Having trouble controling camera FPS style - c++

Question

I've started openGL with C++ recently. I don't have that much experience in C++ but a good experience in other language.
I'm currently working on controlling a camera FPS style to start a small game and add things one by one while I learn. I know this question has been asked often and I read trough a lot of tutorial/Forum.
I did good with gluLookAt(); but I've seen it's not the best way to control FPS camera. I've been working using matrix stack lately and I'm a bit lost.
I have a code working but my rotation seems to be around the central axis or something like that. I also get some weird control that might be linked to Gimbal Locking. I'm experience with them and will use them as soon as I have something good enough.
Why am I rotating around the central axis instead of my camera axis ?
Any insight on how to use glPopMatrix() and glPushMatrix() in the context of my code? I understand the functions but can't understand how to use them when controlling camera.
I tried to keep the most important code and leave the rest, the render and the main. Mouse and keyboard controls are working as intented :
void renderScene(void) {
if(init==1){
glTranslatef(0.0f,-1.0f,-5.0f);
init = 0;
}
// Clear Color and Depth BuffersWDW
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// Reset transformations
//glLoadIdentity();
// Set the camera
glTranslatef(-deltaStrafe,0,-deltaMove);
glRotatef(Pitch,1.0f,0.0f,0.0f);
glRotatef(Yaw,0.0f,1.0f,0.0f);
// Draw ground
glColor3f(0.9f, 0.9f, 0.9f);
glBegin(GL_QUADS);
glVertex3f(-50.0f, 0.0f, -50.0f);
glVertex3f(-50.0f, 0.0f, 50.0f);
glVertex3f( 50.0f, 0.0f, 50.0f);
glVertex3f( 50.0f, 0.0f, -50.0f);
glEnd();
// Draw 36 SnowMan
for(int i = -3; i < 3; i++)
for(int j=-3; j < 3; j++) {
glPushMatrix();
glTranslatef(i*10.0,0,j * 10.0);
if(i==j){
drawSnowMan();
}
else{
drawTree();
}
glPopMatrix();
}
glutSwapBuffers();
printConsole();
}
and the main function :
int main(int argc, char **argv) {
// init GLUT and create window
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
glutInitWindowPosition(780,0);
glutInitWindowSize(800,800);
glutCreateWindow("Physic Engine");
// register callbacks
glutDisplayFunc(renderScene);
glutReshapeFunc(changeSize);
glutIdleFunc(renderScene);
// OpenGL init
glEnable(GL_DEPTH_TEST);
// enter GLUT event processing cycle
glutMainLoop();
return 1;
}
Thanks!
Edit : Changed the order of rotation/translation as suggested to :
glRotatef(Yaw,0.0f,1.0f,0.0f);
glRotatef(Pitch,1.0f,0.0f,0.0f);
glTranslatef(-deltaStrafe,0,-deltaMove);
However my camera aren't rotation on their own axis. They seems to be rotation around center axis and I'm poiting toward (0,0,0) if I don't move. How can I rotate around the camera axis as a standard FPS ? Thanks.

Answer 1

What you did is translate then rotate.
Rotate Camera, translate camera, and then draw your scene. Rotation is always applied around the origin, so if you rotate and then translate, you apply the rotation, and then translate the rotated frame of reference.
You should also reverse the order of pitch and yaw, for similar reasons.
You should also limit pitch such that you don't rotate more than 90 degrees upward or downward, or it might be disorientating.
Also, quaternions are not necessary unless you are applying rotations on arbitrary axis.