SDL加载和缩放图片小例子

来源：互联网发布：关系数据库的发展动向编辑：程序博客网时间：2024/04/30 05:25

借助于SDL开发包，写的关于SDL加载和缩放图片的小例子；

#include<SDL/SDL.h>
#include<SDL/SDL_image.h>
#include <SDL/SDL_rotozoom.h>

int main(int argc,char *argv[])
{

SDL_Rect rect = {0,0,640,480};
SDL_Rect myrect={0,0,640,480};
SDL_Rect bmprect;
SDL_Surface *image;
SDL_Surface *bmp;

SDL_Event event;
bmprect.x = rect.x ;
bmprect.y = rect.y;
bmprect.w = rect.w-200 ;
bmprect.h = rect.h-200 ;
SDL_Init(SDL_INIT_VIDEO);

SDL_Surface *screen=SDL_SetVideoMode(640,480,0,SDL_INIT_NOPARACHUTE);
if(screen==NULL) {
printf("setVideoMode Failure");
exit(1);
}
image=SDL_LoadBMP("sample.bmp");
if(image==NULL){
printf("load Failure\n");
exit(1);
}
int sw = image->w;
int sh = image->h;

double xz = (double)bmprect.w/(double)sw;
double yz = (double)bmprect.h/(double)sh;

while(1){

  SDL_FillRect(screen,&myrect,0); //清屏函数，也可以对某一块区域进行设置颜色可以达到清屏的效果
        bmp = rotozoomSurfaceXY(image,0,xz,yz,1);  //缩放
  SDL_BlitSurface(bmp,NULL,screen,&bmprect); .//将图片添加到screen
  SDL_UpdateRects(screen,1,&rect);  //刷新
  SDL_FreeSurface(bmp);

  SDL_WaitEvent(&event);   //事件了
  switch(event.type)
  {

  case SDL_KEYDOWN:if(event.key.keysym.scancode == 9)
    {
     SDL_FreeSurface(image);
     SDL_Quit(); exit(0);
    }

break;
case SDL_MOUSEMOTION:

   break;
  case SDL_KEYUP:
    printf("scancode=%d\n",event.key.keysym.scancode);
     if(event.key.keysym.scancode == 98)
    {
     bmprect.y-=10;

    }
    else if(event.key.keysym.scancode == 102)
    {
     bmprect.x+=10;

    }
    else if(event.key.keysym.scancode == 100)
    {
     bmprect.x-=10;

    }
    else if(event.key.keysym.scancode == 104)
    {
     bmprect.y+=10;

    }
    else if(event.key.keysym.scancode == 21)
    {
     bmprect.w+=10;
     bmprect.h+=10;
    }
    else if(event.key.keysym.scancode == 20)
    {
     bmprect.w-=10;
     bmprect.h-=10;
    }
    break;
  case SDL_MOUSEBUTTONDOWN: break;
  case SDL_MOUSEBUTTONUP:
   break;
  case SDL_QUIT:
   exit(1);

  }
  xz = (double)bmprect.w/(double)sw;  //缩放的尺寸

yz = (double)bmprect.h/(double)sh;
}

SDL_FreeSurface(image);
sleep(3);
SDL_Quit();

}

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