Linear interpolation of triangles using digital differential analysis

An image processing method for generating pixel data based on information concerning a primitive to be drawn and simultaneously processing a plurality of pixels, the method comprising:

• receiving, at a set-up data storage circuit, information concerning the primitive;
• storing, at the set-up data storage circuit, the received information;
• judging, by the set-up data storage circuit, whether at least one pixel of the plurality of pixels is located inside the primitive;
• designating, by a large region movement circuit, a large region which includes a plurality of unit regions and which intersects the primitive;
• if at least one pixel of the plurality of pixels is judged to be located inside the primitive, transmitting the received information from the set-up data storage circuit to a pixel inside/outside judgment circuit;
• judging, by the pixel inside/outside judgment circuit, whether at least one pixel of plurality of pixels is located in the intersection of the large region and the primitive;
• if at least one pixel of the plurality of pixels is located in the intersection of the large region and the primitive, generating large region data which include data corresponding to the large region and data corresponding to one or more pixels of the plurality of pixels located in the intersection;
• storing the large region data;
• dividing, by a large region data division circuit, the large region data into a plurality of unit region data corresponding to the plurality of unit regions;
• outputting the plurality of unit region data to a texture engine circuit;
• processing, by the texture engine, different unit region data of the plurality of unit region data sequentially and not simultaneously, while processing pixels corresponding to each of the plurality of unit region data simultaneously;
• receiving, at a memory interface circuit, information based on the plurality of unit region data;
• and
• performing graphics drawing processing in parallel for a plurality of pixels located in a predetermined region of the primitive based on information based on the divided region data.

An image processing apparatus for generating pixel data based on information concerning a primitive to be drawn and simultaneously processing a plurality of pixels, the apparatus comprising:

• a digital differential analyzer (DDA) set-up circuit configured to calculate set-up data based in part on a difference from a pixel contained in the primitive to be drawn to edges of the primitive to be drawn;
• a triangle DDA circuit coupled to the DDA set-up circuit and for receiving the set-up data, the triangle DDA circuit comprising:
• a large region data generation circuit for receiving the set-up data and generating large region data, the large region data generation circuit comprising:
• a set-up data storage circuit for receiving the set-up data, storing the set-up data, and judging whether at least one pixel of the plurality of pixels is located inside the primitive;
• a large region movement circuit coupled to the set-up data storage circuit, the large region movement circuit for designating a large region which includes a plurality of unit regions and which intersects the primitive, and for outputting data indicating the large region to the set-up data storage circuit;
• and
• a pixel inside/outside judgment circuit coupled to the set-up data storage circuit, the pixel inside/outside judgment circuit, if at least one pixel of the plurality of pixels is located inside the primitive, for receiving set-up data and the data indicating the large region from set-up data storage circuit, judging whether at least one pixel of the plurality of pixels is located in the intersection of the large region and the primitive and, if at least one pixel of the plurality of pixels is located in the intersection of the large region and the primitive, for generating large region data which include data corresponding to the large region and data corresponding to one or more pixels of the plurality of pixels located in the intersection,
• wherein the large region movement circuit is also coupled to the pixel inside/outside judgment circuit and upon receiving information from the pixel inside/outside judgment circuit indicative that judging has been performed as to whether or not at least one pixel of the plurality of pixels is located in the intersection of the large region and the primitive, the large region movement circuit moves the large region to an adjacent large region intersecting the primitive and outputs data indicating the moved large region to the set-up data storage circuit;
• a large region data storage circuit coupled to the large region data generation circuit and for receiving the generated large region data for storage;
• a large region data division circuit coupled to the large region data storage circuit and for receiving the stored large region data, the large region data division circuit for dividing the received large region data into a plurality of unit region data corresponding to the plurality of unit regions;
• a texture engine circuit coupled to the triangle DDA circuit and for receiving the plurality of unit region data sequentially at a predetermined timing from the large region data division circuit, the texture engine circuit for generating the pixel data based on the plurality of unit region data, wherein the texture engine is for processing different unit region data of the plurality of unit region data sequentially and not simultaneously, while processing pixels corresponding to each of the plurality of unit region data simultaneously;
• and
• a memory interface circuit coupled to the texture engine circuit and for receiving the pixel data, the received pixel data being indicative of a color value of a pixel in the primitive to be drawn.