path: root/src/main.cc

// This file is part of the 64k demo project.
// It serves as the application entry point.
// Orchestrates platform initialization, main loop, and subsystem coordination.

#include "audio/audio.h"
#include "audio/gen.h"
#include "audio/synth.h"
#include "generated/assets.h" // Include generated asset header
#include "gpu/gpu.h"
#include "platform.h"
#include "util/math.h"
#include <GLFW/glfw3.h>
#include <math.h>
#include <stdio.h>
#include <string.h>
#include <vector>

#define DEMO_BPM 128.0f
#define SECONDS_PER_BEAT (60.0f / DEMO_BPM)
#define SPEC_FRAMES 16

struct SpecHeader {
  char magic[4];
  int32_t version;
  int32_t dct_size;
  int32_t num_frames;
};

int register_spec_asset(AssetId id) {
  size_t size;
  const uint8_t *data = GetAsset(id, &size);
  if (!data || size < sizeof(SpecHeader)) return -1;

  const SpecHeader *header = (const SpecHeader *)data;
  const float *spectral_data = (const float *)(data + sizeof(SpecHeader));

  Spectrogram spec;
  spec.spectral_data_a = spectral_data;
  spec.spectral_data_b = spectral_data; // No double-buffer for static assets
  spec.num_frames = header->num_frames;

  return synth_register_spectrogram(&spec);
}

static float *g_spec_buffer_a[SPEC_FRAMES * DCT_SIZE] = {0};
static float *g_spec_buffer_b[SPEC_FRAMES * DCT_SIZE] = {0};

// Global storage for the melody to ensure it persists
std::vector<float> g_melody_data;

int generate_melody() {
  g_melody_data.clear();
  int melody_frames = 0;

  // Simple C Minor pentatonic-ish sequence
  float notes[] = {261.63f, 311.13f, 349.23f, 392.00f, 466.16f, 523.25f};
  int num_notes = 6;

  // 128 beats at 128 BPM = 60 seconds
  // Generate a random sequence
  srand(12345); // Fixed seed for reproducibility

  for (int i = 0; i < 128; ++i) {
    if (i % 4 == 0) continue; // Rest on beat 1 of every bar

    NoteParams params = {};
    params.base_freq = notes[rand() % num_notes];
    if (rand() % 4 == 0) params.base_freq *= 2.0f; // Occasional octave up

    params.duration_sec = (rand() % 2 == 0) ? 0.2f : 0.4f;
    params.amplitude = 0.4f;
    params.attack_sec = 0.05f;
    params.decay_sec = 0.1f;
    params.vibrato_rate = 6.0f;
    params.vibrato_depth = 1.5f;
    params.num_harmonics = 4;
    params.harmonic_decay = 0.6f;
    params.pitch_randomness = 0.5f;
    params.amp_randomness = 0.05f;

    int note_frames = 0;
    std::vector<float> note_data =
        generate_note_spectrogram(params, &note_frames);

    // Apply some post-processing for texture
    apply_spectral_noise(note_data, note_frames, 0.2f); // Add grit
    if (i % 2 == 0) {
      apply_spectral_comb(note_data, note_frames, 10.0f,
                          0.8f); // Phaser-like effect
    }

    // Calculate offset in frames
    // i is the beat index (quarter notes)
    // 1 beat = 60 / 128 seconds = 0.46875 sec
    float beat_time = i * SECONDS_PER_BEAT;
    int frame_offset = (int)(beat_time * 32000.0f / DCT_SIZE);

    paste_spectrogram(g_melody_data, &melody_frames, note_data, note_frames,
                      frame_offset);
  }

  Spectrogram spec;
  spec.spectral_data_a = g_melody_data.data();
  spec.spectral_data_b = g_melody_data.data();
  spec.num_frames = melody_frames;

  return synth_register_spectrogram(&spec);
}

float *generate_tone(float *buffer, float freq) {
  if (buffer == nullptr) {
    buffer = (float *)calloc(SPEC_FRAMES * DCT_SIZE, sizeof(float));
  } else {
    memset(buffer, 0, SPEC_FRAMES * DCT_SIZE * sizeof(float));
  }
  for (int frame = 0; frame < SPEC_FRAMES; ++frame) {
    float *spec_frame = buffer + frame * DCT_SIZE;
    float amplitude = 1000. * powf(1.0f - (float)frame / SPEC_FRAMES, 2.0f);

    int bin = (int)(freq / (32000.0f / 2.0f) * DCT_SIZE);
    if (bin > 0 && bin < DCT_SIZE) { spec_frame[bin] = amplitude; }
  }
  return buffer;
}

int main(int argc, char **argv) {
  bool fullscreen_enabled = false;
  double seek_time = 0.0;

#ifndef STRIP_ALL
  for (int i = 1; i < argc; ++i) {
    if (strcmp(argv[i], "--fullscreen") == 0) {
      fullscreen_enabled = true;
    } else if (strcmp(argv[i], "--seek") == 0 && i + 1 < argc) {
      seek_time = atof(argv[i + 1]);
      i++;
    }
  }
#else
  (void)argc;
  (void)argv;
  fullscreen_enabled = true;
#endif /* STRIP_ALL */

  platform_init_window(fullscreen_enabled);
  int width, height;
  glfwGetFramebufferSize(platform_get_window(), &width, &height);
  gpu_init(platform_get_window(), width, height);
  audio_init();

  // Register drum assets
  int kick_id = register_spec_asset(AssetId::ASSET_KICK_1);
  int snare_id = register_spec_asset(AssetId::ASSET_SNARE_1);
  int hihat_id = register_spec_asset(AssetId::ASSET_HIHAT_1);

  // Still keep the dynamic tone for bass
  const float *g_spec_buffer_a = generate_tone(nullptr, 110.0f); // A2
  const float *g_spec_buffer_b = generate_tone(nullptr, 110.0f);
  const Spectrogram bass_spec = {g_spec_buffer_a, g_spec_buffer_b, SPEC_FRAMES};
  int bass_id = synth_register_spectrogram(&bass_spec);

  // Generate and play melody
  int melody_id = generate_melody();
  synth_trigger_voice(melody_id, 0.6f, 0.0f);

  double last_beat_time = 0.0;
  int beat_count = 0;

  auto update_game_logic = [&](double t) {
    if (t - last_beat_time > SECONDS_PER_BEAT / 2.0) { // 8th notes
      last_beat_time = t;                              // Sync to t

      const int step = beat_count % 16;

      // Kick on 1, 9, 11, 14...
      if (step == 0 || step == 8 || step == 10 || step == 13) {
        synth_trigger_voice(kick_id, 1.0f, 0.0f);
      }

      // Snare on 4, 12
      if (step == 4 || step == 12) {
        synth_trigger_voice(snare_id, 0.8f, step & 8 ? -1.0f : 1.0f);
      }

      // Hihat on every offbeat
      if (step % 2 == 1) { synth_trigger_voice(hihat_id, 0.5f, 0.3f); }

      // Bass pattern
      if (step % 4 == 0) {
        float *back_buffer = synth_begin_update(bass_id);
        if (back_buffer) {
          float bass_freq = (step < 8) ? 110.0f : 164.82f; // A3 then E3
          generate_tone(back_buffer, bass_freq);
          synth_commit_update(bass_id);
        }
        synth_trigger_voice(bass_id, 0.9f, 1.2f);
      }

      ++beat_count;
    }
  };

#ifndef STRIP_ALL
  if (seek_time > 0.0) {
    printf("Seeking to %.2f seconds...\n", seek_time);

    // Simulate audio/game logic
    // We step at ~60hz
    const double step = 1.0 / 60.0;
    for (double t = 0.0; t < seek_time; t += step) {
      update_game_logic(t);
      audio_render_silent((float)step);
    }

    // Simulate Visuals
    gpu_simulate_until((float)seek_time);
  }
#endif

  // Start real audio
  audio_start();

  while (!platform_should_close()) {
    platform_poll();

    double current_time = platform_get_time() + seek_time; // Offset logic time

    update_game_logic(current_time);

    int width, height;
    glfwGetFramebufferSize(platform_get_window(), &width, &height);
    float aspect_ratio = (float)width / (float)height;

    // Adjusted multiplier for visuals (preventing constant 1.0 saturation)
    float raw_peak = synth_get_output_peak();
    float visual_peak = fminf(raw_peak * 8.0f, 1.0f);

    float beat = fmodf((float)current_time * DEMO_BPM / 60.0f, 1.0f);
    gpu_draw(visual_peak, aspect_ratio, (float)current_time, beat);
    audio_update();
  }

  audio_shutdown();
  gpu_shutdown();
  platform_shutdown();
  return 0;
}