text: #include "animation_blend_space_2d.h"
  #include "math/delaunay.h"
  
  void AnimationNodeBlendSpace2D::set_tree(AnimationTree *p_player) {
  	AnimationRootNode::set_tree(p_player);
  
  	for(int i=0;i<blend_points_used;i++) {
  		blend_points[i].node->set_tree(p_player);
  	}
  }
  
  
  void AnimationNodeBlendSpace2D::add_blend_point(const Ref<AnimationRootNode> &p_node, const Vector2 &p_position, int p_at_index) {
  	ERR_FAIL_COND(blend_points_used >= MAX_BLEND_POINTS);
  	ERR_FAIL_COND(p_node.is_null());
  	ERR_FAIL_COND(p_node->get_parent().is_valid());
  	ERR_FAIL_COND(p_at_index < -1 || p_at_index > blend_points_used);
  
  	if (p_at_index == -1 || p_at_index == blend_points_used) {
  		p_at_index = blend_points_used;
  	} else {
  		for (int i = blend_points_used - 1; i > p_at_index; i--) {
  			blend_points[i] = blend_points[i - 1];
  		}
  		for (int i = 0; i < triangles.size(); i++) {
  			for (int j = 0; j < 3; j++) {
  				if (triangles[i].points[j] >= p_at_index) {
  					triangles[i].points[j]++;
  				}
  			}
  		}
  	}
  	blend_points[p_at_index].node = p_node;
  	blend_points[p_at_index].position = p_position;
  
  	blend_points[p_at_index].node->set_parent(this);
  	blend_points[p_at_index].node->set_tree(get_tree());
  	blend_points_used++;
  
  	if (auto_triangles) {
  		trianges_dirty = true;
  	}
  }
  
  void AnimationNodeBlendSpace2D::set_blend_point_position(int p_point, const Vector2 &p_position) {
  	ERR_FAIL_INDEX(p_point, blend_points_used);
  	blend_points[p_point].position = p_position;
  	if (auto_triangles) {
  		trianges_dirty = true;
  	}
  }
  void AnimationNodeBlendSpace2D::set_blend_point_node(int p_point, const Ref<AnimationRootNode> &p_node) {
  	ERR_FAIL_INDEX(p_point, blend_points_used);
  	ERR_FAIL_COND(p_node.is_null());
  
  	if (blend_points[p_point].node.is_valid()) {
  		blend_points[p_point].node->set_parent(NULL);
  		blend_points[p_point].node->set_tree(NULL);
  	}
  	blend_points[p_point].node = p_node;
  	blend_points[p_point].node->set_parent(this);
  	blend_points[p_point].node->set_tree(get_tree());
  }
  Vector2 AnimationNodeBlendSpace2D::get_blend_point_position(int p_point) const {
  	ERR_FAIL_INDEX_V(p_point, blend_points_used, Vector2());
  	return blend_points[p_point].position;
  }
  Ref<AnimationRootNode> AnimationNodeBlendSpace2D::get_blend_point_node(int p_point) const {
  	ERR_FAIL_INDEX_V(p_point, blend_points_used, Ref<AnimationRootNode>());
  	return blend_points[p_point].node;
  }
  void AnimationNodeBlendSpace2D::remove_blend_point(int p_point) {
  	ERR_FAIL_INDEX(p_point, blend_points_used);
  
  	blend_points[p_point].node->set_parent(NULL);
  	blend_points[p_point].node->set_tree(NULL);
  
  	for (int i = 0; i < triangles.size(); i++) {
  		bool erase = false;
  		for (int j = 0; j < 3; j++) {
  			if (triangles[i].points[j] == p_point) {
  				erase = true;
  				break;
  			} else if (triangles[i].points[j] > p_point) {
  				triangles[i].points[j]--;
  			}
  		}
  		if (erase) {
  			triangles.remove(i);
  
  			i--;
  		}
  	}
  
  	for (int i = p_point; i < blend_points_used - 1; i++) {
  		blend_points[i] = blend_points[i + 1];
  	}
  	blend_points_used--;
  }
  
  int AnimationNodeBlendSpace2D::get_blend_point_count() const {
  
  	return blend_points_used;
  }
  
  bool AnimationNodeBlendSpace2D::has_triangle(int p_x, int p_y, int p_z) const {
  
  	ERR_FAIL_INDEX_V(p_x, blend_points_used, false);
  	ERR_FAIL_INDEX_V(p_y, blend_points_used, false);
  	ERR_FAIL_INDEX_V(p_z, blend_points_used, false);
  
  	BlendTriangle t;
  	t.points[0] = p_x;
  	t.points[1] = p_y;
  	t.points[2] = p_z;
  
  	SortArray<int> sort;
  	sort.sort(t.points, 3);
  
  	for (int i = 0; i < triangles.size(); i++) {
  		bool all_equal = true;
  		for (int j = 0; j < 3; j++) {
  			if (triangles[i].points[j] != t.points[j]) {
  				all_equal = false;
  				break;
  			}
  		}
  		if (all_equal)
  			return true;
  	}
  
  	return false;
  }
  
  void AnimationNodeBlendSpace2D::add_triangle(int p_x, int p_y, int p_z, int p_at_index) {
  
  	ERR_FAIL_INDEX(p_x, blend_points_used);
  	ERR_FAIL_INDEX(p_y, blend_points_used);
  	ERR_FAIL_INDEX(p_z, blend_points_used);
  
  	_update_triangles();
  
  	BlendTriangle t;
  	t.points[0] = p_x;
  	t.points[1] = p_y;
  	t.points[2] = p_z;
  
  	SortArray<int> sort;
  	sort.sort(t.points, 3);
  
  	for (int i = 0; i < triangles.size(); i++) {
  		bool all_equal = true;
  		for (int j = 0; j < 3; j++) {
  			if (triangles[i].points[j] != t.points[j]) {
  				all_equal = false;
  				break;
  			}
  		}
  		ERR_FAIL_COND(all_equal);
  	}
  
  	if (p_at_index == -1 || p_at_index == triangles.size()) {
  		triangles.push_back(t);
  	} else {
  		triangles.insert(p_at_index, t);
  	}
  }
  int AnimationNodeBlendSpace2D::get_triangle_point(int p_triangle, int p_point) {
  
  	_update_triangles();
  
  	ERR_FAIL_INDEX_V(p_point, 3, -1);
  	ERR_FAIL_INDEX_V(p_triangle, triangles.size(), -1);
  	return triangles[p_triangle].points[p_point];
  }
  void AnimationNodeBlendSpace2D::remove_triangle(int p_triangle) {
  	ERR_FAIL_INDEX(p_triangle, triangles.size());
  
  	triangles.remove(p_triangle);
  }
  
  int AnimationNodeBlendSpace2D::get_triangle_count() const {
  	return triangles.size();
  }
  
  void AnimationNodeBlendSpace2D::set_min_space(const Vector2 &p_min) {
  
  	min_space = p_min;
  	if (min_space.x >= max_space.x) {
  		min_space.x = max_space.x - 1;
  	}
  	if (min_space.y >= max_space.y) {
  		min_space.y = max_space.y - 1;
  	}
  }
  Vector2 AnimationNodeBlendSpace2D::get_min_space() const {
  	return min_space;
  }
  
  void AnimationNodeBlendSpace2D::set_max_space(const Vector2 &p_max) {
  
  	max_space = p_max;
  	if (max_space.x <= min_space.x) {
  		max_space.x = min_space.x + 1;
  	}
  	if (max_space.y <= min_space.y) {
  		max_space.y = min_space.y + 1;
  	}
  }
  Vector2 AnimationNodeBlendSpace2D::get_max_space() const {
  	return max_space;
  }
  
  void AnimationNodeBlendSpace2D::set_snap(const Vector2 &p_snap) {
  	snap = p_snap;
  }
  Vector2 AnimationNodeBlendSpace2D::get_snap() const {
  	return snap;
  }
  
  void AnimationNodeBlendSpace2D::set_blend_position(const Vector2 &p_pos) {
  	blend_pos = p_pos;
  }
  Vector2 AnimationNodeBlendSpace2D::get_blend_position() const {
  	return blend_pos;
  }
  
  void AnimationNodeBlendSpace2D::set_x_label(const String &p_label) {
  	x_label = p_label;
  }
  String AnimationNodeBlendSpace2D::get_x_label() const {
  	return x_label;
  }
  
  void AnimationNodeBlendSpace2D::set_y_label(const String &p_label) {
  	y_label = p_label;
  }
  String AnimationNodeBlendSpace2D::get_y_label() const {
  	return y_label;
  }
  
  void AnimationNodeBlendSpace2D::_add_blend_point(int p_index, const Ref<AnimationRootNode> &p_node) {
  	if (p_index == blend_points_used) {
  		add_blend_point(p_node, Vector2());
  	} else {
  		set_blend_point_node(p_index, p_node);
  	}
  }
  
  void AnimationNodeBlendSpace2D::_set_triangles(const Vector<int> &p_triangles) {
  
  	if (auto_triangles)
  		return;
  	ERR_FAIL_COND(p_triangles.size() % 3 != 0);
  	for (int i = 0; i < p_triangles.size(); i += 3) {
  		add_triangle(p_triangles[i + 0], p_triangles[i + 1], p_triangles[i + 2]);
  	}
  }
  
  Vector<int> AnimationNodeBlendSpace2D::_get_triangles() const {
  
  	Vector<int> t;
  	if (auto_triangles && trianges_dirty)
  		return t;
  
  	t.resize(triangles.size() * 3);
  	for (int i = 0; i < triangles.size(); i++) {
  		t[i * 3 + 0] = triangles[i].points[0];
  		t[i * 3 + 1] = triangles[i].points[1];
  		t[i * 3 + 2] = triangles[i].points[2];
  	}
  	return t;
  }
  
  void AnimationNodeBlendSpace2D::_update_triangles() {
  
  	if (!auto_triangles || !trianges_dirty)
  		return;
  
  	trianges_dirty = false;
  	triangles.clear();
  	if (blend_points_used < 3)
  		return;
  
  	Vector<Vector2> points;
  	points.resize(blend_points_used);
  	for (int i = 0; i < blend_points_used; i++) {
  		points[i] = blend_points[i].position;
  	}
  
  	Vector<Delaunay2D::Triangle> triangles = Delaunay2D::triangulate(points);
  
  	for (int i = 0; i < triangles.size(); i++) {
  		add_triangle(triangles[i].points[0], triangles[i].points[1], triangles[i].points[2]);
  	}
  }
  
  Vector2 AnimationNodeBlendSpace2D::get_closest_point(const Vector2 &p_point) {
  
  	_update_triangles();
  
  	if (triangles.size() == 0)
  		return Vector2();
  
  	Vector2 best_point;
  	bool first = true;
  
  	for (int i = 0; i < triangles.size(); i++) {
  		Vector2 points[3];
  		for (int j = 0; j < 3; j++) {
  			points[j] = get_blend_point_position(get_triangle_point(i, j));
  		}
  
  		if (Geometry::is_point_in_triangle(p_point, points[0], points[1], points[2])) {
  
  			return p_point;
  		}
  
  		for (int j = 0; j < 3; j++) {
  			Vector2 s[2] = {
  				points[j],
  				points[(j + 1) % 3]
  			};
  			Vector2 closest = Geometry::get_closest_point_to_segment_2d(p_point, s);
  			if (first || closest.distance_to(p_point) < best_point.distance_to(p_point)) {
  				best_point = closest;
  				first = false;
  			}
  		}
  	}
  
  	return best_point;
  }
  
  void AnimationNodeBlendSpace2D::_blend_triangle(const Vector2 &p_pos, const Vector2 *p_points, float *r_weights) {
  
  	if (p_pos.distance_squared_to(p_points[0]) < CMP_EPSILON2) {
  		r_weights[0] = 1;
  		r_weights[1] = 0;
  		r_weights[2] = 0;
  		return;
  	}
  	if (p_pos.distance_squared_to(p_points[1]) < CMP_EPSILON2) {
  		r_weights[0] = 0;
  		r_weights[1] = 1;
  		r_weights[2] = 0;
  		return;
  	}
  	if (p_pos.distance_squared_to(p_points[2]) < CMP_EPSILON2) {
  		r_weights[0] = 0;
  		r_weights[1] = 0;
  		r_weights[2] = 1;
  		return;
  	}
  
  	Vector2 v0 = p_points[1] - p_points[0];
  	Vector2 v1 = p_points[2] - p_points[0];
  	Vector2 v2 = p_pos - p_points[0];
  
  	float d00 = v0.dot(v0);
  	float d01 = v0.dot(v1);
  	float d11 = v1.dot(v1);
  	float d20 = v2.dot(v0);
  	float d21 = v2.dot(v1);
  	float denom = (d00 * d11 - d01 * d01);
  	if (denom == 0) {
  		r_weights[0] = 1;
  		r_weights[1] = 0;
  		r_weights[2] = 0;
  		return;
  	}
  	float v = (d11 * d20 - d01 * d21) / denom;
  	float w = (d00 * d21 - d01 * d20) / denom;
  	float u = 1.0f - v - w;
  
  	r_weights[0] = u;
  	r_weights[1] = v;
  	r_weights[2] = w;
  }
  
  float AnimationNodeBlendSpace2D::process(float p_time, bool p_seek) {
  
  	_update_triangles();
  
  	if (triangles.size() == 0)
  		return 0;
  
  	Vector2 best_point;
  	bool first = true;
  	int blend_triangle = -1;
  	float blend_weights[3] = { 0, 0, 0 };
  
  	for (int i = 0; i < triangles.size(); i++) {
  		Vector2 points[3];
  		for (int j = 0; j < 3; j++) {
  			points[j] = get_blend_point_position(get_triangle_point(i, j));
  		}
  
  		if (Geometry::is_point_in_triangle(blend_pos, points[0], points[1], points[2])) {
  
  			blend_triangle = i;
  			_blend_triangle(blend_pos, points, blend_weights);
  			break;
  		}
  
  		for (int j = 0; j < 3; j++) {
  			Vector2 s[2] = {
  				points[j],
  				points[(j + 1) % 3]
  			};
  			Vector2 closest = Geometry::get_closest_point_to_segment_2d(blend_pos, s);
  			if (first || closest.distance_to(blend_pos) < best_point.distance_to(blend_pos)) {
  				best_point = closest;
  				blend_triangle = i;
  				first = false;
  				float d = s[0].distance_to(s[1]);
  				if (d == 0.0) {
  					blend_weights[j] = 1.0;
  					blend_weights[(j + 1) % 3] = 0.0;
  					blend_weights[(j + 2) % 3] = 0.0;
  				} else {
  					float c = s[0].distance_to(closest) / d;
  
  					blend_weights[j] = 1.0 - c;
  					blend_weights[(j + 1) % 3] = c;
  					blend_weights[(j + 2) % 3] = 0.0;
  				}
  			}
  		}
  	}
  
  	ERR_FAIL_COND_V(blend_triangle == -1, 0); //should never reach here
  
  	int triangle_points[3];
  	for (int j = 0; j < 3; j++) {
  		triangle_points[j] = get_triangle_point(blend_triangle, j);
  	}
  
  	first = true;
  	float mind;
  	for (int i = 0; i < blend_points_used; i++) {
  
  		bool found = false;
  		for (int j = 0; j < 3; j++) {
  			if (i == triangle_points[j]) {
  				//blend with the given weight
  				float t = blend_node(blend_points[i].node, p_time, p_seek, blend_weights[j], FILTER_IGNORE, false);
  				if (first || t < mind) {
  					mind = t;
  					first = false;
  				}
  				found = true;
  				break;
  			}
  		}
  
  		if (!found) {
  			//ignore
  			blend_node(blend_points[i].node, p_time, p_seek, 0, FILTER_IGNORE, false);
  		}
  	}
  	return mind;
  }
  
  String AnimationNodeBlendSpace2D::get_caption() const {
  	return "BlendSpace2D";
  }
  
  void AnimationNodeBlendSpace2D::_validate_property(PropertyInfo &property) const {
  	if (property.name.begins_with("blend_point_")) {
  		String left = property.name.get_slicec('/', 0);
  		int idx = left.get_slicec('_', 2).to_int();
  		if (idx >= blend_points_used) {
  			property.usage = 0;
  		}
  	}
  	AnimationRootNode::_validate_property(property);
  }
  
  void AnimationNodeBlendSpace2D::set_auto_triangles(bool p_enable) {
  	auto_triangles = p_enable;
  	if (auto_triangles) {
  		trianges_dirty = true;
  	}
  }
  
  bool AnimationNodeBlendSpace2D::get_auto_triangles() const {
  	return auto_triangles;
  }
  
  void AnimationNodeBlendSpace2D::_bind_methods() {
  
  	ClassDB::bind_method(D_METHOD("add_blend_point", "node", "pos", "at_index"), &AnimationNodeBlendSpace2D::add_blend_point, DEFVAL(-1));
  	ClassDB::bind_method(D_METHOD("set_blend_point_position", "point", "pos"), &AnimationNodeBlendSpace2D::set_blend_point_position);
  	ClassDB::bind_method(D_METHOD("get_blend_point_position", "point"), &AnimationNodeBlendSpace2D::get_blend_point_position);
  	ClassDB::bind_method(D_METHOD("set_blend_point_node", "point", "node"), &AnimationNodeBlendSpace2D::set_blend_point_node);
  	ClassDB::bind_method(D_METHOD("get_blend_point_node", "point"), &AnimationNodeBlendSpace2D::get_blend_point_node);
  	ClassDB::bind_method(D_METHOD("remove_blend_point", "point"), &AnimationNodeBlendSpace2D::remove_blend_point);
  	ClassDB::bind_method(D_METHOD("get_blend_point_count"), &AnimationNodeBlendSpace2D::get_blend_point_count);
  
  	ClassDB::bind_method(D_METHOD("add_triangle", "x", "y", "z", "at_index"), &AnimationNodeBlendSpace2D::add_triangle, DEFVAL(-1));
  	ClassDB::bind_method(D_METHOD("get_triangle_point", "triangle", "point"), &AnimationNodeBlendSpace2D::get_triangle_point);
  	ClassDB::bind_method(D_METHOD("remove_triangle", "triangle"), &AnimationNodeBlendSpace2D::remove_triangle);
  	ClassDB::bind_method(D_METHOD("get_triangle_count"), &AnimationNodeBlendSpace2D::get_triangle_count);
  
  	ClassDB::bind_method(D_METHOD("set_min_space", "min_space"), &AnimationNodeBlendSpace2D::set_min_space);
  	ClassDB::bind_method(D_METHOD("get_min_space"), &AnimationNodeBlendSpace2D::get_min_space);
  
  	ClassDB::bind_method(D_METHOD("set_max_space", "max_space"), &AnimationNodeBlendSpace2D::set_max_space);
  	ClassDB::bind_method(D_METHOD("get_max_space"), &AnimationNodeBlendSpace2D::get_max_space);
  
  	ClassDB::bind_method(D_METHOD("set_snap", "snap"), &AnimationNodeBlendSpace2D::set_snap);
  	ClassDB::bind_method(D_METHOD("get_snap"), &AnimationNodeBlendSpace2D::get_snap);
  
  	ClassDB::bind_method(D_METHOD("set_blend_position", "pos"), &AnimationNodeBlendSpace2D::set_blend_position);
  	ClassDB::bind_method(D_METHOD("get_blend_position"), &AnimationNodeBlendSpace2D::get_blend_position);
  
  	ClassDB::bind_method(D_METHOD("set_x_label", "text"), &AnimationNodeBlendSpace2D::set_x_label);
  	ClassDB::bind_method(D_METHOD("get_x_label"), &AnimationNodeBlendSpace2D::get_x_label);
  
  	ClassDB::bind_method(D_METHOD("set_y_label", "text"), &AnimationNodeBlendSpace2D::set_y_label);
  	ClassDB::bind_method(D_METHOD("get_y_label"), &AnimationNodeBlendSpace2D::get_y_label);
  
  	ClassDB::bind_method(D_METHOD("_add_blend_point", "index", "node"), &AnimationNodeBlendSpace2D::_add_blend_point);
  
  	ClassDB::bind_method(D_METHOD("_set_triangles", "triangles"), &AnimationNodeBlendSpace2D::_set_triangles);
  	ClassDB::bind_method(D_METHOD("_get_triangles"), &AnimationNodeBlendSpace2D::_get_triangles);
  
  	ClassDB::bind_method(D_METHOD("set_auto_triangles", "enable"), &AnimationNodeBlendSpace2D::set_auto_triangles);
  	ClassDB::bind_method(D_METHOD("get_auto_triangles"), &AnimationNodeBlendSpace2D::get_auto_triangles);
  
  	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "auto_triangles", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_auto_triangles", "get_auto_triangles");
  
  	for (int i = 0; i < MAX_BLEND_POINTS; i++) {
  		ADD_PROPERTYI(PropertyInfo(Variant::OBJECT, "blend_point_" + itos(i) + "/node", PROPERTY_HINT_RESOURCE_TYPE, "AnimationRootNode", PROPERTY_USAGE_NOEDITOR | PROPERTY_USAGE_INTERNAL | PROPERTY_USAGE_DO_NOT_SHARE_ON_DUPLICATE), "_add_blend_point", "get_blend_point_node", i);
  		ADD_PROPERTYI(PropertyInfo(Variant::VECTOR2, "blend_point_" + itos(i) + "/pos", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR | PROPERTY_USAGE_INTERNAL), "set_blend_point_position", "get_blend_point_position", i);
  	}
  
  	ADD_PROPERTY(PropertyInfo(Variant::POOL_INT_ARRAY, "triangles", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR | PROPERTY_USAGE_INTERNAL), "_set_triangles", "_get_triangles");
  
  	ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "min_space", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_min_space", "get_min_space");
  	ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "max_space", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_max_space", "get_max_space");
  	ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "snap", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_snap", "get_snap");
  	ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "blend_position", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_blend_position", "get_blend_position");
  	ADD_PROPERTY(PropertyInfo(Variant::STRING, "x_label", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_x_label", "get_x_label");
  	ADD_PROPERTY(PropertyInfo(Variant::STRING, "y_label", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_y_label", "get_y_label");
  }
  
  AnimationNodeBlendSpace2D::AnimationNodeBlendSpace2D() {
  
  	auto_triangles = true;
  	blend_points_used = 0;
  	max_space = Vector2(1, 1);
  	min_space = Vector2(-1, -1);
  	snap = Vector2(0.1, 0.1);
  	x_label = "x";
  	y_label = "y";
  	trianges_dirty = false;
  }
  
  AnimationNodeBlendSpace2D::~AnimationNodeBlendSpace2D() {
  
  	for (int i = 0; i < blend_points_used; i++) {
  		blend_points[i].node->set_parent(this);
  		blend_points[i].node->set_tree(get_tree());
  	}
  }
  