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在子弹类中，我必须改变游戏的角度，我在移动方法中增加了角度，事实是图像在移动，它没有改变角度。我借助渲染中的 STD“cout”子弹角度重定向了控制台中设置角度的结果：“bullets[i]->getangle()”。在我看来，它给出了正确的结果，但我不知道为什么图像不会改变角度。

 //bullet.h 
        #ifndef BULLET_H_INCLUDED
    #define BULLET_H_INCLUDED
    #include <SDL/SDL.h>
    #include <iostream>
    class bullet
        {
            SDL_Rect box;
            int xvel,yvel,angle;
            SDL_Surface *image,*bull;
        public:
            bullet ();
            bullet(SDL_Surface* img,int x,int y,int xvel,int yvel,int angle);
            void move();
            void show(SDL_Surface* screen);
            SDL_Rect* getRect();
            SDL_Surface* load_image(const char* filename,SDL_Surface* screen);
            int getangle();
            void setangle(int angle);
        };
        #endif // BULLET_H_INCLUDED
        //bullet.cpp 
        #include "bullet.h"
    #include "SDL_rotozoom.h"
    //first  construc
    bullet::bullet(SDL_Surface* img,int x,int y,int xVel,int yVel,int ang)
    {
    box.x=x;
    box.y=y;
    image=img;
    box.w=image->w;
    box.h=image->h;
    xvel=xVel;
    yvel=yVel;
    angle=ang;
    }
    //second construc
    bullet::bullet()
    {
    angle+=30;
    }
    //move methode
    void bullet::move()
    {
    box.x+=xvel;
    box.y+=yvel;
    angle+=20;
    }
    //get the angle
    int bullet::getangle()
    {
    return angle;
    }
    // set the angle
    void bullet::setangle(int agl)
    {
    angle = ((((angle + agl) % 360) + 360) % 360)
    }
    //methode to show bullet
    void bullet::show(SDL_Surface* screen)
    {
        SDL_BlitSurface(image,NULL,screen,&box);
    }
    // methode to get bullet rectangle
    SDL_Rect* bullet::getRect()
    {
    return &box ;
    }
    // methode that load the image
     SDL_Surface* bullet::load_image(const char* filename,SDL_Surface* screen)
     {
    SDL_Surface* tmp=SDL_LoadBMP(filename);
    SDL_Surface* tmp2=SDL_DisplayFormat(tmp);
    SDL_SetColorKey(tmp2,SDL_SRCCOLORKEY,SDL_MapRGB(screen->format,0x00,0xff,0xff));
    SDL_Surface* rotozoomimage=rotozoomSurface(tmp2,angle,1.0,0);
    SDL_FreeSurface(tmp);
    SDL_FreeSurface(tmp2);
    return rotozoomimage;
    }

        // loadimage methode 
        SDL_Surface* bullet::load_image(const char* filename,SDL_Surface* screen)
        {
          SDL_Surface* tmp=SDL_LoadBMP(filename);
          SDL_Surface* tmp2=SDL_DisplayFormat(tmp);
          SDL_SetColorKey(tmp2,SDL_SRCCOLORKEY,SDL_MapRGB(screen->format,0x00,0xff,0xff));
          SDL_Surface* rotozoomimage=rotozoomSurface(tmp2,angle,1.0,0);
          SDL_FreeSurface(tmp);
          SDL_FreeSurface(tmp2);
          return rotozoomimage;
        }

        // move methode 
        void bullet::move()
        {
          box.x+=xvel;
          box.y+=yvel;
          angle+=20;
        }

        // getter and setter 
        int bullet::getangle()
        {
          return angle;
        }
        void bullet::setangle(int agl)
        {
          if (angle>=360)
          {
            angle-=360;
          }
          else if (angle<=-360)
          {
            angle+=360;
          }
          angle+=agl;
        }

        //class game 
        //logique part 
        // game.cpp
        // logique
        .
        .
        .
        for (int i=0;i<bullets.size();i++)
        {
          bullets[i]->setangle(20);
          std::cout<<"bullet angle :"<<bullets[i]->getangle()<<std::endl;
          bullets[i]->move();
        }
        //render part 
        for (int i=0;i<bullets.size();i++)
        {
          bullets[i]->show(screen);
          std::cout<<"bullet angle in render :"<<bullets[i]->getangle()<<std::endl;
        }
        SDL_Flip(screen);
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1 回答 1

1

据我所知，angle加载图像后，您永远不会使用任何东西。
当角度发生变化时，您需要旋转图像。

于 2013-06-13T12:38:37.477 回答