android动态壁纸---线条(5)

            drawLine(c, -400, -400,  400, -400, -400, -400);
            drawLine(c,  400, -400,  400,  400, -400, -400);
            drawLine(c,  400,  400,  400,  400,  400, -400);
            drawLine(c, -400,  400,  400, -400,  400, -400);
            c.restore();
        }
        /*
         * Draw a 3 dimensional line on to the screen
         */
        void drawLine(Canvas c, int x1, int y1, int z1, int x2, int y2, int z2) {
            long now = SystemClock.elapsedRealtime();
            float xrot = ((float)(now - mStartTime)) / 1000;
            float yrot = (0.5f - mOffset) * 2.0f;
            float zrot = 0;
            // 3D transformations
            // rotation around X-axis
            float newy1 = (float)(Math.sin(xrot) * z1 + Math.cos(xrot) * y1);
            float newy2 = (float)(Math.sin(xrot) * z2 + Math.cos(xrot) * y2);
            float newz1 = (float)(Math.cos(xrot) * z1 - Math.sin(xrot) * y1);
            float newz2 = (float)(Math.cos(xrot) * z2 - Math.sin(xrot) * y2);
            // rotation around Y-axis
            float newx1 = (float)(Math.sin(yrot) * newz1 + Math.cos(yrot) * x1);
            float newx2 = (float)(Math.sin(yrot) * newz2 + Math.cos(yrot) * x2);
            newz1 = (float)(Math.cos(yrot) * newz1 - Math.sin(yrot) * x1);
            newz2 = (float)(Math.cos(yrot) * newz2 - Math.sin(yrot) * x2);
            // 3D-to-2D projection
            float startX = newx1 / (4 - newz1 / 400);