| 摘要 |
PURPOSE:To realize texture mapping to a high-speed sphere by providing a circular arc generator to generate a lattice point to represent the circular arc of a radius (r), a u-axis mapper of a first sequence of points generator, and a v-axis mapper of a second sequence of points generator. CONSTITUTION:The circular arc generator 111 is used for drawing the circle of the radius (r) on a screen plane. The lattice point (x, y) to be drawn is supplied successively to the v-axis mapper 101, and the u-axis mapper 131 inputs the maximum value umax of the u-axis of a texture area, and samples a picture element on the u-axis by a function of second degree. Output data is the lattice point in the form of u, y, and this data too is supplied successively to the v-axis mapper. The v-axis mapper 101 inputs the maximum value vmax of v-axis of the texture area, and selects the data of the same value of the output (y) from among the outputs u, y of the u-axis mapper 131 and the outputs x, y of the circular arc generator 111, and generates successively the output value of the v-axis to be sampled on the basis of the outputs u, x and the maximum value vmax. |
