#ifndef GJK_H
#define GJK_H

#define GJK_DEBUG RTC

#if GJK_DEBUG
extern u32 gjk_debug_steps;
#endif

struct gjk_menkowski_point {
    struct v2 p0;  /* Support point of first shape in dir */
    struct v2 p1;  /* Support point of second shape in -dir */
    struct v2 p;   /* Menkowski difference point */
};

struct gjk_simplex {
    u32 len;
    struct gjk_menkowski_point a, b, c;
};

/* Returns simple true or false indicating shape collision */
b32 gjk_boolean(struct v2_array shape0, struct v2_array shape1);

struct gjk_contact_pair {
    struct v2 p0, p1;
};

struct gjk_prototype { struct v2 points[64]; u32 len; };
struct gjk_contact_points_result {

    struct gjk_contact_pair pairs[2];
    u32 num_pairs;

    /* For debugging */
    b32 solved;
    struct gjk_simplex simplex;
    struct gjk_prototype prototype;
};

struct gjk_contact_points_result gjk_contact_points(struct v2_array shape0, struct v2_array shape1);

struct v2_array menkowski(struct arena *arena, struct v2_array poly0, struct v2_array poly1);

struct v2_array cloud(struct arena *arena, struct v2_array poly0, struct v2_array poly1);

#if 0
struct gjk_extended_result {
    b32 colliding;
    struct v2 p0, p1;  /* Closest points (or penetrating points if colliding) on each shape */

    /* For debugging */
    b32 solved;
    struct gjk_simplex simplex;
    struct gjk_prototype prototype;
};

/* Returns whether shapes are colliding well as closest / penetrating points on each shape.  */
struct gjk_extended_result gjk_extended(struct v2_array shape0, struct v2_array shape1);
#endif

#if 0

struct gjk_extended_result {
    b32 colliding;
    struct v2 p0, p1;  /* Closest points on each shape */

    /* For debugging */
    struct gjk_simplex simplex;
    b32 velocity_intersects;
    b32 solved;
    struct gjk_prototype prototype;
};

struct gjk_extended_result gjk_extended(struct v2_array shape0, struct v2_array shape1, struct v2 linear_velocity);

struct v2_array menkowski(struct arena *arena, struct v2_array poly0, struct v2_array poly1, struct v2 linear_velocity);

struct v2_array cloud(struct arena *arena, struct v2_array poly0, struct v2_array poly1, struct v2 linear_velocity);

#endif

#endif