NAME
SoTriangleStripSet -
The SoTriangleStripSet class is used to render and control non-indexed
triangle strips.
Triangle strips are specified using the numVertices field.
SYNOPSIS
#include <Inventor/nodes/SoTriangleStripSet.h>
Inherits SoNonIndexedShape.
Public Member Functions
SoTriangleStripSet (void)
virtual void GLRender (SoGLRenderAction *action)
virtual void getPrimitiveCount (SoGetPrimitiveCountAction *action)
virtual SbBool generateDefaultNormals (SoState *state, SoNormalBundle
*nb)
Static Public Member Functions
static void initClass (void)
Public Attributes
SoMFInt32 numVertices
Protected Member Functions
virtual ~SoTriangleStripSet ()
virtual void generatePrimitives (SoAction *action)
virtual void computeBBox (SoAction *action, SbBox3f &box, SbVec3f
¢er)
virtual SbBool generateDefaultNormals (SoState *, SoNormalCache *)
Detailed Description
The SoTriangleStripSet class is used to render and control non-indexed
triangle strips.
Triangle strips are specified using the numVertices field.
Coordinates, normals, materials and texture coordinates are all fetched
in order from the current state or from the vertexProperty node if set.
(To render triangle strips from vertex indices, use the
SoIndexedTriangleStripSet node.)
The numVertices field may be used for multiple strips, coordinates will
be fetched with a monotonically increasing index from the coordinates
on the traversal state stack (i.e. typically from the last
SoCoordinate3 node encountered during traversal).
For example, if numVertices is set to [3, 4, 5, 3], this node would
specify a triangle from coordinates 0, 1 and 2, a triangle strip from
coordinates 3, 4, 5 and 6, a triangle strip from coordinates 7, 8, 9,
10 and 11 and finally a triangle from coordinates 12, 13, 14.
Or to put it another way: in a tristrip there will always be two
vertices more than there are triangles. Realize that you are handling
data on the vertex level (not polygon-level), and that the triangles
are laid out like this, given 5 vertices:
1-----3-----5
/ /
/ /
2-----4
.fi
The above figure in scene graph file format:
#Inventor V2.1 ascii
Separator {
Coordinate3 {
point [ -2 1 0, -1 -1 0, 0 1 0, 1 -1 0, 2 1 0 ]
}
TriangleStripSet {
numVertices [ 5 ]
}
}
.fi
The scene graph above in a viewer:
Strips are converted into triangles the way OpenGL does it, of course, so for the dirty details, check out the documentation of OpenGL’s GL_TRIANGLE_STRIP primitive rendering type.
Binding PER_PART (per strip), PER_VERTEX, PER_FACE or OVERALL can be set for material, and normals. The default material binding is OVERALL. The default normal binding is PER_VERTEX.
FILE FORMAT/DEFAULTS:
TriangleStripSet {
vertexProperty NULL
startIndex 0
numVertices -1
}
See also:
SoIndexedTriangleStripSet
Constructor & Destructor Documentation
SoTriangleStripSet::SoTriangleStripSet (void) Constructor.
SoTriangleStripSet::~SoTriangleStripSet () [protected, virtual] Destructor.
Member Function Documentation
void SoTriangleStripSet::initClass (void) [static] Sets up initialization
for data common to all instances of this class, like submitting
necessary information to the Coin type system.
Reimplemented from SoNonIndexedShape.
void SoTriangleStripSet::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 SoTriangleStripSet::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.
SbBool SoTriangleStripSet::generateDefaultNormals (SoState * state,
SoNormalBundle * bundle) [virtual] This API member is considered
internal to the library, as it is not likely to be of interest to the
application programmer.
Subclasses should override this method to generate default normals
using the SoNormalBundle class. TRUE should be returned if normals were
generated, FALSE otherwise.
Default method returns FALSE.
This function is an extension for Coin, and it is not available in the
original SGI Open Inventor v2.1 API.
Reimplemented from SoVertexShape.
void SoTriangleStripSet::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 SoTriangleStripSet::computeBBox (SoAction * action, SbBox3f & box,
SbVec3f & center) [protected, virtual] Implemented by SoShape
subclasses to let the SoShape superclass know the exact size and
weighted center point of the shape’s bounding box.
The bounding box and center point should be calculated and returned in
the local coordinate system.
The method implements action behavior for shape nodes for
SoGetBoundingBoxAction. It is invoked from SoShape::getBoundingBox().
(Subclasses should not override SoNode::getBoundingBox().)
The box parameter sent in is guaranteed to be an empty box, while
center is undefined upon function entry.
Implements SoShape.
SbBool SoTriangleStripSet::generateDefaultNormals (SoState * state,
SoNormalCache * cache) [protected, virtual] This API member is
considered internal to the library, as it is not likely to be of
interest to the application programmer.
Subclasses should override this method to generate default normals
using the SoNormalCache class. This is more effective than using
SoNormalGenerator. Return TRUE if normals were generated, FALSE
otherwise.
Default method just returns FALSE.
This function is an extension for Coin, and it is not available in the
original SGI Open Inventor v2.1 API.
Reimplemented from SoVertexShape.
Member Data Documentation
SoMFInt32 SoTriangleStripSet::numVertices Specifies the number of vertices
in each triangle strip. The vertices are fetched from the current
coordinate node, or from the vertexProperty field if present.
Author
Generated automatically by Doxygen for Coin from the source code.