/*************************************************************************/
/*  collision_shape_2d.cpp                                               */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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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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#include "collision_shape_2d.h"

#include "collision_object_2d.h"
#include "scene/resources/concave_polygon_shape_2d.h"
#include "scene/resources/convex_polygon_shape_2d.h"

void CollisionShape2D::_shape_changed() {
	update();
}

void CollisionShape2D::_update_in_shape_owner(bool p_xform_only) {
	parent->shape_owner_set_transform(owner_id, get_transform());
	if (p_xform_only) {
		return;
	}
	parent->shape_owner_set_disabled(owner_id, disabled);
	parent->shape_owner_set_one_way_collision(owner_id, one_way_collision);
	parent->shape_owner_set_one_way_collision_margin(owner_id, one_way_collision_margin);
}

void CollisionShape2D::_notification(int p_what) {
	switch (p_what) {
		case NOTIFICATION_PARENTED: {
			parent = Object::cast_to<CollisionObject2D>(get_parent());
			if (parent) {
				owner_id = parent->create_shape_owner(this);
				if (shape.is_valid()) {
					parent->shape_owner_add_shape(owner_id, shape);
				}
				_update_in_shape_owner();
			}
		} break;

		case NOTIFICATION_ENTER_TREE: {
			if (parent) {
				_update_in_shape_owner();
			}
		} break;

		case NOTIFICATION_LOCAL_TRANSFORM_CHANGED: {
			if (parent) {
				_update_in_shape_owner(true);
			}
		} break;

		case NOTIFICATION_UNPARENTED: {
			if (parent) {
				parent->remove_shape_owner(owner_id);
			}
			owner_id = 0;
			parent = nullptr;
		} break;

		case NOTIFICATION_DRAW: {
			ERR_FAIL_COND(!is_inside_tree());

			if (!Engine::get_singleton()->is_editor_hint() && !get_tree()->is_debugging_collisions_hint()) {
				break;
			}

			if (!shape.is_valid()) {
				break;
			}

			rect = Rect2();

			Color draw_col = get_tree()->get_debug_collisions_color();
			if (disabled) {
				float g = draw_col.get_v();
				draw_col.r = g;
				draw_col.g = g;
				draw_col.b = g;
				draw_col.a *= 0.5;
			}
			shape->draw(get_canvas_item(), draw_col);

			rect = shape->get_rect();
			rect = rect.grow(3);

			if (one_way_collision) {
				// Draw an arrow indicating the one-way collision direction
				draw_col = get_tree()->get_debug_collisions_color().inverted();
				if (disabled) {
					draw_col = draw_col.darkened(0.25);
				}
				Vector2 line_to(0, 20);
				draw_line(Vector2(), line_to, draw_col, 2);
				real_t tsize = 8;

				Vector<Vector2> pts{
					line_to + Vector2(0, tsize),
					line_to + Vector2(Math_SQRT12 * tsize, 0),
					line_to + Vector2(-Math_SQRT12 * tsize, 0)
				};

				Vector<Color> cols{ draw_col, draw_col, draw_col };

				draw_primitive(pts, cols, Vector<Vector2>());
			}
		} break;
	}
}

void CollisionShape2D::set_shape(const Ref<Shape2D> &p_shape) {
	if (p_shape == shape) {
		return;
	}
	if (shape.is_valid()) {
		shape->disconnect("changed", callable_mp(this, &CollisionShape2D::_shape_changed));
	}
	shape = p_shape;
	update();
	if (parent) {
		parent->shape_owner_clear_shapes(owner_id);
		if (shape.is_valid()) {
			parent->shape_owner_add_shape(owner_id, shape);
		}
		_update_in_shape_owner();
	}

	if (shape.is_valid()) {
		shape->connect("changed", callable_mp(this, &CollisionShape2D::_shape_changed));
	}

	update_configuration_warnings();
}

Ref<Shape2D> CollisionShape2D::get_shape() const {
	return shape;
}

bool CollisionShape2D::_edit_is_selected_on_click(const Point2 &p_point, double p_tolerance) const {
	if (!shape.is_valid()) {
		return false;
	}

	return shape->_edit_is_selected_on_click(p_point, p_tolerance);
}

TypedArray<String> CollisionShape2D::get_configuration_warnings() const {
	TypedArray<String> warnings = Node::get_configuration_warnings();

	if (!Object::cast_to<CollisionObject2D>(get_parent())) {
		warnings.push_back(RTR("CollisionShape2D only serves to provide a collision shape to a CollisionObject2D derived node. Please only use it as a child of Area2D, StaticBody2D, RigidDynamicBody2D, CharacterBody2D, etc. to give them a shape."));
	}
	if (!shape.is_valid()) {
		warnings.push_back(RTR("A shape must be provided for CollisionShape2D to function. Please create a shape resource for it!"));
	}

	Ref<ConvexPolygonShape2D> convex = shape;
	Ref<ConcavePolygonShape2D> concave = shape;
	if (convex.is_valid() || concave.is_valid()) {
		warnings.push_back(RTR("Polygon-based shapes are not meant be used nor edited directly through the CollisionShape2D node. Please use the CollisionPolygon2D node instead."));
	}

	return warnings;
}

void CollisionShape2D::set_disabled(bool p_disabled) {
	disabled = p_disabled;
	update();
	if (parent) {
		parent->shape_owner_set_disabled(owner_id, p_disabled);
	}
}

bool CollisionShape2D::is_disabled() const {
	return disabled;
}

void CollisionShape2D::set_one_way_collision(bool p_enable) {
	one_way_collision = p_enable;
	update();
	if (parent) {
		parent->shape_owner_set_one_way_collision(owner_id, p_enable);
	}
}

bool CollisionShape2D::is_one_way_collision_enabled() const {
	return one_way_collision;
}

void CollisionShape2D::set_one_way_collision_margin(real_t p_margin) {
	one_way_collision_margin = p_margin;
	if (parent) {
		parent->shape_owner_set_one_way_collision_margin(owner_id, one_way_collision_margin);
	}
}

real_t CollisionShape2D::get_one_way_collision_margin() const {
	return one_way_collision_margin;
}

void CollisionShape2D::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_shape", "shape"), &CollisionShape2D::set_shape);
	ClassDB::bind_method(D_METHOD("get_shape"), &CollisionShape2D::get_shape);
	ClassDB::bind_method(D_METHOD("set_disabled", "disabled"), &CollisionShape2D::set_disabled);
	ClassDB::bind_method(D_METHOD("is_disabled"), &CollisionShape2D::is_disabled);
	ClassDB::bind_method(D_METHOD("set_one_way_collision", "enabled"), &CollisionShape2D::set_one_way_collision);
	ClassDB::bind_method(D_METHOD("is_one_way_collision_enabled"), &CollisionShape2D::is_one_way_collision_enabled);
	ClassDB::bind_method(D_METHOD("set_one_way_collision_margin", "margin"), &CollisionShape2D::set_one_way_collision_margin);
	ClassDB::bind_method(D_METHOD("get_one_way_collision_margin"), &CollisionShape2D::get_one_way_collision_margin);

	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "shape", PROPERTY_HINT_RESOURCE_TYPE, "Shape2D"), "set_shape", "get_shape");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "disabled"), "set_disabled", "is_disabled");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "one_way_collision"), "set_one_way_collision", "is_one_way_collision_enabled");
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "one_way_collision_margin", PROPERTY_HINT_RANGE, "0,128,0.1"), "set_one_way_collision_margin", "get_one_way_collision_margin");
}

CollisionShape2D::CollisionShape2D() {
	set_notify_local_transform(true);
}