Display Methods on Triang1d

 

   GRAPE(triang1d, "display")()

TRIANG1D *triang1d

The instance tr is rendered on the standard device in a default manner. In fact "display" is an interactive interface for "pipe" (see below).

   GRAPE(triang1d, "pipe")(top, shape, tail, scal, diskr, eps)

TRIANG1D *triang
void (*top)(arg,x,y)
/* function describing the top, arg between 0 and 1 */
void (*tail)(arg,x,y)
/* describing the end, arg between 0 and 1 */
void (*shape)(arg,x,y)
/* function describing cross-section, arg between -pi/2 and pi/2 */
double scal
/* factor for scaling */
int diskr
/* parameter for discretization */
double eps
/* parameter to change between the */
/* calculation with the Frenet frame */
/* or a simpler one */

A pipe around a Triang1d instance is constructed and displayed on the standard device. The shape of the spike, the end and the appearance of a cross-section of the pipe can be specified by function descriptions. Default functions for top, tail and shape are function descriptions of an arrow, an ellipse and a ball (arrow, ellipse, ball). The function description of a ball is used if one of the function variable is a NULL pointer.

The number of polygons which are put together to build the pipe can be varied with the parameter diskr. The size of the cross-section can be manipulated with scal. With a small value eps (default) the calculation of the pipe is made with the Frenet frame. A very small value of the second derivative of the curve determined through the polygon causes problems in the calculation of the pipe. Therefore the possibility to work not with the Frenet frame is given through the variable eps representing a lower bound for the second derivative.

   GRAPE(triang1d, "tube-disp")()

TRIANG1D * triang1d

The instance triang1d is rendered on the standard device in a default manner. "tube-disp" calls g_draw_tube (which is a faster and less flexible version of "pipe") to draw a tube around the Triang1d instance.

       

GRAPE(triang1d, "points-disp")()

GRAPE(triang1d, "points")(radius)

TRIANG1D *triang1d
double radius

The Triang1d instance is rendered as a cloud of points. The ball radius is controlled by a ruler which is added to the manager by the interactive method "points-disp".