add vecn.sub(...), .mul(...), .div(...), .length(...), .normalize(...)

src/logic/scripting/lua/libvecn.cpp

@@ -2,42 +2,83 @@
 
 #include <glm/glm.hpp>
 
-template<
-    uint n, 
-    glm::vec<n, float>(*tofunc)(lua::State*, int),
-    int(*setfunc)(lua::State*, int, glm::vec<n, float>)
->
-static int l_add(lua::State* L) {
+template<int n, template<class> class Op>
+static int l_binop(lua::State* L) {
     uint argc = lua::gettop(L);
-    auto a = tofunc(L, 1);
-    auto b = tofunc(L, 2);
+    auto a = lua::tovec<n>(L, 1);
+    auto b = lua::tovec<n>(L, 2);
+    Op op;
     switch (argc) {
         case 2:
             lua::createtable(L, n, 0);
             for (uint i = 0; i < n; i++) {
-                lua::pushnumber(L, a[i]+b[i]);
+                lua::pushnumber(L, op(a[i], b[i]));
                 lua::rawseti(L, i+1);
             }
             return 1;
         case 3:
-            return setfunc(L, 3, a + b);
+            return lua::setvec(L, 3, op(a, b));
         default: {
             throw std::runtime_error("invalid arguments number (2 or 3 expected)");
         }
     }
 }
 
+template<int n>
+static int l_normalize(lua::State* L) {
+    uint argc = lua::gettop(L);
+    auto vec = glm::normalize(lua::tovec<n>(L, 1));
+    switch (argc) {
+        case 1:
+            lua::createtable(L, n, 0);
+            for (uint i = 0; i < n; i++) {
+                lua::pushnumber(L, vec[i]);
+                lua::rawseti(L, i+1);
+            }
+            return 1;
+        case 3:
+            return lua::setvec(L, 3, vec);
+        default: {
+            throw std::runtime_error("invalid arguments number (1 or 2 expected)");
+        }
+    }
+}
+
+template<int n>
+static int l_len(lua::State* L) {
+    auto vec = lua::tovec<n>(L, 1);
+    if (lua::gettop(L) != 1) {
+        throw std::runtime_error("invalid arguments number (1 expected)");
+    }
+    return lua::pushnumber(L, glm::length(vec));
+}
+
 const luaL_Reg vec2lib [] = {
-    {"add", lua::wrap<l_add<2, lua::tovec2, lua::setvec<2>>>},
+    {"add", lua::wrap<l_binop<2, std::plus>>},
+    {"sub", lua::wrap<l_binop<2, std::minus>>},
+    {"mul", lua::wrap<l_binop<2, std::multiplies>>},
+    {"div", lua::wrap<l_binop<2, std::divides>>},
+    {"normalize", lua::wrap<l_normalize<2>>},
+    {"length", lua::wrap<l_len<2>>},
     {NULL, NULL}
 };
 
 const luaL_Reg vec3lib [] = {
-    {"add", lua::wrap<l_add<3, lua::tovec3, lua::setvec<3>>>},
+    {"add", lua::wrap<l_binop<3, std::plus>>},
+    {"sub", lua::wrap<l_binop<3, std::minus>>},
+    {"mul", lua::wrap<l_binop<3, std::multiplies>>},
+    {"div", lua::wrap<l_binop<3, std::divides>>},
+    {"normalize", lua::wrap<l_normalize<3>>},
+    {"length", lua::wrap<l_len<3>>},
     {NULL, NULL}
 };
 
 const luaL_Reg vec4lib [] = {
-    {"add", lua::wrap<l_add<4, lua::tovec4, lua::setvec<4>>>},
+    {"add", lua::wrap<l_binop<4, std::plus>>},
+    {"sub", lua::wrap<l_binop<4, std::minus>>},
+    {"mul", lua::wrap<l_binop<4, std::multiplies>>},
+    {"div", lua::wrap<l_binop<4, std::divides>>},
+    {"normalize", lua::wrap<l_normalize<4>>},
+    {"length", lua::wrap<l_len<4>>},
     {NULL, NULL}
 };

src/logic/scripting/lua/lua_util.hpp

@@ -328,6 +328,22 @@ namespace lua {
         setglobal(L, name);
     } 
 
+    template<int n>
+    inline glm::vec<n, float> tovec(lua::State* L, int idx) { 
+        pushvalue(L, idx);
+        if (!istable(L, idx) || objlen(L, idx) < n) {
+            throw std::runtime_error("value must be an array of "+std::to_string(n)+" numbers");
+        }
+        glm::vec<n, float> vec;
+        for (int i = 0; i < n; i++) {
+            rawgeti(L, 1);
+            vec[i] = tonumber(L, -1); 
+            pop(L);
+        }
+        pop(L);
+        return vec;
+    }
+
     inline glm::vec2 tovec2(lua::State* L, int idx) { 
         pushvalue(L, idx);
         if (!istable(L, idx) || objlen(L, idx) < 2) {