From a8a87a0922a33d38ed80165ee62f9dc35bd08a3d Mon Sep 17 00:00:00 2001
From: Pascal Getreuer <50221757+getreuer@users.noreply.github.com>
Date: Fri, 7 Jul 2023 08:47:16 -0600
Subject: [PATCH] [Core] Simplify audio_duration_to_ms() and
audio_ms_to_duration(), reduce firmware size by a few bytes. (#21427)
---
platforms/test/drivers/audio_pwm.h | 16 +++
platforms/test/drivers/audio_pwm_hardware.c | 20 ++++
quantum/audio/audio.c | 45 +++++---
tests/audio/config.h | 18 +++
tests/audio/test.mk | 16 +++
tests/audio/test_audio.cpp | 118 ++++++++++++++++++++
6 files changed, 220 insertions(+), 13 deletions(-)
create mode 100644 platforms/test/drivers/audio_pwm.h
create mode 100644 platforms/test/drivers/audio_pwm_hardware.c
create mode 100644 tests/audio/config.h
create mode 100644 tests/audio/test.mk
create mode 100644 tests/audio/test_audio.cpp
diff --git a/platforms/test/drivers/audio_pwm.h b/platforms/test/drivers/audio_pwm.h
new file mode 100644
index 00000000000..9a3fa88cec3
--- /dev/null
+++ b/platforms/test/drivers/audio_pwm.h
@@ -0,0 +1,16 @@
+// Copyright 2023 Google LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see .
+
+#pragma once
diff --git a/platforms/test/drivers/audio_pwm_hardware.c b/platforms/test/drivers/audio_pwm_hardware.c
new file mode 100644
index 00000000000..336e4f58449
--- /dev/null
+++ b/platforms/test/drivers/audio_pwm_hardware.c
@@ -0,0 +1,20 @@
+// Copyright 2023 Google LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see .
+
+#include "audio.h"
+
+void audio_driver_initialize(void) {}
+void audio_driver_start() {}
+void audio_driver_stop() {}
diff --git a/quantum/audio/audio.c b/quantum/audio/audio.c
index 2570ad9cd1e..0300483a938 100644
--- a/quantum/audio/audio.c
+++ b/quantum/audio/audio.c
@@ -547,20 +547,39 @@ void audio_decrease_tempo(uint8_t tempo_change) {
note_tempo -= tempo_change;
}
-// TODO in the int-math version are some bugs; songs sometimes abruptly end - maybe an issue with the timer/system-tick wrapping around?
+/**
+ * Converts from units of 1/64ths of a beat to milliseconds.
+ *
+ * Round-off error is at most 1 millisecond.
+ *
+ * Conversion will never overflow for duration_bpm <= 699, provided that
+ * note_tempo is at least 10. This is quite a long duration, over ten beats.
+ *
+ * Beware that for duration_bpm > 699, the result may overflow uint16_t range
+ * when duration_bpm is large compared to note_tempo:
+ *
+ * duration_bpm * 60 * 1000 / (64 * note_tempo) > UINT16_MAX
+ *
+ * duration_bpm > (2 * 65535 / 1875) * note_tempo
+ * = 69.904 * note_tempo.
+ */
uint16_t audio_duration_to_ms(uint16_t duration_bpm) {
-#if defined(__AVR__)
- // doing int-math saves us some bytes in the overall firmware size, but the intermediate result is less accurate before being cast to/returned as uint
- return ((uint32_t)duration_bpm * 60 * 1000) / (64 * note_tempo);
- // NOTE: beware of uint16_t overflows when note_tempo is low and/or the duration is long
-#else
- return ((float)duration_bpm * 60) / (64 * note_tempo) * 1000;
-#endif
+ return ((uint32_t)duration_bpm * 1875) / ((uint_fast16_t)note_tempo * 2);
}
+
+/**
+ * Converts from units of milliseconds to 1/64ths of a beat.
+ *
+ * Round-off error is at most 1/64th of a beat.
+ *
+ * This conversion never overflows: since duration_ms <= UINT16_MAX = 65535
+ * and note_tempo <= 255, the result is always in uint16_t range:
+ *
+ * duration_ms * 64 * note_tempo / 60 / 1000
+ * <= 65535 * 2 * 255 / 1875
+ * = 17825.52
+ * <= UINT16_MAX.
+ */
uint16_t audio_ms_to_duration(uint16_t duration_ms) {
-#if defined(__AVR__)
- return ((uint32_t)duration_ms * 64 * note_tempo) / 60 / 1000;
-#else
- return ((float)duration_ms * 64 * note_tempo) / 60 / 1000;
-#endif
+ return ((uint32_t)duration_ms * 2 * note_tempo) / 1875;
}
diff --git a/tests/audio/config.h b/tests/audio/config.h
new file mode 100644
index 00000000000..d0c4ddadbd3
--- /dev/null
+++ b/tests/audio/config.h
@@ -0,0 +1,18 @@
+// Copyright 2023 Google LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see .
+
+#pragma once
+
+#include "test_common.h"
diff --git a/tests/audio/test.mk b/tests/audio/test.mk
new file mode 100644
index 00000000000..a2c71d95878
--- /dev/null
+++ b/tests/audio/test.mk
@@ -0,0 +1,16 @@
+# Copyright 2023 Google LLC
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see .
+
+AUDIO_ENABLE = yes
diff --git a/tests/audio/test_audio.cpp b/tests/audio/test_audio.cpp
new file mode 100644
index 00000000000..ef34748b060
--- /dev/null
+++ b/tests/audio/test_audio.cpp
@@ -0,0 +1,118 @@
+// Copyright 2023 Google LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see .
+
+#include
+#include
+
+#include "gtest/gtest.h"
+#include "keyboard_report_util.hpp"
+#include "test_common.hpp"
+
+namespace {
+
+class AudioTest : public TestFixture {
+ public:
+ uint16_t infer_tempo() {
+ return audio_ms_to_duration(1875) / 2;
+ }
+};
+
+TEST_F(AudioTest, OnOffToggle) {
+ audio_on();
+ EXPECT_TRUE(audio_is_on());
+
+ audio_off();
+ EXPECT_FALSE(audio_is_on());
+
+ audio_toggle();
+ EXPECT_TRUE(audio_is_on());
+
+ audio_toggle();
+ EXPECT_FALSE(audio_is_on());
+}
+
+TEST_F(AudioTest, ChangeTempo) {
+ for (int tempo = 50; tempo <= 250; tempo += 50) {
+ audio_set_tempo(tempo);
+ EXPECT_EQ(infer_tempo(), tempo);
+ }
+
+ audio_set_tempo(10);
+ audio_increase_tempo(25);
+ EXPECT_EQ(infer_tempo(), 35);
+
+ audio_decrease_tempo(4);
+ EXPECT_EQ(infer_tempo(), 31);
+
+ audio_increase_tempo(250);
+ EXPECT_EQ(infer_tempo(), 255);
+
+ audio_set_tempo(9);
+ EXPECT_EQ(infer_tempo(), 10);
+
+ audio_decrease_tempo(100);
+ EXPECT_EQ(infer_tempo(), 10);
+}
+
+TEST_F(AudioTest, BpmConversion) {
+ const int tol = 1;
+
+ audio_set_tempo(120);
+ // At 120 bpm, there are 2 beats per second, and a whole note is 500 ms.
+ EXPECT_NEAR(audio_duration_to_ms(64 /* whole note */), 500, tol);
+ EXPECT_NEAR(audio_ms_to_duration(500), 64, tol);
+ EXPECT_EQ(audio_duration_to_ms(0), 0);
+ EXPECT_EQ(audio_ms_to_duration(0), 0);
+
+ audio_set_tempo(10);
+ // At 10 bpm, UINT16_MAX ms corresponds to 699/64 beats and is the longest
+ // duration that can be converted without overflow.
+ EXPECT_NEAR(audio_ms_to_duration(UINT16_MAX), 699, tol);
+ EXPECT_NEAR(audio_duration_to_ms(699), 65531, tol);
+
+ audio_set_tempo(255);
+ // At 255 bpm, UINT16_MAX ms corresponds to 17825/64 beats and is the longest
+ // duration that can be converted without overflow.
+ EXPECT_NEAR(audio_ms_to_duration(UINT16_MAX), 17825, tol);
+ EXPECT_NEAR(audio_duration_to_ms(17825), 65533, tol);
+
+ std::mt19937 rng(0 /*seed*/);
+ std::uniform_int_distribution dist_tempo(10, 255);
+ std::uniform_int_distribution dist_ms(0, UINT16_MAX);
+
+ // Test bpm <-> ms conversions for random tempos and durations.
+ for (int trial = 0; trial < 50; ++trial) {
+ const int tempo = dist_tempo(rng);
+ const int duration_ms = dist_ms(rng);
+ SCOPED_TRACE("tempo " + testing::PrintToString(tempo) + ", duration " + testing::PrintToString(duration_ms) + " ms");
+
+ audio_set_tempo(tempo);
+ int duration_bpm = std::round((64.0f / (60.0f * 1000.0f)) * duration_ms * tempo);
+ ASSERT_NEAR(audio_ms_to_duration(duration_ms), duration_bpm, tol);
+
+ int roundtrip_ms = std::round((60.0f * 1000.0f / 64.0f) * duration_bpm / tempo);
+ // Because of round-off error, duration_ms and roundtrip_ms may differ by
+ // about (60 * 1000 / 64) / tempo.
+ int roundtrip_tol = tol * (60.0f * 1000.0f / 64.0f) / tempo;
+ ASSERT_NEAR(roundtrip_ms, duration_ms, roundtrip_tol);
+
+ // Only test converting back to ms if the result would be in uint16_t range.
+ if (roundtrip_ms <= UINT16_MAX) {
+ ASSERT_NEAR(audio_duration_to_ms(duration_bpm), roundtrip_ms, tol);
+ }
+ }
+}
+
+} // namespace