一个简单的飞机大战游戏，但是运行时会很卡，就是移动飞机时会有严重的滞后感。不仅没有按下键盘就移动的感觉，而且在按键盘的上下左右键的时候，整个窗口会很卡（就像小学上微机课打开个浏览器就卡半天的感觉），绘制的飞机图片会在卡的时候直接闪没有。问的chatgpt，说是peekmessage的问题。求大佬看一下怎么解决

#include<iostream>
#include<string.h>
#include<easyx.h>
#pragma comment(lib,"MSIMG32.LIB")
#define SPEED 5
POINT fly_pos{ 150,320 };
inline void putimage_a(int x, int y, IMAGE* img) {
	int h = img->getheight();
	int w = img->getwidth();
	AlphaBlend(GetImageHDC(NULL), x, y, w, h,
		GetImageHDC(img), 0, 0, w, h, { AC_SRC_OVER,0,255,AC_SRC_ALPHA });
}
class Fly {
public: 
	const int fly_width = 90;
	const int fly_height = 102;
	Fly() {
		loadimage(&fly, _T("img/飞机.png"));
	}
	~Fly() {

	}
	void getboard(const ExMessage&msg) {
		switch (msg.message) {
		case WM_KEYDOWN:
			switch (msg.vkcode) {
			case VK_UP:
				is_move_up = true;
				break;
			case VK_DOWN:
				is_move_down = true;
				break;
			case VK_LEFT:
				is_move_left = true;
				break;
			case VK_RIGHT:
				is_move_right = true;
				break;
			}	
			break;
		case WM_KEYUP:
			switch (msg.vkcode) {
			case VK_UP:
				is_move_up = false;
				break;
			case VK_DOWN:
				is_move_down = false;
				break;
			case VK_LEFT:
				is_move_left = false;
				break;
			case VK_RIGHT:
				is_move_right = false;
				break;
			}
			break;
		}
	}
	void move() {
		//实现斜向正向方向的速度一致
		putimage_a(position.x, position.y, &fly);
		int dir_x = is_move_right - is_move_left;
		int dir_y = is_move_down - is_move_up;
		double len = sqrt(dir_x * dir_x + dir_y * dir_y);
		if (len != 0) {
			double re_speed_x = dir_x / len;
			double re_speed_y = dir_y / len;
			position.x += (int)(re_speed_x * SPEED);
			position.y += (int)(re_speed_y * SPEED);
		}
		//边界情况限制
		if (position.x < 0)position.x = 0;
		if (position.y < 0)position.y = 0;
		if (position.x + fly_w >= 400)position.x = 400 - fly_w;
		if (position.y + fly_h >= 640)position.y = 640 - fly_h;
	}
	const POINT& GetPosition()const {
		return position;
	}
private:
	const int fly_w = 90;
	const int fly_h = 102;
private:
	IMAGE fly;
	POINT position = { 150,320 };
	bool is_move_up = false;
	bool is_move_down = false;
	bool is_move_left = false;
	bool is_move_right = false;
};

int main() {
	bool running = 1;
	IMAGE background;
	ExMessage msg;
	Fly fly;
	initgraph(400, 640);
	loadimage(&background, _T("img/背景2.png"));
	BeginBatchDraw();
	
	while (running) {
		while (peekmessage(&msg)) {
			cleardevice();
			putimage(0, 0, &background);
			fly.getboard(msg);
			fly.move();
			FlushBatchDraw();

		}

		EndBatchDraw();
	}
	getchar();
	return 0;
}