OpenGL Torus

gistfile1.cpp

  void MyTorus(float u,float v,GLfloat fv[]){

  const float TWO_PI= 3.141f*2;
	float r=0.4f;
	float R=1.3f;
	float x_u=r*(float)cos(TWO_PI*u)+R;

	fv[0]=x_u*(float)cos(TWO_PI*v);	//x-coordinate
	fv[1]=r*(float)sin(TWO_PI*u);	//y-coordinate
	fv[2]=x_u*(float)sin(TWO_PI*v);	//z-coordinate
}
 
void main(){
    ...
  
    GLfloat vertex1[3];
  	GLfloat vertex2[3];
  	GLfloat vertex3[3];
  	GLfloat vertex4[3];
  
  	float u,v, delta_u=0.05f,delta_v=0.05f;
    
    glBegin(GL_QUADS); // each pair of glVertex will form a line
  
  	// draw body of cylinder
  	for(u=0;u<1;u+=delta_u){
  		for(v=0;v<1;v+=delta_v){
  			glColor3f(u,v,1-u*v);
  			MyTorus(u,v,vertex1);
  			MyTorus(u+delta_u,v,vertex2);
  			MyTorus(u+delta_u,v+delta_v,vertex3);
  			MyTorus(u,v+delta_v,vertex4);
  			glVertex3fv(vertex1);			
  			glVertex3fv(vertex2);
  			glVertex3fv(vertex3);
  			glVertex3fv(vertex4);
  		}
  	}
  
  	glEnd();
    
}