Glyph-mask render buffer

Patent metadata

Field	Value
Publication number	US-10186237-B2
Application number	US-201715612756-A
Country	US
Kind code	B2
Filing date	Jun 2, 2017
Priority date	Jun 2, 2017
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

Systems, methods, and computer readable media to improve the operation of a computer's display system are described. In general, techniques are disclosed for retaining glyph-mask information for text associated with a region that may be arbitrarily moved across a screen. More particularly, techniques disclosed herein utilize an additional off-screen buffer referred to as the glyph-mask buffer. The glyph-mask buffer coincides with an existing side buffer in extent, but is used only to retain anti-aliased glyph information (i.e., glyph-masks). When the side buffer's content is updated, the effect of that update on the region's text may be reflected in an update to the glyph-mask buffer. At display time, the region corresponding to the side buffer, and the text therein, may be properly rendered at any screen location by combining the screen's target display area (background), the side buffer and the glyph-mask buffer.

First claim

The invention claimed is:

1. A method for displaying content on a display unit, comprising:
storing, in a first memory, first information for display on a display unit, the display unit having a full display area, the first memory corresponding to a first region of the full display area, the first region corresponding to less than all of the display unit's full display area, wherein the first information includes color and transparency content;
storing, in a second memory, glyph-mask information of the first information, the second memory having a size equal to the first memory;
detecting a change in location of the first region to a second region of the full display area, the second region having second information;
updating the first information in the first memory to new information based on the first information, the second information and the glyph-mask information; and
updating the glyph-mask information in the second memory by—
removing the glyph-mask information from the second memory when the glyph-mask information corresponds to opaque new information in the first memory, and
blending the glyph-mask information in the second memory with the new information when the glyph-mask information corresponds to translucent new information in the first memory.

2. The method of claim 1 , wherein updating the second information in the second memory further comprises retaining the glyph-mask information in the second memory when the glyph-mask information corresponds to transparent new information in the first memory.

3. The method of claim 1 , wherein storing first information in a first memory further comprises determining the first information includes anti-aliased text information.

4. The method of claim 3 , wherein the glyph-mask information comprises the anti-aliased text information.

5. The method of claim 1 , wherein updating the first information comprises blending the first information's color and transparency content with color and transparency information of the second information.

6. The method of claim 1 , wherein the first and second memory comprise memory not directly displayed on the display unit.

7. The method of claim 6 , wherein the first and second memory comprise backing memory of a display system's compositing engine.

8. A non-transitory program storage device comprising instructions stored thereon to cause one or more processors to:
store, in a first memory, first information for display on a display unit, the display unit having a full display area, the first memory corresponding to a first region of the full display area and less than all of the display unit's full display area, wherein the first information includes color and transparency content;
store, in a second memory, glyph-mask information of the first information, the second memory having a size equal to the first memory;
detect a change in location of the first region to a second region of the full display area, the second region having second information;
update the first information in the first memory to new information based on the first information, the second information and the glyph-mask information;
remove the glyph-mask information from the second memory when the glyph-mask information corresponds to opaque new information in the first memory; and
blend the glyph-mask information in the second memory with the new information when the glyph-mask information corresponds to translucent new information in the first memory.

9. The non-transitory program storage device of claim 8 , wherein further comprising instructions to retain the glyph-mask information in the second memory when the glyph-mask information corresponds to transparent new information in the first memory.

10. The non-transitory program storage device of claim 8 , wherein the instructions to store first information in a first memory further comprise instructions to determine the first information includes anti-aliased text information.

11. The non-transitory program storage device of claim 10 , wherein the glyph-mask information comprises the anti-aliased text information.

12. The non-transitory program storage device of claim 8 , wherein the instructions to update the first information comprise instructions to blend the first information's color and transparency content with color and transparency information of the second information.

13. The non-transitory program storage device of claim 8 , wherein the first and second memory comprise memory not directly displayed on the display unit.

14. The non-transitory program storage device of claim 13 , wherein the first and second memory comprise backing memory of a display system's compositing engine.

15. A system comprising:
a display unit having a full display area;
memory operatively coupled to the display unit;
a compositing engine coupled to the memory; and
one or more processors operatively coupled to the display unit, the memory, and the compositing engine, the one or more processors configured to execute instructions stored in the memory to cause the system to—
store, by the compositing engine in a first buffer in the memory, first information for display on the display unit, the first buffer corresponding to a first region of the full display area and less than all of the display unit's full display area, wherein the first information includes color and transparency content,
store, by the compositing engine in a second buffer in the memory, glyph-mask information of the first information, the second buffer having a size equal to the first buffer,
detect a change in location of the first region to a second region of the full display area, the second region having second information,
update, by the compositing engine, the first information in the first buffer to new information based on the first information, the second information and the glyph-mask information,
remove, by the compositing engine, the glyph-mask information from the second buffer when the glyph-mask information corresponds to opaque new information in the first buffer, and
replace, by the compositing engine, the glyph-mask information in the second buffer with a blend of the new information and the glyph-mask information when the glyph-mask information corresponds to translucent new information in the first buffer.

16. The system of claim 15 , wherein the instructions further comprise instructions to retain the glyph-mask information in the second buffer when the glyph-mask information corresponds to transparent new information in the first buffer.

17. The system of claim 15 , wherein the instructions to store first information in a first buffer further comprise instructions to determine the first information includes anti-aliased text information.

18. The system of claim 17 , wherein the glyph-mask information comprises the anti-aliased text information.

19. The system of claim 15 , wherein the instructions to update the first information comprise instructions to blend the first information's color and transparency content with color and transparency information of the second information.

20. The system of claim 15 , wherein the first and second buffers comprise memory not directly displayed on the display unit.

21. The system of claim 20 , wherein the first and second buffers comprise backing memory of the compositing engine, wherein the compositing engine is provided by an operating system.

Assignees

• Apple Inc

Inventors

• Ciechanowski Bartosz

Classifications

• G09G5/32

  with means for controlling the display position {(see provisionally G09G5/42)} · CPC title

• G09G5/393

  Arrangements for updating the contents of the bit-mapped memory · CPC title

• G09G5/28

  for enhancement of character form, e.g. smoothing · CPC title

• G09G5/397 Primary

  Arrangements specially adapted for transferring the contents of two or more bit-mapped memories to the screen simultaneously, e.g. for mixing or overlay (G09G5/02 takes precedence) · CPC title

• G09G5/377

  for mixing or overlaying two or more graphic patterns (G09G5/02, G09G5/397 take precedence) · CPC title