Something

struct perspective {
	float xangle, yangle;
	float scale;
	float sensitivity;
};

struct perspective glPerspective;

void
mousehandler(SDL_MouseMotionEvent mouseEvent)
{

	if (moveperspective) {
		glPerspective.xangle += mouseEvent.xrel;
		glPerspective.yangle += mouseEvent.yrel;
		updatePerspective();
	}
}

void
updatePerspective(void)
{	
	glMatrixMode(GL_MODELVIEW);

	glLoadIdentity();
	glRotatef(glPerspective.yangle * glPerspective.sensitivity, 1, 0, 0);
	glRotatef(glPerspective.xangle * glPerspective.sensitivity, 0, 1, 0);
}