pfCircle2d(3pf) OpenGL Performer 3.2.2 libpf C Reference Pages
NAME
pfGetCircle2dClassType, pfNewCircle2d, pfCircle2dRadius,
pfGetCircle2dRadius, pfCircle2dEvalPt, pfCircle2dEvalTan,
pfCircle2dEvalCurv, pfCircle2dEvalNorm, pfCircle2dEvalAll - A two-
dimensional parametric circle
FUNCTION SPECIFICATION
#include <Performer/pf.h>
pfType * pfGetCircle2dClassType(void);
pfCircle2d * pfNewCircle2d(void *arena);
void pfCircle2dRadius(pfCircle2d *circle, pfReal radius);
pfReal pfGetCircle2dRadius(pfCircle2d *circle);
void pfCircle2dEvalPt(pfCircle2d *circle, pfReal u, pfReal v,
pfVec2 &pnt);
void pfCircle2dEvalTan(pfCircle2d *circle, pfReal u, pfReal v,
pfVec2 &tan);
void pfCircle2dEvalCurv(pfCircle2d *circle, pfReal u, pfReal v,
pfReal *curv);
void pfCircle2dEvalNorm(pfCircle2d *circle, pfReal u, pfReal v,
pfVec2 &norm);
void pfCircle2dEvalAll(pfCircle2d *circle, pfVec2 &pnt,
pfVec2 &tan, pfReal *curv, pfVec2 &norm);
PARENT CLASS FUNCTIONS
The OpenGL Performer class pfCircle2d is derived from the parent class
pfCurve2d, so each of these member functions of class pfCurve2d are also
directly usable with objects of class pfCircle2d. Casting an object of
class pfCircle2d to an object of class pfCurve2d is taken care of
automatically. This is also true for casts to objects of ancestor
classes of class pfCurve2d.
void pfCurve2dBeginT(pfCurve2d *curve, pfReal t);
void pfCurve2dEndT(pfCurve2d *curve, pfReal t);
pfReal pfGetCurve2dBeginT(pfCurve2d *curve);
pfReal pfGetCurve2dEndT(pfCurve2d *curve);
void pfCurve2dSetClosed(pfCurve2d *curve, pfLoop loopVal);
pfLoop pfGetCurve2dClosed(pfCurve2d *curve);
void pfCurve2dClosedTol(pfCurve2d *curve, pfReal tol);
pfReal pfGetCurve2dClosedTol(pfCurve2d *curve);
void pfCurve2dEvalPt(pfCurve2d *curve, pfReal t, pfVec2 &pt);
void pfCurve2dEvalTan(pfCurve2d *curve, pfReal t, pfVec2 &pt);
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pfCircle2d(3pf) OpenGL Performer 3.2.2 libpf C Reference Pages
void pfCurve2dEvalNorm(pfCurve2d *curve, pfReal t, pfVec2 &pt);
void pfCurve2dEvalCurv(pfCurve2d *curve, pfReal *curv);
void pfCurve2dEvalAll(pfCurve2d *curve, pfReal t, pfVec2 &pt,
pfVec2 &tan, pfReal *curv, pfVec2 norm);
Since the class pfCurve2d is itself derived from the parent class pfRep,
objects of class pfCircle2d can also be used with these functions
designed for objects of class pfRep.
void pfRepOrigin(pfRep *rep, const pfVec3 origin);
void pfRepOrient(pfRep *rep, const pfMatrix mat);
void pfGetRepOrigin(pfRep *rep, pfVec3* origin);
void pfGetRepOrient(pfRep *rep, pfMatrix *mat);
Since the class pfRep is itself derived from the parent class pfGeode,
objects of class pfCircle2d can also be used with these functions
designed for objects of class pfGeode.
int pfAddGSet(pfGeode* geode, pfGeoSet* gset);
int pfRemoveGSet(pfGeode* geode, pfGeoSet* gset);
int pfInsertGSet(pfGeode* geode, int index, pfGeoSet* gset);
int pfReplaceGSet(pfGeode* geode, pfGeoSet* old, pfGeoSet* new);
pfGeoSet * pfGetGSet(const pfGeode* geode, int index);
int pfGetNumGSets(const pfGeode* geode);
Since the class pfGeode is itself derived from the parent class pfNode,
objects of class pfCircle2d can also be used with these functions
designed for objects of class pfNode.
pfGroup * pfGetParent(const pfNode *node, int i);
int pfGetNumParents(const pfNode *node);
void pfNodeBSphere(pfNode *node, pfSphere *bsph, int mode);
int pfGetNodeBSphere(pfNode *node, pfSphere *bsph);
pfNode* pfClone(pfNode *node, int mode);
pfNode* pfBufferClone(pfNode *node, int mode, pfBuffer *buf);
int pfFlatten(pfNode *node, int mode);
int pfNodeName(pfNode *node, const char *name);
const char * pfGetNodeName(const pfNode *node);
pfNode* pfFindNode(pfNode *node, const char *pathName,
pfType *type);
pfNode* pfLookupNode(const char *name, pfType* type);
int pfNodeIsectSegs(pfNode *node, pfSegSet *segSet,
pfHit **hits[]);
void pfNodeTravMask(pfNode *node, int which, uint mask,
int setMode, int bitOp);
uint pfGetNodeTravMask(const pfNode *node, int which);
void pfNodeTravFuncs(pfNode* node, int which,
pfNodeTravFuncType pre, pfNodeTravFuncType post);
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pfCircle2d(3pf) OpenGL Performer 3.2.2 libpf C Reference Pages
void pfGetNodeTravFuncs(const pfNode* node, int which,
pfNodeTravFuncType *pre, pfNodeTravFuncType *post);
void pfNodeTravData(pfNode *node, int which, void *data);
void * pfGetNodeTravData(const pfNode *node, int which);
void pfNodeTravMode(pfNode* node, int which, int mode,
int val);
int pfGetNodeTravMode(const pfNode* node, int which,
int mode);
Since the class pfNode is itself derived from the parent class pfObject,
objects of class pfCircle2d can also be used with these functions
designed for objects of class pfObject.
void pfUserDataSlot(pfObject *obj, int slot, void *data);
void pfUserData(pfObject *obj, void *data);
void* pfGetUserDataSlot(pfObject *obj, int slot);
void* pfGetUserData(pfObject *obj);
int pfGetNumUserData(pfObject *obj);
int pfGetNamedUserDataSlot(const char *name);
const char* pfGetUserDataSlotName(int slot);
int pfGetNumNamedUserDataSlots(void);
int pfDeleteGLHandle(pfObject *obj);
Since the class pfObject is itself derived from the parent class
pfMemory, objects of class pfCircle2d can also be used with these
functions designed for objects of class pfMemory.
pfType * pfGetType(const void *ptr);
int pfIsOfType(const void *ptr, pfType *type);
int pfIsExactType(const void *ptr, pfType *type);
const char * pfGetTypeName(const void *ptr);
int pfRef(void *ptr);
int pfUnref(void *ptr);
int pfUnrefDelete(void *ptr);
int pfUnrefGetRef(void *ptr);
int pfGetRef(const void *ptr);
int pfCopy(void *dst, void *src);
int pfDelete(void *ptr);
int pfIsFluxed(void *ptr);
int pfCompare(const void *ptr1, const void *ptr2);
void pfPrint(const void *ptr, uint which, uint verbose,
FILE *file);
void * pfGetArena(void *ptr);
DESCRIPTION
pfCircle2d defines a two dimensional circle parametrized on t:
u(t) = radius * cos(t);
v(t) = radius * sin(t);
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pfCircle2d(3pf) OpenGL Performer 3.2.2 libpf C Reference Pages
The default domain is [0, 2*pi].
The circle is subject to rotation and translation by the matrix
orientation and vector origin, which are members of the super class
pfRep. If orientation isn't set, evalTan, evalNorm and evalCurv are
functionally calculated. The normal is the vector from the origin to the
poiint on the circle. When orientation is set, evalTan, evalCurv are
calculated by finite difference method which is subject to numerical
errors. The normal could be reversed depending on the direction of the
circle.
pfGetCircle2dClassType returns the pfType* for the class pfCircle2d. The
pfType* returned by pfGetCircle2dClassType is the same as the pfType*
returned by invoking pfGetType on any instance of class pfCircle2d.
Because OpenGL Performer allows subclassing of built-in types, when
decisions are made based on the type of an object, it is usually better
to use pfIsOfType to test if an object is of a type derived from a
Performer type rather than to test for strict equality of the pfType*'s.
pfNewCircle2d creates an instance of an pfCircle2d with radius set to 1.
By default the parametric domain is defined as [0, 2*pi].
pfCircle2dRadius sets the radius of the circle to radius.
pfGetCircle2dRadius returns the value of the circle's radius.
pfCircle2dEvalPt Computes the point on the circle. The result is put in
pnt. Notice that there is a translation by origin, which is the member of
the superclass pfRep.
pfCircle2dEvalTan Computes the derivatives (-r*sin(t), r*cos(t)) and puts
the result in tan.
pfCircle2dEvalCurv Computes the curvature and stores it in curv. The
curvature is the inverse of the radius and is cached as a member
curvature. If the orientation matrix is set, it is calculated by finite
difference method.
pfCircle2dEvalNorm Computes the principal normal of the circle and stores
it in norm.
pfCircle2dEvalAll Evaluates the point, tangent, curvature and normal.
SEE ALSO
pfRep, pfGeode, pfCurve2d
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