Method and apparatus for video graphics antialiasing

An apparatus for display antialiasing comprising:

• a sample memory, wherein the sample memory stores a plurality of pixel entries, wherein each pixel entry of the plurality of pixel entries includes a plurality of pixel samples;
• a frame buffer operably coupled to the sample memory, wherein the frame buffer stores a pixel array, wherein each element of the pixel array describes a pixel of the display, wherein
• when pixel data corresponding to a pixel of the pixel array can be reduced to a compressed sample set, the compressed sample set is stored in an element of the pixel array corresponding to the pixel, and
• when pixel data corresponding to the pixel requires more than the compressed sample set to describe the pixel, a pointer to a pixel entry of the sample memory is stored in the element of the pixel array, wherein the pixel data corresponding to the pixel is stored in the pixel entry;
• and
• a compressed sample block operably coupled to the frame buffer and the sample memory, wherein the compressed sample block determines whether pixel data sets can be summarized in compressed sample sets, and wherein the compressed sample block controls storage of pixel data in the frame buffer and the sample memory.

A method for antialiasing comprising:

• receiving a pixel fragment corresponding to a stored pixel in a pixel array, wherein the pixel fragment is characterized by pixel fragment data, and wherein the stored pixel is characterized by stored pixel data;
• merging the pixel fragment with the stored pixel to produce a resultant pixel, wherein the resultant pixel is characterized by resultant pixel data;
• storing the resultant pixel data, wherein storing includes:
• when the resultant pixel data can be described with a compressed sample set, storing the compressed sample set in the pixel array;
• when the resultant pixel data cannot be described with a compressed sample set:
• storing a sample set representing the resultant pixel data;
• and
• storing a pointer in the pixel array, wherein the pointer points to the sample set.

An antialiasing video graphics system, comprising:

• a frame buffer that stores a two-descriptor array, wherein each pixel of the video graphics system has a corresponding element in the two-descriptor array;
• a sample memory that stores a multi-sample array, wherein each element of the multi-sample array stores a predetermined number of samples;
• a next element counter, wherein the next element counter stores a next free element location of the multi-sample array;
• a stack, wherein the stack stores released locations corresponding to released multi-sample array entries;
• a controller operably coupled to the frame buffer, the sample memory, the next element counter and the stack, wherein the controller includes instructions, wherein when the instructions are executed by the controller, the controller performs the steps of:
• receiving a pixel fragment that corresponds to a pixel of the video graphics system;
• merging the pixel fragment with pixel data corresponding to the pixel to produce a resultant pixel, wherein the resultant pixel is characterized by resultant pixel data;
• and
• storing the resultant pixel data, wherein storing includes:
• when the resultant pixel data can be described with a two-descriptor data set, storing the two-descriptor data set in the frame buffer in the element of the two-descriptor array corresponding to the pixel;
• and
• when the resultant pixel data requires a multi-sample data set:
• determining if a stack contains a released entry;
• when the stack contains the released entry, popping the released entry from the stack for use as a sample memory element address;
• when the stack does not contain the released entry, retrieving the sample memory element address from the next element counter,
• storing the multi-sample data at the sample memory element address in the sample memory;
• and
• storing a pointer in the frame buffer in the element of the two-descriptor array corresponding to the pixel, wherein the pointer points to the multi-sample data set.