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Diffstat (limited to 'libs/input/AccelerationCurve.cpp')
| -rw-r--r-- | libs/input/AccelerationCurve.cpp | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/libs/input/AccelerationCurve.cpp b/libs/input/AccelerationCurve.cpp new file mode 100644 index 0000000000..0a92a71596 --- /dev/null +++ b/libs/input/AccelerationCurve.cpp @@ -0,0 +1,63 @@ +/* + * Copyright 2024 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 <input/AccelerationCurve.h> + +#include <array> +#include <limits> + +#include <log/log_main.h> + +#define LOG_TAG "AccelerationCurve" + +namespace android { + +namespace { + +// The last segment must have an infinite maximum speed, so that all speeds are covered. +constexpr std::array<AccelerationCurveSegment, 4> kSegments = {{ + {32.002, 3.19, 0}, + {52.83, 4.79, -51.254}, + {119.124, 7.28, -182.737}, + {std::numeric_limits<double>::infinity(), 15.04, -1107.556}, +}}; + +static_assert(kSegments.back().maxPointerSpeedMmPerS == std::numeric_limits<double>::infinity()); + +constexpr std::array<double, 15> kSensitivityFactors = {1, 2, 4, 6, 7, 8, 9, 10, + 11, 12, 13, 14, 16, 18, 20}; + +} // namespace + +std::vector<AccelerationCurveSegment> createAccelerationCurveForPointerSensitivity( + int32_t sensitivity) { + LOG_ALWAYS_FATAL_IF(sensitivity < -7 || sensitivity > 7, "Invalid pointer sensitivity value"); + std::vector<AccelerationCurveSegment> output; + output.reserve(kSegments.size()); + + // The curves we want to produce for different sensitivity values are actually the same curve, + // just scaled in the Y (gain) axis by a sensitivity factor and a couple of constants. + double commonFactor = 0.64 * kSensitivityFactors[sensitivity + 7] / 10; + for (AccelerationCurveSegment seg : kSegments) { + output.push_back(AccelerationCurveSegment{seg.maxPointerSpeedMmPerS, + commonFactor * seg.baseGain, + commonFactor * seg.reciprocal}); + } + + return output; +} + +} // namespace android
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