| 摘要 |
A method and an apparatus for forming a scan line are provided to divide a triangle of a first type into two parts, split data required to form a scan line into two signals and respectively output the split data signals through two output operations in order to reduce the width of FIFO(First Input First Output). The type of a triangle having first, second and third vertexes is judged(701). Bottom to middle left side, bottom to middle right side, middle to bottom left side, and middle to bottom right side of the triangle are determined according to the type of the triangle(703,705). Parameters at a first point which is located on the bottom to middle left side and has y coordinates of y1 and a third point which is located on the middle to bottom left side and has y coordinates of y2 are calculated(707). Step values on the bottom to middle left side and the middle to bottom left side are calculated(709). Parameters at a second point which is located on the bottom to middle right side and has y coordinates of y1 and a fourth point which is located on the middle to bottom right side and has y coordinates of y2 are calculated(711). Step values on the bottom to middle right side and the middle to bottom right side are calculated(713). When the triangle is a first type, data of a triangle having the first and second vertexes and a fourth vertex is stored in FIFO(717). The fourth vertex has the same y coordinates as the second vertex and is located on a side of the triangle. Data of a triangle having the second vertex, the fourth vertex and the third vertex is stored in the FIFO(719). |
