ale-sys 0.1.2

/* *****************************************************************************
 * A.L.E (Arcade Learning Environment)
 * Copyright (c) 2009-2013 by Yavar Naddaf, Joel Veness, Marc G. Bellemare,
 *   Matthew Hausknecht, and the Reinforcement Learning and Artificial Intelligence
 *   Laboratory
 * Released under the GNU General Public License; see License.txt for details.
 *
 * Based on: Stella  --  "An Atari 2600 VCS Emulator"
 * Copyright (c) 1995-2007 by Bradford W. Mott and the Stella team
 *
 * *****************************************************************************
 *  diplay_screen.cpp
 *
 *  Supports displaying the screen via SDL.
 **************************************************************************** */

#include "display_screen.h"

#include <algorithm>

#include "SoundSDL.hxx"

#ifdef __USE_SDL

namespace ale {

DisplayScreen::DisplayScreen(MediaSource* mediaSource, Sound* sound,
                             ColourPalette& palette)
    : manual_control_active(false), media_source(mediaSource), my_sound(sound),
      colour_palette(palette), delay_msec(17) {
  screen_height = media_source->height();
  screen_width = media_source->width();
  assert(window_height >= screen_height);
  assert(window_width >= screen_width);
  yratio = window_height / (float)screen_height;
  xratio = window_width / (float)screen_width;
  if (SDL_Init(SDL_INIT_VIDEO) < 0) {
    fprintf(stderr, "Could not initialize SDL: %s\n", SDL_GetError());
    exit(1);
  }
  screen = SDL_SetVideoMode(window_width, window_height, 8, SDL_HWPALETTE);
  if (screen == NULL) {
    fprintf(stderr, "Couldn't Initialize Screen: %s\n", SDL_GetError());
    exit(1);
  }
  SDL_WM_SetCaption("ALE Viz", NULL);
  fprintf(stderr,
          "Screen Display Active. [Manual Control Mode] 'm' "
          "[Slowdown] 'a' [Speedup] 's' [VolumeDown] '[' [VolumeUp] ']'.\n");

  last_frame_time = SDL_GetTicks();
}

DisplayScreen::~DisplayScreen() { SDL_Quit(); }

void DisplayScreen::display_screen() {
  if (SDL_MUSTLOCK(screen)) {
    if (SDL_LockSurface(screen) < 0) {
      fprintf(stderr, "Can't lock screen: %s\n", SDL_GetError());
      return;
    }
  }
  // Convert the media sources frame into the screen matrix representation
  int xciel = int(xratio) + 1;
  int yciel = int(yratio) + 1;
  uInt8* pi_curr_frame_buffer = media_source->currentFrameBuffer();
  int y, x, r, g, b;
  SDL_Rect rect;
  for (int i = 0; i < screen_width * screen_height; i++) {
    y = i / screen_width;
    x = i - (y * screen_width);
    colour_palette.getRGB(pi_curr_frame_buffer[i], r, g, b);
    rect.x = (int)(x * xratio);
    rect.y = (int)(y * yratio);
    rect.w = xciel;
    rect.h = yciel;
    SDL_FillRect(screen, &rect, SDL_MapRGB(screen->format, r, g, b));
  }
  if (SDL_MUSTLOCK(screen)) {
    SDL_UnlockSurface(screen);
  }
  SDL_UpdateRect(screen, 0, 0, 0, 0);
  poll();

  // Wait a while, calibrating so that the delay remains the same
  Uint32 newTime = SDL_GetTicks();
  Uint32 delta = newTime - std::min(last_frame_time, newTime);

  if (delta < delay_msec) {
    SDL_Delay(delay_msec - delta);
  } else {
    // Try to keep up with the delay
    last_frame_time = SDL_GetTicks() + delta - delay_msec;
  }
}

void DisplayScreen::poll() {
  SDL_Event event;
  while (SDL_PollEvent(&event)) {
    handleSDLEvent(event);
  }
};

void DisplayScreen::handleSDLEvent(const SDL_Event& event) {
  switch (event.type) {
    case SDL_QUIT:
      exit(0);
      break;
    case SDL_KEYDOWN:
      switch (event.key.keysym.sym) {
        case SDLK_m:
          manual_control_active = !manual_control_active;
          if (manual_control_active) {
            fprintf(stderr, "Manual Control Enabled: [Move] "
                            "Arrow keys [Fire] Space [NO-OP] Return.\n");
          } else {
            fprintf(stderr, "Manual Control Disabled\n");
          }
          break;
        case SDLK_s:
          delay_msec = delay_msec > 5 ? delay_msec - 5 : 0;
          fprintf(stderr, "[Speedup] %d msec delay\n", delay_msec);
          break;
        case SDLK_a:
          delay_msec = delay_msec + 5;
          fprintf(stderr, "[Slowdown] %d msec delay\n", delay_msec);
          break;
#ifdef SOUND_SUPPORT
        case SDLK_LEFTBRACKET:
          fprintf(stderr, "[VolumeDown]\n");
          for (int i = 0; i < 5; ++i) {
            ((SoundSDL*)my_sound)->adjustVolume(-1);
          }
          break;
        case SDLK_RIGHTBRACKET:
          fprintf(stderr, "[VolumeUp]\n");
          for (int i = 0; i < 5; ++i) {
            ((SoundSDL*)my_sound)->adjustVolume(1);
          }
          break;
#endif  // SOUND_SUPPORT
        default:
          break;
      }
      break;
    default:
      break;
  }
};

Action DisplayScreen::getUserAction() {
  if (!manual_control_active) {
    return UNDEFINED;
  }
  Action a = PLAYER_A_NOOP;
  poll();
  SDL_PumpEvents();
  Uint8* keymap = SDL_GetKeyState(NULL);
  // Break out of this loop if the 'p' key is pressed
  if (keymap[SDLK_p]) {
    return PLAYER_A_NOOP;
    // Triple Actions
  } else if (keymap[SDLK_UP] && keymap[SDLK_RIGHT] && keymap[SDLK_SPACE]) {
    a = PLAYER_A_UPRIGHTFIRE;
  } else if (keymap[SDLK_UP] && keymap[SDLK_LEFT] && keymap[SDLK_SPACE]) {
    a = PLAYER_A_UPLEFTFIRE;
  } else if (keymap[SDLK_DOWN] && keymap[SDLK_RIGHT] && keymap[SDLK_SPACE]) {
    a = PLAYER_A_DOWNRIGHTFIRE;
  } else if (keymap[SDLK_DOWN] && keymap[SDLK_LEFT] && keymap[SDLK_SPACE]) {
    a = PLAYER_A_DOWNLEFTFIRE;
    // Double Actions
  } else if (keymap[SDLK_UP] && keymap[SDLK_LEFT]) {
    a = PLAYER_A_UPLEFT;
  } else if (keymap[SDLK_UP] && keymap[SDLK_RIGHT]) {
    a = PLAYER_A_UPRIGHT;
  } else if (keymap[SDLK_DOWN] && keymap[SDLK_LEFT]) {
    a = PLAYER_A_DOWNLEFT;
  } else if (keymap[SDLK_DOWN] && keymap[SDLK_RIGHT]) {
    a = PLAYER_A_DOWNRIGHT;
  } else if (keymap[SDLK_UP] && keymap[SDLK_SPACE]) {
    a = PLAYER_A_UPFIRE;
  } else if (keymap[SDLK_DOWN] && keymap[SDLK_SPACE]) {
    a = PLAYER_A_DOWNFIRE;
  } else if (keymap[SDLK_LEFT] && keymap[SDLK_SPACE]) {
    a = PLAYER_A_LEFTFIRE;
  } else if (keymap[SDLK_RIGHT] && keymap[SDLK_SPACE]) {
    a = PLAYER_A_RIGHTFIRE;
    // Single Actions
  } else if (keymap[SDLK_SPACE]) {
    a = PLAYER_A_FIRE;
  } else if (keymap[SDLK_RETURN]) {
    a = PLAYER_A_NOOP;
  } else if (keymap[SDLK_LEFT]) {
    a = PLAYER_A_LEFT;
  } else if (keymap[SDLK_RIGHT]) {
    a = PLAYER_A_RIGHT;
  } else if (keymap[SDLK_UP]) {
    a = PLAYER_A_UP;
  } else if (keymap[SDLK_DOWN]) {
    a = PLAYER_A_DOWN;
  }
  return a;
}

}  // namespace ale

#endif  // __USE_SDL