Right Parabolic Cylinder

Collaboration diagram for Right Parabolic Cylinder:

Files
file	rpc.h

Data Structures
struct	rt_rpc_internal

Macros
#define	RT_RPC_CK_MAGIC(_p)   BU_CKMAG(_p, RT_RPC_INTERNAL_MAGIC, "rt_rpc_internal")

Functions
int	rt_mk_parabola (struct rt_pnt_node *pts, fastf_t r, fastf_t b, fastf_t dtol, fastf_t ntol, fastf_t min_abs)
DEPRECATED int	rt_mk_parabola_old (struct rt_pnt_node *pts, fastf_t r, fastf_t b, fastf_t dtol, fastf_t ntol)

Detailed Description

Macro Definition Documentation

RT_RPC_CK_MAGIC

#define RT_RPC_CK_MAGIC

(

_p

)

BU_CKMAG(_p, RT_RPC_INTERNAL_MAGIC, "rt_rpc_internal")

Definition at line 477 of file geom.h.

Function Documentation

rt_mk_parabola()

int rt_mk_parabola ( struct rt_pnt_node *  pts, fastf_t  r, fastf_t  b, fastf_t  dtol, fastf_t  ntol, fastf_t  min_abs  )

extern

Approximate a parabola with line segments.

Parameters

pts	Linked list of points; must have at least two nodes on entry.
r	Rectangular half-width of the parabola.
b	Breadth (half-height) of the parabola.
dtol	Maximum allowable chord-to-curve distance (mm).
ntol	Maximum allowable normal-deviation angle (radians); pass M_PI to ignore normal tolerance.
min_abs	Minimum absolute span (mm) below which subdivision stops, preventing runaway recursion from extremely tight tolerances.

Recommended min_abs values:

• 0.05 is a conservative default suitable for most CAD geometry. A full circle at this dtol requires ~300 segments; finer values rarely produce visible improvement on typical display hardware.
• 0.005 produces noticeably smoother curves on very small features but can multiply polygon counts by 10x or more.
• Values below dtol have no additional effect until dtol itself pushes subdivision to segments shorter than min_abs.
• SMALL_FASTF (~1e-37) disables the floor entirely, matching the deprecated rt_mk_parabola_old() behavior; use only when the geometry is known to be free of degenerate cases that could trigger unbounded recursion.

Returns

Number of additional points inserted into pts.

rt_mk_parabola_old()

DEPRECATED int rt_mk_parabola_old ( struct rt_pnt_node *  pts, fastf_t  r, fastf_t  b, fastf_t  dtol, fastf_t  ntol  )

extern

Deprecated:

use rt_mk_parabola() with an explicit min_abs argument. Preserves the original behavior of trusting the caller's tolerances unconditionally (equivalent to min_abs = SMALL_FASTF).