#ifndef UTIL_H
#define UTIL_H

#include <GL/gl.h>

#include <vector>

using namespace std;

typedef int soffs; // 32 bit
typedef unsigned int uoffs;
#define OFFS_BITS 31
#define SOFFS_MIN (soffs)-(1 << (OFFS_BITS - 1))
#define MAXEXTENT ((1UL << OFFS_BITS) - 1)

#define GLFLOAT_MAX 1e30
#define GLFLOAT_MIN -1e30

struct sector {
  soffs x, y, z;

  void offset (int subindex, uoffs extent)
  {
    if (subindex & 1) x += extent;
    if (subindex & 2) y += extent;
    if (subindex & 4) z += extent;
  }
};

struct point {
  GLfloat x, y, z;

  point () { };
  point (GLfloat x, GLfloat y, GLfloat z) : x(x), y(y), z(z) { };
};

struct colour {
  GLfloat r, g, b, a;
  colour (GLfloat r = 1., GLfloat g = 1., GLfloat b = 1., GLfloat a = 1.) : r(r), g(g), b(b), a(a) { };
};

struct vec3 {
  GLfloat x, y, z;
  vec3 () { };
  vec3 (GLfloat x, GLfloat y, GLfloat z) : x(x), y(y), z(z) { };

  const vec3 operator -() const
  { return vec3 (-x, -y, -z); }
};

const vec3 normalize (const vec3 &v);
const vec3 cross (const vec3 &a, const vec3 &b);
GLfloat dot (const vec3 &a, const vec3 &b);

struct texc {
  GLfloat s, t;
  texc () { };
  texc (GLfloat s, GLfloat t) : s(s), t(t) { };
};

struct box {
  point a, b;

  void reset ()
  {
    a = point (GLFLOAT_MAX, GLFLOAT_MAX, GLFLOAT_MAX);
    b = point (GLFLOAT_MIN, GLFLOAT_MIN, GLFLOAT_MIN);
  }

  void add (const box &o);
  void add (const point &p);
};

struct light {
  point p;
  colour c;
  GLfloat intensity;
  GLfloat radius;
};

struct material {
  colour diffuse, specular, emission;
  GLfloat shininess;
};

struct entity_base;
struct draw_context;

#endif