From 676700ecfa71870eb99c76ad04c62fe937350807 Mon Sep 17 00:00:00 2001
From: _Redstone_c_ <myredstone1024@gmail.com>
Date: Tue, 2 Feb 2021 17:30:13 +0800
Subject: [PATCH] Jumping

---
 Assets/Scenes/SampleScene.unity |  2 +
 Assets/Scripts/MovingSphere.cs  | 77 ++++++++++++++++++++++++++++++---
 2 files changed, 74 insertions(+), 5 deletions(-)

diff --git a/Assets/Scenes/SampleScene.unity b/Assets/Scenes/SampleScene.unity
index 867852a..c219f9b 100644
--- a/Assets/Scenes/SampleScene.unity
+++ b/Assets/Scenes/SampleScene.unity
@@ -1001,6 +1001,8 @@ MonoBehaviour:
   m_EditorClassIdentifier: 
   maxSpeed: 10
   maxAcceleration: 10
+  jumpHeight: 2
+  maxAirJumps: 1
 --- !u!54 &1695436951
 Rigidbody:
   m_ObjectHideFlags: 0
diff --git a/Assets/Scripts/MovingSphere.cs b/Assets/Scripts/MovingSphere.cs
index 879ea9f..9a1612f 100644
--- a/Assets/Scripts/MovingSphere.cs
+++ b/Assets/Scripts/MovingSphere.cs
@@ -6,11 +6,22 @@ public class MovingSphere : MonoBehaviour
     private float maxSpeed = 10f;
 
     [SerializeField, Range(0f, 100f)]
-    private float maxAcceleration = 10f;
-    
+    private float maxAcceleration = 10f, maxAirAcceleration = 1f;
+
+    [SerializeField, Range(0f, 10f)]
+    float jumpHeight = 2f;
+
+    [SerializeField, Range(0, 5)]
+    int maxAirJumps = 0;
+
     private Rigidbody body;
 
-    private Vector3 desiredVelocity;
+    private Vector3 desiredVelocity = new Vector3(0f, 0f, 0f);
+    private bool desiredJump = false;
+
+    private bool onGround;
+    private int jumpPhase;
+    private Vector3 velocity;
 
     private void Awake()
     {
@@ -24,14 +35,70 @@ public class MovingSphere : MonoBehaviour
         playerInput.y = Input.GetAxis("Vertical");
         playerInput = Vector2.ClampMagnitude(playerInput, 1f);
         desiredVelocity = new Vector3(playerInput.x, 0f, playerInput.y) * maxSpeed;
+
+        desiredJump |= Input.GetButtonDown("Jump");
     }
 
     private void FixedUpdate()
     {
-        var velocity = body.velocity;
-        float maxSpeedChange = maxAcceleration * Time.deltaTime;
+        UpdateState();
+
+        float acceleration = onGround ? maxAcceleration : maxAirAcceleration;
+        float maxSpeedChange = acceleration * Time.deltaTime;
         velocity.x = Mathf.MoveTowards(velocity.x, desiredVelocity.x, maxSpeedChange);
         velocity.z = Mathf.MoveTowards(velocity.z, desiredVelocity.z, maxSpeedChange);
+
+        if (desiredJump)
+        {
+            desiredJump = false;
+            Jump();
+        }
+
         body.velocity = velocity;
+
+        onGround = false;
     }
+
+    private void UpdateState()
+    {
+        velocity = body.velocity;
+        if (onGround)
+        {
+            jumpPhase = 0;
+        }
+    }
+
+    private void OnCollisionEnter(Collision collision)
+    {
+        EvaluateCollision(collision);
+    }
+    
+    private void OnCollisionStay(Collision collision)
+    {
+        EvaluateCollision(collision);
+    }
+
+    private void EvaluateCollision(Collision collision)
+    {
+        for (int i = 0; i < collision.contactCount; i++)
+        {
+            var normal = collision.GetContact(i).normal;
+            onGround |= normal.y >= 0.9f;
+        }
+    }
+
+    private void Jump()
+    {
+        if (onGround || jumpPhase < maxAirJumps)
+        {
+            jumpPhase++;
+            float jumpSpeed = Mathf.Sqrt(-2f * Physics.gravity.y * jumpHeight);
+            if (velocity.y > 0f)
+            {
+                jumpSpeed = Mathf.Max(jumpSpeed - velocity.y, 0f);
+            }
+            velocity.y += jumpSpeed;
+        }
+    }
+
 }