ParametricCurve Class Reference

A virtual base class for parametric curves. More...

Inheritance diagram for ParametricCurve:

## Public Member Functions

bool adjustPoint (float t, float px, float py, float pz)
Recomputes the curve such that it passes through the point (px, py, pz) at time t, but keeps the same tangent value at that point. More...

bool adjustPt (float t, float px, float py, float pz, float tx, float ty, float tz)
Recomputes the curve such that it passes through the point (px, py, pz) with the tangent (tx, ty, tz). More...

bool adjustTangent (float t, float tx, float ty, float tz)
Recomputes the curve such that it has the tangent (tx, ty, tz) at time t, but keeps the same position at the point. More...

float calcLength ()
Approximates the length of the entire curve to within a few decimal places. More...

float calcLength (float from, float to)
Approximates the length of the curve segment from parametric time 'from' to time 'to'. More...

float findLength (float start_t, float length_offset)
Returns the parametric value corresponding to the indicated distance along the curve from the starting parametric value. More...

bool get2ndtangent (float t, LVecBase3 tangent2)

int getCurveType ()
Returns the flag indicating the use to which the curve is intended to be put. More...

float getMaxT ()
Returns the upper bound of t for the entire curve. More...

int getNumDimensions ()
Returns the number of significant dimensions in the curve's vertices, as set by a previous call to set_num_dimensions(). More...

bool getPoint (float t, LVecBase3 point)

bool getPt (float t, LVecBase3 point, LVecBase3 tangent)

bool getTangent (float t, LVecBase3 tangent)

bool isValid ()
Returns true if the curve is defined. More...

bool recompute ()
Recalculates the curve, if necessary. More...

setCurveType (int type)
Sets the flag indicating the use to which the curve is intended to be put. More...

setNumDimensions (int num)
Specifies the number of significant dimensions in the curve's vertices. More...

bool stitch (const ParametricCurve a, const ParametricCurve b)
Regenerates this curve as one long curve: the first curve connected end-to- end with the second one. More...

bool writeEgg (Filename filename, CoordinateSystem cs)
Writes an egg description of the nurbs curve to the specified output file. More...

bool writeEgg (Ostream out, const Filename filename, CoordinateSystem cs)
Writes an egg description of the nurbs curve to the specified output stream. More...

Public Member Functions inherited from PandaNode
PandaNode __copy__ ()

object __deepcopy__ (object memo)

__init__ (str name)

int __traverse__ (Visitproc visit, void arg)

Adds a new child to the node. More...

Adds a new child to the node, directly as a stashed child. More...

Adjusts the hide/show bits of this particular node. More...

Light asLight ()
Cross-casts the node to a Light pointer, if it is one of the four kinds of Light nodes, or returns NULL if it is not. More...

clearAttrib (TypeHandle type)
Removes the render attribute of the given type from this node. More...

clearAttrib (int slot)
Removes the render attribute of the given type from this node. More...

clearBounds ()
Reverses the effect of a previous call to set_bounds(), and allows the node's bounding volume to be automatically computed once more based on the contents of the node. More...

clearEffect (TypeHandle type)
Removes the render effect of the given type from this node. More...

Resets this node to have no render effects. More...

clearPythonTag (object key)

Resets this node to leave the render state alone. More...

Removes the value defined for this key on this particular node. More...

Resets the transform on this node to the identity transform. More...

clearUnexpectedChange (unsigned int flags)
Sets one or more of the PandaNode::UnexpectedChange bits off, indicating that the corresponding property may once again change on this node. More...

PandaNode combineWith (PandaNode other)
Collapses this PandaNode with the other PandaNode, if possible, and returns a pointer to the combined PandaNode, or NULL if the two PandaNodes cannot safely be combined. More...

int compareTags (const PandaNode other)
Returns a number less than 0, 0, or greater than 0, to indicate the similarity of tags between this node and the other one. More...

copyAllProperties (PandaNode other)
Copies the TransformState, RenderState, RenderEffects, tags, Python tags, and the show/hide state from the other node onto this one. More...

Makes another instance of all the children of the other node, copying them to this node. More...

Allocates and returns a complete copy of this PandaNode and the entire scene graph rooted at this PandaNode. More...

copyTags (PandaNode other)
Copies all of the tags stored on the other node onto this node. More...

int countNumDescendants ()
Returns the number of nodes at and below this level. More...

Returns the index of the indicated child node, if it is a child, or -1 if it is not. More...

Returns the index of the indicated parent node, if it is a parent, or -1 if it is not. More...

Returns the index of the indicated stashed node, if it is a stashed child, or -1 if it is not. More...

const RenderAttrib getAttrib (TypeHandle type)
Returns the render attribute of the indicated type, if it is defined on the node, or NULL if it is not. More...

const RenderAttrib getAttrib (int slot)
Returns the render attribute of the indicated type, if it is defined on the node, or NULL if it is not. More...

Returns the external bounding volume of this node: a bounding volume that contains the user bounding volume, the internal bounding volume, and all of the children's bounding volumes. More...

This flavor of get_bounds() return the external bounding volume, and also fills in seq with the bounding volume's current sequence number. More...

BoundingVolume::BoundsType getBoundsType ()
Returns the bounding volume type set with set_bounds_type(). More...

Returns the nth child node of this node. More...

list getChildren ()

Returns the sort index of the nth child node of this node (that is, the number that was passed to add_child()). More...

Returns the set of bits in draw_show_mask that are considered meaningful. More...

Returns the hide/show bits of this particular node. More...

const RenderEffect getEffect (TypeHandle type)
Returns the render effect of the indicated type, if it is defined on the node, or NULL if it is not. More...

Returns the complete RenderEffects that will be applied to this node. More...

Returns the union of all of the enum FancyBits values corresponding to the various "fancy" attributes that are set on the node. More...

Returns the node's internal bounding volume. More...

Returns the total number of vertices that will be rendered by this particular node alone, not accounting for its children. More...

Returns the "into" collide mask for this node. More...

Returns the subset of CollideMask bits that may be set for this particular type of PandaNode. More...

Returns the total number of vertices that will be rendered by this node and all of its descendents. More...

Returns the union of all into_collide_mask() values set at CollisionNodes at this level and below. More...

Returns the set of bits in get_net_draw_show_mask() that have been explicitly set via adjust_draw_mask(), rather than implicitly inherited. More...

Returns the union of all draw_show_mask values–of renderable nodes only– at this level and below. More...

Returns the number of child nodes this node has. More...

Returns the number of parent nodes this node has. More...

Returns the number of stashed nodes this node has. More...

Returns a ClipPlaneAttrib which represents the union of all of the clip planes that have been turned off at this level and below. More...

Returns the nth parent node of this node. More...

list getParents ()

Returns the transform that has been set as this node's "previous" position. More...

object getPythonTag (object key)

object getPythonTagKeys ()

object getPythonTags ()

Returns an object that can be used to walk through the list of children of the node. More...

Returns the nth stashed child of this node. More...

list getStashed ()

Returns the sort index of the nth stashed node of this node (that is, the number that was passed to add_child()). More...

Returns the complete RenderState that will be applied to all nodes at this level and below, as set on this node. More...

Retrieves the user-defined value that was previously set on this node for the particular key, if any. More...

object getTagKeys ()

Returns the transform that has been set on this particular node. More...

unsigned int getUnexpectedChange (unsigned int flags)
Returns nonzero if any of the bits in the input parameter are set on this node, or zero if none of them are set. More...

bool hasAttrib (TypeHandle type)
Returns true if there is a render attribute of the indicated type defined on this node, or false if there is not. More...

bool hasAttrib (int slot)
Returns true if there is a render attribute of the indicated type defined on this node, or false if there is not. More...

bool hasDirtyPrevTransform ()
Returns true if this node has the _dirty_prev_transform flag set, which indicates its _prev_transform is different from its _transform value (in pipeline stage 0). More...

bool hasEffect (TypeHandle type)
Returns true if there is a render effect of the indicated type defined on this node, or false if there is not. More...

bool hasPythonTag (object key)

Returns true if a value has been defined on this node for the particular key (even if that value is the empty string), or false if no value has been set. More...

bool hasTags ()
Returns true if the node has any tags (or any Python tags) at all, false if it has none. More...

bool isAmbientLight ()
Returns true if this is an AmbientLight, false if it is not a light, or it is some other kind of light. More...

bool isBoundsStale ()
Returns true if the bounding volume of this node is stale and will be implicitly recomputed at the next call to get_bounds(), or false if it is fresh and need not be recomputed. More...

bool isCollisionNode ()
A simple downcast check. More...

Returns the current state of the "final" flag. More...

bool isGeomNode ()
A simple downcast check. More...

bool isLodNode ()
A simple downcast check. More...

bool isOverallHidden ()
Returns true if the node has been hidden to all cameras by clearing its overall bit. More...

bool isSceneRoot ()
Returns true if this particular node is known to be the render root of some active DisplayRegion associated with the global GraphicsEngine, false otherwise. More...

bool isUnderSceneRoot ()
Returns true if this particular node is in a live scene graph: that is, it is a child or descendent of a node that is itself a scene root. More...

listTags (Ostream out, str separator)
Writes a list of all the tag keys assigned to the node to the indicated stream. More...

ls (Ostream out, int indent_level)
Lists all the nodes at and below the current path hierarchically. More...

PandaNode makeCopy ()
Returns a newly-allocated PandaNode that is a shallow copy of this one. More...

Indicates that the bounding volume, or something that influences the bounding volume (or any of the other things stored in CData, like net_collide_mask), may have changed for this node, and that it must be recomputed. More...

Should be called by a derived class to mark the internal bounding volume stale, so that compute_internal_bounds() will be called when the bounding volume is next requested. More...

output (Ostream out)

prepareScene (GraphicsStateGuardianBase gsg, const RenderState node_state)
Walks through the scene graph beginning at this node, and does whatever initialization is required to render the scene properly with the indicated GSG. More...

Removes all the children from the node at once, including stashed children. More...

Removes the indicated child from the node. More...

Removes the nth child from the node. More...

Removes the nth stashed child from the node. More...

Searches for the orig_child node in the node's list of children, and replaces it with the new_child instead. More...

replaceNode (PandaNode other)
Inserts this node into the scene graph in place of the other one, and removes the other node. More...

Resets the transform that represents this node's "previous" position to the same as the current transform. More...

setAttrib (const RenderAttrib attrib, int override)
Adds the indicated render attribute to the scene graph on this node. More...

setBound (const BoundingVolume volume)
Deprecated. More...

setBounds (const BoundingVolume volume)
Resets the bounding volume so that it is the indicated volume. More...

setBoundsType (BoundingVolume::BoundsType bounds_type)
Specifies the desired type of bounding volume that will be created for this node. More...

setEffect (const RenderEffect effect)
Adds the indicated render effect to the scene graph on this node. More...

Sets the complete RenderEffects that will be applied this node. More...

setFinal (bool flag)
Sets the "final" flag on this PandaNode. More...

setOverallHidden (bool overall_hidden)
Sets or clears the hidden flag. More...

Sets the transform that represents this node's "previous" position, one frame ago, for the purposes of detecting motion for accurate collision calculations. More...

setPythonTag (object key, object value)

Sets the complete RenderState that will be applied to all nodes at this level and below. More...

Associates a user-defined value with a user-defined key which is stored on the node. More...

Sets the transform that will be applied to this node and below. More...

setUnexpectedChange (unsigned int flags)
Sets one or more of the PandaNode::UnexpectedChange bits on, indicating that the corresponding property should not change again on this node. More...

Stashes the indicated child node. More...

Stashes the indicated child node. More...

Moves all the children from the other node onto this node. More...

Returns the indicated stashed node to normal child status. More...

Returns the indicated stashed node to normal child status. More...

write (Ostream out, int indent_level)

Public Member Functions inherited from TypedWritable
object __reduce__ ()

object __reduce_persist__ (object pickler)

VectorUchar encodeToBamStream ()
Converts the TypedWritable object into a single stream of data using a BamWriter, and returns that data as a bytes object. More...

bool encodeToBamStream (VectorUchar data, BamWriter writer)
Converts the TypedWritable object into a single stream of data using a BamWriter, and stores that data in the indicated string. More...

This internal function is intended to be called by each class's make_from_bam() method to read in all of the relevant data from the BamFile for the new object. More...

Returns the current bam_modified counter. More...

markBamModified ()
Increments the bam_modified counter, so that this object will be invalidated and retransmitted on any open bam streams. More...

Public Member Functions inherited from TypedObject
TypeHandle getType ()

int getTypeIndex ()
Returns the internal index number associated with this object's TypeHandle, a unique number for each different type. More...

bool isExactType (TypeHandle handle)
Returns true if the current object is the indicated type exactly. More...

bool isOfType (TypeHandle handle)
Returns true if the current object is or derives from the indicated type. More...

Public Member Functions inherited from ReferenceCount
int getRefCount ()
Returns the current reference count. More...

ref ()
Explicitly increments the reference count. More...

bool testRefCountIntegrity ()
Does some easy checks to make sure that the reference count isn't completely bogus. More...

bool testRefCountNonzero ()
Does some easy checks to make sure that the reference count isn't zero, or completely bogus. More...

bool unref ()
Explicitly decrements the reference count. More...

Public Member Functions inherited from Namable
__init__ (const Namable)

__init__ (str initial_name)

clearName ()
Resets the Namable's name to empty. More...

str getName ()

bool hasName ()
Returns true if the Namable has a nonempty name set, false if the name is empty. More...

output (Ostream out)
Outputs the Namable. More...

setName (str name)

## Static Public Member Functions

static TypeHandle getClassType ()

Static Public Member Functions inherited from PandaNode
Reads the bytes created by a previous call to encode_to_bam_stream(), and extracts and returns the single object on those bytes. More...

Returns a DrawMask that is appropriate for rendering to all cameras. More...

static TypeHandle getClassType ()

Returns the special bit that, when specifically cleared in the node's DrawMask, indicates that the node is hidden to all cameras, regardless of the remaining DrawMask bits. More...

Visits all nodes in the world with the _dirty_prev_transform flag–that is, all nodes whose _prev_transform is different from the _transform in pipeline stage 0–and resets the _prev_transform to be the same as _transform. More...

Static Public Member Functions inherited from TypedWritableReferenceCount
Reads the bytes created by a previous call to encode_to_bam_stream(), and extracts and returns the single object on those bytes. More...

static TypeHandle getClassType ()

Static Public Member Functions inherited from TypedWritable
static TypeHandle getClassType ()

Static Public Member Functions inherited from TypedObject
static TypeHandle getClassType ()

Static Public Member Functions inherited from ReferenceCount
static TypeHandle getClassType ()

Static Public Member Functions inherited from Namable
static TypeHandle getClassType ()

Public Types inherited from PandaNode
enum  FancyBits {
FB_transform = 1, FB_state = 2, FB_effects = 4, FB_tag = 16,
FB_draw_mask = 32, FB_cull_callback = 64
}

enum  UnexpectedChange {
UC_parents = 1, UC_children = 2, UC_transform = 4, UC_state = 8,
}

Public Attributes inherited from PandaNode
Returns a DrawMask that is appropriate for rendering to all cameras. More...

bool bounds_stale
Returns true if the bounding volume of this node is stale and will be implicitly recomputed at the next call to get_bounds(), or false if it is fresh and need not be recomputed. More...

BoundingVolume::BoundsType bounds_type
Returns the bounding volume type set with set_bounds_type(). More...

PandaNode::Children children
Returns an object that can be used to walk through the list of children of the node. More...

Returns the set of bits in draw_show_mask that are considered meaningful. More...

Returns the hide/show bits of this particular node. More...

ConstPointerToRenderEffects effects
Returns the complete RenderEffects that will be applied to this node. More...

bool final
Returns the current state of the "final" flag. More...

ConstPointerToBoundingVolume internal_bounds
Returns the node's internal bounding volume. More...

int internal_vertices
Returns the total number of vertices that will be rendered by this particular node alone, not accounting for its children. More...

Returns the "into" collide mask for this node. More...

Returns the subset of CollideMask bits that may be set for this particular type of PandaNode. More...

int nested_vertices
Returns the total number of vertices that will be rendered by this node and all of its descendents. More...

Returns the special bit that, when specifically cleared in the node's DrawMask, indicates that the node is hidden to all cameras, regardless of the remaining DrawMask bits. More...

bool overall_hidden
Returns true if the node has been hidden to all cameras by clearing its overall bit. More...

PandaNode::Parents parents
Returns an object that can be used to walk through the list of parents of the node, similar to get_children() and get_stashed(). More...

ConstPointerToTransformState prev_transform
Returns the transform that has been set as this node's "previous" position. More...

object python_tags

PandaNode::Stashed stashed
Returns the nth stashed child of this node. More...

ConstPointerToRenderState state
Returns the complete RenderState that will be applied to all nodes at this level and below, as set on this node. More...

String tags []

ConstPointerToTransformState transform
Returns the transform that has been set on this particular node. More...

Public Attributes inherited from TypedObject
TypeHandle type
Returns the TypeHandle representing this object's type. More...

Public Attributes inherited from ReferenceCount
int ref_count
The current reference count. More...

Public Attributes inherited from Namable
const String name

## Detailed Description

A virtual base class for parametric curves.

This encapsulates all curves in 3-d space defined for a single parameter t in the range [0,get_max_t()].

## Member Function Documentation

 bool adjustPoint ( float t, float px, float py, float pz )

Recomputes the curve such that it passes through the point (px, py, pz) at time t, but keeps the same tangent value at that point.

 bool adjustPt ( float t, float px, float py, float pz, float tx, float ty, float tz )

Recomputes the curve such that it passes through the point (px, py, pz) with the tangent (tx, ty, tz).

 bool adjustTangent ( float t, float tx, float ty, float tz )

Recomputes the curve such that it has the tangent (tx, ty, tz) at time t, but keeps the same position at the point.

## ◆ calcLength() [1/2]

 float calcLength ( )

Approximates the length of the entire curve to within a few decimal places.

## ◆ calcLength() [2/2]

 float calcLength ( float from, float to )

Approximates the length of the curve segment from parametric time 'from' to time 'to'.

## ◆ findLength()

 float findLength ( float start_t, float length_offset )

Returns the parametric value corresponding to the indicated distance along the curve from the starting parametric value.

This is the inverse of calc_length(): rather than determining the length along the curve between two parametric points, it determines the position in parametric time of a point n units along the curve.

The search distance must not be negative.

## ◆ get2ndtangent()

 bool get2ndtangent ( float t, LVecBase3 tangent2 )

## ◆ getClassType()

 static TypeHandle getClassType ( )
static

## ◆ getCurveType()

 int getCurveType ( )

Returns the flag indicating the use to which the curve is intended to be put.

## ◆ getMaxT()

 float getMaxT ( )

Returns the upper bound of t for the entire curve.

The curve is defined in the range 0.0f <= t <= get_max_t(). This base class function always returns 1.0f; derived classes might override this to return something else.

## ◆ getNumDimensions()

 int getNumDimensions ( )

Returns the number of significant dimensions in the curve's vertices, as set by a previous call to set_num_dimensions().

This is only a hint as to how the curve is intended to be used; the actual number of dimensions of any curve is always three.

## ◆ getPoint()

 bool getPoint ( float t, LVecBase3 point )

## ◆ getPt()

 bool getPt ( float t, LVecBase3 point, LVecBase3 tangent )

## ◆ getTangent()

 bool getTangent ( float t, LVecBase3 tangent )

## ◆ isValid()

 bool isValid ( )

Returns true if the curve is defined.

This base class function always returns true; derived classes might override this to sometimes return false.

## ◆ recompute()

 bool recompute ( )

Recalculates the curve, if necessary.

Returns true if the resulting curve is valid, false otherwise.

## ◆ setCurveType()

 setCurveType ( int type )

Sets the flag indicating the use to which the curve is intended to be put.

This flag is optional and only serves to provide a hint to the egg reader and writer code; it has no effect on the curve's behavior.

Setting the curve type also sets the num_dimensions to 3 or 1 according to the type.

THis flag may have one of the values PCT_XYZ, PCT_HPR, or PCT_T.

## ◆ setNumDimensions()

 setNumDimensions ( int num )

Specifies the number of significant dimensions in the curve's vertices.

This should be one of 1, 2, or 3. Normally, XYZ and HPR curves have three dimensions; time curves should always have one dimension. This only serves as a hint to the mopath editor, and also controls how the curve is written out.

## ◆ stitch()

 bool stitch ( const ParametricCurve a, const ParametricCurve b )

Regenerates this curve as one long curve: the first curve connected end-to- end with the second one.

Either a or b may be the same as 'this'.

Returns true if successful, false on failure or if the curve type does not support stitching.

## ◆ writeEgg() [1/2]

 bool writeEgg ( Filename filename, CoordinateSystem cs )

Writes an egg description of the nurbs curve to the specified output file.

Returns true if the file is successfully written.

## ◆ writeEgg() [2/2]

 bool writeEgg ( Ostream out, const Filename filename, CoordinateSystem cs )

Writes an egg description of the nurbs curve to the specified output stream.

Returns true if the file is successfully written.