anarch/main_csfml.c

/**
  @file main_csfml.c

  This is a csfml (C binding for SFML) implementation of the game front end.
  This is another alternative to the SDL for the PC. This front end is more
  minimal and simple than the SDL, so it's better as a learning resource.

  by Miloslav Ciz (drummyfish), 2020

  Released under CC0 1.0 (https://creativecommons.org/publicdomain/zero/1.0/)
  plus a waiver of all other intellectual property. The goal of this work is
  be and remain completely in the public domain forever, available for any use
  whatsoever.
*/

#include <SFML/Audio.h>
#include <SFML/Graphics.h>
#include <SFML/System.h>
#include <stdint.h>
#include <stdio.h>

#include <SFML/Audio/Types.h>

#define SFG_SCREEN_RESOLUTION_X 640
#define SFG_SCREEN_RESOLUTION_Y 480

#define SFG_DITHERED_SHADOW 1
#define SFG_DIMINISH_SPRITES 1
#define SFG_RESOLUTION_SCALEDOWN 1

#define MUSIC_VOLUME 16

#define WINDOW_SIZE (SFG_SCREEN_RESOLUTION_X * SFG_SCREEN_RESOLUTION_Y)

#include "game.h"
#include "sounds.h"

uint32_t windowPixels[WINDOW_SIZE];

uint32_t paletteRGB32[256]; // SFML can't do 565, so precompute RGB here

sfClock *clock;
sfRenderWindow* window;

uint8_t musicOn = 0;
int8_t mouseWheelState = 0;

int8_t SFG_keyPressed(uint8_t key)
{
  #define k(x) sfKeyboard_isKeyPressed(sfKey ## x)

  switch (key)
  {
    case SFG_KEY_UP: return k(W) || k(Up) || k(Num8); break;
    case SFG_KEY_RIGHT: return k(E) || k(Right) || k(Num6);
      break;
    case SFG_KEY_DOWN:
      return k(S) || k(Down) || k(Num5) || k (Num2); break;
    case SFG_KEY_LEFT: return k(Q) || k(Left) || k(Num4); break;
    case SFG_KEY_A:
      return k(J) || k(Return) || k(LShift) ||
      sfMouse_isButtonPressed(sfMouseLeft); break;
    case SFG_KEY_B: return k(K) || k(LControl) || k(RControl); break;
    case SFG_KEY_C: return k(L); break;
    case SFG_KEY_JUMP: return k(Space); break;
    case SFG_KEY_STRAFE_LEFT: return k(A) || k(Num7); break;
    case SFG_KEY_STRAFE_RIGHT: return k(D) || k(Num9); break;
    case SFG_KEY_MAP: return k(Tab); break;
    case SFG_KEY_CYCLE_WEAPON: return k(F);
    case SFG_KEY_TOGGLE_FREELOOK:
      return sfMouse_isButtonPressed(sfMouseRight);
      break;

    case SFG_KEY_NEXT_WEAPON:
      if (k(P) || k(X))
        return 1;

      if (mouseWheelState > 0)
      {
        mouseWheelState--;
        return 1;
      }
     
      return 0;
      break;

    case SFG_KEY_PREVIOUS_WEAPON:
      if (k(O) || k(Y) || k(Z)) 
        return 1;

      if (mouseWheelState < 0)
      {
        mouseWheelState++;
        return 1;
      }
        
      return 0;
      break;

    case SFG_KEY_MENU: return sfKeyboard_isKeyPressed(sfKeyEscape); break;
    default: return 0; break;

    #undef k
  }

  return 0;
}

void SFG_getMouseOffset(int16_t *x, int16_t *y)
{
  sfVector2u s = sfWindow_getSize((const sfWindow *) window);
  sfVector2i p = sfMouse_getPosition((const sfWindow *) window);

  s.x /= 2;
  s.y /= 2;

  *x = p.x - s.x;
  *y = p.y - s.y;

  p.x = s.x;
  p.y = s.y;

  sfMouse_setPosition(p,(const sfWindow *) window);
}

uint32_t SFG_getTimeMs()
{
  return sfClock_getElapsedTime(clock).microseconds / 1000 ;
}

void SFG_sleepMs(uint16_t timeMs)
{
  sfTime t;
  t.microseconds = timeMs * 1000;
  sfSleep(t);
}

void SFG_setPixel(uint16_t x, uint16_t y, uint8_t colorIndex)
{
  windowPixels[y * SFG_SCREEN_RESOLUTION_X + x] = paletteRGB32[colorIndex];
}


void SFG_setMusic(uint8_t value)
{
  switch (value)
  {
    case SFG_MUSIC_TURN_ON: musicOn = 1; break;
    case SFG_MUSIC_TURN_OFF: musicOn = 0; break;
    case SFG_MUSIC_NEXT: SFG_nextMusicTrack(); break;
    default: break;
  }
}

void SFG_processEvent(uint8_t event, uint8_t data)
{
}

void SFG_save(uint8_t data[SFG_SAVE_SIZE])
{
  FILE *f = fopen("anarch.sav","wb");

  if (f == NULL)
    return;

  fwrite(data,1,SFG_SAVE_SIZE,f);

  fclose(f);
}

uint8_t SFG_load(uint8_t data[SFG_SAVE_SIZE])
{
  FILE *f = fopen("anarch.sav","rb");

  if (f != NULL)
  {
    fread(data,1,SFG_SAVE_SIZE,f);
    fclose(f);
  }

  return 1;
}

/* Because of the csfml sound API we won't use circular audio buffer, but a
   linear buffer that is at each audio update shifted to the left. */

sfSoundStream *sound;

#define AUDIO_BUFFER_SIZE (SFG_SFX_SAMPLE_COUNT * 2) // total size of the buffer
#define AUDIO_BUFFER_OFFSET 400 /* size of the beginning portion of the buffer
                                   that's being played, while the other part
                                   is being filled with audio */

#if AUDIO_BUFFER_OFFSET * 2 > AUDIO_BUFFER_SIZE
  #error "AUDIO_BUFFER_OFFSET must be at most half of AUDIO_BUFFER_SIZE"
#endif

int16_t audioBuffer[AUDIO_BUFFER_SIZE];
uint32_t audioUpdateFrame = 0; // game frame at which audio buffer fill happened

static inline int16_t mixSamples(int16_t sample1, int16_t sample2)
{
  return sample1 + sample2;
}

void SFG_playSound(uint8_t soundIndex, uint8_t volume)
{
  uint16_t volumeScale = 1 << (volume / 37);

  uint32_t pos = AUDIO_BUFFER_OFFSET +
    ((SFG_game.frame - audioUpdateFrame) * SFG_MS_PER_FRAME * 8);

  for (int i = 0; i < SFG_SFX_SAMPLE_COUNT; ++i)
  {
    if (pos >= AUDIO_BUFFER_SIZE)
      break;

    audioBuffer[pos] = mixSamples(audioBuffer[pos], 
      (128 - SFG_GET_SFX_SAMPLE(soundIndex,i)) * volumeScale);

    pos++;
  }
}

sfBool soundFill(sfSoundStreamChunk *data, void *userdata)
{
  for (uint32_t i = 0; i < AUDIO_BUFFER_SIZE - AUDIO_BUFFER_OFFSET; ++i)
    audioBuffer[i] = audioBuffer[i + AUDIO_BUFFER_OFFSET];
  
  for (uint32_t i = AUDIO_BUFFER_SIZE - AUDIO_BUFFER_OFFSET; 
    i < AUDIO_BUFFER_SIZE; ++i)
    audioBuffer[i] = 0;

  if (musicOn)
    for (uint32_t i = 0; i < AUDIO_BUFFER_OFFSET; ++i) // mix in the music
    {
      audioBuffer[i] = mixSamples((SFG_getNextMusicSample() - 
        SFG_musicTrackAverages[SFG_MusicState.track]) * MUSIC_VOLUME,
        audioBuffer[i]);
    }

  data->samples = audioBuffer;
  data->sampleCount = AUDIO_BUFFER_OFFSET;

  audioUpdateFrame = SFG_game.frame;

  return sfTrue;
}

void soundSeek(sfTime t, void *userData)
{
}

int main()
{
  sfVideoMode mode = {SFG_SCREEN_RESOLUTION_X, SFG_SCREEN_RESOLUTION_Y, 32};
  sfEvent event;
  clock = sfClock_create();
  sfClock_restart(clock);

  SFG_init();

  for (int i = 0; i < AUDIO_BUFFER_SIZE; ++i)
    audioBuffer[i] = 0;

  sound = sfSoundStream_create(soundFill,soundSeek,1,8000,0);

  for (int i = 0; i < 256; ++i) // precompute RGB palette
  {
    uint16_t col565 = paletteRGB565[i];

    paletteRGB32[i] = 0xff000000 | ((col565 << 19) & 0xf80000) |
      ((col565 << 5) & 0xfc00) | ((col565 >> 8) & 0xf8);
  }

  sfTexture* windowTexture =
    sfTexture_create(SFG_SCREEN_RESOLUTION_X,SFG_SCREEN_RESOLUTION_Y);

  sfTexture_setSmooth(windowTexture,sfTrue);

  sfSprite* windowSprite = sfSprite_create();

  window = sfRenderWindow_create(mode, "Anarch", sfResize | sfClose, NULL);
  sfSprite_setTexture(windowSprite, windowTexture, sfTrue);

  sfWindow_setMouseCursorVisible((sfWindow *) window,sfFalse);
  sfWindow_setVerticalSyncEnabled((sfWindow *) window,sfFalse);

  sfSoundStream_play(sound);

  while (sfRenderWindow_isOpen(window))
  {
    while (sfRenderWindow_pollEvent(window,&event))
      if (event.type == sfEvtClosed)
        sfRenderWindow_close(window);
      else if (event.type == sfEvtMouseWheelMoved)
        mouseWheelState = event.mouseWheel.delta;

    if (!SFG_mainLoopBody())
      break;

    sfTexture_updateFromPixels(windowTexture,(const sfUint8 *) windowPixels,
      SFG_SCREEN_RESOLUTION_X,SFG_SCREEN_RESOLUTION_Y,0,0);
    sfRenderWindow_clear(window, sfBlack);
    sfRenderWindow_drawSprite(window,windowSprite,NULL);
    sfRenderWindow_display(window);
  }

  sfSoundStream_stop(sound);
  sfSoundStream_destroy(sound);
  sfSprite_destroy(windowSprite);
  sfTexture_destroy(windowTexture);
  sfRenderWindow_destroy(window);
  sfClock_destroy(clock);

  return 0;
}