Patent ID: 6977652

Claim:
A polygon rendering device comprising: a polygon division section for dividing, based on polygon data which specifies a polygon to be rendered, the polygon into a plurality of partial polygons such that at least one of the plurality of partial polygons has formed therein, from vertices thereof, a plurality of triangles which respectively share a vertex of the polygon; and a partial polygon rendering section for performing a rendering process and, without requiring, further division of any of the plurality of partial polygons, generating partial image data which represents an image of the at least one partial polygon from partial polygon data, wherein a plurality of partial image data represents an image of the polygon when combined, the polygon data includes n sets of vertex coordinates P 1 to Pn of the polygon in such an order that the polygon can be rendered in one stroke in a forward direction, and said polygon division section selects one of the vertex coordinates P 1 to Pn of the polygon data as a reference vertex Pb (b=1, 2, . . . , n), and in the forward direction, selects a vertex Pc positioned adjacent to the reference vertex Pb and a vertex P(c+1) positioned adjacent to the vertex Pc, and a triangle ΔPb Pc P(c+1) formed by the reference vertex Pb, and the vertexes Pc and P(c+1) carries, in and on, no other vertex Pi (i=1, 2, . . . , n, and i≠b, i≠c, i≠c+1) belonging to the polygon and not yet selected, and an angle ∠Pb Pc P(c+1) formed by the reference vertex Pb, and the vertexes Pc and P(c+1) is smaller than 180 degrees, selects, in addition to the reference vertex Pb and the vertex P(c+1), a vertex P(c+2) which is positioned adjacent to the vertex P(c+1) in the forward direction, and a triangle ΔPb P(c+1) P(c+2) formed by the reference vertex Pb, and the vertexes P(c+1) and P(c+2) carries no other vertex Pj (j=1, 2, . . . , n, and j≠b, j≠c, j≠c+1, j≠c+2) which belongs to the polygon and not yet selected, and an angle ΔPb P(c+1) P(c+2) formed by the reference vertex Pb, and the vertexes P(c+1) and P(c+2) is smaller than 180 degrees, and generates the partial polygon data specifying at least the partial polygon formed by the reference vertex Pb, and the vertexes Pc, P(c+1), and P(c+2).