TOOLS/lua: Add zones.lua

Lua script that enables handling of certain commands depending on where
the mouse pointer is. Mostly useful for mouse-wheel handling via
input.conf.

Example:

MOUSE_BTN3 script-message-to zones commands "*-left: add volume +5"
"default: seek +10"
MOUSE_BTN4 script-message-to zones commands "*-left: add volume -5"
"default: seek -10"

Will changes behavior of Mouse Wheel Up/Down to alter volume if mouse is
in the left zone of the window, but re-adds the default to seek if wheel
is used on other parts.

TOOLS/lua/zones.lua

@@ -0,0 +1,74 @@
+--  zones.lua: mpv script for handling commands depending on where the mouse pointer is at,
+--             mostly for mouse wheel handling, by configuring it via input.conf, e.g.:
+--
+--  Ported from avih's ( https://github.com/avih ) zones.js
+--
+--  Vertical positions can be top, middle, bottom or "*" to represent the whole column.
+--  Horizontal positions can be left, middle, bottom or "*" to represent the whole row.
+--  "default" will be the fallback command to be used if no command is assigned to that area.
+--
+--  input.conf example of use:
+-- # wheel up/down with mouse
+-- MOUSE_BTN3 script_message_to zones commands "middle-right: add brightness  1" "*-left: add volume  5" "default: seek  10"
+-- MOUSE_BTN4 script_message_to zones commands "middle-right: add brightness -1" "*-left: add volume -5"  "default: seek -10"
+
+local ZONE_THRESH_PERCENTAGE = 20;
+-- sides get 20% each, mid gets 60%, same vertically
+
+local msg = mp.msg
+
+function getMouseZone()
+    -- returns the mouse zone as two strings [top/middle/bottom], [left/middle/right], e.g. "middle", "right"
+
+    local screenW, screenH = mp.get_osd_resolution()
+    local mouseX, mouseY   = mp.get_mouse_pos()
+
+    local threshY = screenH * ZONE_THRESH_PERCENTAGE / 100
+    local threshX = screenW * ZONE_THRESH_PERCENTAGE / 100
+
+    local yZone = (mouseY < threshY) and "top"  or (mouseY < (screenH - threshY)) and "middle" or "bottom"
+    local xZone = (mouseX < threshX) and "left" or (mouseX < (screenW - threshX)) and "middle" or "right"
+
+    return yZone, xZone
+end
+
+function main (...)
+    local arg={...}
+    msg.debug('commands: \n\t'..table.concat(arg,'\n\t'))
+
+    local keyY, keyX = getMouseZone()
+    msg.debug("mouse at: " .. keyY .. '-' .. keyX)
+
+    local fallback = nil
+
+    for i, v in ipairs(arg) do
+        cmdY = v:match("^([%w%*]+)%-?[%w%*]*:")
+        cmdX = v:match("^[%w%*]*%-([%w%*]+)%s*:")
+        cmd  = v:match("^[%S]-%s*:%s*(.+)")
+        msg.debug('cmdY: '..tostring(cmdY))
+        msg.debug('cmdX: '..tostring(cmdX))
+        msg.debug('cmd : '..tostring(cmd))
+
+        if (cmdY == keyY and cmdX == keyX) then
+            msg.verbose("running cmd: "..cmd)
+            mp.command(cmd)
+            return
+        elseif  (cmdY == "*"  and cmdX == keyX) or
+                (cmdY == keyY and cmdX == "*") then
+            msg.verbose("running cmd: "..cmd)
+            mp.command(cmd)
+            return
+        elseif cmdY == "default" then
+            fallback = cmd
+        end
+    end
+    if fallback ~= nil then
+        msg.verbose("running cmd: "..fallback)
+        mp.command(fallback)
+        return
+    else
+        msg.debug("no command assigned for "..keyY .. '-' .. keyX)
+        return
+    end
+end
+mp.register_script_message("commands", main)