diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/main.cc | 14 | ||||
| -rw-r--r-- | src/tests/test_variable_tempo.cc | 375 |
2 files changed, 388 insertions, 1 deletions
diff --git a/src/main.cc b/src/main.cc index aba8d4b..9f61f07 100644 --- a/src/main.cc +++ b/src/main.cc @@ -92,10 +92,20 @@ int main(int argc, char** argv) { // int melody_id = generate_melody(); // synth_trigger_voice(melody_id, 0.6f, 0.0f); + // Music time state for variable tempo + static float g_music_time = 0.0f; + static float g_tempo_scale = 1.0f; // 1.0 = normal speed + static double g_last_physical_time = 0.0; + double last_beat_time = 0.0; int beat_count = 0; auto update_game_logic = [&](double t) { + // Calculate delta time and advance music time at scaled rate + const float dt = (float)(t - g_last_physical_time); + g_last_physical_time = t; + g_music_time += dt * g_tempo_scale; + if (t - last_beat_time > (60.0f / g_tracker_score.bpm) / 2.0) { // 8th notes last_beat_time = t; // Sync to t @@ -115,7 +125,9 @@ int main(int argc, char** argv) { */ ++beat_count; } - tracker_update((float)t); + + // Pass music_time (not physical time) to tracker + tracker_update(g_music_time); }; #if !defined(STRIP_ALL) diff --git a/src/tests/test_variable_tempo.cc b/src/tests/test_variable_tempo.cc new file mode 100644 index 0000000..d366ade --- /dev/null +++ b/src/tests/test_variable_tempo.cc @@ -0,0 +1,375 @@ +// This file is part of the 64k demo project. +// It tests variable tempo system with music_time scaling. +// Verifies 2x speed-up and 2x slow-down reset tricks. + +#include "audio/mock_audio_backend.h" +#include "audio/audio.h" +#include "audio/synth.h" +#include "audio/tracker.h" +#include <assert.h> +#include <stdio.h> +#include <cmath> + +#if !defined(STRIP_ALL) + +// Helper: Calculate expected physical time for music_time at constant tempo +static float calc_physical_time(float music_time, float tempo_scale) { + return music_time / tempo_scale; +} + +// Helper: Simulate music time advancement +static float advance_music_time(float current_music_time, float dt, + float tempo_scale) { + return current_music_time + (dt * tempo_scale); +} + +void test_basic_tempo_scaling() { + printf("Test: Basic tempo scaling (1.0x, 2.0x, 0.5x)...\n"); + + MockAudioBackend backend; + audio_set_backend(&backend); + + tracker_init(); + synth_init(); + + // Test 1: Normal tempo (1.0x) + { + backend.clear_events(); + float music_time = 0.0f; + float tempo_scale = 1.0f; + + // Simulate 1 second of physical time + for (int i = 0; i < 10; ++i) { + float dt = 0.1f; // 100ms physical steps + music_time += dt * tempo_scale; + tracker_update(music_time); + } + + // After 1 second physical time at 1.0x tempo: + // music_time should be ~1.0 + printf(" 1.0x tempo: music_time = %.3f (expected ~1.0)\n", music_time); + assert(std::abs(music_time - 1.0f) < 0.01f); + } + + // Test 2: Fast tempo (2.0x) + { + backend.clear_events(); + tracker_init(); // Reset tracker + float music_time = 0.0f; + float tempo_scale = 2.0f; + + // Simulate 1 second of physical time + for (int i = 0; i < 10; ++i) { + float dt = 0.1f; + music_time += dt * tempo_scale; + tracker_update(music_time); + } + + // After 1 second physical time at 2.0x tempo: + // music_time should be ~2.0 + printf(" 2.0x tempo: music_time = %.3f (expected ~2.0)\n", music_time); + assert(std::abs(music_time - 2.0f) < 0.01f); + } + + // Test 3: Slow tempo (0.5x) + { + backend.clear_events(); + tracker_init(); + float music_time = 0.0f; + float tempo_scale = 0.5f; + + // Simulate 1 second of physical time + for (int i = 0; i < 10; ++i) { + float dt = 0.1f; + music_time += dt * tempo_scale; + tracker_update(music_time); + } + + // After 1 second physical time at 0.5x tempo: + // music_time should be ~0.5 + printf(" 0.5x tempo: music_time = %.3f (expected ~0.5)\n", music_time); + assert(std::abs(music_time - 0.5f) < 0.01f); + } + + printf(" ✓ Basic tempo scaling works correctly\n"); +} + +void test_2x_speedup_reset_trick() { + printf("Test: 2x SPEED-UP reset trick...\n"); + + MockAudioBackend backend; + audio_set_backend(&backend); + + tracker_init(); + synth_init(); + + // Scenario: Accelerate to 2.0x, then reset to 1.0x + float music_time = 0.0f; + float tempo_scale = 1.0f; + float physical_time = 0.0f; + + const float dt = 0.1f; // 100ms steps + + // Phase 1: Accelerate from 1.0x to 2.0x over 5 seconds + printf(" Phase 1: Accelerating 1.0x → 2.0x\n"); + for (int i = 0; i < 50; ++i) { + physical_time += dt; + tempo_scale = 1.0f + (physical_time / 5.0f); // Linear acceleration + tempo_scale = fminf(tempo_scale, 2.0f); + + music_time += dt * tempo_scale; + tracker_update(music_time); + } + + printf(" After 5s physical: tempo=%.2fx, music_time=%.3f\n", tempo_scale, + music_time); + assert(tempo_scale >= 1.99f); // Should be at 2.0x + + // Record state before reset + const float music_time_before_reset = music_time; + const size_t events_before_reset = backend.get_events().size(); + + // Phase 2: RESET - back to 1.0x tempo + printf(" Phase 2: RESET to 1.0x tempo\n"); + tempo_scale = 1.0f; + + // Continue for another 2 seconds + for (int i = 0; i < 20; ++i) { + physical_time += dt; + music_time += dt * tempo_scale; + tracker_update(music_time); + } + + printf(" After reset + 2s: tempo=%.2fx, music_time=%.3f\n", tempo_scale, + music_time); + + // Verify: music_time advanced 2.0 units in 2 seconds at 1.0x tempo + const float music_time_delta = music_time - music_time_before_reset; + printf(" Music time delta: %.3f (expected ~2.0)\n", music_time_delta); + assert(std::abs(music_time_delta - 2.0f) < 0.1f); + + printf(" ✓ 2x speed-up reset trick verified\n"); +} + +void test_2x_slowdown_reset_trick() { + printf("Test: 2x SLOW-DOWN reset trick...\n"); + + MockAudioBackend backend; + audio_set_backend(&backend); + + tracker_init(); + synth_init(); + + // Scenario: Decelerate to 0.5x, then reset to 1.0x + float music_time = 0.0f; + float tempo_scale = 1.0f; + float physical_time = 0.0f; + + const float dt = 0.1f; + + // Phase 1: Decelerate from 1.0x to 0.5x over 5 seconds + printf(" Phase 1: Decelerating 1.0x → 0.5x\n"); + for (int i = 0; i < 50; ++i) { + physical_time += dt; + tempo_scale = 1.0f - (physical_time / 10.0f); // Linear deceleration + tempo_scale = fmaxf(tempo_scale, 0.5f); + + music_time += dt * tempo_scale; + tracker_update(music_time); + } + + printf(" After 5s physical: tempo=%.2fx, music_time=%.3f\n", tempo_scale, + music_time); + assert(tempo_scale <= 0.51f); // Should be at 0.5x + + // Record state before reset + const float music_time_before_reset = music_time; + + // Phase 2: RESET - back to 1.0x tempo + printf(" Phase 2: RESET to 1.0x tempo\n"); + tempo_scale = 1.0f; + + // Continue for another 2 seconds + for (int i = 0; i < 20; ++i) { + physical_time += dt; + music_time += dt * tempo_scale; + tracker_update(music_time); + } + + printf(" After reset + 2s: tempo=%.2fx, music_time=%.3f\n", tempo_scale, + music_time); + + // Verify: music_time advanced 2.0 units in 2 seconds at 1.0x tempo + const float music_time_delta = music_time - music_time_before_reset; + printf(" Music time delta: %.3f (expected ~2.0)\n", music_time_delta); + assert(std::abs(music_time_delta - 2.0f) < 0.1f); + + printf(" ✓ 2x slow-down reset trick verified\n"); +} + +void test_pattern_density_swap() { + printf("Test: Pattern density swap at reset points...\n"); + + MockAudioBackend backend; + audio_set_backend(&backend); + + tracker_init(); + synth_init(); + + // Simulate: sparse pattern → accelerate → reset + dense pattern + float music_time = 0.0f; + float tempo_scale = 1.0f; + + // Phase 1: Sparse pattern at normal tempo (first 3 patterns trigger) + printf(" Phase 1: Sparse pattern, normal tempo\n"); + for (float t = 0.0f; t < 3.0f; t += 0.1f) { + music_time += 0.1f * tempo_scale; + tracker_update(music_time); + } + const size_t sparse_events = backend.get_events().size(); + printf(" Events during sparse phase: %zu\n", sparse_events); + + // Phase 2: Accelerate to 2.0x + printf(" Phase 2: Accelerating to 2.0x\n"); + tempo_scale = 2.0f; + for (float t = 0.0f; t < 2.0f; t += 0.1f) { + music_time += 0.1f * tempo_scale; + tracker_update(music_time); + } + const size_t events_at_2x = backend.get_events().size() - sparse_events; + printf(" Additional events during 2.0x: %zu\n", events_at_2x); + + // Phase 3: Reset to 1.0x (in real impl, would switch to denser pattern) + printf(" Phase 3: Reset to 1.0x (simulating denser pattern)\n"); + tempo_scale = 1.0f; + + // At this point, real implementation would trigger a pattern with + // 2x more events per beat to maintain perceived density + + const size_t events_before_reset_phase = backend.get_events().size(); + for (float t = 0.0f; t < 2.0f; t += 0.1f) { + music_time += 0.1f * tempo_scale; + tracker_update(music_time); + } + const size_t events_after_reset = backend.get_events().size(); + + printf(" Events during reset phase: %zu\n", + events_after_reset - events_before_reset_phase); + + // Verify patterns triggered throughout + assert(backend.get_events().size() > 0); + + printf(" ✓ Pattern density swap points verified\n"); +} + +void test_continuous_acceleration() { + printf("Test: Continuous acceleration from 0.5x to 2.0x...\n"); + + MockAudioBackend backend; + audio_set_backend(&backend); + + tracker_init(); + synth_init(); + + float music_time = 0.0f; + float tempo_scale = 0.5f; + float physical_time = 0.0f; + + const float dt = 0.05f; // 50ms steps for smoother curve + + // Accelerate from 0.5x to 2.0x over 10 seconds + printf(" Accelerating 0.5x → 2.0x over 10 seconds\n"); + + float min_tempo = 0.5f; + float max_tempo = 2.0f; + + for (int i = 0; i < 200; ++i) { + physical_time += dt; + float progress = physical_time / 10.0f; // 0.0 to 1.0 + tempo_scale = min_tempo + progress * (max_tempo - min_tempo); + tempo_scale = fmaxf(min_tempo, fminf(max_tempo, tempo_scale)); + + music_time += dt * tempo_scale; + tracker_update(music_time); + + // Log at key points + if (i % 50 == 0) { + printf(" t=%.1fs: tempo=%.2fx, music_time=%.3f\n", physical_time, + tempo_scale, music_time); + } + } + + printf(" Final: tempo=%.2fx, music_time=%.3f\n", tempo_scale, music_time); + + // Verify tempo reached target + assert(tempo_scale >= 1.99f); + + // Verify music_time progressed correctly + // Integral of (0.5 + 1.5t/10) from 0 to 10 = 0.5*10 + 1.5*10²/(2*10) = 5 + 7.5 = 12.5 + const float expected_music_time = 12.5f; + printf(" Expected music_time: %.3f, actual: %.3f\n", expected_music_time, + music_time); + assert(std::abs(music_time - expected_music_time) < 0.5f); + + printf(" ✓ Continuous acceleration verified\n"); +} + +void test_oscillating_tempo() { + printf("Test: Oscillating tempo (sine wave)...\n"); + + MockAudioBackend backend; + audio_set_backend(&backend); + + tracker_init(); + synth_init(); + + float music_time = 0.0f; + float physical_time = 0.0f; + + const float dt = 0.05f; + + // Oscillate tempo between 0.8x and 1.2x + printf(" Oscillating tempo: 0.8x ↔ 1.2x\n"); + + for (int i = 0; i < 100; ++i) { + physical_time += dt; + float tempo_scale = 1.0f + 0.2f * sinf(physical_time * 2.0f); + + music_time += dt * tempo_scale; + tracker_update(music_time); + + if (i % 25 == 0) { + printf(" t=%.2fs: tempo=%.3fx, music_time=%.3f\n", physical_time, + tempo_scale, music_time); + } + } + + // After oscillation, music_time should be approximately equal to physical_time + // (since average tempo is 1.0x) + printf(" Final: physical_time=%.2fs, music_time=%.3f (expected ~%.2f)\n", + physical_time, music_time, physical_time); + + // Allow some tolerance for integral error + assert(std::abs(music_time - physical_time) < 0.5f); + + printf(" ✓ Oscillating tempo verified\n"); +} + +#endif /* !defined(STRIP_ALL) */ + +int main() { +#if !defined(STRIP_ALL) + printf("Running Variable Tempo tests...\n\n"); + test_basic_tempo_scaling(); + test_2x_speedup_reset_trick(); + test_2x_slowdown_reset_trick(); + test_pattern_density_swap(); + test_continuous_acceleration(); + test_oscillating_tempo(); + printf("\n✅ All Variable Tempo tests PASSED\n"); + return 0; +#else + printf("Variable Tempo tests skipped (STRIP_ALL enabled)\n"); + return 0; +#endif /* !defined(STRIP_ALL) */ +} |