Method, apparatus, and system for rendering using a progressive cache

1. A method for rendering, comprising:

defining a rendering request, the rendering request describing an object to be rendered in a single rendering pipeline including a set of stages connected serially to each other as a sequence of stages so that output of a previous stage provides input to a next stage, the sequence of stages including, in order, a preprocessed shape descriptor determination stage, a distance field determination stage, a distance values determination stage, an antialiased intensities determination stage, and a colorized image determination stage, and where the distance field determination stage determines a distance from a point in a co-planar field to an edge of the object, where the sign of the distance is negative if the point is outside the object, positive if the point is inside the object, and points on the edge having a zero distance;

querying a progressive cache to determine a most finished cached element representing a display image satisfying the rendering request, the progressive cache including a set of caches, the set of caches including a preprocessed shape descriptor cache, a distance field cache, a distance values cache, an antialiased intensities cache, and a colorized image cache, each cache in the set of caches arranged to store cached elements in a least finished to a most finished order, there being one cache associated with each stage;

sending the most finished cached element to a starting stage of a rendering pipeline for the object, the starting stage being a next stage of the rendering pipeline corresponding to the most finished cached element; and

sending an output of the starting stage to an input of a next stage of the rendering pipeline, a final stage of the rendering pipeline determining the display image satisfying the rendering request;

and displaying the display image satisfying the rendering request.

2. The method of claim 1 wherein an output of a stage of the rendering pipeline is sent to the progressive cache.

3. The method of claim 1 wherein distance values for a component of a pixel of the display image are stored in the distance values cache.

4. The method of claim 3 wherein the distance values for the component of the pixel of the display image are combined prior to determining an antialiased intensity for the component of the pixel.

5. The method of claim 1 further comprising:

compressing data stored in a particular cache in the set of caches.

6. The method of claim 1 wherein the progressive cache finds a cache element using hashing.

7. The method of claim 1 wherein the progressive cache eliminates least recently used cached elements from a particular cache in the set of caches when the particular cache is full.

8. The method of claim 1 wherein a particular stage in the sequence of stages processes the rendering request.

9. The method of claim 1 wherein the staffing stage associated with the cached element is a next stage of a corresponding stage of a cache of the progressive cache containing the cached element.

10. A system for rendering, comprising:

a rendering pipeline including a set of stages connected serially to each other as a sequence of stages so that output of a previous stage provides input to a next stage, a first stage is configured to receive a rendering request for an object, a last stage is configured to produce a display image corresponding to the object, and the sequence of stages includes, in order, a preprocessed shape descriptor determination stage, a distance field determination stage, a distance values determination stage, an antialiased intensities determination stage, and a colorized image determination stage, and where the distance field determination stage determines a distance from a point in a co-planar field to an edge of the object, where the sign of the distance is negative if the point is outside the object, positive if the point is inside the object, and points on the edge having a zero distance;

a progressive cache including a set of caches arranged to store cached elements in a least finished to a most finished order, the set of caches including a preprocessed shape descriptor cache, a distance field cache, a distance values cache, an antialiased intensities cache, and a colorized image cache; and

a cache controller configured to route a most finished cached element from the progressive cache to a next stage of a corresponding stage of the rendering pipeline and the output of a stage of the rendering pipeline to a corresponding cache of the progressive cache;

means for querying a progressive cache to determine a cached element most representing a display image satisfying a rendering request for an object;

means for sending the cached element to a starting stage of a rendering pipeline for the object, the starting stage associated with the cached element; and

means for sending an output of the starting stage to an input of a next stage of the rendering pipeline, a final stage of the rendering pipeline determining the display image satisfying the rendering request.