Implement new volume conversion functions, add test

Core/Config.cpp

@@ -2092,3 +2092,31 @@ bool PlayTimeTracker::GetPlayedTimeString(const std::string &gameId, std::string
 	*str = ApplySafeSubstitutions(ga->T("Time Played: %1h %2m %3s"), hours, minutes, seconds);
 	return true;
 }
+
+// This matches exactly the old shift-based curve.
+float Volume10ToMultiplier(int volume) {
+	// Allow muting entirely.
+	if (volume <= 0) {
+		return 0.0f;
+	}
+	return powf(2.0f, (float)(volume - 10));
+}
+
+// NOTE: This is used for new volume parameters.
+// It uses a more intuitive-feeling curve.
+float Volume100ToMultiplier(int volume) {
+	// Switch to linear above the 1.0f point.
+	if (volume > 100) {
+		return volume / 100.0f;
+	}
+	return powf(volume * 0.01f, 1.75f);
+}
+
+// Used for migration from the old settings.
+int MultiplierToVolume100(float multiplier) {
+	// Switch to linear above the 1.0f point.
+	if (multiplier > 1.0f) {
+		return multiplier * 100;
+	}
+	return (int)(powf(multiplier, 1.0f / 1.75f) * 100.f + 0.5f);
+}

Core/ConfigValues.h

@@ -34,19 +34,14 @@ constexpr int VOLUME_FULL = 10;
 constexpr int VOLUMEHI_FULL = 100;  // for newer volume params. will convert them all later
 
 // This matches exactly the old shift-based curve.
-inline float Volume10ToMultiplier(int volume) {
-	// Allow muting entirely.
-	if (volume <= 0) {
-		return 0.0f;
-	}
-	return powf(2.0f, (float)(volume - 10));
-}
+float Volume10ToMultiplier(int volume);
 
 // NOTE: This is used for new volume parameters.
 // It uses a more intuitive-feeling curve.
-inline float Volume100ToMultiplier(int volume) {
-	return powf(volume * 0.01f, 1.75f);
-}
+float Volume100ToMultiplier(int volume);
+
+// Used for migration from the old settings.
+int MultiplierToVolume100(float multiplier);
 
 struct ConfigTouchPos {
 	float x;

unittest/UnitTest.cpp

@@ -1218,6 +1218,20 @@ bool TestCrossSIMD() {
 	return true;
 }
 
+bool TestVolumeFunc() {
+	for (int i = 0; i <= 20; i++) {
+		float mul = Volume10ToMultiplier(i);
+
+		int vol100 = MultiplierToVolume100(mul);
+		float mul2 = Volume100ToMultiplier(vol100);
+
+		bool smaller = (fabsf(mul2 - mul) < 0.02f);
+		EXPECT_TRUE(smaller);
+		// printf("%d -> %f -> %d -> %f\n", i, mul, vol100, mul2);
+	}
+	return true;
+}
+
 typedef bool (*TestFunc)();
 struct TestItem {
 	const char *name;
@@ -1282,6 +1296,7 @@ TestItem availableTests[] = {
 	TEST_ITEM(Buffer),
 	TEST_ITEM(SIMD),
 	TEST_ITEM(CrossSIMD),
+	TEST_ITEM(VolumeFunc),
 };
 
 int main(int argc, const char *argv[]) {