Add Mono conversion of the Pong demo

Quick and dirty port by a complete C# newbie,
could probably be optimized a bit.

mono/monkey_pong/Ball.cs

@@ -0,0 +1,38 @@
+using Godot;
+using System;
+
+public class Ball : Area2D
+{
+    private const int BALL_SPEED = 100;
+
+    private Vector2 direction = new Vector2(-1, 0);
+    private int speed = BALL_SPEED;
+
+    private Vector2 initialPos;
+
+    public void SetDirection(Vector2 newDirection)
+    {
+        direction = newDirection;
+    }
+    public Vector2 GetDirection()
+    {
+        return direction;
+    }
+
+    public void Reset()
+    {
+        SetPosition(initialPos);
+        speed = BALL_SPEED;
+        direction = new Vector2(-1, 0);
+    }
+
+    public override void _Ready()
+    {
+        initialPos = GetPosition();
+    }
+
+    public override void _Process(float delta)
+    {
+        SetPosition(GetPosition() + direction * speed * delta);
+    }
+}

mono/monkey_pong/CeilingFloor.cs

@@ -0,0 +1,17 @@
+using Godot;
+using System;
+
+public class CeilingFloor : Area2D
+{
+    [Export]
+    private int yDirection = 1;
+
+    public void OnAreaEntered(Area2D area)
+    {
+        if (area is Ball)
+        {
+            Ball ball = (Ball)area;
+            ball.SetDirection(ball.GetDirection() + new Vector2(0, yDirection));
+        }
+    }
+}

mono/monkey_pong/Paddle.cs

@@ -0,0 +1,39 @@
+using Godot;
+using System;
+
+public class Paddle : Area2D
+{
+    [Export]
+    private int ballDir = 1;
+
+    private const int MOVE_SPEED = 100;
+
+    public override void _Process(float delta)
+    {
+        String which = GetName();
+
+        // Move up and down based on input
+        if (Input.IsActionPressed(which + "_move_up") && GetPosition().y > 0)
+        {
+            Vector2 pos = GetPosition();
+            pos.y -= MOVE_SPEED * delta;
+            SetPosition(pos);
+        }
+        if (Input.IsActionPressed(which + "_move_down") && GetPosition().y < GetViewportRect().Size.y)
+        {
+            Vector2 pos = GetPosition();
+            pos.y += MOVE_SPEED * delta;
+            SetPosition(pos);
+        }
+    }
+
+    public void OnAreaEntered(Area2D area)
+    {
+        if (area is Ball)
+        {
+            // Assign new direction
+            Ball ball = (Ball)area;
+            ball.SetDirection(new Vector2(ballDir, (float)new Random().NextDouble() * 2 - 1).normalized());
+        }
+    }
+}

mono/monkey_pong/Wall.cs

@@ -0,0 +1,15 @@
+using Godot;
+using System;
+
+public class Wall : Area2D
+{
+    public void OnWallAreaEntered(Area2D area)
+    {
+        if (area is Ball)
+        {
+            // Oops, ball went out of game place, reset
+            Ball ball = (Ball)area;
+            ball.Reset();
+        }
+    }
+}

mono/monkey_pong/pong.tscn

@@ -0,0 +1,186 @@
+[gd_scene load_steps=13 format=2]
+
+[ext_resource path="res://Paddle.cs" type="Script" id=1]
+[ext_resource path="res://left_pallete.png" type="Texture" id=2]
+[ext_resource path="res://right_pallete.png" type="Texture" id=3]
+[ext_resource path="res://Ball.cs" type="Script" id=4]
+[ext_resource path="res://ball.png" type="Texture" id=5]
+[ext_resource path="res://separator.png" type="Texture" id=6]
+[ext_resource path="res://Wall.cs" type="Script" id=7]
+[ext_resource path="res://CeilingFloor.cs" type="Script" id=8]
+
+[sub_resource type="RectangleShape2D" id=1]
+
+custom_solver_bias = 0.0
+extents = Vector2( 4, 16 )
+
+[sub_resource type="RectangleShape2D" id=2]
+
+custom_solver_bias = 0.0
+extents = Vector2( 4, 4 )
+
+[sub_resource type="RectangleShape2D" id=3]
+
+custom_solver_bias = 0.0
+extents = Vector2( 10, 200 )
+
+[sub_resource type="RectangleShape2D" id=4]
+
+custom_solver_bias = 0.0
+extents = Vector2( 320, 10 )
+
+[node name="game" type="Node2D"]
+
+[node name="left" type="Area2D" parent="."]
+
+position = Vector2( 67.6285, 192.594 )
+input_pickable = true
+gravity_vec = Vector2( 0, 1 )
+gravity = 98.0
+linear_damp = 0.1
+angular_damp = 1.0
+audio_bus_override = false
+audio_bus_name = "Master"
+script = ExtResource( 1 )
+ballDir = 1
+
+[node name="sprite" type="Sprite" parent="left"]
+
+texture = ExtResource( 2 )
+_sections_unfolded = [ "Transform" ]
+
+[node name="collision" type="CollisionShape2D" parent="left"]
+
+shape = SubResource( 1 )
+
+[node name="right" type="Area2D" parent="."]
+
+position = Vector2( 563.815, 188.919 )
+input_pickable = true
+gravity_vec = Vector2( 0, 1 )
+gravity = 98.0
+linear_damp = 0.1
+angular_damp = 1.0
+audio_bus_override = false
+audio_bus_name = "Master"
+script = ExtResource( 1 )
+ballDir = -1
+
+[node name="sprite" type="Sprite" parent="right"]
+
+texture = ExtResource( 3 )
+_sections_unfolded = [ "Transform" ]
+
+[node name="collision" type="CollisionShape2D" parent="right"]
+
+shape = SubResource( 1 )
+
+[node name="ball" type="Area2D" parent="."]
+
+position = Vector2( 320.5, 191.124 )
+input_pickable = true
+gravity_vec = Vector2( 0, 1 )
+gravity = 98.0
+linear_damp = 0.1
+angular_damp = 1.0
+audio_bus_override = false
+audio_bus_name = "Master"
+script = ExtResource( 4 )
+
+[node name="sprite" type="Sprite" parent="ball"]
+
+texture = ExtResource( 5 )
+_sections_unfolded = [ "Transform" ]
+
+[node name="collision" type="CollisionShape2D" parent="ball"]
+
+shape = SubResource( 2 )
+
+[node name="separator" type="Sprite" parent="."]
+
+position = Vector2( 320, 200 )
+texture = ExtResource( 6 )
+
+[node name="left_wall" type="Area2D" parent="."]
+
+position = Vector2( -10, 200 )
+input_pickable = true
+gravity_vec = Vector2( 0, 1 )
+gravity = 98.0
+linear_damp = 0.1
+angular_damp = 1.0
+audio_bus_override = false
+audio_bus_name = "Master"
+script = ExtResource( 7 )
+_sections_unfolded = [ "Transform" ]
+
+[node name="collision" type="CollisionShape2D" parent="left_wall"]
+
+shape = SubResource( 3 )
+
+[node name="right_wall" type="Area2D" parent="."]
+
+position = Vector2( 650, 200 )
+input_pickable = true
+gravity_vec = Vector2( 0, 1 )
+gravity = 98.0
+linear_damp = 0.1
+angular_damp = 1.0
+audio_bus_override = false
+audio_bus_name = "Master"
+script = ExtResource( 7 )
+_sections_unfolded = [ "Transform" ]
+
+[node name="collision" type="CollisionShape2D" parent="right_wall"]
+
+shape = SubResource( 3 )
+
+[node name="ceiling" type="Area2D" parent="."]
+
+position = Vector2( 320, -10 )
+input_pickable = true
+gravity_vec = Vector2( 0, 1 )
+gravity = 98.0
+linear_damp = 0.1
+angular_damp = 1.0
+audio_bus_override = false
+audio_bus_name = "Master"
+script = ExtResource( 8 )
+_sections_unfolded = [ "Transform" ]
+yDirection = 1
+
+[node name="collision" type="CollisionShape2D" parent="ceiling"]
+
+shape = SubResource( 4 )
+
+[node name="floor" type="Area2D" parent="."]
+
+position = Vector2( 320, 410 )
+input_pickable = true
+gravity_vec = Vector2( 0, 1 )
+gravity = 98.0
+linear_damp = 0.1
+angular_damp = 1.0
+audio_bus_override = false
+audio_bus_name = "Master"
+script = ExtResource( 8 )
+_sections_unfolded = [ "Transform" ]
+yDirection = -1
+
+[node name="collision" type="CollisionShape2D" parent="floor"]
+
+shape = SubResource( 4 )
+
+[connection signal="area_entered" from="left" to="left" method="OnAreaEntered"]
+
+[connection signal="area_entered" from="right" to="right" method="OnAreaEntered"]
+
+[connection signal="area_entered" from="left_wall" to="left_wall" method="OnWallAreaEntered"]
+
+[connection signal="area_entered" from="right_wall" to="right_wall" method="OnWallAreaEntered"]
+
+[connection signal="area_entered" from="ceiling" to="ceiling" method="OnAreaEntered"]
+
+[connection signal="area_entered" from="floor" to="floor" method="OnAreaEntered"]
+
+

mono/monkey_pong/project.godot

@@ -0,0 +1,40 @@
+; Engine configuration file.
+; It's best edited using the editor UI and not directly,
+; since the parameters that go here are not all obvious.
+;
+; Format:
+;   [section] ; section goes between []
+;   param=value ; assign values to parameters
+
+config_version=3
+
+[application]
+
+config/name="Pong with C#"
+run/main_scene="pong.tscn"
+config/icon="res://icon.png"
+
+[display]
+
+window/size/width=640
+window/size/height=400
+window/stretch/mode="2d"
+
+[gdnative]
+
+singletons=[  ]
+
+[input]
+
+left_move_down=[ Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":90,"unicode":0,"echo":false,"script":null)
+ ]
+left_move_up=[ Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":65,"unicode":0,"echo":false,"script":null)
+ ]
+right_move_down=[ Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":16777234,"unicode":0,"echo":false,"script":null)
+ ]
+right_move_up=[ Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":16777232,"unicode":0,"echo":false,"script":null)
+ ]
+
+[rendering]
+
+viewport/default_clear_color=Color( 0, 0, 0, 1 )