#if 0 /*
#/  ================================================================
#/
#/    sinewave.c
#/
#/  ================================================================
#/
#/    Self-compilation shell script
#/
SRC=${0##*./}
BIN=${SRC%.*}
gcc                                 \
  -Wall -Wextra -Werror -pedantic   \
  -Wno-old-style-declaration        \
  -Wno-missing-braces               \
  -Wno-unused-variable              \
  -Wno-unused-but-set-variable      \
  -Wno-unused-parameter             \
  -Wno-overlength-strings           \
  -O3                               \
  -fsanitize=undefined,address,leak \
  -lX11 -lm -lasound                \
  -o $BIN $SRC &&                   \
  ./$BIN $@ && rm $BIN
exit $? # */
#endif

#include "../graphics.c"

i64 time_0        = 0;
i64 audio_samples = 0;

f32 frames[AUDIO_SAMPLE_RATE * AUDIO_NUM_CHANNELS] = {0};

b8 ui_button(f64 x, f64 y, f64 width, f64 height) {
  b8 has_cursor = platform.cursor_x >= x && platform.cursor_x < x + width &&
                  platform.cursor_y >= y && platform.cursor_y < y + height;

  b8 is_pressed = has_cursor && platform.key_down[BUTTON_LEFT];

  if (is_pressed)
    fill_rectangle(OP_SET, 0xffffff, x, y, width, height);
  else if (has_cursor)
    fill_rectangle(OP_SET, 0xa0a000, x, y, width, height);
  else
    fill_rectangle(OP_SET, 0x808030, x, y, width, height);

  return has_cursor && platform.key_pressed[BUTTON_LEFT];
}

void update_and_render_frame(void) {
  i32 num_events = p_handle_events();

  if (num_events > 0) {
    fill_rectangle(OP_SET, 0x202020, 0, 0, platform.frame_width, platform.frame_height);

    if (ui_button(100, 100, 200, 200))
      p_queue_sound(0, AUDIO_SAMPLE_RATE, frames);
  }

  i64 samples_elapsed = ((p_time() - time_0) * AUDIO_SAMPLE_RATE) / 1000 - audio_samples;
  audio_samples      += samples_elapsed;

  p_handle_audio(samples_elapsed);
  p_render_frame();
  p_sleep_for(0);
}

i32 main(i32 argc, c8 **argv) {
  (void) argc;
  (void) argv;

  platform = (Platform) {
    .title         = "Sine Wave",
    .graceful_exit = 1,
  };

  f64 frequency = 440.;

  for (i64 i = 0; i < AUDIO_SAMPLE_RATE; ++i) {
    f64 t = ((f64) i) / AUDIO_SAMPLE_RATE;
    f64 x = sin(t * (M_PI * 2.) * frequency);
    if (t < .005)
      x *= t / .005;
    if (t > .1)
      x *= (1. - t) / .9;
    frames[i * 2]     = (f32) (x * .5);
    frames[i * 2 + 1] = (f32) (x * .5);
  }

  time_0 = p_time();

  p_event_loop();
  return 0;
}