/*************************************************************************/
/*  navigation_polygon.cpp                                               */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
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/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
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/* "Software"), to deal in the Software without restriction, including   */
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/*************************************************************************/

#include "navigation_polygon.h"

#include "core/core_string_names.h"
#include "core/math/geometry_2d.h"
#include "core/os/mutex.h"

#include "thirdparty/misc/polypartition.h"

#ifdef TOOLS_ENABLED
Rect2 NavigationPolygon::_edit_get_rect() const {
	if (rect_cache_dirty) {
		item_rect = Rect2();
		bool first = true;

		for (int i = 0; i < outlines.size(); i++) {
			const Vector<Vector2> &outline = outlines[i];
			const int outline_size = outline.size();
			if (outline_size < 3) {
				continue;
			}
			const Vector2 *p = outline.ptr();
			for (int j = 0; j < outline_size; j++) {
				if (first) {
					item_rect = Rect2(p[j], Vector2(0, 0));
					first = false;
				} else {
					item_rect.expand_to(p[j]);
				}
			}
		}

		rect_cache_dirty = false;
	}
	return item_rect;
}

bool NavigationPolygon::_edit_is_selected_on_click(const Point2 &p_point, double p_tolerance) const {
	for (int i = 0; i < outlines.size(); i++) {
		const Vector<Vector2> &outline = outlines[i];
		const int outline_size = outline.size();
		if (outline_size < 3) {
			continue;
		}
		if (Geometry2D::is_point_in_polygon(p_point, Variant(outline))) {
			return true;
		}
	}
	return false;
}
#endif

void NavigationPolygon::set_vertices(const Vector<Vector2> &p_vertices) {
	{
		MutexLock lock(navigation_mesh_generation);
		navigation_mesh.unref();
	}
	vertices = p_vertices;
	rect_cache_dirty = true;
}

Vector<Vector2> NavigationPolygon::get_vertices() const {
	return vertices;
}

void NavigationPolygon::_set_polygons(const TypedArray<Vector<int32_t>> &p_array) {
	{
		MutexLock lock(navigation_mesh_generation);
		navigation_mesh.unref();
	}
	polygons.resize(p_array.size());
	for (int i = 0; i < p_array.size(); i++) {
		polygons.write[i].indices = p_array[i];
	}
}

TypedArray<Vector<int32_t>> NavigationPolygon::_get_polygons() const {
	TypedArray<Vector<int32_t>> ret;
	ret.resize(polygons.size());
	for (int i = 0; i < ret.size(); i++) {
		ret[i] = polygons[i].indices;
	}

	return ret;
}

void NavigationPolygon::_set_outlines(const TypedArray<Vector<Vector2>> &p_array) {
	outlines.resize(p_array.size());
	for (int i = 0; i < p_array.size(); i++) {
		outlines.write[i] = p_array[i];
	}
	rect_cache_dirty = true;
}

TypedArray<Vector<Vector2>> NavigationPolygon::_get_outlines() const {
	TypedArray<Vector<Vector2>> ret;
	ret.resize(outlines.size());
	for (int i = 0; i < ret.size(); i++) {
		ret[i] = outlines[i];
	}

	return ret;
}

void NavigationPolygon::add_polygon(const Vector<int> &p_polygon) {
	Polygon polygon;
	polygon.indices = p_polygon;
	polygons.push_back(polygon);
	{
		MutexLock lock(navigation_mesh_generation);
		navigation_mesh.unref();
	}
}

void NavigationPolygon::add_outline_at_index(const Vector<Vector2> &p_outline, int p_index) {
	outlines.insert(p_index, p_outline);
	rect_cache_dirty = true;
}

int NavigationPolygon::get_polygon_count() const {
	return polygons.size();
}

Vector<int> NavigationPolygon::get_polygon(int p_idx) {
	ERR_FAIL_INDEX_V(p_idx, polygons.size(), Vector<int>());
	return polygons[p_idx].indices;
}

void NavigationPolygon::clear_polygons() {
	polygons.clear();
	{
		MutexLock lock(navigation_mesh_generation);
		navigation_mesh.unref();
	}
}

Ref<NavigationMesh> NavigationPolygon::get_navigation_mesh() {
	MutexLock lock(navigation_mesh_generation);

	if (navigation_mesh.is_null()) {
		navigation_mesh.instantiate();
		Vector<Vector3> verts;
		{
			verts.resize(get_vertices().size());
			Vector3 *w = verts.ptrw();

			const Vector2 *r = get_vertices().ptr();

			for (int i(0); i < get_vertices().size(); i++) {
				w[i] = Vector3(r[i].x, 0.0, r[i].y);
			}
		}
		navigation_mesh->set_vertices(verts);

		for (int i(0); i < get_polygon_count(); i++) {
			navigation_mesh->add_polygon(get_polygon(i));
		}
	}

	return navigation_mesh;
}

void NavigationPolygon::add_outline(const Vector<Vector2> &p_outline) {
	outlines.push_back(p_outline);
	rect_cache_dirty = true;
}

int NavigationPolygon::get_outline_count() const {
	return outlines.size();
}

void NavigationPolygon::set_outline(int p_idx, const Vector<Vector2> &p_outline) {
	ERR_FAIL_INDEX(p_idx, outlines.size());
	outlines.write[p_idx] = p_outline;
	rect_cache_dirty = true;
}

void NavigationPolygon::remove_outline(int p_idx) {
	ERR_FAIL_INDEX(p_idx, outlines.size());
	outlines.remove_at(p_idx);
	rect_cache_dirty = true;
}

Vector<Vector2> NavigationPolygon::get_outline(int p_idx) const {
	ERR_FAIL_INDEX_V(p_idx, outlines.size(), Vector<Vector2>());
	return outlines[p_idx];
}

void NavigationPolygon::clear_outlines() {
	outlines.clear();
	rect_cache_dirty = true;
}

void NavigationPolygon::make_polygons_from_outlines() {
	{
		MutexLock lock(navigation_mesh_generation);
		navigation_mesh.unref();
	}
	List<TPPLPoly> in_poly, out_poly;

	Vector2 outside_point(-1e10, -1e10);

	for (int i = 0; i < outlines.size(); i++) {
		Vector<Vector2> ol = outlines[i];
		int olsize = ol.size();
		if (olsize < 3) {
			continue;
		}
		const Vector2 *r = ol.ptr();
		for (int j = 0; j < olsize; j++) {
			outside_point.x = MAX(r[j].x, outside_point.x);
			outside_point.y = MAX(r[j].y, outside_point.y);
		}
	}

	outside_point += Vector2(0.7239784, 0.819238); //avoid precision issues

	for (int i = 0; i < outlines.size(); i++) {
		Vector<Vector2> ol = outlines[i];
		int olsize = ol.size();
		if (olsize < 3) {
			continue;
		}
		const Vector2 *r = ol.ptr();

		int interscount = 0;
		//test if this is an outer outline
		for (int k = 0; k < outlines.size(); k++) {
			if (i == k) {
				continue; //no self intersect
			}

			Vector<Vector2> ol2 = outlines[k];
			int olsize2 = ol2.size();
			if (olsize2 < 3) {
				continue;
			}
			const Vector2 *r2 = ol2.ptr();

			for (int l = 0; l < olsize2; l++) {
				if (Geometry2D::segment_intersects_segment(r[0], outside_point, r2[l], r2[(l + 1) % olsize2], nullptr)) {
					interscount++;
				}
			}
		}

		bool outer = (interscount % 2) == 0;

		TPPLPoly tp;
		tp.Init(olsize);
		for (int j = 0; j < olsize; j++) {
			tp[j] = r[j];
		}

		if (outer) {
			tp.SetOrientation(TPPL_ORIENTATION_CCW);
		} else {
			tp.SetOrientation(TPPL_ORIENTATION_CW);
			tp.SetHole(true);
		}

		in_poly.push_back(tp);
	}

	TPPLPartition tpart;
	if (tpart.ConvexPartition_HM(&in_poly, &out_poly) == 0) { //failed!
		ERR_PRINT("NavigationPolygon: Convex partition failed! Failed to convert outlines to a valid NavigationMesh."
				  "\nNavigationPolygon outlines can not overlap vertices or edges inside same outline or with other outlines or have any intersections."
				  "\nAdd the outmost and largest outline first. To add holes inside this outline add the smaller outlines with opposite winding order.");
		return;
	}

	polygons.clear();
	vertices.clear();

	HashMap<Vector2, int> points;
	for (List<TPPLPoly>::Element *I = out_poly.front(); I; I = I->next()) {
		TPPLPoly &tp = I->get();

		struct Polygon p;

		for (int64_t i = 0; i < tp.GetNumPoints(); i++) {
			HashMap<Vector2, int>::Iterator E = points.find(tp[i]);
			if (!E) {
				E = points.insert(tp[i], vertices.size());
				vertices.push_back(tp[i]);
			}
			p.indices.push_back(E->value);
		}

		polygons.push_back(p);
	}

	emit_signal(CoreStringNames::get_singleton()->changed);
}

void NavigationPolygon::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_vertices", "vertices"), &NavigationPolygon::set_vertices);
	ClassDB::bind_method(D_METHOD("get_vertices"), &NavigationPolygon::get_vertices);

	ClassDB::bind_method(D_METHOD("add_polygon", "polygon"), &NavigationPolygon::add_polygon);
	ClassDB::bind_method(D_METHOD("get_polygon_count"), &NavigationPolygon::get_polygon_count);
	ClassDB::bind_method(D_METHOD("get_polygon", "idx"), &NavigationPolygon::get_polygon);
	ClassDB::bind_method(D_METHOD("clear_polygons"), &NavigationPolygon::clear_polygons);
	ClassDB::bind_method(D_METHOD("get_navigation_mesh"), &NavigationPolygon::get_navigation_mesh);

	ClassDB::bind_method(D_METHOD("add_outline", "outline"), &NavigationPolygon::add_outline);
	ClassDB::bind_method(D_METHOD("add_outline_at_index", "outline", "index"), &NavigationPolygon::add_outline_at_index);
	ClassDB::bind_method(D_METHOD("get_outline_count"), &NavigationPolygon::get_outline_count);
	ClassDB::bind_method(D_METHOD("set_outline", "idx", "outline"), &NavigationPolygon::set_outline);
	ClassDB::bind_method(D_METHOD("get_outline", "idx"), &NavigationPolygon::get_outline);
	ClassDB::bind_method(D_METHOD("remove_outline", "idx"), &NavigationPolygon::remove_outline);
	ClassDB::bind_method(D_METHOD("clear_outlines"), &NavigationPolygon::clear_outlines);
	ClassDB::bind_method(D_METHOD("make_polygons_from_outlines"), &NavigationPolygon::make_polygons_from_outlines);

	ClassDB::bind_method(D_METHOD("_set_polygons", "polygons"), &NavigationPolygon::_set_polygons);
	ClassDB::bind_method(D_METHOD("_get_polygons"), &NavigationPolygon::_get_polygons);

	ClassDB::bind_method(D_METHOD("_set_outlines", "outlines"), &NavigationPolygon::_set_outlines);
	ClassDB::bind_method(D_METHOD("_get_outlines"), &NavigationPolygon::_get_outlines);

	ADD_PROPERTY(PropertyInfo(Variant::PACKED_VECTOR2_ARRAY, "vertices", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR | PROPERTY_USAGE_INTERNAL), "set_vertices", "get_vertices");
	ADD_PROPERTY(PropertyInfo(Variant::ARRAY, "polygons", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR | PROPERTY_USAGE_INTERNAL), "_set_polygons", "_get_polygons");
	ADD_PROPERTY(PropertyInfo(Variant::ARRAY, "outlines", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR | PROPERTY_USAGE_INTERNAL), "_set_outlines", "_get_outlines");
}