1 /* 2 * Copyright 2024 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #pragma once 18 19 #include <cstdint> 20 #include <vector> 21 22 namespace android { 23 24 /** 25 * Describes a section of an acceleration curve as a function which outputs a scaling factor (gain) 26 * for the pointer movement, given the speed of the mouse or finger (in mm/s): 27 * 28 * gain(input_speed_mm_per_s) = baseGain + reciprocal / input_speed_mm_per_s 29 */ 30 struct AccelerationCurveSegment { 31 /** 32 * The maximum pointer speed at which this segment should apply, in mm/s. The last segment in a 33 * curve should always set this to infinity. 34 */ 35 double maxPointerSpeedMmPerS; 36 /** The gain for this segment before the reciprocal is taken into account. */ 37 double baseGain; 38 /** The reciprocal part of the formula, which should be divided by the input speed. */ 39 double reciprocal; 40 }; 41 42 /** 43 * Creates an acceleration curve for the given pointer sensitivity value. The sensitivity value 44 * should be between -7 (for the lowest sensitivity) and 7, inclusive. 45 */ 46 std::vector<AccelerationCurveSegment> createAccelerationCurveForPointerSensitivity( 47 int32_t sensitivity); 48 49 } // namespace android 50