Introduce runtime normalization of gyroscope

Config setting is added just in case - default value is good enough for almost every usecase, regardless of exact calibration's presence.

ExampleConfig.ini

@@ -1,7 +1,10 @@
+# GyroNormalizationFactor controls how quickly gyro drift is accounted for
+# Default value of 50 should be good in 99%+ of cases, but rarely one may want to tweak it
 [Linuxmotehook]
 Port=26760
 Orientation=sideways-left
 SendButtons=false
+GyroNormalizationFactor=50
 
 # NunchuckStickCalibration is neutral x, y and minimal max offset from neutral x,y
 # Supported orientation values: normal, sideways-left, sideways-right (likely not useful here), inverted

src/Config.vala

@@ -78,9 +78,20 @@ namespace Linuxmotehook {
 			}
 		}
 
+		private int gyro_normalization_factor_ = 50;
+		public int gyro_normalization_factor {
+			get { return gyro_normalization_factor_; }
+			set {
+				gyro_normalization_factor_ = value;
+				kfile.set_integer(MAIN_GROUP, "GyroNormalizationFactor", value);
+			}
+		}
+
 		construct {
 			kfile = new KeyFile();
 			kfile.set_list_separator(',');
+			// Note: this likely creates a circular reference because of lambdas
+			// Nobody really cares because we're single instance, but still
 			wiimote_configs = new Gee.HashMap<uint64?, WiimoteConfig>(
 				(key) => { return (uint)((key >> 32) ^ key); },
 				(key1, key2) => { return key1 == key2; }
@@ -103,6 +114,9 @@ namespace Linuxmotehook {
 						case "SendButtons":
 							send_buttons_ = kfile.get_boolean(MAIN_GROUP, key);
 							break;
+						case "GyroNormalizationFactor":
+							gyro_normalization_factor_ = kfile.get_integer(MAIN_GROUP, key);
+							break;
 						default:
 							warning("Unknown configuration key %s", key);
 							break;

src/MainDevice.vala

@@ -54,7 +54,8 @@ namespace Linuxmotehook {
 			dev_source.set_callback(cb);
 			dev_source.attach();
 
-			dev.set_mp_normalization(conf.gyro_calibration[0], conf.gyro_calibration[1], conf.gyro_calibration[2], 0);
+			var app_conf = new Config();
+			dev.set_mp_normalization(conf.gyro_calibration[0], conf.gyro_calibration[1], conf.gyro_calibration[2], app_conf.gyro_normalization_factor);
 			update_interfaces(true);
 		}