sandbox/Antoonvh/scatter.h

    A Scattering bview function

    The formulation of the function is inspired by the functions under draw.h and assumes a global int by the name of n_part exists. It works in 2D and 3D.

    #if dimension == 3 
void glPointParameterfv(GLenum pname, const GLfloat * params);
#endif

struct _scatter {
  coord * loc;    // Coordinates
  float s, pc[3], coefs[3]; // point size, colour and distance attenuation coefs.
};

    The function is inspired by the functions under draw.h and assumes a global int by the name of n_part exists.

    trace
void scatter (struct _scatter p){
  bview * view = draw();
#if dimension == 2
  glTranslatef (0., 0., view->lc*view->fov/24.); //from draw_lines()
#else // Dimension == 3
  if (!p.coefs[0]){ // A guess:
    p.coefs[0] = 0.01;
    p.coefs[1] = 0.2;
    p.coefs[2] = 0.5;
  }
  glPointParameterfv(GL_POINT_DISTANCE_ATTENUATION, p.coefs);
#endif
  glEnable (GL_BLEND);
  glEnable (GL_POINT_SMOOTH);
  if (p.pc)
    glColor3f(p.pc[0], p.pc[1], p.pc[2]);
  if (!p.s)
    p.s = 20;
  glPointSize(p.s);
  glBegin (GL_POINTS);
  for (int j = 0; j < n_part; j++){
#if dimension == 2    
    glvertex2d (view, p.loc[j].x, p.loc[j].y);
#else // dimension == 3
    glvertex3d (view, p.loc[j].x, p.loc[j].y, p.loc[j].z);
#endif
  }
  //glDisable (GL_BLEND);
  //glDisable (GL_POINT_SMOOTH);
  glEnd();
  view->ni++; 
}

    Usage

    Test