my motion blur don't work

OpenGL OpenGL: Advanced Coding
1

i have a black window,
what can i do ? Can you help me ?
this is a part of the code :

void display ()
{

glEnableClientState (GL_VERTEX_ARRAY);
glEnableClientState (GL_NORMAL_ARRAY);

glPolygonMode (GL_FRONT_AND_BACK, GL_FILL) ;

//glScalef (3.0, 3.0, 3.0) ;

int objectCounter ;
const datas *pointerArrayStruct=lecteur->getArrayStruct() ;
const int *pointerNumberTotalOfVertices= lecteur->getNumberTotalOfVertices() ;
int MaximumObject=lecteur->getA() ; //affecte le nombre maximum d’objets

glClear (GL_ACCUM_BUFFER_BIT) ;

for (l=0 ; l<=10 ; l++)
{
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT /| GL_ACCUM_BUFFER_BIT/) ;

  glRotatef (10.0, 0.0, 1.0, 0.0) ;
  for (objectCounter=0 ; objectCounter < MaximumObject ; objectCounter++)
  {	
  	glVertexPointer (3, GL_FLOAT, 0, &(pointerArrayStruct[objectCounter].verticesArray[0][0]));
  	glNormalPointer (GL_FLOAT, 0, &(pointerArrayStruct[objectCounter].normalsArray[0][0]));
  	glDrawElements (GL_TRIANGLES, pointerNumberTotalOfVertices[objectCounter],
  		GL_UNSIGNED_INT,&(pointerArrayStruct[objectCounter].numberOfVerticesArray[0][0])) ;
  }
  glAccum(GL_ACCUM, 1.0); 
  //glAccum(GL_RETURN, 1.0);
  //glutSwapBuffers() ;

}

glAccum(GL_RETURN, 1.0);
glutSwapBuffers() ;

}

void main (int argc, char** argv)
{

  lecteur = new ReadAnAse ;
  //cout<<"hello"<<endl ;
  
  glutInit (&argc, argv) ;
  glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH | GLUT_ACCUM) ;
  glutInitWindowSize (640, 480) ;
  glutInitWindowPosition (250,250) ;
  glutCreateWindow (argv [0]) ;

  glEnable( GL_DEPTH_TEST );

  //glutKeyboardFunc (keyboard) ;
  glutReshapeFunc (reshape) ;
  glutDisplayFunc (display) ;
  glutMainLoop () ;

}

2

If you remove (comment out) the accumulation buffer code, does your scene draw as expected?

3

If yes,

  • Query how many bits your accumulation buffers has, maybe you pixelformat has none.
  • The glAccum(GL_RETURN, value) should normalize the summed colors. In your case value should be 1/11. Your image should have been too bright.
  • Does it help if you add a glFinish() before the glAccum(GL_ACCUM, 1.0)? Mustn’t be necessary, though.