joyful/internal/mappingrules/rule_target_axis.go

98 lines
2.6 KiB
Go

package mappingrules
import (
"errors"
"fmt"
"github.com/holoplot/go-evdev"
)
type RuleTargetAxis struct {
DeviceName string
Device RuleTargetDevice
Axis evdev.EvCode
Inverted bool
DeadzoneStart int32
DeadzoneEnd int32
axisSize int32
deadzoneSize int32
}
const (
MinAxisValue = int32(-32768)
MaxAxisValue = int32(32767)
)
func NewRuleTargetAxis(device_name string,
device RuleTargetDevice,
axis evdev.EvCode,
inverted bool,
deadzoneStart int32,
deadzoneEnd int32) (*RuleTargetAxis, error) {
info, err := device.AbsInfos()
if err != nil {
return nil, err
}
if _, ok := info[axis]; !ok {
return nil, fmt.Errorf("device does not support axis %v", axis)
}
if deadzoneStart > deadzoneEnd {
return nil, errors.New("deadzone_end must be a higher value than deadzone_start")
}
deadzoneSize := AbsInt(deadzoneEnd - deadzoneStart)
// Our output range is limited to 16 bits, but we represent values internally with 32 bits.
// As a result, we shouldn't need to worry about integer overruns
axisSize := info[axis].Maximum - info[axis].Minimum - deadzoneSize
if axisSize == 0 {
return nil, errors.New("axis has size 0")
}
return &RuleTargetAxis{
DeviceName: device_name,
Device: device,
Axis: axis,
Inverted: inverted,
DeadzoneStart: deadzoneStart,
DeadzoneEnd: deadzoneEnd,
deadzoneSize: deadzoneSize,
axisSize: axisSize,
}, nil
}
// NormalizeValue takes a raw input value and converts it to a value suitable for output.
//
// Axis inputs are normalized to the full signed int32 range to match the virtual device's axis
// characteristics.
//
// Typically this function is called after RuleTargetAxis.MatchEvent, which checks whether we are
// in the deadzone, among other things.
func (target *RuleTargetAxis) NormalizeValue(value int32) int32 {
axisStrength := float64(value-target.deadzoneSize) / float64(target.axisSize)
if target.Inverted {
axisStrength = 1.0 - axisStrength
}
normalizedValue := LerpInt(MinAxisValue, MaxAxisValue, axisStrength)
return normalizedValue
}
func (target *RuleTargetAxis) CreateEvent(value int32, mode *string) *evdev.InputEvent {
value = ClampInt(value, MinAxisValue, MaxAxisValue)
return &evdev.InputEvent{
Type: evdev.EV_ABS,
Code: target.Axis,
Value: value,
}
}
func (target *RuleTargetAxis) MatchEvent(device RuleTargetDevice, event *evdev.InputEvent) bool {
return device == target.Device &&
event.Type == evdev.EV_ABS &&
event.Code == target.Axis &&
(event.Value < target.DeadzoneStart || event.Value > target.DeadzoneEnd)
}