ege demo

#include <ege.h>

const float base_speed = 0.5f;
const float randspeed = 1.5f;

//自定义函数，用来返回一个0 - m之间的浮点数
float myrand(float m)
{
    return (float)(ege::randomf() * m);
}

//定义一个AniObj类，这个与前一个除了函数名，和update加了返回值以外没有变化
class AniObj
{
public:
    //初始化，设置坐标，速度方向，透明度，创建IMAGE等
    AniObj()
    {
        _x = myrand((float)ege::getwidth());
        _y = myrand((float)ege::getheight());
        _r = ege::random(20) + 20;
        _dx = myrand(randspeed) + base_speed;
        _dy = myrand(randspeed) + base_speed;
        _dx = _dx * float(ege::random(2) * 2.0 - 1);
        _dy = _dy * float(ege::random(2) * 2.0 - 1);
        _alpha = ege::random(250) + 2;
        _da = ege::random(2) * 2 - 1;

        _img = ege::newimage(_r * 2, _r * 2);

        ege::setcolor(ege::hsv2rgb(myrand(360.0f), 1.0f, 1.0f), _img);
        ege::setfillcolor(ege::hsv2rgb(myrand(360.0f), 1.0f, 1.0f), _img);

        ege::fillellipse(_r, _r, _r, _r, _img);
    }

    //释放这个对象时调用
    ~AniObj()
    {
        ege::delimage(_img);
    }

    //更新位置等相关属性
    int update()
    {
        // 当前位置 + 速度
        _x += _dx;
        _y += _dy;
        if (_x < 0) _dx = myrand(randspeed) + base_speed; //碰左
        if (_y < 0) _dy = myrand(randspeed) + base_speed; //碰上
        if (_x >= ege::getwidth() - _r * 2) _dx = -(myrand(randspeed) + base_speed); //碰右
        if (_y >= ege::getheight() - _r * 2) _dy = -(myrand(randspeed) + base_speed); //碰下

                                                                                      // 改变alpha值
        _alpha += _da;
        if (_alpha <= 0)    _da = 1;
        if (_alpha >= 0xFF) _da = -1;
        return 0;
    }

    //根据属性值绘画
    void render()
    {
        ege::putimage_alphatransparent(NULL, _img, (int)_x, (int)_y, ege::BLACK, (unsigned char)_alpha);
    }

    void onkey(int key)
    {
        //
    }

private:
    float _x, _y;
    int _r;
    float _dx, _dy;
    int _alpha, _da;
    ege::PIMAGE _img;
};

class Scene
{
public:
    //初始化，参数为对象个数
    Scene(int nAniObj)
    {
        m_cntObj = nAniObj;
        m_pobj = new AniObj[m_cntObj];
        m_pause = 0;
        m_endscene = 0;
    }
    ~Scene()
    {
        delete[] m_pobj;
    }
    int update()
    {
        // 非暂停状态才更新
        if (m_pause == 0)
        {
            for (int n = 0; n < m_cntObj; ++n)
            {
                m_pobj[n].update();
            }
        }
        return m_endscene;
    }
    void render()
    {
        for (int n = 0; n < m_cntObj; ++n)
        {
            m_pobj[n].render();
        }
    }
    void onkey(int key)
    {
        if (key == 'P' || key == 'p') //按下P键就在播放与暂停之间转换
        {
            m_pause = !m_pause;
        }
        if (key == VK_ESCAPE) //如果是ESC键，就标记为退出场景，VK_ESCAPE是SDK定义的宏
        {
            m_endscene = 1;
        }
    }
private:
    AniObj* m_pobj;
    int m_cntObj;
    int m_pause;
    int m_endscene;
};

void mainloop()
{
    Scene scene(30); //定义场景，初始化参数为30

    for (; ege::is_run(); ege::delay_fps(60))
    {
        while (ege::kbhit())
        {
            int key = ege::getch();
            scene.onkey(key); //所有按键消息发送给scene
        }
        if (scene.update()) //如果update返回非0表示场景结束，这时退出主循环
        {
            break;
        }

        ege::cleardevice();
        scene.render();
    }
}

int main(void)
{
    ege::setinitmode(ege::INIT_ANIMATION);
    // 图形初始化，窗口尺寸640x480
    ege::initgraph(640, 480);
    // 随机数初始化，如果需要使用随机数的话
    ege::randomize();
    // 程序主循环
    mainloop();
    // 关闭绘图设备
    ege::closegraph();
    return 0;
}