1 files changed, 183 insertions, 0 deletions
diff --git a/WorldlineKeepers/Assets/Scripts/Physics/PhysicsManager_CollisionDetection.cs b/WorldlineKeepers/Assets/Scripts/Physics/PhysicsManager_CollisionDetection.cs
new file mode 100644
index 0000000..d5fd913
--- /dev/null
+++ b/WorldlineKeepers/Assets/Scripts/Physics/PhysicsManager_CollisionDetection.cs
@@ -0,0 +1,183 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+/// <summary>
+/// 碰撞检测
+/// </summary>
+public partial class PhysicsManager : Singleton<PhysicsManager>
+{
+
+    /// <summary>
+    /// circle x,y,radius 
+    /// </summary>
+    /// <param name="pos1"></param>
+    /// <param name="r1"></param>
+    /// <param name="pos2"></param>
+    /// <param name="r2"></param>
+    /// <returns></returns>
+    public static bool CircleVsCircle(Vector2 pos1, float r1, Vector2 pos2, float r2)
+    {
+        return (pos1 - pos2).magnitude <= r1 + r2;
+    }
+
+    public static bool CircleVsCircle(Vector3 c1, Vector3 c2)
+    {
+        return (c1.xy() - c2.xy()).magnitude <= c1.z + c2.z;
+    }
+
+    /// <summary>
+    /// intersection是r2对于r1
+    /// </summary>
+    /// <param name="b1"></param>
+    /// <param name="b2"></param>
+    /// <param name="intersection"></param>
+    /// <returns></returns>
+    public static bool BoxVsBox(Vector4 b1, Vector4 b2, out Vector2 intersection)
+    {
+        float b1w = b1.z / 2f, b1h = b1.w / 2f, b2w = b2.z / 2f, b2h = b2.w / 2f;
+        float distX = b2.x - b1.x;
+        float distY = b2.y - b1.y;
+        if(Mathf.Abs(distX) < b1w + b2w && Mathf.Abs(distY) < b1h +b2h)
+        {
+            intersection = new Vector2();
+            intersection.x = Mathf.Sign(distX) * (b1w + b2w - Mathf.Abs(distX));
+            intersection.y = Mathf.Sign(distY) * (b1h + b2h - Mathf.Abs(distY));
+            return true; 
+        }
+        intersection = Vector2.zero;
+        return false;
+    }
+
+    public static bool BoxVsBox(Vector4 b1, Vector4 b2)
+    {
+        float b1w = b1.z / 2f, b1h = b1.w / 2f, b2w = b2.z / 2f, b2h = b2.w / 2f;
+        float distX = b2.x - b1.x;
+        float distY = b2.y - b1.y;
+        if (Mathf.Abs(distX) < b1w + b2w && Mathf.Abs(distY) < b1h + b2h)
+        {
+            return true;
+        }
+        return false;
+    }
+
+    public static bool BoxVsCircle(Vector4 box, Vector2 pos, float radius)
+    {
+        Vector4 boxScaled = box;
+        boxScaled.z = box.z + radius * 2;
+        boxScaled.w = box.w + radius * 2;
+        if (!IsPointInsideBox(boxScaled, pos))
+            return false;
+        Vector2 v = MathUtils.Abs(pos - box.xy());
+        Vector2 u = MathUtils.Max(v - box.zw(), 0);
+        return Vector2.Dot(u, u) < radius * radius;
+    }
+
+    public static bool RayVsCircle(Vector4 ray, Vector3 circle)
+    {
+        Vector4 seg = GetRaySegment(ray);
+        Vector2 dir = ray.zw().normalized;
+        Vector2 center = circle.xy();
+        float u = Vector2.Dot(center - seg.xy(), dir);
+        Vector2 near = new Vector2();
+        if(u <= 0)
+        {
+            near = seg.xy();
+        }
+        else if(u >= ray.zw().magnitude)
+        {
+            near = seg.zw();
+        }
+        else
+        {
+            near = seg.xy() + dir * u;
+        }
+        return (near - center).sqrMagnitude <= circle.z * circle.z;
+    }
+
+
+    // From Real-time Collision Detection, p179
+    // box2d
+    public static bool RayVsBox(Vector4 ray, Vector4 box)
+    {
+        float tmin = float.MinValue;
+        float tmax = float.MaxValue;
+        Vector2 dir = ray.zw().normalized;
+        Vector4 range = GetBoxRange(box); //lowerx,higherx,lowery,highery
+        Vector2 lowerBound = new Vector2(range.x, range.z);
+        Vector2 upperBound = new Vector2(range.y, range.w);
+        //Vector2 normal = new Vector2();
+        Vector2 p = ray.xy();
+
+        for (int i = 0; i < 2; ++i)
+        {
+
+            if (dir[i] < float.Epsilon) // 和x-slab平行
+            {
+                if (p[i] < lowerBound[i] || p[i] > upperBound[i])
+                {
+                    return false;
+                }
+            }
+            else
+            {
+                float inv_d = 1f / dir[i];
+                float t1 = (lowerBound[i] - p[i]) * inv_d;
+                float t2 = (upperBound[i] - p[i]) * inv_d;
+                float s = -1f;
+                if (t1 > t2)
+                {
+                    MathUtils.Swap(ref t1, ref t2);
+                    s = 1f;
+                }
+                if (t1 > tmin)
+                {
+                    //normal = Vector2.zero;
+                    //normal[i] = s;
+                    tmin = t1;
+                }
+
+                tmax = Mathf.Min(tmax, t2);
+
+                if (tmin > tmax)
+                {
+                    return false;
+                }
+            }
+        }
+
+        // Does the ray start inside the box?
+        // Does the ray intersect beyond the max fraction?
+        if (tmin < 0 || ray.zw().magnitude < tmin)
+        {
+            if (IsPointInsideBox(box, p))
+                return true;
+            return false;
+        }
+        //// Intersection.
+        //output->fraction = tmin;
+        //output->normal = normal;
+
+        return true;
+    }
+
+    /// <summary>
+    /// box x,y,w,h circle x,y,raduis
+    /// </summary>
+    /// <param name="box"></param>
+    /// <param name="circle"></param>
+    /// <returns></returns>
+    public static bool BoxVsCircle(Vector4 box, Vector3 circle)
+    {
+        return BoxVsCircle(box, circle.xy(), circle.z);
+    }
+
+    public static bool IsPointInsideBox(Vector4 box, Vector2 point)
+    {
+        return point.x >= box.x - box.z / 2f
+            && point.x <= box.x + box.z / 2f
+            && point.y >= box.y - box.w / 2f
+            && point.y <= box.y + box.w / 2f;
+    }
+
+}