why

    static int SetTexture( T* p, lua_State *L )
    {
        RageTexture *pTexture = Luna<RageTexture>::check(L, 1);
        //RageTexture *pTexture = Luna<RageTextureRenderTarget>::check(L, 1);

        pTexture = TEXTUREMAN->CopyTexture( pTexture );
        p->SetTexture( pTexture );
        return 0;
    }

    static int SetTextureRT( T* p, lua_State *L )
    {
        //RageTexture *pTexture = Luna<RageTexture>::check(L, 1);
        RageTexture *pTexture = Luna<RageTextureRenderTarget>::check(L, 1);

        pTexture = TEXTUREMAN->CopyTexture( pTexture );
        p->SetTexture( pTexture );
        return 0;
    }