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OpenSceneGraph-3.6
OpenSceneGraph/examples/osggeometry/osggeometry.cpp

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/* OpenSceneGraph example, osggeometry.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <osg/Geode>
#include <osg/Geometry>
#include <osg/Material>
#include <osg/Vec3>
#include <osg/MatrixTransform>
#include <osg/Texture2D>
#include <osg/PolygonStipple>
#include <osg/TemplatePrimitiveFunctor>
#include <osg/TemplatePrimitiveIndexFunctor>
#include <osg/io_utils>
#include <osgDB/ReadFile>
#include <osgDB/WriteFile>
#include <osgGA/TrackballManipulator>
#include <osgViewer/Viewer>
#include <osg/Math>
#include <iostream>
// This demo illustrates how to create the various different types of geometry that
// the osg::Geometry class can represent. This demo uses the OpenGL red book diagram of different
// OpenGL Primitives as a template for all the equivalent OpenSceneGraph Primitives. The OpenSceneGraph
// wraps OpenGL very thinly and therefore uses all the same enum and naming conventions. The coordinate data is also
// wrapped around OpenGL's vertex arrays and draw arrays/elements calls. Familiarity with
// OpenGL will help you understand the osg::Geometry class which encapsulate all this, or if you
// haven't learned OpenGL yet, learning osg::Geometry will help you understand how OpenGL
// works!
// 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 coordinate arrays required to specify the coordinates of your objects, and the
// primitives 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().
struct NormalPrint
{
void operator() (const osg::Vec3& v1, bool) const
{
std::cout << "\rpoint("<<v1<<")"<<std::endl;
}
void operator() (const osg::Vec3& v1,const osg::Vec3& v2, bool) const
{
std::cout << "\tline("<<v1<<") ("<<v2<<")"<<std::endl;
}
void operator() (const osg::Vec3& v1,const osg::Vec3& v2,const osg::Vec3& v3, bool) const
{
osg::Vec3 normal = (v2-v1)^(v3-v2);
normal.normalize();
std::cout << "\ttriangle("<<v1<<") ("<<v2<<") ("<<v3<<") "<<") normal ("<<normal<<")"<<std::endl;
}
void operator() (const osg::Vec3& v1,const osg::Vec3& v2,const osg::Vec3& v3,const osg::Vec3& v4, bool) const
{
osg::Vec3 normal = (v2-v1)^(v3-v2);
normal.normalize();
std::cout << "\tquad("<<v1<<") ("<<v2<<") ("<<v3<<") ("<<v4<<") "<<")"<<std::endl;
}
};
// decompose Drawable primitives into triangles, print out these triangles and computed normals.
void printPrimitives(const std::string& name, osg::Drawable& drawable)
{
std::cout<<name<<std::endl;
osg::TemplatePrimitiveFunctor<NormalPrint> tf;
drawable.accept(tf);
std::cout<<std::endl;
}
struct PrimitiveIndexPrint
{
void operator() (unsigned int p1) const
{
std::cout << "\tpoint("<<p1<<")"<<std::endl;
}
void operator() (unsigned int p1, unsigned int p2) const
{
std::cout << "\tline("<<p1<<", "<<p2<<")"<<std::endl;
}
void operator() (unsigned int p1, unsigned int p2, unsigned int p3) const
{
std::cout << "\ttriangle("<<p1<<", "<<p2<<", "<<p3<<")"<<std::endl;
}
void operator() (unsigned int p1, unsigned int p2, unsigned int p3, unsigned int p4) const
{
std::cout << "\tquad("<<p1<<", "<<p2<<", "<<p3<<", "<<p4<<")"<<std::endl;
}
};
// decompose Drawable primitives into triangles, print out these triangles and computed normals.
void printPrimitiveIndices(const std::string& name, osg::Drawable& drawable)
{
std::cout<<name<<std::endl;
osg::TemplatePrimitiveIndexFunctor<PrimitiveIndexPrint> pf;
drawable.accept(pf);
std::cout<<std::endl;
}
/// Create a scene with examples of the different types of OpenGL primitives.
/// The primitives are the same as shown in the OpenGL diagram loaded in
/// createBackground() (Images/primitives.gif).
osg::Node* createScene()
{
// create the Geode (Geometry Node) to contain all our osg::Geometry objects.
osg::Geode* geode = new osg::Geode();
// following are separate blocks for creating POINTS, LINES, LINE_STRIP, LINE_LOOP, POLYGON, QUADS,
// QUAD_STRIP, TRIANGLES, TRIANGLE_STRIP and TRIANGLE_FAN primitives. An image of these primitives
// is provided in the distribution: OpenSceneGraph-Data/Images/primitives.gif.
// create POINTS
{
// create Geometry object to store all the vertices and points primitive.
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 derived from both osg::Array
// and std::vector<>. osg::Array's are reference counted and hence shareable,
// which std::vector<> provides all the convenience, 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 consistency 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,0.0f,1.0f));
// pass the color array to points geometry, note the binding to tell the geometry
// that only use one color for the whole object.
pointsGeom->setColorArray(colors, osg::Array::BIND_OVERALL);
// Set the normal in the same way as the color.
// (0,-1,0) points toward the viewer, in the default coordinate
// setup. Even for POINTS, the normal specified here
// is used to determine how the geometry appears under different
// lighting conditions.
osg::Vec3Array* normals = new osg::Vec3Array;
normals->push_back(osg::Vec3(0.0f,-1.0f,0.0f));
pointsGeom->setNormalArray(normals, osg::Array::BIND_OVERALL);
// create and add a DrawArray Primitive (see include/osg/Primitive). The first
// parameter passed to the DrawArrays constructor is the Primitive::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->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POINTS,0,vertices->size()));
printPrimitiveIndices("POINTS indices", *pointsGeom);
// add the points geometry to the geode.
geode->addDrawable(pointsGeom);
}
// create LINES
{
// create Geometry object to store all the vertices and lines primitive.
osg::Geometry* linesGeom = new osg::Geometry();
// this time we'll preallocate 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 above
osg::Vec4Array* colors = new osg::Vec4Array;
colors->push_back(osg::Vec4(1.0f,1.0f,0.0f,1.0f));
linesGeom->setColorArray(colors, osg::Array::BIND_OVERALL);
// Set the normal in the same way as the color.
// As above for POINTS, this normal is used for the lighting
// calculations of the LINES.
osg::Vec3Array* normals = new osg::Vec3Array;
normals->push_back(osg::Vec3(0.0f,-1.0f,0.0f));
linesGeom->setNormalArray(normals, osg::Array::BIND_OVERALL);
// This time we simply use primitive, and hardwire the number of coords to use
// since we know up front,
linesGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::LINES,0,8));
printPrimitiveIndices("LINES indices", *linesGeom);
// add the points geometry to the geode.
geode->addDrawable(linesGeom);
}
// create LINE_STRIP
{
// create Geometry object to store all the vertices and lines primitive.
osg::Geometry* linesGeom = new osg::Geometry();
// this time we'll preallocate 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 above
osg::Vec4Array* colors = new osg::Vec4Array;
colors->push_back(osg::Vec4(1.0f,1.0f,0.0f,1.0f));
linesGeom->setColorArray(colors, osg::Array::BIND_OVERALL);
// Set the normal in the same way as the color (see note at POINTS, above).
osg::Vec3Array* normals = new osg::Vec3Array;
normals->push_back(osg::Vec3(0.0f,-1.0f,0.0f));
linesGeom->setNormalArray(normals, osg::Array::BIND_OVERALL);
// This time we simply use primitive, and hardwire the number of coords to use
// since we know up front,
linesGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::LINE_STRIP,0,5));
printPrimitiveIndices("LINE_STRIP indices", *linesGeom);
// add the points geometry to the geode.
geode->addDrawable(linesGeom);
}
// create LINE_LOOP
{
// create Geometry object to store all the vertices and lines primitive.
osg::Geometry* linesGeom = new osg::Geometry();
// this time we'll a C arrays to initialize 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 above
osg::Vec4Array* colors = new osg::Vec4Array;
colors->push_back(osg::Vec4(1.0f,1.0f,0.0f,1.0f));
linesGeom->setColorArray(colors, osg::Array::BIND_OVERALL);
// Set the normal in the same way as the color (see note at POINTS, above).
osg::Vec3Array* normals = new osg::Vec3Array;
normals->push_back(osg::Vec3(0.0f,-1.0f,0.0f));
linesGeom->setNormalArray(normals, osg::Array::BIND_OVERALL);
// This time we simply use primitive, and hardwire the number of coords to use
// since we know up front,
linesGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::LINE_LOOP,0,numCoords));
printPrimitiveIndices("LINE_LOOP indices", *linesGeom);
// add the points geometry to the geode.
geode->addDrawable(linesGeom);
}
// Now we'll stop creating separate 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,0.0f,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));
// Note on vertex ordering.
// According to the OpenGL diagram vertices should be specified in a clockwise direction.
// In reality you need to specify coords for polygons in a anticlockwise direction
// for their front face to be pointing towards you; get this wrong and you could
// find back face culling removing the wrong faces of your models. The OpenGL diagram
// is just plain wrong, but it's a nice diagram so we'll keep it for now!
// create POLYGON
{
// create Geometry object to store all the vertices and lines primitive.
osg::Geometry* polyGeom = new osg::Geometry();
// this time we'll use C arrays to initialize the vertices.
// note, anticlockwise ordering.
// note II, OpenGL polygons must be convex, planar polygons, otherwise
// undefined results will occur. If you have concave polygons or ones
// that cross over themselves then use the osgUtil::Tessellator to fix
// the polygons into a set of valid polygons.
osg::Vec3 myCoords[] =
{
osg::Vec3(-1.0464, 0.0f, -0.193626),
osg::Vec3(-1.0258, 0.0f, -0.26778),
osg::Vec3(-0.807461, 0.0f, -0.181267),
osg::Vec3(-0.766264, 0.0f, -0.0576758),
osg::Vec3(-0.980488, 0.0f, -0.094753)
};
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(), osg::Array::BIND_OVERALL);
// use the shared normal array.
polyGeom->setNormalArray(shared_normals.get(), osg::Array::BIND_OVERALL);
// This time we simply use primitive, and hardwire the number of coords to use
// since we know up front,
polyGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POLYGON,0,numCoords));
printPrimitiveIndices("POLYGON indices", *polyGeom);
printPrimitives("POLYGON vertices", *polyGeom);
// add the points geometry to the geode.
geode->addDrawable(polyGeom);
}
// create QUADS
{
// create Geometry object to store all the vertices and lines primitive.
osg::Geometry* polyGeom = new osg::Geometry();
// note, anticlockwise ordering.
osg::Vec3 myCoords[] =
{
osg::Vec3(0.0247182, 0.0f, -0.156548),
osg::Vec3(0.0247182, 0.0f, -0.00823939),
osg::Vec3(-0.160668, 0.0f, -0.0453167),
osg::Vec3(-0.222464, 0.0f, -0.13183),
osg::Vec3(0.238942, 0.0f, -0.251302),
osg::Vec3(0.333696, 0.0f, 0.0329576),
osg::Vec3(0.164788, 0.0f, -0.0453167),
osg::Vec3(0.13595, 0.0f, -0.255421)
};
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(), osg::Array::BIND_OVERALL);
// use the shared normal array.
polyGeom->setNormalArray(shared_normals.get(), osg::Array::BIND_OVERALL);
// This time we simply use primitive, and hardwire the number of coords to use
// since we know up front,
polyGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,numCoords));
printPrimitiveIndices("QUADS indices", *polyGeom);
printPrimitives("QUADS vertices", *polyGeom);
// add the points geometry to the geode.
geode->addDrawable(polyGeom);
}
// create QUAD_STRIP
{
// create Geometry object to store all the vertices and lines primitive.
osg::Geometry* polyGeom = new osg::Geometry();
// note, first coord at top, second at bottom, reverse to that buggy OpenGL image..
osg::Vec3 myCoords[] =
{
osg::Vec3(0.733306, -2.15188e-09, -0.0741545),
osg::Vec3(0.758024, -2.15188e-09, -0.205985),
osg::Vec3(0.885735, -2.15188e-09, -0.0576757),
osg::Vec3(0.885735, -2.15188e-09, -0.214224),
osg::Vec3(0.964009, 9.18133e-09, -0.0370773),
osg::Vec3(1.0464, 9.18133e-09, -0.173027),
osg::Vec3(1.11232, -2.15188e-09, 0.0123591),
osg::Vec3(1.12468, 9.18133e-09, -0.164788),
};
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(), osg::Array::BIND_OVERALL);
// use the shared normal array.
polyGeom->setNormalArray(shared_normals.get(), osg::Array::BIND_OVERALL);
// This time we simply use primitive, and hardwire the number of coords to use
// since we know up front,
polyGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUAD_STRIP,0,numCoords));
printPrimitiveIndices("QUAD_STRIP indices", *polyGeom);
printPrimitives("QUAD_STRIP vertices", *polyGeom);
// add the points geometry to the geode.
geode->addDrawable(polyGeom);
}
// create TRIANGLES, TRIANGLE_STRIP and TRIANGLE_FAN all in one Geometry/
{
// create Geometry object to store all the vertices and lines primitive.
osg::Geometry* polyGeom = new osg::Geometry();
// note, first coord at top, second at bottom, reverse to that buggy OpenGL image..
osg::Vec3 myCoords[] =
{
// TRIANGLES 6 vertices, v0..v5
// note in anticlockwise order.
osg::Vec3(-1.12056, -2.15188e-09, -0.840418),
osg::Vec3(-0.95165, -2.15188e-09, -0.840418),
osg::Vec3(-1.11644, 9.18133e-09, -0.716827),
// note in anticlockwise order.
osg::Vec3(-0.840418, 9.18133e-09, -0.778623),
osg::Vec3(-0.622074, 9.18133e-09, -0.613835),
osg::Vec3(-1.067, 9.18133e-09, -0.609715),
// TRIANGLE STRIP 6 vertices, v6..v11
// note defined top point first,
// then anticlockwise for the next two points,
// then alternating to bottom there after.
osg::Vec3(-0.160668, -2.15188e-09, -0.531441),
osg::Vec3(-0.160668, -2.15188e-09, -0.749785),
osg::Vec3(0.0617955, 9.18133e-09, -0.531441),
osg::Vec3(0.168908, -2.15188e-09, -0.753905),
osg::Vec3(0.238942, -2.15188e-09, -0.531441),
osg::Vec3(0.280139, -2.15188e-09, -0.823939),
// TRIANGLE FAN 5 vertices, v12..v16
// note defined in anticlockwise order.
osg::Vec3(0.844538, 9.18133e-09, -0.712708),
osg::Vec3(1.0258, 9.18133e-09, -0.799221),
osg::Vec3(1.03816, -2.15188e-09, -0.692109),
osg::Vec3(0.988727, 9.18133e-09, -0.568518),
osg::Vec3(0.840418, -2.15188e-09, -0.506723),
};
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(), osg::Array::BIND_OVERALL);
// use the shared normal array.
polyGeom->setNormalArray(shared_normals.get(), osg::Array::BIND_OVERALL);
// This time we simply use primitive, and hardwire the number of coords to use
// since we know up front,
polyGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::TRIANGLES,0,6));
polyGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::TRIANGLE_STRIP,6,6));
polyGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::TRIANGLE_FAN,12,5));
// polygon stipple
osg::StateSet* stateSet = new osg::StateSet();
polyGeom->setStateSet(stateSet);
#if !defined(OSG_GLES1_AVAILABLE) && !defined(OSG_GLES2_AVAILABLE) && !defined(OSG_GL3_AVAILABLE)
osg::PolygonStipple* polygonStipple = new osg::PolygonStipple;
stateSet->setAttributeAndModes(polygonStipple,osg::StateAttribute::OVERRIDE|osg::StateAttribute::ON);
#endif
printPrimitiveIndices("Triangles/Strip/Fan indices", *polyGeom);
printPrimitives("Triangles/Strip/Fan vertices", *polyGeom);
// add the points geometry to the geode.
geode->addDrawable(polyGeom);
}
// Turn off the lighting on the geode. This is not required for setting up
// the geometry. However, by default, lighting is on, and so the normals
// above are used to light the geometry.
// - With lighting turned off, the geometry has the same color
// regardless of the angle you view it from.
// - With lighting turned on, the colors darken as the light moves
// away from the normal.
geode->getOrCreateStateSet()->setMode(GL_LIGHTING,
osg::StateAttribute::OFF | osg::StateAttribute::PROTECTED);
return geode;
}
// define a node callback to animate a transform as a cycle along the y axis, between 0 and 2.0.
class MyTransformCallback : public osg::NodeCallback
{
public:
MyTransformCallback(float angularVelocity)
{
_angular_velocity = angularVelocity;
}
virtual void operator() (osg::Node* node, osg::NodeVisitor* nv)
{
osg::MatrixTransform* transform = dynamic_cast<osg::MatrixTransform*>(node);
if (nv && transform && nv->getFrameStamp())
{
double time = nv->getFrameStamp()->getSimulationTime();
transform->setMatrix(osg::Matrix::translate(0.0f,1.0f+cosf(time*_angular_velocity),0.0f));
}
// must continue subgraph traversal.
traverse(node,nv);
}
protected:
float _angular_velocity;
};
/// Create a quad that sits behind the geometry from createScene()
/// and shows the image from the OpenGL docs that geometry duplicates.
osg::Node* createBackground()
{
// we'll create a texture mapped quad to sit behind the Geometry
osg::ref_ptr<osg::Image> image = osgDB::readRefImageFile("Images/primitives.gif");
if (!image) return NULL;
// create Geometry object to store all the vertices and lines primitive.
osg::Geometry* polyGeom = new osg::Geometry();
// note, anticlockwise ordering.
osg::Vec3 myCoords[] =
{
osg::Vec3(-1.22908f,0.0f,1.0f),
osg::Vec3(-1.22908f,0.0f,-1.0f),
osg::Vec3(1.22908f,0.0f,-1.0f),
osg::Vec3(1.22908f,0.0f,1.0f)
};
int numCoords = sizeof(myCoords)/sizeof(osg::Vec3);
// pass the created vertex array to the points geometry object.
polyGeom->setVertexArray(new osg::Vec3Array(numCoords,myCoords));
osg::Vec4Array* colors = new osg::Vec4Array;
colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
polyGeom->setColorArray(colors, osg::Array::BIND_OVERALL);
// Set the normal in the same way as the color.
osg::Vec3Array* normals = new osg::Vec3Array;
normals->push_back(osg::Vec3(0.0f,-1.0f,0.0f));
polyGeom->setNormalArray(normals, osg::Array::BIND_OVERALL);
osg::Vec2 myTexCoords[] =
{
osg::Vec2(0,1),
osg::Vec2(0,0),
osg::Vec2(1,0),
osg::Vec2(1,1)
};
int numTexCoords = sizeof(myTexCoords)/sizeof(osg::Vec2);
// pass the created tex coord array to the points geometry object,
// and use it to set texture unit 0.
polyGeom->setTexCoordArray(0,new osg::Vec2Array(numTexCoords,myTexCoords));
// we'll use indices and DrawElements to define the primitive this time.
unsigned short myIndices[] =
{
0,
1,
3,
2
};
int numIndices = sizeof(myIndices)/sizeof(unsigned short);
// There are three variants of the DrawElements osg::Primitive, UByteDrawElements which
// contains unsigned char indices, UShortDrawElements which contains unsigned short indices,
// and UIntDrawElements which contains ... unsigned int indices.
// The first parameter to DrawElements is
polyGeom->addPrimitiveSet(new osg::DrawElementsUShort(osg::PrimitiveSet::TRIANGLE_STRIP,numIndices,myIndices));
// new we need to add the texture to the Drawable, we do so by creating a
// StateSet to contain the Texture2D StateAttribute.
osg::StateSet* stateset = new osg::StateSet;
// set up the texture.
osg::Texture2D* texture = new osg::Texture2D;
texture->setImage(image);
stateset->setTextureAttributeAndModes(0, texture,osg::StateAttribute::ON);
polyGeom->setStateSet(stateset);
printPrimitiveIndices("DrawElementsUShort TRIANGLE_STRIP", *polyGeom);
// create the Geode (Geometry Node) to contain all our osg::Geometry objects.
osg::Geode* geode = new osg::Geode();
// add the points geometry to the geode.
geode->addDrawable(polyGeom);
// Turn off the lighting (see note in createScene(), above).
geode->getOrCreateStateSet()->setMode(GL_LIGHTING,
osg::StateAttribute::OFF | osg::StateAttribute::PROTECTED);
// create a transform to move the background back and forward with.
osg::MatrixTransform* transform = new osg::MatrixTransform();
transform->setUpdateCallback(new MyTransformCallback(1.0f));
transform->addChild(geode);
return transform;
}
int main(int, char **)
{
// create the model
osg::Group* root = new osg::Group;
root->addChild( createScene() );
root->addChild( createBackground() );
//osgDB::writeNodeFile(*root,"geometry.osgt");
osgViewer::Viewer viewer;
// add model to viewer.
viewer.setSceneData( root );
return viewer.run();
}
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