Add scale factor field to HapticScale
Add extra field scale factor to the ExtenalVibratorService result to
support continuous scaling haptic channels based on a float scale.
The new updated scale function still converges to 1.0 when it's scaling
up the haptic data, but it no longer applies distortion of the vibration
waveform when it scales down the amplitude.
The new scaling is defined as:
(scale_factor * amplitude)
when scale_factor <= 1
(scale_factor * amplitude) / (1 + (scale_factor - 1) * amplitude^2)
when scale_factor > 1
Bug: 356407385
Flag: android.os.vibrator.haptics_scale_v2_enabled
Test: libvibrator_tests
Change-Id: Ibde6699bf23614e27b50e1ff79e364d942499187
diff --git a/libs/vibrator/ExternalVibrationUtils.cpp b/libs/vibrator/ExternalVibrationUtils.cpp
index 706f3d7..54afb71 100644
--- a/libs/vibrator/ExternalVibrationUtils.cpp
+++ b/libs/vibrator/ExternalVibrationUtils.cpp
@@ -13,6 +13,8 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
+#define LOG_TAG "ExternalVibrationUtils"
+
#include <cstring>
#include <android_os_vibrator.h>
@@ -20,6 +22,7 @@
#include <algorithm>
#include <math.h>
+#include <log/log.h>
#include <vibrator/ExternalVibrationUtils.h>
namespace android::os {
@@ -29,6 +32,7 @@
static constexpr float HAPTIC_SCALE_LOW_RATIO = 3.0f / 4.0f;
static constexpr float HAPTIC_MAX_AMPLITUDE_FLOAT = 1.0f;
static constexpr float SCALE_GAMMA = 0.65f; // Same as VibrationEffect.SCALE_GAMMA
+static constexpr float SCALE_LEVEL_GAIN = 1.4f; // Same as VibrationConfig.DEFAULT_SCALE_LEVEL_GAIN
float getOldHapticScaleGamma(HapticLevel level) {
switch (level) {
@@ -60,9 +64,34 @@
}
}
-/* Same as VibrationScaler.SCALE_LEVEL_* */
-float getHapticScaleFactor(HapticLevel level) {
- switch (level) {
+/* Same as VibrationScaler.getScaleFactor */
+float getHapticScaleFactor(HapticScale scale) {
+ if (android_os_vibrator_haptics_scale_v2_enabled()) {
+ if (scale.getScaleFactor() >= 0) {
+ // ExternalVibratorService provided the scale factor, use it.
+ return scale.getScaleFactor();
+ }
+
+ HapticLevel level = scale.getLevel();
+ switch (level) {
+ case HapticLevel::MUTE:
+ return 0.0f;
+ case HapticLevel::NONE:
+ return 1.0f;
+ default:
+ float scaleFactor = powf(SCALE_LEVEL_GAIN, static_cast<int32_t>(level));
+ if (scaleFactor <= 0) {
+ ALOGE("Invalid scale factor %.2f for level %d, using fallback to 1.0",
+ scaleFactor, static_cast<int32_t>(level));
+ scaleFactor = 1.0f;
+ }
+ return scaleFactor;
+ }
+ }
+ // Same as VibrationScaler.SCALE_FACTOR_*
+ switch (scale.getLevel()) {
+ case HapticLevel::MUTE:
+ return 0.0f;
case HapticLevel::VERY_LOW:
return 0.6f;
case HapticLevel::LOW:
@@ -83,6 +112,14 @@
}
float applyNewHapticScale(float value, float scaleFactor) {
+ if (android_os_vibrator_haptics_scale_v2_enabled()) {
+ if (scaleFactor <= 1 || value == 0) {
+ return value * scaleFactor;
+ } else {
+ // Using S * x / (1 + (S - 1) * x^2) as the scale up function to converge to 1.0.
+ return (value * scaleFactor) / (1 + (scaleFactor - 1) * value * value);
+ }
+ }
float scale = powf(scaleFactor, 1.0f / SCALE_GAMMA);
if (scaleFactor <= 1) {
// Scale down is simply a gamma corrected application of scaleFactor to the intensity.
@@ -115,14 +152,15 @@
return;
}
HapticLevel hapticLevel = scale.getLevel();
- float scaleFactor = getHapticScaleFactor(hapticLevel);
+ float scaleFactor = getHapticScaleFactor(scale);
float adaptiveScaleFactor = scale.getAdaptiveScaleFactor();
float oldGamma = getOldHapticScaleGamma(hapticLevel);
float oldMaxAmplitudeRatio = getOldHapticMaxAmplitudeRatio(hapticLevel);
for (size_t i = 0; i < length; i++) {
if (hapticLevel != HapticLevel::NONE) {
- if (android_os_vibrator_fix_audio_coupled_haptics_scaling()) {
+ if (android_os_vibrator_fix_audio_coupled_haptics_scaling() ||
+ android_os_vibrator_haptics_scale_v2_enabled()) {
buffer[i] = applyNewHapticScale(buffer[i], scaleFactor);
} else {
buffer[i] = applyOldHapticScale(buffer[i], oldGamma, oldMaxAmplitudeRatio);