File: axis_transform.py

package info (click to toggle)
input-remapper 2.1.1-2
  • links: PTS, VCS
  • area: main
  • in suites: forky
  • size: 2,856 kB
  • sloc: python: 27,277; sh: 191; xml: 33; makefile: 3
file content (140 lines) | stat: -rw-r--r-- 4,852 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
# -*- coding: utf-8 -*-
# input-remapper - GUI for device specific keyboard mappings
# Copyright (C) 2025 sezanzeb <b8x45ygc9@mozmail.com>
#
# This file is part of input-remapper.
#
# input-remapper is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# input-remapper is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with input-remapper.  If not, see <https://www.gnu.org/licenses/>.

import math
from typing import Dict, Union


class Transformation:
    """Callable that returns the axis transformation at x."""

    def __init__(
        self,
        # if input values are > max_, the return value will be > 1
        max_: Union[int, float],
        min_: Union[int, float],
        deadzone: float,
        gain: float = 1,
        expo: float = 0,
    ) -> None:
        self._max = max_
        self._min = min_
        self._deadzone = deadzone
        self._gain = gain
        self._expo = expo
        self._cache: Dict[float, float] = {}

    def __call__(self, /, x: Union[int, float]) -> float:
        if x not in self._cache:
            y = (
                self._calc_qubic(self._flatten_deadzone(self._normalize(x)))
                * self._gain
            )
            self._cache[x] = y

        return self._cache[x]

    def set_range(self, min_, max_):
        # TODO docstring
        if min_ != self._min or max_ != self._max:
            self._cache = {}

        self._min = min_
        self._max = max_

    def _normalize(self, x: Union[int, float]) -> float:
        """Move and scale x to be between -1 and 1
        return: x
        """
        if self._min == -1 and self._max == 1:
            return x

        half_range = (self._max - self._min) / 2
        middle = half_range + self._min
        return (x - middle) / half_range

    def _flatten_deadzone(self, x: float) -> float:
        """
         y ^                     y ^
           |                       |
         1 |         /           1 |         /
           |       /               |        /
           |     /         ==>     |    ---
           |   /                   |  /
        -1 | /                  -1 | /
           |------------>          |------------>
            -1       1  x           -1       1  x
        """
        if abs(x) <= self._deadzone:
            return 0

        return (x - self._deadzone * x / abs(x)) / (1 - self._deadzone)

    def _calc_qubic(self, x: float) -> float:
        """Transforms an x value by applying a qubic function

        k = 0 : will yield no transformation f(x) = x
        1 > k > 0 : will yield low sensitivity for low x values
            and high sensitivity for high x values
        -1 < k < 0 : will yield high sensitivity for low x values
            and low sensitivity for high x values

        see also: https://www.geogebra.org/calculator/mkdqueky

        Mathematical definition:
        f(x,d) = d * x + (1 - d) * x ** 3 | d = 1 - k | k ∈ [0,1]
        the function is designed such that if follows these constraints:
        f'(0, d) = d and f(1, d) = 1 and f(-x,d) = -f(x,d)

        for k ∈ [-1,0) the above function is mirrored at y = x
        and d = 1 + k
        """
        k = self._expo

        if k == 0 or x == 0:
            return x

        if 0 < k <= 1:
            d = 1 - k
            return d * x + (1 - d) * x**3

        if -1 <= k < 0:
            # calculate return value with the real inverse solution
            # of y = b * x + a * x ** 3
            # LaTeX  for better readability:
            #
            #  y=\frac{{{\left( \sqrt{27 {{x}^{2}}+\frac{4 {{b}^{3}}}{a}}
            #         +{{3}^{\frac{3}{2}}} x\right) }^{\frac{1}{3}}}}
            #     {{{2}^{\frac{1}{3}}} \sqrt{3} {{a}^{\frac{1}{3}}}}
            #   -\frac{{{2}^{\frac{1}{3}}} b}
            #     {\sqrt{3} {{a}^{\frac{2}{3}}}
            #         {{\left( \sqrt{27 {{x}^{2}}+\frac{4 {{b}^{3}}}{a}}
            #         +{{3}^{\frac{3}{2}}} x\right) }^{\frac{1}{3}}}}
            sign = x / abs(x)
            x = math.fabs(x)
            d = 1 + k
            a = 1 - d
            b = d
            c = (math.sqrt(27 * x**2 + (4 * b**3) / a) + 3 ** (3 / 2) * x) ** (1 / 3)
            y = c / (2 ** (1 / 3) * math.sqrt(3) * a ** (1 / 3)) - (
                2 ** (1 / 3) * b
            ) / (math.sqrt(3) * a ** (2 / 3) * c)
            return y * sign

        raise ValueError("k must be between -1 and 1")