From 1681c649fb23fb656db4733c841ccf921906c378 Mon Sep 17 00:00:00 2001
From: Robert Machmer <robert.machmer@gmail.com>
Date: Sat, 9 Jan 2016 12:06:26 +0100
Subject: [PATCH] Add setter for customizing a node's mass

---
 fd/Node.lua | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fd/Node.lua b/fd/Node.lua
index bd66e20..7d2a409 100644
--- a/fd/Node.lua
+++ b/fd/Node.lua
@@ -23,6 +23,7 @@ function Node.new( id, x, y, anchor, ... )
     local px, py = x or 0, y or 0;
     local ax, ay = 0, 0;
     local vx, vy = 0, 0;
+    local mass = DEFAULT_MASS;
 
     ---
     -- Clamps a value to a certain range.
@@ -69,7 +70,7 @@ function Node.new( id, x, y, anchor, ... )
         dx = dx / distance;
         dy = dy / distance;
 
-        local strength = FORCE_CHARGE * (DEFAULT_MASS / (distance * distance));
+        local strength = FORCE_CHARGE * ( mass / ( distance * distance ));
         applyForce(dx * strength, dy * strength);
     end
 
@@ -114,6 +115,10 @@ function Node.new( id, x, y, anchor, ... )
         return anchor;
     end
 
+    function self:setMass( nmass )
+        mass = nmass;
+    end
+
     return self;
 end