| 摘要 |
A computer method draws overlapped two-dimensional shapes and two-dimensional projections of three-dimensional shapes onto a projection plane in a system of world coordinates X,Y,Z. The method instantiates a plurality of two-dimensional geometry class objects, each of which includes an order attribute specifying an overlapped position for depicting a corresponding two-dimensional shape on a projection plane positioned orthogonally to the Z coordinate of the world coordinate system. The method instantiates a three-dimensional geometry class object including a Z-value for a position along the Z world coordinate of the three-dimensional shape. The method sorts the plurality of two-dimensional geometry class objects by their respective order attributes in a sorting table in the memory. The method sorts the three-dimensional geometry class object by its Z-value in the sorting table and orders it in a composite order with the two-dimensional class objects in the sorting table. The method then draws the two-dimensional shapes and two-dimensional projections of the three-dimensional shapes onto the projection plane in the composite order of the sorting table, to depict an overlapped appearance of the shapes. |
