#ifndef COLLIDER_H
#define COLLIDER_H

#if COLLIDER_DEBUG
extern u32 collider_debug_steps;
#endif

struct collider_support_point {
    struct v2 p;
    u32 i;  /* Index of original point in shape */
};

struct collider_menkowski_point {
    struct v2 p;    /* Menkowski difference point */
    struct collider_support_point s0;   /* Support point of first shape in dir */
    struct collider_support_point s1;   /* Support point of second shape in -dir */
};

struct collider_menkowski_simplex {
    u32 len;
    struct collider_menkowski_point a, b, c;
};

struct collider_menkowski_feature {
    u32 len;
    struct collider_menkowski_point a, b;
};

struct collider_collision_point {
    struct v2 point;
    f32 separation;
    u32 id;  /* Based on polygon edge-to-edge */
};

struct collider_prototype { struct v2 points[64]; u32 len; };
struct collider_collision_points_result {
    struct v2 normal;
    struct collider_collision_point points[2];
    u32 num_points;

    /* For debugging */
    b32 solved;
    struct collider_menkowski_simplex simplex;
    struct collider_prototype prototype;

    /* Clipping faces */
    struct v2 a0, b0, a1, b1;
    struct v2 a0_clipped, b0_clipped, a1_clipped, b1_clipped;
};

struct collider_closest_points_result {
    struct v2 p0, p1;
    b32 colliding;

    /* For debugging */
    b32 solved;
    struct collider_menkowski_simplex simplex;
    struct collider_prototype prototype;
};

struct collider_support_point collider_get_support_point(struct collider_shape *a, struct xform xf, struct v2 dir);

struct collider_collision_points_result collider_collision_points(struct collider_shape *shape0, struct collider_shape *shape1, struct xform xf0, struct xform xf1);

struct collider_closest_points_result collider_closest_points(struct collider_shape *shape0, struct collider_shape *shape1, struct xform xf0, struct xform xf1);

f32 collider_time_of_impact(struct collider_shape *c0, struct collider_shape *c1, struct xform xf0_t0, struct xform xf1_t0, struct xform xf0_t1, struct xform xf1_t1, f32 tolerance, u32 max_iterations);

struct v2_array menkowski(struct arena *arena, struct collider_shape *shape0, struct collider_shape *shape1, struct xform xf0, struct xform xf1, u32 detail);
struct v2_array cloud(struct arena *arena, struct collider_shape *shape0, struct collider_shape *shape1, struct xform xf0, struct xform xf1);

#endif