Hi All, I have the following pseudo-code:
main (){
…other init stuff
glutDisplayFunc (displayIt);
glViewport(0, 0, 640, 480);
glutMainLoop();
}
void displayIt() {
glMatrixMode(GL_PROJECTION); //set the camera
glLoadIdentity(); //load the identity matrix
glOrtho (-50 , 50 , -25 , 50 , -40 , 400);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
GLdouble eyeX = 10.0; GLdouble eyeY = 2.0;
GLdouble eyeZ = 7.0;
gluLookAt(10 , 2 , 7,
0,0,0,
0,1,0);
draw_a_sphere();
glFlush();
}
The code above results in a sphere being displayed…Cool.
Now instead of using glOrtho, I want to use gluPerspective();
and another routing that sets the MODELVIEW matrix
Im really confused regarding the ordering of how I should do operations… This is the bogus code I have now:
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45 , 64/48, 0.1 , 40);
//HOW do I know what to pick for the above,
// guess?
//This is a working function which
//manually loads the modelview matrix
set_ModelView_Matrix(eye, lookat, up);
draw_sphere();
glFlush();
}
The output of this code is a blank screen. Im not sure how to solve this problem.