[onorinbejasus]

I am getting an EXC_BAD_ACCESS, but I have no idea where. GDB is telling me:

0x000000010000664d in __gnu_cxx::new_allocator<gfx::TVec2<float> >::construct () at /usr/include/c++/4.2.1/ext/new_allocator.h:107 107 { ::new(__p) _Tp(__val); }

Any ideas?

[Suryc]

So you can't figure out where it is WITH the source code, yet expect us to find out what the problem is WITHOUT it?

[onorinbejasus]

So I've isolated my error. Does anyone know what this means:

Undefined symbols:
"typeinfo for Constraint", referenced from:
typeinfo for RodConstraintin RodConstraint.o
typeinfo for CircularWireConstraintin CircularWireConstraint.o
ld: symbol(s) not found

I am not looking for a coding fix, just an explanation.

[onorinbejasus]

Here is more of an explanation:

I have an abstract class:

/* Abstract constraint class */
/* Timothy Luciani */

#include "gfx/vec2.h"
#include <vector>

#pragma once

class Constraint{

	public:
		virtual Vec2f *gradient() = 0;
		virtual Vec2f *timeDerivative() = 0;
		virtual std::vector<int> get_particle_index() = 0; // get the particle index
		virtual std::vector<Vec2f> get_velocities() = 0; // get the particle velocity
		virtual void draw();		
};

which I am extending here:

#include "Particle.h"
#include "Constraint.h"
#include <vector>

#define EULER 0
#define SORK 1
#define FORK 2

#pragma once

class CircularWireConstraint: public Constraint{
 
 public:
  CircularWireConstraint(Particle *p, const Vec2f & center, const double radius);

  void draw();
  Vec2f *gradient();
//  Vec2f *timeDerivative();
  std::vector<int> get_particle_index();
  std::vector<Vec2f> get_velocities(); // get the particle velocity
 
 private:

  	Particle *m_p; // current particle
  	Vec2f const m_center; // center of circle
  	double const m_radius; // radius of circle
  
};

#include "CircularWireConstraint.h"
#include <GLUT/glut.h>

#define PI 3.1415926535897932384626433832795

/*--------------------------------------------------------------------
					Draw Circle
--------------------------------------------------------------------*/

static void draw_circle(const Vec2f & vect, float radius)
{
	glBegin(GL_LINE_LOOP);
	glColor3f(0.0,1.0,0.0); 
	for (int i=0; i<360; i=i+18)
	{
		float degInRad = i*PI/180;
		glVertex2f(vect[0]+cos(degInRad)*radius,vect[1]+sin(degInRad)*radius);
	}
	glEnd();
}

/*--------------------------------------------------------------------
					Default Constructor
--------------------------------------------------------------------*/

CircularWireConstraint::CircularWireConstraint(Particle *p, const Vec2f & center, const double radius) :
	m_p(p), m_center(center), m_radius(radius) {
	
}

/*--------------------------------------------------------------------
					Draw Cirlce Constraint
--------------------------------------------------------------------*/
void CircularWireConstraint::draw() // draw the constraint circle
{
	draw_circle(m_center, m_radius);
}


/*--------------------------------------------------------------------
					Find the gradient
--------------------------------------------------------------------*/

Vec2f *CircularWireConstraint::gradient(){ 

	Vec2f *gradient = new Vec2f(0.0,0.0); // create new vector
	
	*gradient = 2 * (m_p->getVector(1,0) - m_center);
	
	return gradient; // return gradient
}
/*--------------------------------------------------------------------
					Find the time derivative
--------------------------------------------------------------------*/
Vec2f *CircularWireConstraint::timeDerivative(){

	Vec2f *time = new Vec2f(0.0, 0.0);
	
	*time = 2 * (m_p->getVector(0,1) - m_center);
	
	return time;

} 

/*--------------------------------------------------------------------
					Get Particle Index
--------------------------------------------------------------------*/

std::vector<int> CircularWireConstraint::get_particle_index(){
	
	std::vector<int> index;
	index.push_back(m_p->get_particle_index()); // return the index of the particles
	
	return index; // return the particles index
}

/*--------------------------------------------------------------------
					Get Particle Index
--------------------------------------------------------------------*/

std::vector<Vec2f> CircularWireConstraint::get_velocities(){

	std::vector<Vec2f> velocity; // make vector
	
	velocity.push_back(m_p->getVector(0,1)); // add velocities
	
	return velocity;
}

When I compile it, I get the error I specified earlier

[jimblumberg]

Please post the complete error messages. It would also help to see how you are using this class (a small compilable snippet that demonstrates the problem).

I would also suggest include guards instead of or with the #pragma once. As explained in the following link: include guards


Jim