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

using System;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Serialization;

namespace Game
{
    public enum EShapeType
    {
        Dot,
        Circle,
        Sector,
        Box,
    }

    public class Shape
    {
        public EShapeType Type;
        public Vector3 Offset;
        public float Height;
        public float SizeX;
        public float SizeY;
        public float Radius;
        public float Angle;
        private List<Vector3> vertices = new List<Vector3>();

        public static Shape NewDot(Vector3 offset)
        {
            var shape = new Shape
            {
                Type = EShapeType.Dot,
                Offset = offset,
            };
            return shape;
        }

        public static Shape NewCircle(Vector3 offset, float height, float radius)
        {
            var shape = new Shape
            {
                Type = EShapeType.Circle,
                Offset = offset,
                Height = height,
                Radius = radius
            };
            return shape;
        }

        public static Shape NewSector(Vector3 offset, float height, float radius, float angle)
        {
            var shape = new Shape
            {
                Type = EShapeType.Sector,
                Offset = offset,
                Height = height,
                Radius = radius,
                Angle = angle
            };
            return shape;
        }

        public static Shape NewBox(Vector3 offset, float height, float sizeX, float sizeY)
        {
            var shape = new Shape
            {
                Type = EShapeType.Box,
                Offset = offset,
                Height = height,
                SizeX = sizeX,
                SizeY = sizeY
            };
            return shape;
        }

        public Vector4 GetAABB(Vector3 direction)
        {
            var aabb = Vector4.zero;
            switch (Type)
            {
                case EShapeType.Circle:
                case EShapeType.Sector:
                    aabb = new Vector4(-Radius, Radius, -Radius, Radius);
                    break;
                case EShapeType.Box:
                    ForeachVertices(direction, (vertex) =>
                    {
                        if (vertex.x < aabb.x) aabb.x = vertex.x;
                        if (vertex.x > aabb.y) aabb.y = vertex.x;
                        if (vertex.z < aabb.z) aabb.z = vertex.z;
                        if (vertex.z > aabb.w) aabb.w = vertex.z;
                    });
                    break;
            }

            return aabb;
        }

        private void SetVertices(Vector3 direction)
        {
            vertices.Clear();
            switch (Type)
            {
                case EShapeType.Circle:
                    for (var i = 0; i < 360; i += 15)
                    {
                        var angle = i * Mathf.Deg2Rad;
                        var x = Mathf.Cos(angle) * Radius;
                        var z = Mathf.Sin(angle) * Radius;
                        vertices.Add(new Vector3(x, 0, z));
                    }

                    break;
                case EShapeType.Sector:
                    var rotAdd = Util.Vec3ToRot(direction);
                    vertices.Add(Vector3.zero);
                    var vertNum = Angle > 15 ? (int)(Angle / 15) : 1;
                    var anglePerVertex = Angle / vertNum;
                    for (var i = 0; i <= vertNum; i++)
                    {
                        var angle = (i * anglePerVertex + rotAdd - Angle / 2) * Mathf.Deg2Rad;
                        var x = Mathf.Cos(angle) * Radius;
                        var z = Mathf.Sin(angle) * Radius;
                        vertices.Add(new Vector3(x, 0, z));
                    }

                    break;
                case EShapeType.Box:
                    var (halfX, halfY) = (SizeX / 2, SizeY / 2);

                    var up = new Vector3(direction.z, 0, -direction.x);
                    var right = new Vector3(direction.x, 0, direction.z);

                    var topLeft = right * halfX - up * halfY;
                    var topRight = right * halfX + up * halfY;
                    var bottomLeft = -right * halfX - up * halfY;
                    var bottomRight = -right * halfX + up * halfY;
                    vertices.Add(topLeft);
                    vertices.Add(topRight);
                    vertices.Add(bottomRight);
                    vertices.Add(bottomLeft);
                    break;
            }
        }

        public void ForeachVertices(Vector3 direction, Action<Vector3> action)
        {
            SetVertices(direction);
            foreach (var item in vertices)
            {
                action(item);
            }
        }

        public void ForeachVerticesPair(Vector3 direction, Action<Vector3, Vector3> action)
        {
            SetVertices(direction);
            for (var i = 0; i < vertices.Count; i++)
            {
                var next = i + 1;
                if (next >= vertices.Count) next = 0;
                action(vertices[i], vertices[next]);
            }
        }
    }
}