Library Functions Manual

NAME¶

SoNurbsCurve - The SoNurbsCurve class is a node for representing smooth curves.

SYNOPSIS¶

#include <Inventor/nodes/SoNurbsCurve.h>

Inherits SoShape.

Public Member Functions¶

virtual SoType getTypeId (void) const
SoNurbsCurve (void)
virtual void GLRender (SoGLRenderAction *action)
virtual void rayPick (SoRayPickAction *action)
virtual void getPrimitiveCount (SoGetPrimitiveCountAction *action)
virtual void getBoundingBox (SoGetBoundingBoxAction *action)
void sendPrimitive (SoAction *, SoPrimitiveVertex *)

Public Member Functions inherited from SoShape
virtual SbBool affectsState (void) const
virtual void notify (SoNotList *nl)
virtual void callback (SoCallbackAction *action)
const SoBoundingBoxCache * getBoundingBoxCache (void) const

Public Member Functions inherited from SoNode
void setOverride (const SbBool state)
SbBool isOverride (void) const
void setNodeType (const NodeType type)
NodeType getNodeType (void) const
virtual SoNode * copy (SbBool copyconnections=FALSE) const
virtual void doAction (SoAction *action)
virtual void GLRenderBelowPath (SoGLRenderAction *action)
virtual void GLRenderInPath (SoGLRenderAction *action)
virtual void GLRenderOffPath (SoGLRenderAction *action)
virtual void getMatrix (SoGetMatrixAction *action)
virtual void handleEvent (SoHandleEventAction *action)
virtual void pick (SoPickAction *action)
virtual void search (SoSearchAction *action)
virtual void write (SoWriteAction *action)
virtual void audioRender (SoAudioRenderAction *action)
virtual void grabEventsSetup (void)
virtual void grabEventsCleanup (void)
virtual void startNotify (void)
uint32_t getNodeId (void) const
virtual SoChildList * getChildren (void) const
virtual void writeInstance (SoOutput *out)
virtual SoNode * addToCopyDict (void) const
virtual void copyContents (const SoFieldContainer *from, SbBool copyconnections)
virtual SoFieldContainer * copyThroughConnection (void) const

Public Member Functions inherited from SoFieldContainer
void setToDefaults (void)
SbBool hasDefaultValues (void) const
SbBool fieldsAreEqual (const SoFieldContainer *container) const
void copyFieldValues (const SoFieldContainer *container, SbBool copyconnections=FALSE)
SbBool set (const char *const fielddata)
void get (SbString &fielddata)
virtual int getFields (SoFieldList &l) const
virtual int getAllFields (SoFieldList &l) const
virtual SoField * getField (const SbName &name) const
virtual SoField * getEventIn (const SbName &name) const
virtual SoField * getEventOut (const SbName &name) const
SbBool getFieldName (const SoField *const field, SbName &name) const
SbBool enableNotify (const SbBool flag)
SbBool isNotifyEnabled (void) const
SbBool set (const char *fielddata, SoInput *input)
void get (SbString &fielddata, SoOutput *out)
virtual SbBool validateNewFieldValue (SoField *field, void *newval)
virtual void addWriteReference (SoOutput *out, SbBool isfromfield=FALSE)
SbBool getIsBuiltIn (void) const
virtual void getFieldsMemorySize (size_t &managed, size_t &unmanaged) const
void setUserData (void *userdata) const
void * getUserData (void) const

Public Member Functions inherited from SoBase
void ref (void) const
void unref (void) const
void unrefNoDelete (void) const
int32_t getRefCount (void) const
void touch (void)
SbBool isOfType (SoType type) const
virtual SbName getName (void) const
virtual void setName (const SbName &newname)
void addAuditor (void *const auditor, const SoNotRec::Type type)
void removeAuditor (void *const auditor, const SoNotRec::Type type)
const SoAuditorList & getAuditors (void) const
SbBool shouldWrite (void)
void assertAlive (void) const

Static Public Member Functions¶

static SoType getClassTypeId (void)
static void initClass (void)

Static Public Member Functions inherited from SoShape
static SoType getClassTypeId (void)
static void initClass (void)
static void getScreenSize (SoState *const state, const SbBox3f &boundingbox, SbVec2s &rectsize)
static float getDecimatedComplexity (SoState *state, float complexity)

Static Public Member Functions inherited from SoNode
static uint32_t getCompatibilityTypes (const SoType &nodetype)
static SoType getClassTypeId (void)
static SoNode * getByName (const SbName &name)
static int getByName (const SbName &name, SoNodeList &l)
static void initClass (void)
static void initClasses (void)
static uint32_t getNextNodeId (void)
static int getActionMethodIndex (const SoType type)
static void getBoundingBoxS (SoAction *action, SoNode *node)
static void GLRenderS (SoAction *action, SoNode *node)
static void callbackS (SoAction *action, SoNode *node)
static void getMatrixS (SoAction *action, SoNode *node)
static void handleEventS (SoAction *action, SoNode *node)
static void pickS (SoAction *action, SoNode *node)
static void rayPickS (SoAction *action, SoNode *node)
static void searchS (SoAction *action, SoNode *node)
static void writeS (SoAction *action, SoNode *node)
static void audioRenderS (SoAction *action, SoNode *node)
static void getPrimitiveCountS (SoAction *action, SoNode *node)

Static Public Member Functions inherited from SoFieldContainer
static void initClass (void)
static SoType getClassTypeId (void)
static void cleanupClass (void)
static void initCopyDict (void)
static void addCopy (const SoFieldContainer *orig, const SoFieldContainer *copy)
static SoFieldContainer * checkCopy (const SoFieldContainer *orig)
static SoFieldContainer * findCopy (const SoFieldContainer *orig, const SbBool copyconnections)
static void copyDone (void)

Static Public Member Functions inherited from SoBase
static void initClass (void)
static SoType getClassTypeId (void)
static void addName (SoBase *const base, const char *const name)
static void removeName (SoBase *const base, const char *const name)
static void incrementCurrentWriteCounter (void)
static void decrementCurrentWriteCounter (void)
static SoBase * getNamedBase (const SbName &name, SoType type)
static int getNamedBases (const SbName &name, SoBaseList &baselist, SoType type)
static SbBool read (SoInput *input, SoBase *&base, SoType expectedtype)
static void setInstancePrefix (const SbString &c)
static void setTraceRefs (SbBool trace)
static SbBool getTraceRefs (void)
static SbBool connectRoute (SoInput *input, const SbName &fromnodename, const SbName &fromfieldname, const SbName &tonodename, const SbName &tofieldname)
static SbBool readRoute (SoInput *input)

Public Attributes¶

SoSFInt32 numControlPoints
SoMFFloat knotVector

Protected Member Functions¶

virtual const SoFieldData * getFieldData (void) const
virtual ~SoNurbsCurve ()
virtual void generatePrimitives (SoAction *action)
virtual void computeBBox (SoAction *action, SbBox3f &box, SbVec3f &center)
virtual SoDetail * createLineSegmentDetail (SoRayPickAction *action, const SoPrimitiveVertex *v1, const SoPrimitiveVertex *v2, SoPickedPoint *pp)

Protected Member Functions inherited from SoShape
SoShape (void)
virtual ~SoShape ()
float getComplexityValue (SoAction *action)
virtual SbBool shouldGLRender (SoGLRenderAction *action)
void beginSolidShape (SoGLRenderAction *action)
void endSolidShape (SoGLRenderAction *action)
void GLRenderBoundingBox (SoGLRenderAction *action)
SbBool shouldPrimitiveCount (SoGetPrimitiveCountAction *action)
SbBool shouldRayPick (SoRayPickAction *const action)
void computeObjectSpaceRay (SoRayPickAction *const action)
void computeObjectSpaceRay (SoRayPickAction *const action, const SbMatrix &matrix)
virtual SoDetail * createTriangleDetail (SoRayPickAction *action, const SoPrimitiveVertex *v1, const SoPrimitiveVertex *v2, const SoPrimitiveVertex *v3, SoPickedPoint *pp)
virtual SoDetail * createPointDetail (SoRayPickAction *action, const SoPrimitiveVertex *v, SoPickedPoint *pp)
void invokeTriangleCallbacks (SoAction *const action, const SoPrimitiveVertex *const v1, const SoPrimitiveVertex *const v2, const SoPrimitiveVertex *const v3)
void invokeLineSegmentCallbacks (SoAction *const action, const SoPrimitiveVertex *const v1, const SoPrimitiveVertex *const v2)
void invokePointCallbacks (SoAction *const action, const SoPrimitiveVertex *const v)
void beginShape (SoAction *const action, const TriangleShape shapetype, SoDetail *const detail=NULL)
void shapeVertex (const SoPrimitiveVertex *const v)
void endShape (void)
void generateVertex (SoPrimitiveVertex *const pv, const SbVec3f &point, const SbBool useTexFunc, const SoTextureCoordinateElement *const tce, const float s, const float t, const SbVec3f &normal)
void generateVertex (SoPrimitiveVertex *const pv, const SbVec3f &point, const SbBool useTexFunc, const SoTextureCoordinateElement *const tce, const float s, const float t, const float r, const SbVec3f &normal)
SbBool startVertexArray (SoGLRenderAction *action, const SoCoordinateElement *coords, const SbVec3f *pervertexnormals, const SbBool texpervertex, const SbBool colorpervertex)
void finishVertexArray (SoGLRenderAction *action, const SbBool vbo, const SbBool normpervertex, const SbBool texpervertex, const SbBool colorpervertex)

Protected Member Functions inherited from SoNode
SoNode (void)
virtual ~SoNode ()
virtual SbBool readInstance (SoInput *in, unsigned short flags)

Protected Member Functions inherited from SoFieldContainer
SoFieldContainer (void)
virtual ~SoFieldContainer ()

Protected Member Functions inherited from SoBase
SoBase (void)
virtual ~SoBase ()
virtual void destroy (void)
SbBool hasMultipleWriteRefs (void) const
SbBool writeHeader (SoOutput *out, SbBool isgroup, SbBool isengine) const
void writeFooter (SoOutput *out) const
virtual const char * getFileFormatName (void) const

Static Protected Member Functions¶

static const SoFieldData ** getFieldDataPtr (void)

Static Protected Member Functions inherited from SoShape
static const SoFieldData ** getFieldDataPtr (void)

Static Protected Member Functions inherited from SoNode
static const SoFieldData ** getFieldDataPtr (void)
static void setNextActionMethodIndex (int index)
static int getNextActionMethodIndex (void)
static void incNextActionMethodIndex (void)
static void setCompatibilityTypes (const SoType &nodetype, const uint32_t bitmask)

Static Protected Member Functions inherited from SoBase
static uint32_t getCurrentWriteCounter (void)
static void staticDataLock (void)
static void staticDataUnlock (void)

Additional Inherited Members¶

Public Types inherited from SoShape
enum TriangleShape { TRIANGLE_STRIP, TRIANGLE_FAN, TRIANGLES, POLYGON, QUADS, QUAD_STRIP, POINTS, LINES, LINE_STRIP }

Public Types inherited from SoNode
enum NodeType { INVENTOR = 0x0000, VRML1 = 0x0001, VRML2 = 0x0002, INVENTOR_1 = 0x0004, INVENTOR_2_0 = 0x0008, INVENTOR_2_1 = 0x0010, INVENTOR_2_5 = 0x0020, INVENTOR_2_6 = 0x0040, COIN_1_0 = 0x0080, COIN_2_0 = 0x0100, EXTENSION = 0x0200, COIN_2_2 = 0x0400, COIN_2_3 = 0x0800, COIN_2_4 = 0x1000, INVENTOR_5_0 = 0x2000, COIN_2_5 = 0x4000, COIN_3_0 = 0x8000, INVENTOR_6_0 = 0x10000 }

Protected Types inherited from SoBase
enum BaseFlags { IS_ENGINE = 0x01, IS_GROUP = 0x02 }

Protected Attributes inherited from SoNode
uint32_t uniqueId

Protected Attributes inherited from SoFieldContainer
SbBool isBuiltIn

Static Protected Attributes inherited from SoNode
static uint32_t nextUniqueId = 1
static int nextActionMethodIndex = 0

Detailed Description¶

The SoNurbsCurve class is a node for representing smooth curves.

A general explanation of NURBS is beyond the scope of the Coin documentation. For detailed information, refer to the specialized literature on the topic (for example 'An Introduction to NURBS: With Historical Perspective' by David F. Rogers). A basic overview of curve and surface rendering using NURBS can be found in chapter 8 of 'The Inventor Mentor'.

Note that knot values should be specified as [0, 1, 2,..., a] rather than [0, 1/a, 2/a,..., 1] to avoid tesselation errors due to floating point precision problems. (Even if the rendered curve looks correct, such issues might surface when e.g. doing picking, since the tesselated representation used internally is not the same as the one you see rendered by OpenGL on-screen.)

A small usage example (drawing a circle using a rational curve):

#Inventor V2.1 ascii
Coordinate4 {


   point [


     0.0 -5.0     0.0 1.0,


     2.5 -2.5     0.0 0.5,


     2.5 -0.66987 0.0 1.0,


     0.0  1.94013 0.0 0.5,


    -2.5 -0.66987 0.0 1.0,


    -2.5 -2.5     0.0 0.5,


     0.0 -5.0     0.0 1.0


   ]
}
NurbsCurve {


   numControlPoints 7


   knotVector [ 0, 0, 0, 1, 1, 2, 2, 3, 3, 3 ]
}
# debug: show all the control points
BaseColor { rgb 1 1 0 }
DrawStyle { pointSize 3 }
PointSet { numPoints 7 }

FILE FORMAT/DEFAULTS:

NurbsCurve {


    numControlPoints 0


    knotVector 0
}

Constructor & Destructor Documentation¶

SoNurbsCurve::SoNurbsCurve (void)¶

Constructor.

SoNurbsCurve::~SoNurbsCurve () [protected], [virtual]¶

Destructor.

Member Function Documentation¶

SoType SoNurbsCurve::getTypeId (void) const [virtual]¶

Returns the type identification of an object derived from a class inheriting SoBase. This is used for run-time type checking and 'downward' casting.

Usage example:

void foo(SoNode * node)
{


  if (node->getTypeId() == SoFile::getClassTypeId()) {


    SoFile * filenode = (SoFile *)node;  // safe downward cast, knows the type


  }
}

For application programmers wanting to extend the library with new nodes, engines, nodekits, draggers or others: this method needs to be overridden in all subclasses. This is typically done as part of setting up the full type system for extension classes, which is usually accomplished by using the pre-defined macros available through for instance Inventor/nodes/SoSubNode.h (SO_NODE_INIT_CLASS and SO_NODE_CONSTRUCTOR for node classes), Inventor/engines/SoSubEngine.h (for engine classes) and so on.

For more information on writing Coin extensions, see the class documentation of the toplevel superclasses for the various class groups.

Reimplemented from SoShape.

const SoFieldData * SoNurbsCurve::getFieldData (void) const [protected], [virtual]¶

Returns a pointer to the class-wide field data storage object for this instance. If no fields are present, returns NULL.

Reimplemented from SoShape.

void SoNurbsCurve::GLRender (SoGLRenderAction * action) [virtual]¶

Action method for the SoGLRenderAction.

This is called during rendering traversals. Nodes influencing the rendering state in any way or who wants to throw geometry primitives at OpenGL overrides this method.

Reimplemented from SoShape.

void SoNurbsCurve::rayPick (SoRayPickAction * action) [virtual]¶

Calculates picked point based on primitives generated by subclasses.

Reimplemented from SoShape.

void SoNurbsCurve::getPrimitiveCount (SoGetPrimitiveCountAction * action) [virtual]¶

Action method for the SoGetPrimitiveCountAction.

Calculates the number of triangle, line segment and point primitives for the node and adds these to the counters of the action.

Nodes influencing how geometry nodes calculates their primitive count also overrides this method to change the relevant state variables.

Reimplemented from SoShape.

void SoNurbsCurve::getBoundingBox (SoGetBoundingBoxAction * action) [virtual]¶

Redefined to notify open caches that this shape contains lines.

Reimplemented from SoShape.

void SoNurbsCurve::sendPrimitive (SoAction * a, SoPrimitiveVertex * p)¶

This method is part of the original SGI Inventor API, but not implemented in Coin, as it looks like a method that should probably have been private in Open Inventor.

void SoNurbsCurve::generatePrimitives (SoAction * action) [protected], [virtual]¶

The method implements action behavior for shape nodes for SoCallbackAction. It is invoked from SoShape::callback(). (Subclasses should not override SoNode::callback().)

The subclass implementations uses the convenience methods SoShape::beginShape(), SoShape::shapeVertex(), and SoShape::endShape(), with SoDetail instances, to pass the primitives making up the shape back to the caller.

Implements SoShape.

void SoNurbsCurve::computeBBox (SoAction * action, SbBox3f & box, SbVec3f & center) [protected], [virtual]¶

Calculates the bounding box of all control points, and sets the center to the average of these points.

Implements SoShape.

SoDetail * SoNurbsCurve::createLineSegmentDetail (SoRayPickAction * action, const SoPrimitiveVertex * v1, const SoPrimitiveVertex * v2, SoPickedPoint * pp) [protected], [virtual]¶

Will create line detail for a SoPickedPoint. This method will only be called internally, when generatePrimitives() is used for picking (SoShape::rayPick() is not overridden).

This method returns NULL in Open Inventor, and subclasses will need to override this method to create details for a SoPickedPoint.

This is not necessary with Coin. Of course, if you choose to override it, it will work in the same way as Open Inventor.

For this to work, you must supply a face or line detail when generating primitives. If you supply NULL for the detail argument in SoShape::beginShape(), you'll have to override this method.

Reimplemented from SoShape.

Member Data Documentation¶

SoSFInt32 SoNurbsCurve::numControlPoints¶

Number of control points to use in this NURBS curve.

SoMFFloat SoNurbsCurve::knotVector¶

The knot vector.

Values should be specified as [0, 1, 2,..., a] rather than [0, 1/a, 2/a,..., 1] to avoid tesselation errors due to floating point precision problems.

Author¶

Generated automatically by Doxygen for Coin from the source code.

Version 3.1.3

Coin

Source file:	SoNurbsCurve.3.en.gz (from Coin-devel 3.1.3-7.1)
Source last updated:	2024-05-08T09:17:19Z
Converted to HTML:	2024-11-21T01:43:44Z