add vec2, vec3, vec4 libraries

src/logic/scripting/lua/libvecn.cpp

@@ -0,0 +1,43 @@
+#include "api_lua.hpp"
+
+#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) {
+    uint argc = lua::gettop(L);
+    auto a = tofunc(L, 1);
+    auto b = tofunc(L, 2);
+    switch (argc) {
+        case 2:
+            lua::createtable(L, n, 0);
+            for (uint i = 0; i < n; i++) {
+                lua::pushnumber(L, a[i]+b[i]);
+                lua::rawseti(L, i+1);
+            }
+            return 1;
+        case 3:
+            return setfunc(L, 3, a + b);
+        default: {
+            throw std::runtime_error("invalid arguments number (2 or 3 expected)");
+        }
+    }
+}
+
+const luaL_Reg vec2lib [] = {
+    {"add", lua::wrap<l_add<2, lua::tovec2, lua::setvec<2>>>},
+    {NULL, NULL}
+};
+
+const luaL_Reg vec3lib [] = {
+    {"add", lua::wrap<l_add<3, lua::tovec3, lua::setvec<3>>>},
+    {NULL, NULL}
+};
+
+const luaL_Reg vec4lib [] = {
+    {"add", lua::wrap<l_add<4, lua::tovec4, lua::setvec<4>>>},
+    {NULL, NULL}
+};