OpenGL (SDL,C++) - 3d collision detection - functions.h

/*3d Collision detection (sphere-sphere, plane-sphere), I only upload the functions.cpp, the functions.h and third.cpp, the rest of the files are not changed. The third.cpp already contain the material of the next tutorial, because I recordedit after this one.
http://www.youtube.com/user/thecplusplusguy
*/
#include <SDL/SDL.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <cstdlib>
#include <vector>
#include <string>
#include <algorithm>
#include <fstream>
#include <cstdio>
#include <iostream>
#include <cmath>
#include "objloader.h"
#ifndef FUNCTION_H
#define FUNCTION_H

void drawCube(float size);
void drawSkybox(float size);
void initskybox();
void killskybox();
void lockCamera();
void moveCamera(float,float);
void moveCamerraUp(float,float);
void Control(float,float,bool);
void UpdateCamera();
unsigned int loadTexture(const char*);
bool raysphere(float xc,float yc, float zc,float xd,float yd, float zd,float xs,float ys, float zs,float r,float* dist=NULL,coordinate* point=NULL);
bool rayplane(float nx,float ny,float nz,float xs,float ys,float zs,float xd,float yd,float zd,coordinate p1,coordinate p2,coordinate p3,coordinate p4,float* dist=NULL,coordinate* point=NULL);
float trianglearea(coordinate p1,coordinate p2,coordinate p3);
bool spheresphere(coordinate& c1,float r1,coordinate c2,float r2);
float pointdistance(coordinate c1,coordinate c2);
void moveTo(coordinate c);
coordinate camPos();
bool sphereplane(coordinate& sp, coordinate vn,coordinate p1,coordinate p2,coordinate p3, coordinate p4,float r);
void loadAnimation(std::vector<unsigned int>&,std::string,int);
#endif