Restoril Small Quantity

C #: An image that moves with the keyboard


We have seen the basics of how
display images on screen using C # and SDL

. 
 
 
 
 A second more detailed example could afford to move the character with the arrow keys at a rate of 50 frames per second, so (you have the following comments the source): 

/ * Example SDL

access from C # (2), using Tao.SDL

By Nacho Cabanes

* /

 
 using Tao. Sdl   
 
; 
 
 
   using System; 
 
   / / For IntPtr (pointer images, etc)       
   public class    Sdl02  
  { 
         private static 
 
     void   
  Main 
   (        )              {                          short     anchoPantalla   = 
    800      ; 
  
  
             short     altoPantalla   =     600      ;     
               int     bitsColor   =     24      ;   
  
             int     flags   =   Sdl    .    SDL_HWSURFACE    Sdl  
.   SDL_DOUBLEBUF     (   anchoPantalla  ,    altoPantalla  ,    bitsColor  , flags   
  )    ;     
 
  / / indicate that it is cut to leave the hidden display    
 
 Sdl.   SDL_Rect rect2 
    = new      Sdl.   SDL_Rect   (   0   ,   0  , 
 
   (    short    ) 
  anchoPantalla  ,  
   (  
  short    
)   altoPantalla  )    ; 
 Sdl 
 
   
.   SDL_SetClipRect   (  pantallaOculta  , ref 
  rect2  )    ;       / / Load an image    IntPtr image  ;    image   =    Sdl.   SDL_LoadBMP   (   "personaje.bmp"   )    ;      if     (  image  =   =  IntPtr  .  
 Zero 
 ) {          System.     Console.     WriteLine ( 
 
 "Image does not exist!"   
)    ;   
 
  Environment. Exit     (      4)    ;      
}       / / Part repetitive     bool finished = false   ;      short   x  = 400    
 
;       short   and  = 300     ;      short   anchoImagen  = 
  50   ;       short   altoImagen  =   50   ; 
 
  SDL  .  
 SDL_Event event 
 ;  
    int   numkeys  ;  
     byte     [   ] 
 
 keys  ;       of     
 {     / / Check event      Sdl.   SDL_PollEvent 
 
 (  out event  )    ;    keys  
 =   Sdl.   SDL_GetKeyState   (  out numkeys 
 )    ;    
 
   / / Let's see if you've pressed a cursor arrow      if     (  keys   [ 
 Sdl 
 .   SDLK_UP  
]     
 = 1 =   
  )     y  -   = 2     ;     
 if     (  keys   [  Sdl  .   SDLK_DOWN  ]   
 
 
 = 1 =   
  )      + y   =  2    ;      if     (  keys   [  Sdl  .  
 SDLK_LEFT 
 ]      = 1 =     
)     x  -   = 2     ;      if     (  keys   [  Sdl  .  
 SDLK_RIGHT 
 ]    =   =     
 1)     x  +   =   2   ;      if     (    keys [Sdl    .  
 SDLK_ESCAPE 
 ]    =   =     
 1)      finished = true   ;        / / Clear screen      Sdl.   SDL_Rect  origin = new        SDL. 
 
 SDL_Rect   (      0, 0   
 ,     anchoPantalla  ,   altoPantalla  )    ;      SDL.   SDL_FillRect   (  pantallaOculta  ,   ref 
 
 origin,       0) 
 
 
 ;  
     / / Draw in their new home  coordinates       = new     Sdl.   SDL_Rect   (   0   ,   0  ,  
 anchoImagen 
 ,   altoImagen  )    ;    
   Sdl.   SDL_Rect  dest = new        Sdl.   SDL_Rect   (  x  ,   and  ,   
 
  anchoImagen , 
  altoImagen  )    ;      Sdl.   SDL_BlitSurface   (    image, ref     origin,    pantallaOculta  , ref dest    )    ;  
 
     / / show the screen Sdl   hidden   .   SDL_Flip   (  pantallaOculta  )    ;      
 / / And wait 20 ms 
     System. Threading    . Thread    . Sleep 
    (      20)    ;    
   }      while    ( 
 
! 
 finished  ) 
    ;       / / Finally, close SDL Sdl     .   SDL_Quit   (
 
  ) 
   ;      }      }        the differences with the previous source are:       
 When initializing, we add a new option, Sdl.SDL_FULLSCREEN, so that the "game" to run full screen instead of on window. We use a loop 
 
 "do ... while" to repeat until you press the ESC key.   SDL_Event is the type of data used to check the "events", such as keystrokes or mouse, or using the joystick.   With SDL_PollEvent forcing them to look at what events are pending analysis.   SDL_GetkeyState get an array that gives us the current status of each key. Then we can look each of these keys by accessing the array with the key name in English as well: keys [Sdl.SDLK_RIGHT]   SDL_FillRect fills a rectangle with some color. It's an easy way to clear the screen or part of it.