured to determine a position of a point primitive within a sub-pixel grid, the processing electronics further configured to determine a size of the point primitive, the processing electronics further configured to determine a positional relationship between a pixel and the sub-pixel grid;

a storage circuit configured to determine a first sample bit mask based on the determined size and based on the determined position of the point primitive; and

at least one set of selector circuits configured to select a second sample bit mask the size of the pixel based on the first sample bit mask and based on the positional relationship between the pixel and the sub-pixel grid, the second sample bit mask indicating which sub-pixels within the pixel are to be illuminated on the electronic display to represent the point primitive.

2. The system of claim 1, wherein the processing electronics are further configured to determine a positional relationship between a second pixel and the point primitive, the at least one set of selector circuits being further configured to generate a third sample bit mask the size of the second pixel based on the first sample bit mask and the determined positional relationship between the second pixel and the sub-pixel grid, the third sample bit mask indicating which sub-pixels within the second pixel are to be illuminated on the electronic display to represent the point primitive.

3. The system of claim 2, wherein the determining a positional relationship and generating a bit mask are repeated for each pixel the point primitive at least partially overlaps.

4. The system of claim 1, wherein the at least one set of selector circuits comprises a first set of selector circuits aligned with a first coordinate axis and a second set of selector circuits aligned with a second coordinate axis, the first set of selector circuits receiving a coordinate on the first coordinate axis of the positional relationship between the pixel and the sub-pixel grid, the second set of selector circuits receiving a coordinate on the second coordinate axis of the positional relationship between the pixel and the sub-pixel grid.

5. The system of claim 1, wherein the at least one set of selector circuits comprises barrel shifter or multiplexer circuits and/or the storage circuit comprises a look-up table.

6. The system of claim 1, wherein the sub-pixel grid is rectangular and the at least one set of selector circuits comprises a selector circuit for each row of the sub-pixel grid and a selector circuit for each column of the sub-pixel grid.

7. The system of claim 1, wherein multiple point primitives are rendered with sizes ranging from zero to a size determined by the sub-pixel grid size.

8. The system of claim 7, wherein point primitives larger than the sub-pixel grid size are rendered using an alternate solution.

9. The system of claim 1, wherein at least a portion of the sub-pixels at the corner of the grid are omitted because they lie outside the largest point size within the pixel grid.

10. The system of claim 1, wherein the point size comprises enough bits to allow an incremental size change on a small point primitives to alter the resulting sample bit mask by no more than one sample at a time.

11. A method for rendering point primitives for output to an electronic display, comprising:

determining a position of a point primitive within a sub-pixel grid using processing electronics;

determining a size of the point primitive using processing electronics;

determining a positional relationship between a pixel and the sub-pixel grid using processing electronics;

determining a first sample bit mask based on the determined size and based on the determined position of the point primitive using a storage circuit; and

generating a second sample bit mask the size of the pixel based on the first sample bit mask and based on the positional relationship between the pixel and the sub-pixel grid using at least one set of selector circuits, the second sample bit mask indicating which sub-pixels within the pixel are to be illuminated on the electronic display to represent the point primitive.

12. The method of claim 11, further comprising:

determining a positional relationship between a second pixel and the point primitive using the processing electronics,

generating a third sample bit mask the size of the second pixel based on the first sample bit mask and the determined positional relationship between the second pixel and the sub-pixel grid using the at least one set of selector circuits, the third sample bit mask indicating which sub-pixels within the second pixel are to be illuminated on the electronic display to represent the point primitive.

13. The method of claim 12, wherein the determining a positional relationship and generating a bit mask are repeated for each pixel the point primitive at least partially overlaps.

14. The method of claim 11, wherein the at least one set of selector circuits comprises a first set of selector circuits aligned with a first coordinate axis and a second set of selector circuits aligned with a second coordinate axis, the first set of selector circuits receiving a coordinate on the first coordinate axis of the positional relationship between the pixel and the sub-pixel grid, the second set of selector circuits receiving a coordinate on the second coordinate axis of the positional relationship between the pixel and the sub-pixel grid.

15. The method of claim 11, wherein the at least one set of selector circuits comprises barrel shifter or multiplexer circuits and/or the storage circuit comprises a look-up table.

16. The method of claim 11, wherein the sub-pixel grid is rectangular and the at least one set of selector circuits comprises a selector circuit for each row of the sub-pixel grid and a selector circuit for each column of the sub-pixel grid.

17. The method of claim 11, wherein multiple point primitives are rendered with sizes ranging from zero to a size determined by the pixel grid size.

18. The method of claim 17, wherein point primitives larger than the sub-pixel grid size are rendered using an alternate solution.

19. The method of claim 11, wherein the point size comprises enough bits to allow an incremental size change on a small point primitives to alter the resulting sample bit mask by no more than one sample at a time.

20. An apparatus for rendering point primitives for output to an electronic display, comprising:

means for determining a position of a point primitive within a sub-pixel grid;

means for determining a size of the point primitive;

means for determining a positional relationship between a pixel and the sub-pixel grid;

means for determining a first sample bit mask based on the determined size and based on the determined position of the point primitive; and

means for generating a second sample bit mask the size of the pixel based on the first sample bit mask and based on the positional relationship between the pixel and the sub-pixel grid, the second sample bit mask indicating which sub-pixels within the pixel are to be illuminated on the electronic display to represent the point primitive.