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Rewriting the osggeomtry demo to illustrate more primitive types.

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Robert Osfield
2002-06-28 11:11:20 +00:00
parent 975e2fe709
commit f809ef8a7b
1 changed files with 311 additions and 137 deletions
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src/Demos/osggeometry/osggeometry.cpp
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@@ -11,150 +11,330 @@
#include <osg/Math>
// ----------------------------------------------------------------------
// Global variables - this is basically the stuff wh ich will be animated
// ----------------------------------------------------------------------
class MyTransformCallback : public osg::NodeCallback{
// This demos uses the illustrates how to creates the various different types of geometry that
// the osg::Geometry class can represent. This demos uses the OpenGL red books diagram of different
// OpenGL Primitives as a template for all the equivilant OpenSceneGraph Primitives. The OpenSceneGraph
// wraps OpenGL very thinly so uses all the same enum and naming conventions. The coordinate data is also
// wrapped around OpenGL's vertex arrays and draw arrays/elements calls. Familarity with
// OpenGL will help understand the the osg::Geometry class which encapsulate all this, or if you
// havn't learnt OpenGL yet, learning osg::Geometry will help you understand how OpenGL
// works!
public:
// The osg::Geometry class "is a" subclass of osg::Drawable base class, so is an object that provides
// a draw method for drawing objects in the scene. osg::Geometry contains all the vertex, normal
// color and texture coordate arrays required to specify the coordinates of your objects, and the
// primtives join these coordinates together as the points, lines or surfaces that you will see
// rendered on your screen.
//
// This demo is split into two functions, the createScene() function which creates the scene graph
// with the various primitives in it, and the main() which sets up a basic viewer window and
// adds to the it the scene generated by createScene().
MyTransformCallback(osg::Transform* node,float angularVelocity)
{
_nodeToOperateOn = node;
_angular_velocity = angularVelocity;
_previousTraversalNumber = -1;
_orig_t = _timer.tick();
}
virtual void operator() (osg::Node* node, osg::NodeVisitor* nv)
{
if (nv)
{
if (_nodeToOperateOn && node==_nodeToOperateOn)
{
// ensure that we do not operate on this node more than
// once during this traversal. This is an issue since node
// can be shared between multiple parents.
if (nv->getTraversalNumber()!=_previousTraversalNumber)
{
osg::Timer_t new_t = _timer.tick();
float delta_angle = _angular_velocity*_timer.delta_s(_orig_t,new_t);
osg::Matrix matrix;
matrix.makeRotate(delta_angle,1.0f,1.0f,1.0f);
matrix *= osg::Matrix::translate(1.0f,0.0f,0.0f);
matrix *= osg::Matrix::rotate(delta_angle,0.0f,0.0f,1.0f);
_nodeToOperateOn->setMatrix(matrix);
_previousTraversalNumber = nv->getTraversalNumber();
}
}
}
// must continue subgraph traversal.
traverse(node,nv);
}
protected:
osg::Transform* _nodeToOperateOn;
float _angular_velocity;
int _previousTraversalNumber;
osg::Timer _timer;
osg::Timer_t _orig_t;
};
osg::Geode* createGeometryCube()
osg::Geode* createScene()
{
// create the Geode (Geometry Node) to contain all our osg::Geometry objects.
osg::Geode* geode = new osg::Geode();
// -------------------------------------------
// Set up a new Geometry which will be our cube
// -------------------------------------------
osg::Geometry* cube = new osg::Geometry();
// follows are seperate blocks for creating POINTS, LINES, LINE_STRIP, LINE_LOOP, POLYGON, QUADS,
// QUAD_STRIP, TRIANGLES, TRIANGLE_STRIP and TRIANGLE_FAN primtives. A image of these primtives
// are provided in the distribution : OpenSceneGraph-Data/Images/primtives.gif.
// set up the primitives
// create POINTS
{
// create Geometry object to store all the vetices and points primtive.
osg::Geometry* pointsGeom = new osg::Geometry();
// create a Vec3Array and add to it all my coordinates.
// Like all the *Array variants (see include/osg/Array) , Vec3Array is derivied from both osg::Array
// and std::vector<>. osg::Array's are reference counted and hence sharable,
// which std::vector<> provides all the convinience, flexibility and robustness
// of the most popular of all STL containers.
osg::Vec3Array* vertices = new osg::Vec3Array;
vertices->push_back(osg::Vec3(-1.02168, -2.15188e-09, 0.885735));
vertices->push_back(osg::Vec3(-0.976368, -2.15188e-09, 0.832179));
vertices->push_back(osg::Vec3(-0.873376, 9.18133e-09, 0.832179));
vertices->push_back(osg::Vec3(-0.836299, -2.15188e-09, 0.885735));
vertices->push_back(osg::Vec3(-0.790982, 9.18133e-09, 0.959889));
// pass the created vertex array to the points geometry object.
pointsGeom->setVertexArray(vertices);
// create the color of the geometry, one single for the whole geometry.
// for consitency of design even one single color must added as an element
// in a color array.
osg::Vec4Array* colors = new osg::Vec4Array;
// add a white color, colors take the form r,g,b,a with 0.0 off, 1.0 full on.
colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
// pass the color arry to points geometry, note the binding to tell the geometry
// that only use one color for the whole object.
pointsGeom->setColorArray(colors);
pointsGeom->setColorBinding(osg::Geometry::BIND_OVERALL);
// set the normal in the same way color.
osg::Vec3Array* normals = new osg::Vec3Array;
normals->push_back(osg::Vec3(0.0f,-1.0f,0.0f));
pointsGeom->setNormalArray(normals);
pointsGeom->setNormalBinding(osg::Geometry::BIND_OVERALL);
// create and add a DrawArray Primitive (see include/osg/Primtive). The first
// paramter passed to the DrawArrays constructor is the Primtive::Mode which
// in this case is POINTS (which has the same value GL_POINTS), the second
// parameter is the index position into the vertex array of the first point
// to draw, and the third parameter is the number of points to draw.
pointsGeom->addPrimitive(new osg::DrawArrays(osg::Primitive::POINTS,0,vertices->size()));
// add the points geomtry to the geode.
geode->addDrawable(pointsGeom);
}
// create LINES
{
// create Geometry object to store all the vetices and lines primtive.
osg::Geometry* linesGeom = new osg::Geometry();
// this time we'll prealloacte the vertex array to the size we
// need and then simple set them as array elements, 8 points
// makes 4 line segments.
osg::Vec3Array* vertices = new osg::Vec3Array(8);
(*vertices)[0].set(-1.13704, -2.15188e-09, 0.40373);
(*vertices)[1].set(-0.856897, -2.15188e-09, 0.531441);
(*vertices)[2].set(-0.889855, -2.15188e-09, 0.444927);
(*vertices)[3].set(-0.568518, -2.15188e-09, 0.40373);
(*vertices)[4].set(-1.00933, -2.15188e-09, 0.370773);
(*vertices)[5].set(-0.716827, -2.15188e-09, 0.292498);
(*vertices)[6].set(-1.07936, 9.18133e-09, 0.317217);
(*vertices)[7].set(-0.700348, 9.18133e-09, 0.362533);
// pass the created vertex array to the points geometry object.
linesGeom->setVertexArray(vertices);
// set the colors as before, plus using the aobve
osg::Vec4Array* colors = new osg::Vec4Array;
colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
linesGeom->setColorArray(colors);
linesGeom->setColorBinding(osg::Geometry::BIND_OVERALL);
// set the normal in the same way color.
osg::Vec3Array* normals = new osg::Vec3Array;
normals->push_back(osg::Vec3(0.0f,-1.0f,0.0f));
linesGeom->setNormalArray(normals);
linesGeom->setNormalBinding(osg::Geometry::BIND_OVERALL);
// This time we simply use primitive, and hardwire the number of coords to use
// since we know up front,
linesGeom->addPrimitive(new osg::DrawArrays(osg::Primitive::LINES,0,8));
// add the points geomtry to the geode.
geode->addDrawable(linesGeom);
}
cube->addPrimitive(new osg::DrawArrays(osg::Primitive::POLYGON,0,4));
cube->addPrimitive(new osg::DrawArrays(osg::Primitive::POLYGON,4,4));
cube->addPrimitive(new osg::DrawArrays(osg::Primitive::POLYGON,8,4));
cube->addPrimitive(new osg::DrawArrays(osg::Primitive::POLYGON,12,4));
cube->addPrimitive(new osg::DrawArrays(osg::Primitive::POLYGON,16,4));
cube->addPrimitive(new osg::DrawArrays(osg::Primitive::POLYGON,20,4));
// set up coords.
osg::Vec3Array* coords = new osg::Vec3Array;
coords->resize(24);
(*coords)[0].set( -1.0000f, 1.0000f, -1.000f );
(*coords)[1].set( 1.0000f, 1.0000f, -1.0000f );
(*coords)[2].set( 1.0000f, -1.0000f, -1.0000f );
(*coords)[3].set( -1.0000f, -1.0000f, -1.000 );
(*coords)[4].set( 1.0000f, 1.0000f, -1.0000f );
(*coords)[5].set( 1.0000f, 1.0000f, 1.0000f );
(*coords)[6].set( 1.0000f, -1.0000f, 1.0000f );
(*coords)[7].set( 1.0000f, -1.0000f, -1.0000f );
(*coords)[8].set( 1.0000f, 1.0000f, 1.0000f );
(*coords)[9].set( -1.0000f, 1.0000f, 1.000f );
(*coords)[10].set( -1.0000f, -1.0000f, 1.000f );
(*coords)[11].set( 1.0000f, -1.0000f, 1.0000f );
(*coords)[12].set( -1.0000f, 1.0000f, 1.000 );
(*coords)[13].set( -1.0000f, 1.0000f, -1.000 );
(*coords)[14].set( -1.0000f, -1.0000f, -1.000 );
(*coords)[15].set( -1.0000f, -1.0000f, 1.000 );
(*coords)[16].set( -1.0000f, 1.0000f, 1.000 );
(*coords)[17].set( 1.0000f, 1.0000f, 1.0000f );
(*coords)[18].set( 1.0000f, 1.0000f, -1.0000f );
(*coords)[19].set( -1.0000f, 1.0000f, -1.000f );
(*coords)[20].set( -1.0000f, -1.0000f, 1.000f );
(*coords)[21].set( -1.0000f, -1.0000f, -1.000f );
(*coords)[22].set( 1.0000f, -1.0000f, -1.0000f );
(*coords)[23].set( 1.0000f, -1.0000f, 1.0000f );
// create LINE_STRIP
{
// create Geometry object to store all the vetices and lines primtive.
osg::Geometry* linesGeom = new osg::Geometry();
// this time we'll prealloacte the vertex array to the size
// and then use an iterator to fill in the values, a bit perverse
// but does demonstrate that we have just a standard std::vector underneath.
osg::Vec3Array* vertices = new osg::Vec3Array(5);
osg::Vec3Array::iterator vitr = vertices->begin();
(vitr++)->set(-0.0741545, -2.15188e-09, 0.416089);
(vitr++)->set(0.234823, -2.15188e-09, 0.259541);
(vitr++)->set(0.164788, -2.15188e-09, 0.366653);
(vitr++)->set(-0.0288379, -2.15188e-09, 0.333695);
(vitr++)->set(-0.0453167, -2.15188e-09, 0.280139);
// pass the created vertex array to the points geometry object.
linesGeom->setVertexArray(vertices);
// set the colors as before, plus using the aobve
osg::Vec4Array* colors = new osg::Vec4Array;
colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
linesGeom->setColorArray(colors);
linesGeom->setColorBinding(osg::Geometry::BIND_OVERALL);
cube->setVertexArray( coords );
// set up the normals.
osg::Vec3Array* cubeNormals = new osg::Vec3Array;
cubeNormals->resize(6);
(*cubeNormals)[0].set(0.0f,0.0f,-1.0f);
(*cubeNormals)[1].set(1.0f,0.0f,0.0f);
(*cubeNormals)[2].set(0.0f,0.0f,1.0f);
(*cubeNormals)[3].set(-1.0f,0.0f,0.0f);
(*cubeNormals)[4].set(0.0f,1.0f,0.0f);
(*cubeNormals)[5].set(0.0f,-1.0f,0.0f);
cube->setNormalArray( cubeNormals );
cube->setNormalBinding( osg::Geometry::BIND_PER_PRIMITIVE );
// set the normal in the same way color.
osg::Vec3Array* normals = new osg::Vec3Array;
normals->push_back(osg::Vec3(0.0f,-1.0f,0.0f));
linesGeom->setNormalArray(normals);
linesGeom->setNormalBinding(osg::Geometry::BIND_OVERALL);
// ---------------------------------------
// Set up a StateSet to make the cube red
// ---------------------------------------
osg::StateSet* cubeState = new osg::StateSet();
osg::Material* redMaterial = new osg::Material();
osg::Vec4 red( 1.0f, 0.0f, 0.0f, 1.0f );
redMaterial->setDiffuse( osg::Material::FRONT_AND_BACK, red );
cubeState->setAttribute( redMaterial );
cube->setStateSet( cubeState );
// This time we simply use primitive, and hardwire the number of coords to use
// since we know up front,
linesGeom->addPrimitive(new osg::DrawArrays(osg::Primitive::LINE_STRIP,0,5));
// add the points geomtry to the geode.
geode->addDrawable(linesGeom);
}
// create LINE_LOOP
{
// create Geometry object to store all the vetices and lines primtive.
osg::Geometry* linesGeom = new osg::Geometry();
// this time we'll a C arrays to initilize the vertices.
osg::Vec3 myCoords[] =
{
osg::Vec3(0.741546, -2.15188e-09, 0.453167),
osg::Vec3(0.840418, -2.15188e-09, 0.304858),
osg::Vec3(1.12468, -2.15188e-09, 0.300738),
osg::Vec3(1.03816, 9.18133e-09, 0.453167),
osg::Vec3(0.968129, -2.15188e-09, 0.337815),
osg::Vec3(0.869256, -2.15188e-09, 0.531441)
};
int numCoords = sizeof(myCoords)/sizeof(osg::Vec3);
osg::Vec3Array* vertices = new osg::Vec3Array(numCoords,myCoords);
// pass the created vertex array to the points geometry object.
linesGeom->setVertexArray(vertices);
// set the colors as before, plus using the aobve
osg::Vec4Array* colors = new osg::Vec4Array;
colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
linesGeom->setColorArray(colors);
linesGeom->setColorBinding(osg::Geometry::BIND_OVERALL);
// set the normal in the same way color.
osg::Vec3Array* normals = new osg::Vec3Array;
normals->push_back(osg::Vec3(0.0f,-1.0f,0.0f));
linesGeom->setNormalArray(normals);
linesGeom->setNormalBinding(osg::Geometry::BIND_OVERALL);
// This time we simply use primitive, and hardwire the number of coords to use
// since we know up front,
linesGeom->addPrimitive(new osg::DrawArrays(osg::Primitive::LINE_LOOP,0,numCoords));
// add the points geomtry to the geode.
geode->addDrawable(linesGeom);
}
// now we'll stop creating seperate normal and color arrays
// since we are using the same values all the time, we'll just
// share the same ColorArray and NormalArrays..
// set the colors as before, use a ref_ptr rather than just
// standard C pointer, as that in the case of it not being
// assigned it will still be cleaned up automatically.
osg::ref_ptr<osg::Vec4Array> shared_colors = new osg::Vec4Array;
shared_colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
// same trick for shared normal.
osg::ref_ptr<osg::Vec3Array> shared_normals = new osg::Vec3Array;
shared_normals->push_back(osg::Vec3(0.0f,-1.0f,0.0f));
// create POLYGON
{
// create Geometry object to store all the vetices and lines primtive.
osg::Geometry* polyGeom = new osg::Geometry();
// this time we'll a C arrays to initilize the vertices.
osg::Vec3 myCoords[] =
{
osg::Vec3(-0.980488, -2.15188e-09, -0.094753),
osg::Vec3(-0.766264, -2.15188e-09, -0.0576758),
osg::Vec3(-0.807461, -2.15188e-09, -0.181267),
osg::Vec3(-1.0258, -2.15188e-09, -0.26778),
osg::Vec3(-1.0464, 9.18133e-09, -0.193626)
};
int numCoords = sizeof(myCoords)/sizeof(osg::Vec3);
osg::Vec3Array* vertices = new osg::Vec3Array(numCoords,myCoords);
// pass the created vertex array to the points geometry object.
polyGeom->setVertexArray(vertices);
// use the shared color array.
polyGeom->setColorArray(shared_colors.get());
polyGeom->setColorBinding(osg::Geometry::BIND_OVERALL);
// use the shared normal array.
polyGeom->setNormalArray(shared_normals.get());
polyGeom->setNormalBinding(osg::Geometry::BIND_OVERALL);
// This time we simply use primitive, and hardwire the number of coords to use
// since we know up front,
polyGeom->addPrimitive(new osg::DrawArrays(osg::Primitive::POLYGON,0,numCoords));
// add the points geomtry to the geode.
geode->addDrawable(polyGeom);
}
// create QUADS
{
// create Geometry object to store all the vetices and lines primtive.
osg::Geometry* polyGeom = new osg::Geometry();
osg::Vec3 myCoords[] =
{
osg::Vec3(-0.222464, 9.18133e-09, -0.13183),
osg::Vec3(-0.160668, 9.18133e-09, -0.0453167),
osg::Vec3(0.0247182, 9.18133e-09, -0.00823939),
osg::Vec3(0.0247182, 9.18133e-09, -0.156548),
osg::Vec3(0.13595, -2.15188e-09, -0.255421),
osg::Vec3(0.164788, 9.18133e-09, -0.0453167),
osg::Vec3(0.333696, 9.18133e-09, 0.0329576),
osg::Vec3(0.238942, -2.15188e-09, -0.251302)
};
int numCoords = sizeof(myCoords)/sizeof(osg::Vec3);
osg::Vec3Array* vertices = new osg::Vec3Array(numCoords,myCoords);
// pass the created vertex array to the points geometry object.
polyGeom->setVertexArray(vertices);
// use the shared color array.
polyGeom->setColorArray(shared_colors.get());
polyGeom->setColorBinding(osg::Geometry::BIND_OVERALL);
// use the shared normal array.
polyGeom->setNormalArray(shared_normals.get());
polyGeom->setNormalBinding(osg::Geometry::BIND_OVERALL);
// This time we simply use primitive, and hardwire the number of coords to use
// since we know up front,
polyGeom->addPrimitive(new osg::DrawArrays(osg::Primitive::QUADS,0,numCoords));
// add the points geomtry to the geode.
geode->addDrawable(polyGeom);
}
geode->addDrawable( cube );
return geode;
}
@@ -174,15 +354,9 @@ int main( int argc, char **argv )
// configure the viewer from the commandline arguments, and eat any
// parameters that have been matched.
viewer.readCommandLine(commandLine);
osg::Transform* myTransform = new osg::Transform();
myTransform->addChild( createGeometryCube() );
// move node in a circle at 90 degrees a sec.
myTransform->setAppCallback(new MyTransformCallback(myTransform,osg::inDegrees(90.0f)));
// add model to viewer.
viewer.addViewport( myTransform );
viewer.addViewport( createScene() );
// register trackball maniupulators.
viewer.registerCameraManipulator(new osgGA::TrackballManipulator);