From 8f33a65c744d2d2a1d375df927fb3d7a1e0351c8 Mon Sep 17 00:00:00 2001
From: Giovanni Harting <539@idlegandalf.com>
Date: Fri, 5 Dec 2025 00:57:30 +0100
Subject: [PATCH] feat: add touch swipe system brightness and volume controls

---
 scripts/touch-gestures.lua | 363 +++++++++++++++++++++++++++++++++++++
 1 file changed, 363 insertions(+)
 create mode 100644 scripts/touch-gestures.lua

diff --git a/scripts/touch-gestures.lua b/scripts/touch-gestures.lua
new file mode 100644
index 0000000..54e7576
--- /dev/null
+++ b/scripts/touch-gestures.lua
@@ -0,0 +1,363 @@
+--[[
+  touch-gestures.lua - tablet-friendly swipe controls for mpv.
+
+  Features:
+    * Vertical swipes on the right edge raise/lower system volume; swipes on the left edge adjust screen brightness via brightnessctl.
+    * Prefers PipeWire (`wpctl`) for volume, falls back to PulseAudio (`pactl`) automatically.
+    * Configurable gesture zones, pixels-per-step sensitivity, per-control step sizes, and optional inverted direction.
+    * Shows OSD feedback after each adjustment so you know the new volume/brightness values.
+
+  Configuration:
+    Edit the `config` table below to tune zone widths, step sizes, and OSD duration; script-opts files are ignored.
+]]
+
+local config = {
+  pixels_per_step = 80, -- fallback pixels per step when height unknown
+  steps_per_screen = 40, -- target steps across full height; 50% height ≈ 100% change with 5% steps
+  deadzone_px = 4, -- ignore tiny jiggles before the first step (lower = snappier)
+  volume_step = 5, -- percent per step
+  brightness_step = 5, -- screen brightness percent per step
+  max_volume = 130, -- clamp volume to this ceiling
+  invert_vertical = false, -- true flips the swipe direction
+  left_zone_ratio = 0.35, -- fraction of width reserved for brightness (left side)
+  right_zone_ratio = 0.35, -- fraction of width reserved for volume (right side)
+  osd_duration = 1.2, -- seconds OSD stays visible; set 0 to disable
+  log_debug = false, -- set true to log gesture details
+  start_on_move = true, -- begin a gesture on move in edge zones (helps touch devices without BTN events)
+  brightnessctl_path = "brightnessctl",
+  brightness_device = "", -- optional; empty lets brightnessctl pick
+  wpctl_path = "wpctl",
+  pactl_path = "pactl",
+}
+
+-- No edits are required below unless you want to change script behavior.
+
+local mp = require("mp")
+local msg = require("mp.msg")
+local utils = require("mp.utils")
+
+local show_osd
+
+local state = {
+  active = false,
+  zone = nil,
+  accum = 0,
+  last_x = 0,
+  last_y = 0,
+  volume_backend = nil, -- "wpctl" or "pactl"
+  cached_volume_pct = nil,
+  cached_brightness_pct = nil,
+}
+
+local function dbg(text)
+  if config.log_debug then
+    msg.info("touch-gestures: " .. text)
+  end
+end
+
+local function clamp(value, min_v, max_v)
+  if value < min_v then
+    return min_v
+  end
+  if value > max_v then
+    return max_v
+  end
+  return value
+end
+
+local function run_cmd(args)
+  local res = utils.subprocess({ args = args, cancellable = false })
+  if not res or res.error or res.status ~= 0 then
+    local err = res and (res.stderr or res.error) or "unknown"
+    msg.warn(("touch-gestures cmd failed (%s): %s"):format(table.concat(args, " "), err))
+    return nil
+  end
+  return res.stdout or ""
+end
+
+local function pick_volume_backend()
+  if state.volume_backend then
+    return state.volume_backend
+  end
+  local wp = run_cmd({ config.wpctl_path, "--version" })
+  if wp then
+    state.volume_backend = "wpctl"
+    dbg("using wpctl for volume")
+    return state.volume_backend
+  end
+  local pa = run_cmd({ config.pactl_path, "--version" })
+  if pa then
+    state.volume_backend = "pactl"
+    dbg("using pactl for volume")
+    return state.volume_backend
+  end
+  msg.error("No volume backend found (wpctl/pactl). Install PipeWire or PulseAudio tools.")
+  return nil
+end
+
+local function brightness_args(extra)
+  local args = { config.brightnessctl_path }
+  if config.brightness_device ~= nil and config.brightness_device ~= "" then
+    table.insert(args, "-d")
+    table.insert(args, config.brightness_device)
+  end
+  for _, v in ipairs(extra) do
+    table.insert(args, v)
+  end
+  return args
+end
+
+local function current_brightness_percent()
+  if state.cached_brightness_pct ~= nil then
+    return state.cached_brightness_pct
+  end
+  local cur = run_cmd(brightness_args({ "get" }))
+  local max = run_cmd(brightness_args({ "max" }))
+  if not cur or not max then
+    return nil
+  end
+  local c = tonumber(cur)
+  local m = tonumber(max)
+  if not c or not m or m <= 0 then
+    return nil
+  end
+  state.cached_brightness_pct = clamp((c / m) * 100, 0, 100)
+  return state.cached_brightness_pct
+end
+
+local function set_brightness_percent(pct)
+  local target = clamp(pct, 0, 100)
+  local ok = run_cmd(brightness_args({ "set", string.format("%.2f%%", target) }))
+  if ok then
+    state.cached_brightness_pct = target
+    show_osd("Brightness", string.format("%d%%", math.floor(target + 0.5)))
+  end
+end
+
+local function current_volume_percent()
+  if state.cached_volume_pct ~= nil then
+    return state.cached_volume_pct
+  end
+  local backend = pick_volume_backend()
+  if backend == "wpctl" then
+    local out = run_cmd({ config.wpctl_path, "get-volume", "@DEFAULT_AUDIO_SINK@" })
+    if not out then
+      return nil
+    end
+    local val = out:match("(%d?%.?%d+)")
+    val = val and tonumber(val)
+    if not val then
+      return nil
+    end
+    state.cached_volume_pct = clamp(val * 100, 0, config.max_volume)
+    return state.cached_volume_pct
+  elseif backend == "pactl" then
+    local out = run_cmd({ config.pactl_path, "get-sink-volume", "@DEFAULT_SINK@" })
+    if not out then
+      return nil
+    end
+    local pct = out:match("(%d+)%%%s")
+    pct = pct and tonumber(pct)
+    if not pct then
+      return nil
+    end
+    state.cached_volume_pct = clamp(pct, 0, config.max_volume)
+    return state.cached_volume_pct
+  end
+  return nil
+end
+
+local function set_volume_percent(pct)
+  local backend = pick_volume_backend()
+  if not backend then
+    return
+  end
+  local target = clamp(pct, 0, config.max_volume)
+  if backend == "wpctl" then
+    run_cmd({
+      config.wpctl_path,
+      "set-volume",
+      "@DEFAULT_AUDIO_SINK@",
+      string.format("%.4f", target / 100),
+    })
+  elseif backend == "pactl" then
+    run_cmd({
+      config.pactl_path,
+      "set-sink-volume",
+      "@DEFAULT_SINK@",
+      string.format("%d%%", math.floor(target + 0.5)),
+    })
+  end
+  state.cached_volume_pct = target
+  show_osd("Volume", string.format("%d%%", math.floor(target + 0.5)))
+end
+
+local function surface_size()
+  local w = mp.get_property_number("osd-width", 0)
+  local h = mp.get_property_number("osd-height", 0)
+  if w <= 0 then
+    w = mp.get_property_number("display-width", 0)
+  end
+  if h <= 0 then
+    h = mp.get_property_number("display-height", 0)
+  end
+  return w, h
+end
+
+local function pick_zone(x, width)
+  if width <= 0 then
+    return nil
+  end
+  local left_limit = width * config.left_zone_ratio
+  local right_start = width * (1 - config.right_zone_ratio)
+  if x <= left_limit then
+    return "brightness"
+  end
+  if x >= right_start then
+    return "volume"
+  end
+  return nil
+end
+
+function show_osd(label, value)
+  if config.osd_duration > 0 then
+    mp.osd_message(string.format("%s: %s", label, value), config.osd_duration)
+  end
+end
+
+local function apply_steps(kind, steps)
+  if steps == 0 then
+    return
+  end
+  if kind == "volume" then
+    local current = current_volume_percent()
+    if not current then
+      return
+    end
+    local next_value = current + (steps * config.volume_step)
+    set_volume_percent(next_value)
+  elseif kind == "brightness" then
+    local current = current_brightness_percent()
+    if not current then
+      return
+    end
+    local next_value = current + (steps * config.brightness_step)
+    set_brightness_percent(next_value)
+  end
+end
+
+local function reset_state()
+  if state.active and config.log_debug then
+    dbg(string.format("end gesture zone=%s accum=%.2f", tostring(state.zone), state.accum))
+  end
+  state.active = false
+  state.zone = nil
+  state.accum = 0
+  state.last_x = 0
+  state.last_y = 0
+end
+
+local function start_gesture(pos, zone)
+  state.active = true
+  state.zone = zone
+  state.accum = 0
+  state.last_x = pos.x
+  state.last_y = pos.y
+  dbg(string.format("start gesture zone=%s at (%.0f,%.0f)", zone, pos.x, pos.y))
+end
+
+local function update_gesture(_, pos)
+  if not pos or not pos.x or not pos.y then
+    return
+  end
+
+  if not state.active and config.start_on_move then
+    local width = surface_size()
+    local zone = pick_zone(pos.x, width)
+    if zone then
+      start_gesture(pos, zone)
+    else
+      return
+    end
+  end
+
+  if not state.active then
+    return
+  end
+
+  local dy = pos.y - state.last_y
+  if config.invert_vertical then
+    dy = -dy
+  end
+
+  state.last_x = pos.x
+  state.last_y = pos.y
+
+  if math.abs(state.accum) < config.deadzone_px then
+    state.accum = state.accum + dy
+    if math.abs(state.accum) < config.deadzone_px then
+      return
+    end
+    -- once deadzone crossed, drop the deadzone offset so first step is clean
+    if state.accum > 0 then
+      state.accum = state.accum - config.deadzone_px
+    else
+      state.accum = state.accum + config.deadzone_px
+    end
+  else
+    state.accum = state.accum + dy
+  end
+
+  local step_pixels = config.pixels_per_step
+  if config.steps_per_screen and config.steps_per_screen > 0 then
+    local _, surf_h = surface_size()
+    if surf_h and surf_h > 0 then
+      step_pixels = surf_h / config.steps_per_screen
+    end
+  end
+  if step_pixels <= 0 then
+    step_pixels = 1
+  end
+
+  local steps = state.accum / step_pixels
+  local whole_steps = steps > 0 and math.floor(steps) or math.ceil(steps)
+
+  if whole_steps ~= 0 then
+    dbg(
+      string.format("zone=%s dy=%.2f accum=%.2f steps=%d", state.zone, dy, state.accum, whole_steps)
+    )
+    apply_steps(state.zone, -whole_steps)
+    state.accum = state.accum - (whole_steps * step_pixels)
+  end
+end
+
+local forwarding_click = false
+
+local function handle_touch(event)
+  if forwarding_click then
+    return
+  end
+
+  if event.event == "down" then
+    local pos = mp.get_property_native("mouse-pos")
+    if not pos or not pos.x or not pos.y then
+      return
+    end
+
+    local width = surface_size()
+    local zone = pick_zone(pos.x, width)
+    if not zone then
+      forwarding_click = true
+      mp.commandv("keypress", "mouse_btn0")
+      forwarding_click = false
+      return
+    end
+
+    start_gesture(pos, zone)
+  elseif event.event == "up" then
+    reset_state()
+  end
+end
+
+mp.add_forced_key_binding("mouse_btn0", "touch-gestures", handle_touch, { complex = true })
+mp.observe_property("mouse-pos", "native", update_gesture)