From 692f97ba9c292b6f22b597117ef69b89aeb90bc6 Mon Sep 17 00:00:00 2001
From: Marcelo Fernandez <marcelofg55@gmail.com>
Date: Sun, 30 Jul 2017 19:39:14 -0300
Subject: [PATCH] Ported move_and_slide funcs from 3.0 branch

---
 scene/2d/physics_body_2d.cpp | 86 ++++++++++++++++++++++++++++++++++++
 scene/2d/physics_body_2d.h   | 12 +++++
 2 files changed, 98 insertions(+)

diff --git a/scene/2d/physics_body_2d.cpp b/scene/2d/physics_body_2d.cpp
index 1df932b49d8..b6f451c3fd2 100644
--- a/scene/2d/physics_body_2d.cpp
+++ b/scene/2d/physics_body_2d.cpp
@@ -1177,6 +1177,82 @@ Vector2 KinematicBody2D::move_to(const Vector2 &p_position) {
 	return move(p_position - get_global_pos());
 }
 
+Vector2 KinematicBody2D::move_and_slide(const Vector2 &p_linear_velocity, const Vector2 &p_floor_direction, float p_slope_stop_min_velocity, int p_max_bounces) {
+
+	Vector2 motion = (move_and_slide_floor_velocity + p_linear_velocity) * get_fixed_process_delta_time();
+	Vector2 lv = p_linear_velocity;
+
+	move_and_slide_on_floor = false;
+	move_and_slide_on_ceiling = false;
+	move_and_slide_on_wall = false;
+	move_and_slide_colliders.clear();
+	move_and_slide_floor_velocity = Vector2();
+
+	while (p_max_bounces) {
+
+		motion = move(motion);
+
+		if (is_colliding()) {
+
+			if (p_floor_direction == Vector2()) {
+				//all is a wall
+				move_and_slide_on_wall = true;
+			} else {
+				if (get_collision_normal().dot(p_floor_direction) > Math::cos(Math::deg2rad((float)45))) { //floor
+
+					move_and_slide_on_floor = true;
+					move_and_slide_floor_velocity = get_collider_velocity();
+
+					if (get_travel().length() < 1 && ABS((lv.x - move_and_slide_floor_velocity.x)) < p_slope_stop_min_velocity) {
+						revert_motion();
+						return Vector2();
+					}
+				} else if (get_collision_normal().dot(p_floor_direction) < Math::cos(Math::deg2rad((float)45))) { //ceiling
+					move_and_slide_on_ceiling = true;
+				} else {
+					move_and_slide_on_wall = true;
+				}
+			}
+
+			motion = get_collision_normal().slide(motion);
+			lv = get_collision_normal().slide(lv);
+			Variant collider = _get_collider();
+			if (collider.get_type() != Variant::NIL) {
+				move_and_slide_colliders.push_back(collider);
+			}
+
+		} else {
+			break;
+		}
+
+		p_max_bounces--;
+		if (motion == Vector2())
+			break;
+	}
+
+	return lv;
+}
+
+bool KinematicBody2D::is_move_and_slide_on_floor() const {
+
+	return move_and_slide_on_floor;
+}
+
+bool KinematicBody2D::is_move_and_slide_on_wall() const {
+
+	return move_and_slide_on_wall;
+}
+
+bool KinematicBody2D::is_move_and_slide_on_ceiling() const {
+
+	return move_and_slide_on_ceiling;
+}
+
+Array KinematicBody2D::get_move_and_slide_colliders() const {
+
+	return move_and_slide_colliders;
+}
+
 bool KinematicBody2D::test_move(const Vector2 &p_motion) {
 
 	ERR_FAIL_COND_V(!is_inside_tree(), false);
@@ -1249,6 +1325,12 @@ void KinematicBody2D::_bind_methods() {
 
 	ObjectTypeDB::bind_method(_MD("move", "rel_vec"), &KinematicBody2D::move);
 	ObjectTypeDB::bind_method(_MD("move_to", "position"), &KinematicBody2D::move_to);
+	ObjectTypeDB::bind_method(_MD("move_and_slide", "linear_velocity", "floor_normal", "slope_stop_min_velocity", "max_bounces"), &KinematicBody2D::move_and_slide, DEFVAL(Vector2(0, 0)), DEFVAL(5), DEFVAL(4));
+
+	ObjectTypeDB::bind_method(_MD("get_move_and_slide_colliders"), &KinematicBody2D::get_move_and_slide_colliders);
+	ObjectTypeDB::bind_method(_MD("is_move_and_slide_on_floor"), &KinematicBody2D::is_move_and_slide_on_floor);
+	ObjectTypeDB::bind_method(_MD("is_move_and_slide_on_ceiling"), &KinematicBody2D::is_move_and_slide_on_ceiling);
+	ObjectTypeDB::bind_method(_MD("is_move_and_slide_on_wall"), &KinematicBody2D::is_move_and_slide_on_wall);
 
 	ObjectTypeDB::bind_method(_MD("test_move", "rel_vec"), &KinematicBody2D::test_move);
 	ObjectTypeDB::bind_method(_MD("test_move_from", "from", "rel_vec"), &KinematicBody2D::test_move_from);
@@ -1279,6 +1361,10 @@ KinematicBody2D::KinematicBody2D()
 	collider_shape = 0;
 
 	margin = 0.08;
+
+	move_and_slide_on_floor = false;
+	move_and_slide_on_ceiling = false;
+	move_and_slide_on_wall = false;
 }
 KinematicBody2D::~KinematicBody2D() {
 }
diff --git a/scene/2d/physics_body_2d.h b/scene/2d/physics_body_2d.h
index c0e22fc3a70..dc0d45bcf51 100644
--- a/scene/2d/physics_body_2d.h
+++ b/scene/2d/physics_body_2d.h
@@ -286,6 +286,12 @@ class KinematicBody2D : public PhysicsBody2D {
 	Variant collider_metadata;
 	Vector2 travel;
 
+	Vector2 move_and_slide_floor_velocity;
+	bool move_and_slide_on_floor;
+	bool move_and_slide_on_ceiling;
+	bool move_and_slide_on_wall;
+	Array move_and_slide_colliders;
+
 	Variant _get_collider() const;
 
 	_FORCE_INLINE_ bool _ignores_mode(Physics2DServer::BodyMode) const;
@@ -314,6 +320,12 @@ public:
 	void set_collision_margin(float p_margin);
 	float get_collision_margin() const;
 
+	Vector2 move_and_slide(const Vector2 &p_linear_velocity, const Vector2 &p_floor_direction = Vector2(0, 0), float p_slope_stop_min_velocity = 5, int p_max_bounces = 4);
+	bool is_move_and_slide_on_floor() const;
+	bool is_move_and_slide_on_wall() const;
+	bool is_move_and_slide_on_ceiling() const;
+	Array get_move_and_slide_colliders() const;
+
 	KinematicBody2D();
 	~KinematicBody2D();
 };