ReImplementInLua

ReImplementInLua.cs

    using UnityEngine;
    using System.Collections;
    using XLua;

    [GCOptimize(OptimizeFlag.PackAsTable)]
    public struct PushAsTableStruct
    {
        public int x;
        public int y;
    }

    public class ReImplementInLua : MonoBehaviour {

        // Use this for initialization
        void Start () {
            LuaEnv luaenv = new LuaEnv();
            //这两个例子都必须生成代码才能正常运行
            //例子1：改造Vector3
            //沿用Vector3原来的映射方案Vector3 -> userdata，但是把Vector3的方法实现改为lua实现，通过xlua.genaccessor实现不经过C#直接操作内存
            //改为不经过C#的好处是性能更高，而且你可以省掉相应的生成代码以达成省text段的效果
            //映射仍然沿用的好处是userdata比table更省内存，但操作字段比table性能稍低，当然，你也可以结合例子2的思路，把Vector3也改为映射到table
            luaenv.DoString(@"
                function test_vector3(title, v1, v2)
                   print(title)
                   print(v1.x, v1.y, v1.z)
                   print(v1, v2)
                   print(v1 + v2)
                   v1:Set(v1.x - v2.x, v1.y - v2.y, v1.z - v2.z)
                   print(v1)
                   print(CS.UnityEngine.Vector3.Normalize(v1))
                end
                test_vector3('----before change metatable----', CS.UnityEngine.Vector3(1, 2, 3), CS.UnityEngine.Vector3(7, 8, 9))

                local get_x, set_x = xlua.genaccessor(0, 8)
                local get_y, set_y = xlua.genaccessor(4, 8)
                local get_z, set_z = xlua.genaccessor(8, 8)

                local fields_getters = {
                    x = get_x, y = get_y, z = get_z
                }
                local fields_setters = {
                    x = set_x, y = set_y, z = set_z
                }

                local ins_methods = {
                    Set = function(o, x, y, z)
                        set_x(o, x)
                        set_y(o, y)
                        set_z(o, z)
                    end
                }

                local mt = {
                    __index = function(o, k)
                        --print('__index', k)
                        if ins_methods[k] then return ins_methods[k] end
                        return fields_getters[k] and fields_getters[k](o)
                    end,

                    __newindex = function(o, k, v)
                        return fields_setters[k] and fields_setters[k](o, v) or error('no such field ' .. k)
                    end,

                    __tostring = function(o)
                        return string.format('vector3 { %f, %f, %f}', o.x, o.y, o.z)
                    end,

                    __add = function(a, b)
                        return CS.UnityEngine.Vector3(a.x + b.x, a.y + b.y, a.z + b.z)
                    end
                }

                xlua.setmetatable(CS.UnityEngine.Vector3, mt)
                test_vector3('----after change metatable----', CS.UnityEngine.Vector3(1, 2, 3), CS.UnityEngine.Vector3(7, 8, 9))
            ");

            Debug.Log("++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++");

            //例子2：struct映射到table改造
            //PushAsTableStruct传送到lua侧将会是table，例子里头还为这个table添加了一个成员方法SwapXY，静态方法Print，打印格式化，以及构造函数
            luaenv.DoString(@"
                local mt = {
                    __index = {
                        SwapXY = function(o) --成员函数
                            o.x, o.y = o.y, o.x
                        end
                    },

                    __tostring = function(o) --打印格式化函数
                        return string.format('struct { %d, %d}', o.x, o.y)
                    end,
                }

                xlua.setmetatable(CS.PushAsTableStruct, mt)

                local PushAsTableStruct = {
                    Print = function(o) --静态函数
                        print(o.x, o.y)
                    end
                }

                setmetatable(PushAsTableStruct, {
                    __call = function(_, x, y) --构造函数
                        return setmetatable({x = x, y = y}, mt)
                    end
                })

                xlua.setclass(CS, 'PushAsTableStruct', PushAsTableStruct)
            ");

            PushAsTableStruct test;
            test.x = 100;
            test.y = 200;
            luaenv.Global.Set("from_cs", test);

            luaenv.DoString(@"
                print('--------------from csharp---------------------')
                assert(type(from_cs) == 'table')
                print(from_cs)
                CS.PushAsTableStruct.Print(from_cs)
                from_cs:SwapXY()
                print(from_cs)

                print('--------------from lua---------------------')
                local from_lua = CS.PushAsTableStruct(4, 5)
                assert(type(from_lua) == 'table')
                print(from_lua)
                CS.PushAsTableStruct.Print(from_lua)
                from_lua:SwapXY()
                print(from_lua)
            ");

            luaenv.Dispose();
        }

        // Update is called once per frame
        void Update () {

        }
    }

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