Touhou/client/Assets/Game/Scripts/Util/Shape/UtilShape.cs

using UnityEngine;

namespace Game
{
    public static class UtilShape
    {
        public static bool IsOverlap(Shape shape, Shape circle,
            Vector3 shapePos, Vector3 circlePos, Vector3 shapeDir, Vector3 circleDir)
        {
            if (circle.Type != EShapeType.Circle)
            {
                Util.Print("第二个形状参数必须为圆形:", circle.Type);
                return false;
            }

            //检查Y
            var (shapeCenter, circleCenter) = (shapePos + shape.Offset, circlePos + circle.Offset);
            var (shapeYMin, shapeYMax) = (shapeCenter.y, shapeCenter.y + shape.Height);
            var (circleYMin, circleYMax) = (circleCenter.y, circleCenter.y + circle.Height);

            if (shapeYMin > circleYMax || shapeYMax < circleYMin)
            {
                return false;
            }

            //保底距离
            var dist = Vector3.Distance(shapeCenter, circleCenter);
            if (dist < 0.01f)
            {
                return true;
            }

            //检查AABB
            var (shapeAABB, circleAABB) = (shape.GetAABB(shapeDir), circle.GetAABB(circleDir));
            var shapeXMin = shapeAABB.x + shapeCenter.x;
            var shapeXMax = shapeAABB.y + shapeCenter.x;
            var shapeZMin = shapeAABB.z + shapeCenter.z;
            var shapeZMax = shapeAABB.w + shapeCenter.z;
            var circleXMin = circleAABB.x + circleCenter.x;
            var circleXMax = circleAABB.y + circleCenter.x;
            var circleZMin = circleAABB.z + circleCenter.z;
            var circleZMax = circleAABB.w + circleCenter.z;

            if (shapeXMin > circleXMax || shapeXMax < circleXMin || shapeZMin > circleZMax || shapeZMax < circleZMin)
            {
                return false;
            }

            //检查形状
            switch (shape.Type)
            {
                case EShapeType.Dot:
                    return true;
                case EShapeType.Circle:
                case EShapeType.Sector: //TODO
                    var distance = Vector3.Distance(shapeCenter, circleCenter);
                    return distance < shape.Radius + circle.Radius;
                case EShapeType.Box:
                    var dir = circleCenter - shapeCenter;
                    var circleCenterNew = Quaternion.FromToRotation(shapeDir, Vector3.right) * dir;
                    var (shapeSizeX, shapeSizeY) = (SizeX: shape.SizeX, SizeY: shape.SizeY);
                    return RectCircleIntersection(shapeSizeX, shapeSizeY, circle.Radius, circleCenterNew);
            }

            return false;
        }

        private static bool RectCircleIntersection(float sizeX, float sizeY, float circleRadius, Vector3 circleCenter)
        {
            var distX = Mathf.Abs(circleCenter.x) - sizeX;
            var distY = Mathf.Abs(circleCenter.z) - sizeY;

            if (distX <= circleRadius && distY <= circleRadius)
            {
                if (distX <= 0f || distY <= 0f)
                {
                    return true;
                }

                var cornerDistanceSquared = Mathf.Pow(distX, 2f) + Mathf.Pow(distY, 2f);
                return cornerDistanceSquared <= Mathf.Pow(circleRadius, 2f);
            }

            return false;
        }
    }
}