Initial release 1.0.0HEADv1.0.0master

1 files changed, 85 insertions, 0 deletions

diff --git a/brightness/__init__.py b/brightness/__init__.py
new file mode 100644
index 0000000..c5b497f
--- /dev/null
+++ b/brightness/__init__.py
@@ -0,0 +1,85 @@
+# Copyright (C) 2023  Tomasz Kramkowski <tomasz@kramkow.ski>
+# SPDX-License-Identifier: MIT
+
+import argparse
+import math
+import sys
+from pathlib import Path
+from typing import Type, TypeVar
+
+T = TypeVar("T", bound="LogFloat")
+
+
+class LogFloat(float):
+    @classmethod
+    def from_val(cls: Type[T], val: int) -> T:
+        return cls(math.log(val + 1))
+
+    @classmethod
+    def from_pct(cls: Type[T], pct: float, log_max: "LogFloat") -> T:
+        return cls(pct / 100.0 * log_max)
+
+    def to_val(self) -> int:
+        return round(math.e**self) - 1
+
+    def __add__(self, other: "LogFloat") -> "LogFloat":
+        return LogFloat(super().__add__(other))
+
+
+def _parse_limit(limit: str, log_max_brightness: LogFloat) -> int:
+    if limit[-1] == "%":
+        return LogFloat.from_pct(float(limit[:-1]), log_max_brightness).to_val()
+    return int(limit)
+
+
+def main(argv: list[str] = sys.argv) -> int:
+    ap = argparse.ArgumentParser(description="Adjust sysfs backlight with a log scale")
+    ap.add_argument(
+        "-m",
+        "--min",
+        help="An artificial minimum brightness (percentage or raw value) limit",
+        default="0",
+    )
+    ap.add_argument(
+        "-M",
+        "--max",
+        help="An artificial maximum brightness (percentage or raw value) limit",
+    )
+    ap.add_argument(
+        "backlight",
+        help="Path to sysfs backlight (e.g. /sys/class/backlight/amdgpu_bl0)",
+    )
+    ap.add_argument(
+        "adjustment",
+        help="Percentage adjustment (e.g. +10 or -6.25) or absolute value (e.g. 50)",
+    )
+    args = ap.parse_args(argv[1:])
+
+    backlight = Path(args.backlight)
+
+    with open(backlight / "brightness") as f:
+        brightness = int(f.read().rstrip())
+    log_brightness = LogFloat.from_val(brightness)
+
+    with open(backlight / "max_brightness") as f:
+        max_brightness = int(f.read().rstrip())
+    log_max_brightness = LogFloat.from_val(max_brightness)
+
+    if args.adjustment[0] in {"-", "+"}:
+        diff = LogFloat.from_pct(float(args.adjustment), log_max_brightness)
+        new_brightness = (log_brightness + diff).to_val()
+        if diff != 0 and new_brightness == brightness:
+            new_brightness += int(math.copysign(1, diff))
+    else:
+        new_brightness = LogFloat.from_pct(
+            float(args.adjustment), log_max_brightness
+        ).to_val()
+
+    max_limit = max_brightness
+    if args.max is not None:
+        max_limit = _parse_limit(args.max, log_max_brightness)
+    min_limit = _parse_limit(args.min, log_max_brightness)
+    new_brightness = max(min_limit, min(new_brightness, max_limit))
+    with open(backlight / "brightness", "w") as f:
+        f.write(str(new_brightness))
+    return 0