diff --git a/ss/PlainSpin.cc b/ss/PlainSpin.cc
index 759f91d..6a7d7e8 100644
--- a/ss/PlainSpin.cc
+++ b/ss/PlainSpin.cc
@@ -30,7 +30,7 @@ PlainSpin::PlainSpin(SSMain * _SSMain) : SSMode(_SSMain)
 void PlainSpin::update()
 {
     SSMode::update();
-	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
     int numMonitors = m_SSMain->getNumMonitors();
     int width = m_SSMain->getWidth();
     int height = m_SSMain->getHeight();
diff --git a/ss/Towers.cc b/ss/Towers.cc
index 6269ae2..36d1693 100644
--- a/ss/Towers.cc
+++ b/ss/Towers.cc
@@ -174,7 +174,7 @@ void Towers::update()
     for (unsigned int i = 0; i < delta / 2; i++)
         worldStep();
 
-	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
     int numMonitors = m_SSMain->getNumMonitors();
     int width = m_SSMain->getWidth();
     int height = m_SSMain->getHeight();
@@ -269,36 +269,36 @@ void Towers_collide_callback(void * data, dGeomID o1, dGeomID o2)
 {
     const int maxNumContacts = 2;
     Towers * t = (Towers *) data;
-	static dContact contact[maxNumContacts];
-	dBodyID b1 = dGeomGetBody(o1);
-	dBodyID b2 = dGeomGetBody(o2);
-	if (b1 && b2 && dAreConnected(b1, b2))
-		return;
-	int num = dCollide(o1, o2, maxNumContacts,
-	        &contact[0].geom, sizeof(dContact));
-	int i;
-	for (i = 0; i < num; i++)
-	{
-		contact[i].surface.mode =
-			dContactSlip1 | dContactSlip2 | dContactBounce |
-			dContactSoftERP | dContactSoftCFM | dContactApprox1;
-		contact[i].surface.mu = 0.5;
-		contact[i].surface.slip1 = 0.0;
-		contact[i].surface.slip2 = 0.0;
-		contact[i].surface.soft_erp = 0.8;
-		contact[i].surface.soft_cfm = 0.01;
-		contact[i].surface.bounce = 0.0;
-		dJointID joint = dJointCreateContact(t->m_world,
-		        t->m_contactJointGroup, contact + i);
-		dJointAttach(joint, b1, b2);
-	}
+    static dContact contact[maxNumContacts];
+    dBodyID b1 = dGeomGetBody(o1);
+    dBodyID b2 = dGeomGetBody(o2);
+    if (b1 && b2 && dAreConnected(b1, b2))
+        return;
+    int num = dCollide(o1, o2, maxNumContacts,
+            &contact[0].geom, sizeof(dContact));
+    int i;
+    for (i = 0; i < num; i++)
+    {
+        contact[i].surface.mode =
+            dContactSlip1 | dContactSlip2 | dContactBounce |
+            dContactSoftERP | dContactSoftCFM | dContactApprox1;
+        contact[i].surface.mu = 0.5;
+        contact[i].surface.slip1 = 0.0;
+        contact[i].surface.slip2 = 0.0;
+        contact[i].surface.soft_erp = 0.8;
+        contact[i].surface.soft_cfm = 0.01;
+        contact[i].surface.bounce = 0.0;
+        dJointID joint = dJointCreateContact(t->m_world,
+                t->m_contactJointGroup, contact + i);
+        dJointAttach(joint, b1, b2);
+    }
 }
 
 /* invokes ODE to do physics on our world */
 void Towers::worldStep()
 {
-	dSpaceCollide(m_space, this, Towers_collide_callback);
-	dWorldQuickStep(m_world, WORLD_STEP);
-	dJointGroupEmpty(m_contactJointGroup);
+    dSpaceCollide(m_space, this, Towers_collide_callback);
+    dWorldQuickStep(m_world, WORLD_STEP);
+    dJointGroupEmpty(m_contactJointGroup);
 }