services/inputflinger/reader/mapper/JoystickInputMapper.h

/*
 * Copyright (C) 2019 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.
 */

#ifndef _UI_INPUTREADER_JOYSTICK_INPUT_MAPPER_H
#define _UI_INPUTREADER_JOYSTICK_INPUT_MAPPER_H

#include "InputMapper.h"

namespace android {

class JoystickInputMapper : public InputMapper {
public:
    explicit JoystickInputMapper(InputDevice* device);
    virtual ~JoystickInputMapper();

    virtual uint32_t getSources() override;
    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo) override;
    virtual void dump(std::string& dump) override;
    virtual void configure(nsecs_t when, const InputReaderConfiguration* config,
                           uint32_t changes) override;
    virtual void reset(nsecs_t when) override;
    virtual void process(const RawEvent* rawEvent) override;

private:
    struct Axis {
        RawAbsoluteAxisInfo rawAxisInfo;
        AxisInfo axisInfo;

        bool explicitlyMapped; // true if the axis was explicitly assigned an axis id

        float scale;      // scale factor from raw to normalized values
        float offset;     // offset to add after scaling for normalization
        float highScale;  // scale factor from raw to normalized values of high split
        float highOffset; // offset to add after scaling for normalization of high split

        float min;        // normalized inclusive minimum
        float max;        // normalized inclusive maximum
        float flat;       // normalized flat region size
        float fuzz;       // normalized error tolerance
        float resolution; // normalized resolution in units/mm

        float filter;           // filter out small variations of this size
        float currentValue;     // current value
        float newValue;         // most recent value
        float highCurrentValue; // current value of high split
        float highNewValue;     // most recent value of high split

        void initialize(const RawAbsoluteAxisInfo& rawAxisInfo, const AxisInfo& axisInfo,
                        bool explicitlyMapped, float scale, float offset, float highScale,
                        float highOffset, float min, float max, float flat, float fuzz,
                        float resolution) {
            this->rawAxisInfo = rawAxisInfo;
            this->axisInfo = axisInfo;
            this->explicitlyMapped = explicitlyMapped;
            this->scale = scale;
            this->offset = offset;
            this->highScale = highScale;
            this->highOffset = highOffset;
            this->min = min;
            this->max = max;
            this->flat = flat;
            this->fuzz = fuzz;
            this->resolution = resolution;
            this->filter = 0;
            resetValue();
        }

        void resetValue() {
            this->currentValue = 0;
            this->newValue = 0;
            this->highCurrentValue = 0;
            this->highNewValue = 0;
        }
    };

    // Axes indexed by raw ABS_* axis index.
    KeyedVector<int32_t, Axis> mAxes;

    void sync(nsecs_t when, bool force);

    bool haveAxis(int32_t axisId);
    void pruneAxes(bool ignoreExplicitlyMappedAxes);
    bool filterAxes(bool force);

    static bool hasValueChangedSignificantly(float filter, float newValue, float currentValue,
                                             float min, float max);
    static bool hasMovedNearerToValueWithinFilteredRange(float filter, float newValue,
                                                         float currentValue, float thresholdValue);

    static bool isCenteredAxis(int32_t axis);
    static int32_t getCompatAxis(int32_t axis);

    static void addMotionRange(int32_t axisId, const Axis& axis, InputDeviceInfo* info);
    static void setPointerCoordsAxisValue(PointerCoords* pointerCoords, int32_t axis, float value);
};

} // namespace android

#endif // _UI_INPUTREADER_JOYSTICK_INPUT_MAPPER_H