function check_hitstop()
{
	if global.hitstop > 0
		return true;
	else
		return false;
}
/// @desc 优雅地检测该实例的sprite当前动画是否到达最后一帧
function animation_end()
{
	if animation_spd == 0
		return false;
    return (image_index + animation_spd >= image_number);
}
/// @desc 优雅地将该实例的sprite替换为给定值，并将sprite_index归零
/// @param {Asset.GMSprite} _sprite 将要替换为的sprite
function set_sprite(_sprite)
{
	if sprite_index != _sprite
	{
        sprite_index = _sprite;
        image_index = 0;
    }
}

function camera_snap()
{
	oCamera.x = oCamera.x_to;
	oCamera.y = oCamera.y_to;	
}

/// @desc 触发屏幕震动
/// @param {Real} _magnitude 以像素计算的震动强度
// @param {Real} _frames 以帧计算的持续时间
function screen_shake(_magnitude)//, _duration)
{
    // 只有当新的震动比当前的更强时才覆盖
    with(oCamera)
	{
        if _magnitude > shake_magnitude
		{
            shake_magnitude = _magnitude;
            //shake_duration = _duration;
        }
    }
}