sdl_pumpevents.c

#include <stdio.h>
#include <stdlib.h>
#include <SDL/SDL.h>

#include <emscripten.h>
// bug - SDL_GetKeyboardState doesn't return scancodes, it returns keycodes, so acts exactly like
// SDL_GetKeyState instead
#define SDL_GetKeyState SDL_GetKeyboardState

int result = 0;

int loop1()
{
   unsigned i;
   int r = 0;

   // method 1: SDL_PollEvent loop
   SDL_Event e;
   while (SDL_PollEvent(&e));

   const Uint8 *keys = SDL_GetKeyState(NULL);
   if (keys[SDLK_LEFT])
      r = 1;

   return r;
}

int loop2()
{
   unsigned i;
   int r = 0;
   
   // method 2: SDL_PumpEvents
   SDL_PumpEvents();

   const Uint8 *keys = SDL_GetKeyState(NULL);
   if (keys[SDLK_RIGHT])
      r = 2;

   return r;
}

int alphakey()
{
   unsigned i;
   int r = 0;

   SDL_PumpEvents();

   const Uint8 *keys = SDL_GetKeyState(NULL);
   if (keys[SDLK_a])
      r = 4;

   return r;
}

int main(int argc, char *argv[])
{
   SDL_Init(SDL_INIT_EVERYTHING);
   SDL_SetVideoMode(600, 400, 32, SDL_SWSURFACE);

   emscripten_run_script("keydown(37);"); // left
   result += loop1();
   emscripten_run_script("keydown(39);"); // right
   result += loop2();
   emscripten_run_script("keydown(65);"); // A
   result += alphakey();
   REPORT_RESULT();
   return 0;
}