Method of rendering graphical objects

• US 20050206653A1
• Filed: 03/04/2005
• Published: 09/22/2005
• Est. Priority Date: 03/16/2004
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Beaumont, Ian Richard
• Granted Patent: US 7,277,095 B2
• Time in Patent Office: Days
• US Class Current: 345/629
• CPC Class Codes: G06T 11/40 Filling a planar surface by adding surface attributes, e.g. colour or texture

Abstract

A method (900) of combining a plurality of objects is disclosed. The method (900) efficiently combines a set of contiguous graphical objects to generate a high level compiled object representing the combination of the contiguous objects. The method (900) may be used to combine such contiguous objects even if the objects have different fill types. The method (900) outputs the compiled object to a display list. The compiled object has an associated meta-fill (835). The meta-fill (835) is a compound fill, which may be used to describe a collection of fills associated with the compiled object.

Claims

1. A method of rendering a plurality of graphical objects, each of said graphical objects comprising a predetermined object outline, a predetermined z-order, and an associated fill, the object outline for a particular object defining an area in which said particular object is filled, said method comprising the steps of:

combining each of said objects to form a grouped object, said grouped object comprising a grouped object outline and an associated compound fill, said compound fill comprising one or more fill data structures representing the fills associated with said graphical objects; and

rendering said grouped object according to said grouped object outline, wherein one or more fills used to render said grouped object are determined according to said compound fill.

2. A method according to claim 1, wherein said grouped object outline follows one or more of said predetermined object outlines or parts thereof.

3. A method according to claim 1, wherein said objects are consecutive in z-order and said grouped object is assigned the lowest z-order among said objects.

4. A method according to claim 1, further comprising the step of determining if said objects satisfy predetermined criteria.

5. A method according to claim 1, wherein one or more graphical objects that have the same single coloured fills are represented as one or more single coloured fills in said compound fill.

6. A method according to claim 1, wherein one or more graphical objects that have a linear colour change are represented as one or more linear blend fills in said compound fill.

7. A method according to claim 4, wherein one of said predetermined criteria is that each of said objects has two parallel sides.

8. A method according to claim 7, wherein one of said predetermined criteria is that each of said parallel sides has the same angle of orientation.

9. A method according to claim 8, wherein one of said predetermined criteria is that each of said objects (i) overlap or (ii) abut over the whole length of said parallel sides.

10. A method according to claim 1, further comprising the step of storing lengths of pixel runs in said compound fill.

11. A method according to claim 1, wherein said fills are represented in said compound fill as a linked list of fill data structures that describe said fills.

12. A method according to claim 11, further comprising the step of storing a pointer to a first fill in said data structure.

13. A method according to claim 1, wherein each of said fills are flat fills.

14. A method according to claim 1, wherein the object outline for each of said graphical objects comprises one or more edges.

15. A method according to claim 1, wherein the object outline is a path.

16. A method according to claim 1, wherein the object outline is a polygon defined by a plurality of points.

20. A method according to claim 1, further comprising the step of storing a tracking point in said compound fill.

17. A compound fill for rendering a graphical object, said graphical object comprising a predetermined object outline and said compound fill, the predetermined object outline defining an area in which said graphical object is filled, wherein said compound fill is configured as a data structure containing a plurality of fills, said fills defining a manner in which said graphic object is to be filled upon rendering.

18. A compound fill according to claim 18, wherein said graphical object is formed from a plurality of graphical objects.

19. A compound fill according to claim 18, wherein said data structure is a linked list.

21. A method according to claim 21, wherein said tracking point is used to determine a current fill within said compound fill for rendering said grouped object.

22. An apparatus for rendering a plurality of graphical objects, each of said graphical objects comprising a predetermined object outline, a predetermined z-order, and an associated fill, the object outline for a particular object defining an area in which said particular object is filled, said apparatus comprising:

combining means for combining each of said objects to form a grouped object, said grouped object comprising a grouped object outline and an associated compound fill, said compound fill comprising one or more fill data structures representing the fills associated with said graphical objects; and

rendering means for rendering said grouped object according to said grouped object outline, wherein one or more fills used to render said grouped object are determined according to said compound fill.

23. A computer program for rendering a plurality of graphical objects, each of said graphical objects comprising a predetermined object outline, a predetermined z-order, and an associated fill, the object outline for a particular object defining an area in which said particular object is filled, said program comprising:

code for combining each of said objects to form a grouped object, said grouped object comprising a grouped object outline and an associated compound fill, said compound fill comprising one or more fill data structures representing the fills associated with said graphical objects; and

code for rendering said grouped object according to said grouped object outline, wherein one or more fills used to render said grouped object are determined according to said compound fill.

24. A computer program product including a computer readable medium having recorded thereon a computer program for rendering a plurality of graphical objects, each of said graphical objects comprising a predetermined object outline, a predetermined z-order, and an associated fill, the object outline for a particular object defining an area in which said particular object is filled, said program comprising:

code for combining each of said objects to form a grouped object, said grouped object comprising a grouped object outline and an associated compound fill, said compound fill comprising one or more fill data structures representing the fills associated with said graphical objects; and

code for rendering said grouped object according to said grouped object outline, wherein one or more fills used to render said grouped object are determined according to said compound fill.