/*************************************************************************/
/*  shape_2d_sw.h                                                        */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
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/*************************************************************************/
#ifndef SHAPE_2D_2DSW_H
#define SHAPE_2D_2DSW_H

#include "servers/physics_2d_server.h"
#define _SEGMENT_IS_VALID_SUPPORT_TRESHOLD 0.99998

/*

SHAPE_LINE, ///< plane:"plane"
SHAPE_SEGMENT, ///< real_t:"length"
SHAPE_CIRCLE, ///< real_t:"radius"
SHAPE_RECTANGLE, ///< vec3:"extents"
SHAPE_CONVEX_POLYGON, ///< array of planes:"planes"
SHAPE_CONCAVE_POLYGON, ///< Vector2 array:"triangles" , or Dictionary with "indices" (int array) and "triangles" (Vector2 array)
SHAPE_CUSTOM, ///< Server-Implementation based custom shape, calling shape_create() with this value will result in an error

*/

class Shape2DSW;

class ShapeOwner2DSW : public RID_Data{
public:

	virtual void _shape_changed()=0;
	virtual void remove_shape(Shape2DSW *p_shape)=0;

	virtual ~ShapeOwner2DSW() {}
};

class Shape2DSW : public RID_Data {

	RID self;
	Rect2 aabb;
	bool configured;
	real_t custom_bias;

	Map<ShapeOwner2DSW*,int> owners;
protected:

	void configure(const Rect2& p_aabb);
public:

	_FORCE_INLINE_ void set_self(const RID& p_self) { self=p_self; }
	_FORCE_INLINE_ RID get_self() const {return  self; }

	virtual Physics2DServer::ShapeType get_type() const=0;

	_FORCE_INLINE_ Rect2 get_aabb() const { return aabb; }
	_FORCE_INLINE_ bool is_configured() const { return configured; }

	virtual bool is_concave() const { return false; }

	virtual bool contains_point(const Vector2& p_point) const=0;

	virtual void project_rangev(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const=0;
	virtual void project_range_castv(const Vector2& p_cast, const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const=0;
	virtual Vector2 get_support(const Vector2& p_normal) const;
	virtual void get_supports(const Vector2& p_normal,Vector2 *r_supports,int & r_amount) const=0;

	virtual bool intersect_segment(const Vector2& p_begin,const Vector2& p_end,Vector2 &r_point, Vector2 &r_normal) const=0;
	virtual real_t get_moment_of_inertia(real_t p_mass,const Size2& p_scale) const=0;
	virtual void set_data(const Variant& p_data)=0;
	virtual Variant get_data() const=0;

	_FORCE_INLINE_ void set_custom_bias(real_t p_bias) { custom_bias=p_bias; }
	_FORCE_INLINE_ real_t get_custom_bias() const { return custom_bias; }

	void add_owner(ShapeOwner2DSW *p_owner);
	void remove_owner(ShapeOwner2DSW *p_owner);
	bool is_owner(ShapeOwner2DSW *p_owner) const;
	const Map<ShapeOwner2DSW*,int>& get_owners() const;


	_FORCE_INLINE_ void get_supports_transformed_cast(const Vector2& p_cast,const Vector2& p_normal,const Transform2D& p_xform,Vector2 *r_supports,int & r_amount) const {

		get_supports(p_xform.basis_xform_inv(p_normal).normalized(),r_supports,r_amount);
		for(int i=0;i<r_amount;i++)
			r_supports[i]=p_xform.xform(r_supports[i]);

		if (r_amount==1) {

			if (Math::abs( p_normal.dot(p_cast.normalized()) )<(1.0-_SEGMENT_IS_VALID_SUPPORT_TRESHOLD) ) {
				//make line because they are parallel
				r_amount=2;
				r_supports[1]=r_supports[0]+p_cast;
			} else if (p_cast.dot(p_normal)>0) {
				//normal points towards cast, add cast
				r_supports[0]+=p_cast;
			}

		} else {

			if (Math::abs( p_normal.dot(p_cast.normalized()) )<(1.0-_SEGMENT_IS_VALID_SUPPORT_TRESHOLD) ) {
				//optimize line and make it larger because they are parallel
				if ((r_supports[1]-r_supports[0]).dot(p_cast)>0) {
					//larger towards 1
					r_supports[1]+=p_cast;
				} else {
					//larger towards 0
					r_supports[0]+=p_cast;
				}
			} else if (p_cast.dot(p_normal)>0) {
				//normal points towards cast, add cast
				r_supports[0]+=p_cast;
				r_supports[1]+=p_cast;
			}

		}
	}

	Shape2DSW();
	virtual ~Shape2DSW();
};

//let the optimizer do the magic
#define DEFAULT_PROJECT_RANGE_CAST \
virtual void project_range_castv(const Vector2& p_cast, const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const {\
	project_range_cast(p_cast,p_normal,p_transform,r_min,r_max);\
}\
_FORCE_INLINE_ void project_range_cast(const Vector2& p_cast, const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const {\
\
	real_t mina,maxa;\
	real_t minb,maxb;\
	Transform2D ofsb=p_transform;\
	ofsb.elements[2]+=p_cast;\
	project_range(p_normal,p_transform,mina,maxa);\
	project_range(p_normal,ofsb,minb,maxb);	\
	r_min=MIN(mina,minb);\
	r_max=MAX(maxa,maxb);\
}

class LineShape2DSW : public Shape2DSW {


	Vector2 normal;
	real_t d;

public:

	_FORCE_INLINE_ Vector2 get_normal() const { return normal; }
	_FORCE_INLINE_ real_t get_d() const { return d; }

	virtual Physics2DServer::ShapeType get_type() const { return Physics2DServer::SHAPE_LINE; }

	virtual void project_rangev(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const { project_range(p_normal,p_transform,r_min,r_max); }
	virtual void get_supports(const Vector2& p_normal,Vector2 *r_supports,int & r_amount) const;

	virtual bool contains_point(const Vector2& p_point) const;
	virtual bool intersect_segment(const Vector2& p_begin,const Vector2& p_end,Vector2 &r_point, Vector2 &r_normal) const;
	virtual real_t get_moment_of_inertia(real_t p_mass,const Size2& p_scale) const;

	virtual void set_data(const Variant& p_data);
	virtual Variant get_data() const;

	_FORCE_INLINE_ void project_range(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const {
		//real large
		r_min=-1e10;
		r_max=1e10;
	}

	virtual void project_range_castv(const Vector2& p_cast, const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const {
		project_range_cast(p_cast,p_normal,p_transform,r_min,r_max);
	}

	_FORCE_INLINE_ void project_range_cast(const Vector2& p_cast, const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const {
		//real large
		r_min=-1e10;
		r_max=1e10;
	}



};


class RayShape2DSW : public Shape2DSW {


	real_t length;

public:


	_FORCE_INLINE_  real_t get_length() const { return length; }

	virtual Physics2DServer::ShapeType get_type() const { return Physics2DServer::SHAPE_RAY; }

	virtual void project_rangev(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const { project_range(p_normal,p_transform,r_min,r_max); }
	virtual void get_supports(const Vector2& p_normal,Vector2 *r_supports,int & r_amount) const;

	virtual bool contains_point(const Vector2& p_point) const;
	virtual bool intersect_segment(const Vector2& p_begin,const Vector2& p_end,Vector2 &r_point, Vector2 &r_normal) const;
	virtual real_t get_moment_of_inertia(real_t p_mass,const Size2& p_scale) const;

	virtual void set_data(const Variant& p_data);
	virtual Variant get_data() const;

	_FORCE_INLINE_ void project_range(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const {
		//real large
		r_max = p_normal.dot(p_transform.get_origin());
		r_min = p_normal.dot(p_transform.xform(Vector2(0,length)));
		if (r_max<r_min) {

			SWAP(r_max,r_min);
		}
	}

	DEFAULT_PROJECT_RANGE_CAST


	_FORCE_INLINE_ RayShape2DSW() {}
	_FORCE_INLINE_ RayShape2DSW(real_t p_length) { length=p_length; }
};


class SegmentShape2DSW : public Shape2DSW {


	Vector2 a;
	Vector2 b;
	Vector2 n;

public:


	_FORCE_INLINE_ const Vector2& get_a() const { return a; }
	_FORCE_INLINE_ const Vector2& get_b() const { return b; }
	_FORCE_INLINE_ const Vector2& get_normal() const { return n; }

	virtual Physics2DServer::ShapeType get_type() const { return Physics2DServer::SHAPE_SEGMENT; }

	_FORCE_INLINE_ Vector2 get_xformed_normal(const Transform2D& p_xform) const {

		return (p_xform.xform(b) - p_xform.xform(a)).normalized().tangent();
	}
	virtual void project_rangev(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const { project_range(p_normal,p_transform,r_min,r_max); }
	virtual void get_supports(const Vector2& p_normal,Vector2 *r_supports,int & r_amount) const;

	virtual bool contains_point(const Vector2& p_point) const;
	virtual bool intersect_segment(const Vector2& p_begin,const Vector2& p_end,Vector2 &r_point, Vector2 &r_normal) const;
	virtual real_t get_moment_of_inertia(real_t p_mass,const Size2& p_scale) const;

	virtual void set_data(const Variant& p_data);
	virtual Variant get_data() const;

	_FORCE_INLINE_ void project_range(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const {
		//real large
		r_max = p_normal.dot(p_transform.xform(a));
		r_min = p_normal.dot(p_transform.xform(b));
		if (r_max<r_min) {

			SWAP(r_max,r_min);
		}
	}

	DEFAULT_PROJECT_RANGE_CAST

	_FORCE_INLINE_ SegmentShape2DSW() {}
	_FORCE_INLINE_ SegmentShape2DSW(const Vector2& p_a,const Vector2& p_b,const Vector2& p_n) { a=p_a; b=p_b; n=p_n; }
};


class CircleShape2DSW : public Shape2DSW {


	real_t radius;

public:

	_FORCE_INLINE_ const real_t& get_radius() const { return radius; }

	virtual Physics2DServer::ShapeType get_type() const { return Physics2DServer::SHAPE_CIRCLE; }

	virtual void project_rangev(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const { project_range(p_normal,p_transform,r_min,r_max); }
	virtual void get_supports(const Vector2& p_normal,Vector2 *r_supports,int & r_amount) const;

	virtual bool contains_point(const Vector2& p_point) const;
	virtual bool intersect_segment(const Vector2& p_begin,const Vector2& p_end,Vector2 &r_point, Vector2 &r_normal) const;
	virtual real_t get_moment_of_inertia(real_t p_mass,const Size2& p_scale) const;

	virtual void set_data(const Variant& p_data);
	virtual Variant get_data() const;

	_FORCE_INLINE_ void project_range(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const {
		//real large
		real_t d = p_normal.dot( p_transform.get_origin() );

		// figure out scale at point
		Vector2 local_normal = p_transform.basis_xform_inv(p_normal);
		real_t scale = local_normal.length();

		r_min = d - (radius) * scale;
		r_max = d + (radius) * scale;
	}


	DEFAULT_PROJECT_RANGE_CAST

};



class RectangleShape2DSW : public Shape2DSW {


	Vector2 half_extents;

public:

	_FORCE_INLINE_ const Vector2& get_half_extents() const { return half_extents; }

	virtual Physics2DServer::ShapeType get_type() const { return Physics2DServer::SHAPE_RECTANGLE; }

	virtual void project_rangev(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const { project_range(p_normal,p_transform,r_min,r_max); }
	virtual void get_supports(const Vector2& p_normal,Vector2 *r_supports,int & r_amount) const;

	virtual bool contains_point(const Vector2& p_point) const;
	virtual bool intersect_segment(const Vector2& p_begin,const Vector2& p_end,Vector2 &r_point, Vector2 &r_normal) const;
	virtual real_t get_moment_of_inertia(real_t p_mass,const Size2& p_scale) const;

	virtual void set_data(const Variant& p_data);
	virtual Variant get_data() const;

	_FORCE_INLINE_ void project_range(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const {
		// no matter the angle, the box is mirrored anyway
		r_max=-1e20;
		r_min=1e20;
		for(int i=0;i<4;i++) {

			real_t d=p_normal.dot(p_transform.xform(Vector2( ((i&1)*2-1)*half_extents.x, ((i>>1)*2-1)*half_extents.y )));

			if (d>r_max)
				r_max=d;
			if (d<r_min)
				r_min=d;

		}
	}



	_FORCE_INLINE_ Vector2 get_circle_axis(const Transform2D& p_xform, const Transform2D& p_xform_inv,const Vector2& p_circle) const {

		Vector2 local_v = p_xform_inv.xform(p_circle);

		Vector2 he(
			(local_v.x<0) ? -half_extents.x : half_extents.x,
			(local_v.y<0) ? -half_extents.y : half_extents.y
		);

		return (p_xform.xform(he)-p_circle).normalized();
	}

	_FORCE_INLINE_ Vector2 get_box_axis(const Transform2D& p_xform, const Transform2D& p_xform_inv,const RectangleShape2DSW *p_B,const Transform2D& p_B_xform, const Transform2D& p_B_xform_inv) const {

		Vector2 a,b;

		{
			Vector2 local_v = p_xform_inv.xform(p_B_xform.get_origin());

			Vector2 he(
				(local_v.x<0) ? -half_extents.x : half_extents.x,
				(local_v.y<0) ? -half_extents.y : half_extents.y
			);

			a=p_xform.xform(he);

		}
		{
			Vector2 local_v = p_B_xform_inv.xform(p_xform.get_origin());

			Vector2 he(
				(local_v.x<0) ? -p_B->half_extents.x : p_B->half_extents.x,
				(local_v.y<0) ? -p_B->half_extents.y : p_B->half_extents.y
			);

			b=p_B_xform.xform(he);

		}

		return (a-b).normalized();
	}


	DEFAULT_PROJECT_RANGE_CAST

};

class CapsuleShape2DSW : public Shape2DSW {


	real_t radius;
	real_t height;

public:

	_FORCE_INLINE_ const real_t& get_radius() const { return radius; }
	_FORCE_INLINE_ const real_t& get_height() const { return height; }

	virtual Physics2DServer::ShapeType get_type() const { return Physics2DServer::SHAPE_CAPSULE; }

	virtual void project_rangev(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const { project_range(p_normal,p_transform,r_min,r_max); }
	virtual void get_supports(const Vector2& p_normal,Vector2 *r_supports,int & r_amount) const;

	virtual bool contains_point(const Vector2& p_point) const;
	virtual bool intersect_segment(const Vector2& p_begin,const Vector2& p_end,Vector2 &r_point, Vector2 &r_normal) const;
	virtual real_t get_moment_of_inertia(real_t p_mass,const Size2& p_scale) const;

	virtual void set_data(const Variant& p_data);
	virtual Variant get_data() const;

	_FORCE_INLINE_ void project_range(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const {
		// no matter the angle, the box is mirrored anyway
		Vector2 n=p_transform.basis_xform_inv(p_normal).normalized();
		real_t h = (n.y > 0) ? height : -height;

		n *= radius;
		n.y += h * 0.5;

		r_max = p_normal.dot(p_transform.xform(n));
		r_min = p_normal.dot(p_transform.xform(-n));

		if (r_max<r_min) {

			SWAP(r_max,r_min);
		}

		//ERR_FAIL_COND( r_max < r_min );
	}

	DEFAULT_PROJECT_RANGE_CAST

};




class ConvexPolygonShape2DSW : public Shape2DSW {


	struct Point {

		Vector2 pos;
		Vector2 normal; //normal to next segment
	};

	Point *points;
	int point_count;

public:

	_FORCE_INLINE_ int get_point_count() const { return point_count; }
	_FORCE_INLINE_ const Vector2& get_point(int p_idx) const { return points[p_idx].pos; }
	_FORCE_INLINE_ const Vector2& get_segment_normal(int p_idx) const { return points[p_idx].normal; }
	_FORCE_INLINE_ Vector2 get_xformed_segment_normal(const Transform2D& p_xform, int p_idx) const {

		Vector2 a = points[p_idx].pos;
		p_idx++;
		Vector2 b = points[p_idx==point_count?0:p_idx].pos;
		return (p_xform.xform(b)-p_xform.xform(a)).normalized().tangent();
	}

	virtual Physics2DServer::ShapeType get_type() const { return Physics2DServer::SHAPE_CONVEX_POLYGON; }

	virtual void project_rangev(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const { project_range(p_normal,p_transform,r_min,r_max); }
	virtual void get_supports(const Vector2& p_normal,Vector2 *r_supports,int & r_amount) const;

	virtual bool contains_point(const Vector2& p_point) const;
	virtual bool intersect_segment(const Vector2& p_begin,const Vector2& p_end,Vector2 &r_point, Vector2 &r_normal) const;
	virtual real_t get_moment_of_inertia(real_t p_mass,const Size2& p_scale) const;

	virtual void set_data(const Variant& p_data);
	virtual Variant get_data() const;

	_FORCE_INLINE_ void project_range(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const {
		// no matter the angle, the box is mirrored anyway

		r_min = r_max = p_normal.dot(p_transform.xform(points[0].pos));
		for(int i=1;i<point_count;i++) {

			real_t d = p_normal.dot(p_transform.xform(points[i].pos));
			if (d>r_max)
				r_max=d;
			if (d<r_min)
				r_min=d;

		}

	}

	DEFAULT_PROJECT_RANGE_CAST

	ConvexPolygonShape2DSW();
	~ConvexPolygonShape2DSW();
};


class ConcaveShape2DSW : public Shape2DSW {

public:

	virtual bool is_concave() const { return true; }
	typedef void (*Callback)(void* p_userdata,Shape2DSW *p_convex);

	virtual void cull(const Rect2& p_local_aabb,Callback p_callback,void* p_userdata) const=0;

};

class ConcavePolygonShape2DSW : public ConcaveShape2DSW {

	struct Segment {

		int points[2];
	};

	Vector<Segment> segments;
	Vector<Point2> points;

	struct BVH {

		Rect2 aabb;
		int left,right;
	};


	Vector<BVH> bvh;
	int bvh_depth;


	struct BVH_CompareX {

		_FORCE_INLINE_ bool operator ()(const BVH& a, const BVH& b) const {

			return (a.aabb.pos.x+a.aabb.size.x*0.5) < (b.aabb.pos.x+b.aabb.size.x*0.5);
		}
	};

	struct BVH_CompareY {

		_FORCE_INLINE_ bool operator ()(const BVH& a, const BVH& b) const {

			return (a.aabb.pos.y+a.aabb.size.y*0.5) < (b.aabb.pos.y+b.aabb.size.y*0.5);
		}
	};

	int _generate_bvh(BVH *p_bvh,int p_len,int p_depth);

public:

	virtual Physics2DServer::ShapeType get_type() const { return Physics2DServer::SHAPE_CONCAVE_POLYGON; }

	virtual void project_rangev(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const { /*project_range(p_normal,p_transform,r_min,r_max);*/ }
	virtual void project_range(const Vector2& p_normal, const Transform2D& p_transform, real_t &r_min, real_t &r_max) const { /*project_range(p_normal,p_transform,r_min,r_max);*/ }
	virtual void get_supports(const Vector2& p_normal,Vector2 *r_supports,int & r_amount) const;

	virtual bool contains_point(const Vector2& p_point) const;
	virtual bool intersect_segment(const Vector2& p_begin,const Vector2& p_end,Vector2 &r_point, Vector2 &r_normal) const;

	virtual real_t get_moment_of_inertia(real_t p_mass,const Size2& p_scale) const { return 0; }

	virtual void set_data(const Variant& p_data);
	virtual Variant get_data() const;

	virtual void cull(const Rect2& p_local_aabb,Callback p_callback,void* p_userdata) const;


	DEFAULT_PROJECT_RANGE_CAST

};

#undef DEFAULT_PROJECT_RANGE_CAST

#endif // SHAPE_2D_2DSW_H