InputFlinger: Support amplitude control for InputDeviceVibrator
Add support for sending multi-channel rumble amplitudes to input
devices supporting FF_RUMBLE.
Bug: 38511270
Bug: 136215622
Test: Connect a gamepad whose driver supports FF_RUMBLE, find it
with the android input framework, and do something like this:
// waveform where rumble magnitude doubles every 2 seconds
VibrationEffect effect = VibrationEffect.createWaveform(
new long[] { 2000L, 2000L, 2000L, 2000L, 2000L },
new int[] { 16, 32, 64, 128, 255 },
-1);
inputDevice.getVibrator().vibrate(effect);
Change-Id: I2f059e085c106cbca2372c72d09a9f579d35e4c7
diff --git a/services/inputflinger/VibrationElement.cpp b/services/inputflinger/VibrationElement.cpp
new file mode 100644
index 0000000..a69f5d0
--- /dev/null
+++ b/services/inputflinger/VibrationElement.cpp
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "VibrationElement.h"
+
+#include <android-base/stringprintf.h>
+
+#include <algorithm>
+#include <cinttypes>
+
+using android::base::StringPrintf;
+
+namespace android {
+
+// The sentinel to use the default amplitude
+static const int DEFAULT_AMPLITUDE = -1;
+
+// The vibration magnitude for the "DEFAULT_AMPLITUDE" magnitude constant.
+static const uint16_t DEFAULT_MAGNITUDE = 0xc000;
+
+void VibrationElement::dump(std::string& dump) const {
+ dump += StringPrintf("[duration=%lldms, channels=[", duration.count());
+
+ if (channels.size()) {
+ dump += std::to_string(channels[0]);
+ std::for_each(channels.begin() + 1, channels.end(), [&dump](int channel) {
+ dump += ", ";
+ dump += std::to_string(channel);
+ });
+ }
+ dump += "]]";
+}
+
+uint16_t VibrationElement::getChannel(int id) const {
+ if (id >= (int)channels.size()) {
+ return 0;
+ }
+
+ // android framework uses DEFAULT_AMPLITUDE to signal that the vibration
+ // should use some built-in default value, denoted here as DEFAULT_MAGNITUDE
+ if (channels[id] == DEFAULT_AMPLITUDE) {
+ return DEFAULT_MAGNITUDE;
+ }
+
+ // convert range [0,255] to [0,65535] (android framework to linux ff ranges)
+ return ((uint16_t)channels[id]) << 8;
+}
+
+bool VibrationElement::isOn() const {
+ return std::any_of(channels.begin(), channels.end(),
+ [](uint16_t channel) { return channel != 0; });
+}
+
+} // namespace android