add mat4.scale mutating overload

src/logic/scripting/lua/libmat4.cpp

@@ -7,6 +7,8 @@ static int l_idt(lua::State* L) {
     return lua::pushmat4(L, glm::mat4(1.0f));
 }
 
+/// @brief  mat4.scale(matrix=idt: array[16], scale: array[3]) -> array[16]
+/// Modifies matrix
 static int l_scale(lua::State* L) {
     uint argc = lua::gettop(L);
     switch (argc) {
@@ -19,6 +21,11 @@ static int l_scale(lua::State* L) {
             auto scale = lua::tovec3(L, 2);
             return lua::pushmat4(L, glm::scale(matrix, scale));
         }
+        case 3: {
+            auto matrix = lua::tomat4(L, 1);
+            auto scale = lua::tovec3(L, 2);
+            return lua::setmat4(L, 3, glm::scale(matrix, scale));
+        }
         default: {
             throw std::runtime_error("invalid number of arguments (1 or 2 expected)");
         }

src/logic/scripting/lua/lua_util.hpp

@@ -206,6 +206,18 @@ namespace lua {
         }
         return 1;
     }
+    /// @brief pushes matrix table to the stack and updates it with glm matrix 
+    inline int setmat4(lua::State* L, int idx, glm::mat4 matrix) {
+        pushvalue(L, idx);
+        for (uint y = 0; y < 4; y++) {
+            for (uint x = 0; x < 4; x++) {
+                uint i = y * 4 + x;
+                pushnumber(L, matrix[y][x]);
+                rawseti(L, i+1);
+            }
+        }
+        return 1;
+    }
     inline int pushcfunction(lua::State* L, lua_CFunction func) {
         lua_pushcfunction(L, func);
         return 1;