Original Post
I''m very new to SDL and am experimenting with keyboard input by creating a rectangle and trying to make it possible to move it by pressing the arrow keys. I''m probably doing something obvious... When the program starts, pressing the arrow keys does nothing. What am I doing wrong? Here''s the code:
#include "SDL.h"
#include <stdlib.h>
enum {
SCREENWIDTH = 512,
SCREENHEIGHT = 384,
SCREENBPP = 0,
SCREENFLAGS = SDL_ANYFORMAT
} ;
int main( int argc, char* argv[] )
{
SDL_Init ( SDL_INIT_VIDEO ) ;
atexit ( SDL_Quit ) ;
SDL_Surface* pSurface = SDL_SetVideoMode ( SCREENWIDTH , SCREENHEIGHT ,
SCREENBPP , SCREENFLAGS ) ;
SDL_Event event ;
for ( ; ; )
{
if ( SDL_PollEvent ( &event ) )
{
if ( event.type == SDL_QUIT ) break ;
}
SDL_Rect rect ;
rect.x = 8 ;
rect.y = 8 ;
rect.w = 20 ;
rect.h = 20 ;
//fill the rectangle
SDL_FillRect ( pSurface , ▭ ,
SDL_MapRGB ( pSurface->format , 0 ,
0 , 255 ) ) ;
while( SDL_PollEvent( &event ) ){
switch( event.type ){
/* Look for a keypress */
case SDL_KEYDOWN:
/* Check the SDLKey values and move change the coords */
switch( event.key.keysym.sym ){
case SDLK_LEFT:
rect.x -= 1;
break;
case SDLK_RIGHT:
rect.x += 1;
break;
case SDLK_UP:
rect.y -= 1;
break;
case SDLK_DOWN:
rect.y += 1;
break;
default:
break;
}
break;
}
}
SDL_UpdateRect ( pSurface , 0 , 0 , 0 , 0 ) ;
}
return ( 0 ) ;
}
