我使用SDL2轮询事件并将键盘按键转发给游戏对象。我从SDL_KEYDOWN
事件类型传入SDL_KeyBoardEvent
变量。我似乎不明白如何管理在输入过程中按住修改键的情况。
我比较MODK_Keys枚举和SDL_KeyBoardEvent的key.keysym.mod值,似乎它不应该进入顶部if循环,但它确实如此。如果我只按住shift
并按a
等任意键,则输出是第一个If语句中的意外输出。它显示
1 0
Ctrl + Alt + Shift + 97
此( key.keysym.mod & ( KMOD_LCTRL | KMOD_RCTRL ) )
在输出过程中等于零,但是否通过逻辑表达式?下面是if语句
void KeyDown(SDL_KeyboardEvent key) {
if( !( key.keysym.sym == SDLK_LSHIFT || key.keysym.sym == SDLK_RSHIFT || key.keysym.sym == SDLK_LCTRL || key.keysym.sym == SDLK_RCTRL || key.keysym.sym == SDLK_LALT || key.keysym.sym == SDLK_RALT )) {
if( ( key.keysym.mod & ( KMOD_LSHIFT | KMOD_RSHIFT ) > 0 ) && ( key.keysym.mod & ( KMOD_LCTRL | KMOD_RCTRL ) > 0 ) && ( key.keysym.mod & ( KMOD_LALT | KMOD_RALT ) > 0 )) {
std::cout << ( key.keysym.mod & ( KMOD_LSHIFT | KMOD_RSHIFT ) ) << " " << ( key.keysym.mod & ( KMOD_LCTRL | KMOD_RCTRL ) ) << std::endl;
std::cout << "Ctrl + Alt + Shift + " << key.keysym.sym << std::endl;
}
else if ( ( key.keysym.mod & ( KMOD_LSHIFT | KMOD_RSHIFT ) > 0 ) && ( key.keysym.mod & ( KMOD_LCTRL | KMOD_RCTRL ) > 0 )) {
std::cout << "Shift + Ctrl + " << key.keysym.sym << std::endl;
}
else if ( ( key.keysym.mod & ( KMOD_LSHIFT | KMOD_RSHIFT ) > 0 ) && ( key.keysym.mod & ( KMOD_LALT | KMOD_RALT ) > 0 )) {
std::cout << "Shift + Alt + " << key.keysym.sym << std::endl;
}
else if ( ( key.keysym.mod & ( KMOD_LCTRL | KMOD_RCTRL ) > 0 ) && ( key.keysym.mod & ( KMOD_LALT | KMOD_RALT ) > 0 )) {
std::cout << "Ctrl + Alt + " << key.keysym.sym << std::endl;
}
else if ( key.keysym.mod & ( KMOD_LSHIFT | KMOD_RSHIFT ) > 0 ) {
std::cout << "Shift + " << key.keysym.sym << std::endl;
}
else if ( key.keysym.mod & ( KMOD_LALT | KMOD_RALT ) > 0 ) {
std::cout << "Alt + " << key.keysym.sym << std::endl;
}
else if ( key.keysym.mod & ( KMOD_LCTRL | KMOD_RCTRL ) > 0 ) {
std::cout << "Ctrl + " << key.keysym.sym << std::endl;
}
else {
std::cout << "Unmodded " << key.keysym.sym << " MODS: " << key.keysym.mod << std::endl;
}
}
}
睡了一觉,试了一种不同的方法。显然我的操作顺序出错了。
使下列开关工作(在所有表达式上更改)
( key.keysym.mod & ( KMOD_LSHIFT | KMOD_RSHIFT ) > 0 )
(( key.keysym.mod & ( KMOD_LSHIFT | KMOD_RSHIFT )) > 0 )
有效的函数是
void KeyDown(SDL_KeyboardEvent key) {
if( !( key.keysym.sym == SDLK_LSHIFT || key.keysym.sym == SDLK_RSHIFT || key.keysym.sym == SDLK_LCTRL || key.keysym.sym == SDLK_RCTRL || key.keysym.sym == SDLK_LALT || key.keysym.sym == SDLK_RALT )) {
if( (( key.keysym.mod & ( KMOD_LSHIFT | KMOD_RSHIFT )) > 0 ) && (( key.keysym.mod & ( KMOD_LCTRL | KMOD_RCTRL )) > 0 ) && (( key.keysym.mod & ( KMOD_LALT | KMOD_RALT )) > 0 )) {
std::cout << "Ctrl + Alt + Shift + " << key.keysym.sym << std::endl;
}
else if ( (( key.keysym.mod & ( KMOD_LSHIFT | KMOD_RSHIFT )) > 0 ) && (( key.keysym.mod & ( KMOD_LCTRL | KMOD_RCTRL )) > 0 )) {
std::cout << "Shift + Ctrl + " << key.keysym.sym << std::endl;
}
else if ( (( key.keysym.mod & ( KMOD_LSHIFT | KMOD_RSHIFT )) > 0 ) && (( key.keysym.mod & ( KMOD_LALT | KMOD_RALT )) > 0 )) {
std::cout << "Shift + Alt + " << key.keysym.sym << std::endl;
}
else if ( (( key.keysym.mod & ( KMOD_LCTRL | KMOD_RCTRL )) > 0 ) && (( key.keysym.mod & ( KMOD_LALT | KMOD_RALT )) > 0 )) {
std::cout << "Ctrl + Alt + " << key.keysym.sym << std::endl;
}
else if (( key.keysym.mod & ( KMOD_LSHIFT | KMOD_RSHIFT )) > 0 ) {
std::cout << "Shift + " << key.keysym.sym << std::endl;
}
else if (( key.keysym.mod & ( KMOD_LALT | KMOD_RALT )) > 0 ) {
std::cout << "Alt + " << key.keysym.sym << std::endl;
}
else if (( key.keysym.mod & ( KMOD_LCTRL | KMOD_RCTRL )) > 0 ) {
std::cout << "Ctrl + " << key.keysym.sym << std::endl;
}
else {
std::cout << "Unmodded " << key.keysym.sym << " MODS: " << key.keysym.mod << std::endl;
}
}
}