Fix Android node selection distance (#6187)

src/touchscreengui.h

@@ -156,6 +156,14 @@ class TouchScreenGUI
 
 	double getPitch() { return m_camera_pitch; }
 
+	/*!
+	 * Returns a line which describes what the player is pointing at.
+	 * The starting point and looking direction are significant,
+	 * the line should be scaled to match its length to the actual distance
+	 * the player can reach.
+	 * The line starts at the camera and ends on the camera's far plane.
+	 * The coordinates do not contain the camera offset.
+	 */
 	line3d<f32> getShootline() { return m_shootline; }
 
 	void step(float dtime);
@@ -180,6 +188,12 @@ class TouchScreenGUI
 	double m_camera_yaw_change;
 	double m_camera_pitch;
 
+	/*!
+	 * A line starting at the camera and pointing towards the
+	 * selected object.
+	 * The line ends on the camera's far plane.
+	 * The coordinates do not contain the camera offset.
+	 */
 	line3d<f32> m_shootline;
 
 	rect<s32> m_control_pad_rect;