/*************************************************************************/
/*  light_occluder_2d.cpp                                                */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
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/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
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/* "Software"), to deal in the Software without restriction, including   */
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#include "light_occluder_2d.h"
#include "core/math/geometry_2d.h"

#include "core/config/engine.h"

#define LINE_GRAB_WIDTH 8

#ifdef TOOLS_ENABLED
Rect2 OccluderPolygon2D::_edit_get_rect() const {
	if (rect_cache_dirty) {
		if (closed) {
			const Vector2 *r = polygon.ptr();
			item_rect = Rect2();
			for (int i = 0; i < polygon.size(); i++) {
				Vector2 pos = r[i];
				if (i == 0) {
					item_rect.position = pos;
				} else {
					item_rect.expand_to(pos);
				}
			}
			rect_cache_dirty = false;
		} else {
			if (polygon.size() == 0) {
				item_rect = Rect2();
			} else {
				Vector2 d = Vector2(LINE_GRAB_WIDTH, LINE_GRAB_WIDTH);
				item_rect = Rect2(polygon[0] - d, 2 * d);
				for (int i = 1; i < polygon.size(); i++) {
					item_rect.expand_to(polygon[i] - d);
					item_rect.expand_to(polygon[i] + d);
				}
			}
		}
	}

	return item_rect;
}

bool OccluderPolygon2D::_edit_is_selected_on_click(const Point2 &p_point, double p_tolerance) const {
	if (closed) {
		return Geometry2D::is_point_in_polygon(p_point, Variant(polygon));
	} else {
		const real_t d = LINE_GRAB_WIDTH / 2 + p_tolerance;
		const Vector2 *points = polygon.ptr();
		for (int i = 0; i < polygon.size() - 1; i++) {
			Vector2 p = Geometry2D::get_closest_point_to_segment(p_point, &points[i]);
			if (p.distance_to(p_point) <= d) {
				return true;
			}
		}

		return false;
	}
}
#endif

void OccluderPolygon2D::set_polygon(const Vector<Vector2> &p_polygon) {
	polygon = p_polygon;
	rect_cache_dirty = true;
	RS::get_singleton()->canvas_occluder_polygon_set_shape(occ_polygon, p_polygon, closed);
	emit_changed();
}

Vector<Vector2> OccluderPolygon2D::get_polygon() const {
	return polygon;
}

void OccluderPolygon2D::set_closed(bool p_closed) {
	if (closed == p_closed) {
		return;
	}
	closed = p_closed;
	if (polygon.size()) {
		RS::get_singleton()->canvas_occluder_polygon_set_shape(occ_polygon, polygon, closed);
	}
	emit_changed();
}

bool OccluderPolygon2D::is_closed() const {
	return closed;
}

void OccluderPolygon2D::set_cull_mode(CullMode p_mode) {
	cull = p_mode;
	RS::get_singleton()->canvas_occluder_polygon_set_cull_mode(occ_polygon, RS::CanvasOccluderPolygonCullMode(p_mode));
}

OccluderPolygon2D::CullMode OccluderPolygon2D::get_cull_mode() const {
	return cull;
}

RID OccluderPolygon2D::get_rid() const {
	return occ_polygon;
}

void OccluderPolygon2D::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_closed", "closed"), &OccluderPolygon2D::set_closed);
	ClassDB::bind_method(D_METHOD("is_closed"), &OccluderPolygon2D::is_closed);

	ClassDB::bind_method(D_METHOD("set_cull_mode", "cull_mode"), &OccluderPolygon2D::set_cull_mode);
	ClassDB::bind_method(D_METHOD("get_cull_mode"), &OccluderPolygon2D::get_cull_mode);

	ClassDB::bind_method(D_METHOD("set_polygon", "polygon"), &OccluderPolygon2D::set_polygon);
	ClassDB::bind_method(D_METHOD("get_polygon"), &OccluderPolygon2D::get_polygon);

	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "closed"), "set_closed", "is_closed");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "cull_mode", PROPERTY_HINT_ENUM, "Disabled,ClockWise,CounterClockWise"), "set_cull_mode", "get_cull_mode");
	ADD_PROPERTY(PropertyInfo(Variant::PACKED_VECTOR2_ARRAY, "polygon"), "set_polygon", "get_polygon");

	BIND_ENUM_CONSTANT(CULL_DISABLED);
	BIND_ENUM_CONSTANT(CULL_CLOCKWISE);
	BIND_ENUM_CONSTANT(CULL_COUNTER_CLOCKWISE);
}

OccluderPolygon2D::OccluderPolygon2D() {
	occ_polygon = RS::get_singleton()->canvas_occluder_polygon_create();
	closed = true;
	cull = CULL_DISABLED;
	rect_cache_dirty = true;
}

OccluderPolygon2D::~OccluderPolygon2D() {
	RS::get_singleton()->free(occ_polygon);
}

void LightOccluder2D::_poly_changed() {
#ifdef DEBUG_ENABLED
	update();
#endif
}

void LightOccluder2D::_notification(int p_what) {
	if (p_what == NOTIFICATION_ENTER_CANVAS) {
		RS::get_singleton()->canvas_light_occluder_attach_to_canvas(occluder, get_canvas());
		RS::get_singleton()->canvas_light_occluder_set_transform(occluder, get_global_transform());
		RS::get_singleton()->canvas_light_occluder_set_enabled(occluder, is_visible_in_tree());
	}
	if (p_what == NOTIFICATION_TRANSFORM_CHANGED) {
		RS::get_singleton()->canvas_light_occluder_set_transform(occluder, get_global_transform());
	}
	if (p_what == NOTIFICATION_VISIBILITY_CHANGED) {
		RS::get_singleton()->canvas_light_occluder_set_enabled(occluder, is_visible_in_tree());
	}

	if (p_what == NOTIFICATION_DRAW) {
		if (Engine::get_singleton()->is_editor_hint()) {
			if (occluder_polygon.is_valid()) {
				Vector<Vector2> poly = occluder_polygon->get_polygon();

				if (poly.size()) {
					if (occluder_polygon->is_closed()) {
						Vector<Color> color;
						color.push_back(Color(0, 0, 0, 0.6));
						draw_polygon(Variant(poly), color);
					} else {
						int ps = poly.size();
						const Vector2 *r = poly.ptr();
						for (int i = 0; i < ps - 1; i++) {
							draw_line(r[i], r[i + 1], Color(0, 0, 0, 0.6), 3);
						}
					}
				}
			}
		}
	}

	if (p_what == NOTIFICATION_EXIT_CANVAS) {
		RS::get_singleton()->canvas_light_occluder_attach_to_canvas(occluder, RID());
	}
}

#ifdef TOOLS_ENABLED
Rect2 LightOccluder2D::_edit_get_rect() const {
	return occluder_polygon.is_valid() ? occluder_polygon->_edit_get_rect() : Rect2();
}

bool LightOccluder2D::_edit_is_selected_on_click(const Point2 &p_point, double p_tolerance) const {
	return occluder_polygon.is_valid() ? occluder_polygon->_edit_is_selected_on_click(p_point, p_tolerance) : false;
}
#endif

void LightOccluder2D::set_occluder_polygon(const Ref<OccluderPolygon2D> &p_polygon) {
#ifdef DEBUG_ENABLED
	if (occluder_polygon.is_valid()) {
		occluder_polygon->disconnect("changed", callable_mp(this, &LightOccluder2D::_poly_changed));
	}
#endif
	occluder_polygon = p_polygon;

	if (occluder_polygon.is_valid()) {
		RS::get_singleton()->canvas_light_occluder_set_polygon(occluder, occluder_polygon->get_rid());
	} else {
		RS::get_singleton()->canvas_light_occluder_set_polygon(occluder, RID());
	}

#ifdef DEBUG_ENABLED
	if (occluder_polygon.is_valid()) {
		occluder_polygon->connect("changed", callable_mp(this, &LightOccluder2D::_poly_changed));
	}
	update();
#endif
}

Ref<OccluderPolygon2D> LightOccluder2D::get_occluder_polygon() const {
	return occluder_polygon;
}

void LightOccluder2D::set_occluder_light_mask(int p_mask) {
	mask = p_mask;
	RS::get_singleton()->canvas_light_occluder_set_light_mask(occluder, mask);
}

int LightOccluder2D::get_occluder_light_mask() const {
	return mask;
}

String LightOccluder2D::get_configuration_warning() const {
	String warning = Node2D::get_configuration_warning();

	if (!occluder_polygon.is_valid()) {
		if (!warning.empty()) {
			warning += "\n\n";
		}
		warning += TTR("An occluder polygon must be set (or drawn) for this occluder to take effect.");
	}

	if (occluder_polygon.is_valid() && occluder_polygon->get_polygon().size() == 0) {
		if (!warning.empty()) {
			warning += "\n\n";
		}
		warning += TTR("The occluder polygon for this occluder is empty. Please draw a polygon.");
	}

	return warning;
}

void LightOccluder2D::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_occluder_polygon", "polygon"), &LightOccluder2D::set_occluder_polygon);
	ClassDB::bind_method(D_METHOD("get_occluder_polygon"), &LightOccluder2D::get_occluder_polygon);

	ClassDB::bind_method(D_METHOD("set_occluder_light_mask", "mask"), &LightOccluder2D::set_occluder_light_mask);
	ClassDB::bind_method(D_METHOD("get_occluder_light_mask"), &LightOccluder2D::get_occluder_light_mask);

	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "occluder", PROPERTY_HINT_RESOURCE_TYPE, "OccluderPolygon2D"), "set_occluder_polygon", "get_occluder_polygon");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "light_mask", PROPERTY_HINT_LAYERS_2D_RENDER), "set_occluder_light_mask", "get_occluder_light_mask");
}

LightOccluder2D::LightOccluder2D() {
	occluder = RS::get_singleton()->canvas_light_occluder_create();
	mask = 1;
	set_notify_transform(true);
}

LightOccluder2D::~LightOccluder2D() {
	RS::get_singleton()->free(occluder);
}