From 927b35a45d37c4e9b0277dbf107f1f0fa2e117f1 Mon Sep 17 00:00:00 2001
From: Irlan <->
Date: Tue, 24 Jul 2018 16:46:28 -0300
Subject: [PATCH] bugfix

---
 include/bounce/dynamics/body.h      |  8 ++++++
 src/bounce/dynamics/cloth/cloth.cpp | 40 +++++++++++++++--------------
 2 files changed, 29 insertions(+), 19 deletions(-)

diff --git a/include/bounce/dynamics/body.h b/include/bounce/dynamics/body.h
index 2980f6a..7fe2d5a 100644
--- a/include/bounce/dynamics/body.h
+++ b/include/bounce/dynamics/body.h
@@ -152,6 +152,9 @@ public:
 
 	// Get the local position of the center of mass.
 	b3Vec3 GetLocalCenter() const;
+	
+	// Get the velocity at a given point.
+	b3Vec3 GetPointVelocity(const b3Vec3& point) const;
 
 	// Get the linear velocity of the center of mass.
 	b3Vec3 GetLinearVelocity() const;
@@ -556,6 +559,11 @@ inline void b3Body::SetGravityScale(float32 scale)
 	}
 }
 
+inline b3Vec3 b3Body::GetPointVelocity(const b3Vec3& point) const
+{
+	return m_linearVelocity + b3Cross(m_angularVelocity, point - m_sweep.worldCenter);
+}
+
 inline b3Vec3 b3Body::GetLinearVelocity() const
 {
 	return m_linearVelocity;
diff --git a/src/bounce/dynamics/cloth/cloth.cpp b/src/bounce/dynamics/cloth/cloth.cpp
index 904ebcb..81ba63f 100644
--- a/src/bounce/dynamics/cloth/cloth.cpp
+++ b/src/bounce/dynamics/cloth/cloth.cpp
@@ -594,18 +594,6 @@ void b3Cloth::UpdateContacts()
 			}
 		}
 
-#if 0
-		// Notify the new contact state
-		if (c0.n_active == false && c->n_active == true)
-		{
-			// The contact has begun
-		}
-
-		if (c0.n_active == true && c->active_n == false)
-		{
-			// The contact has ended
-		}
-#endif
 		if (c->n_active == false)
 		{
 			continue;
@@ -618,13 +606,16 @@ void b3Cloth::UpdateContacts()
 		}
 
 		b3Shape* s = c->s2;
+		b3Body* b = s->GetBody();
 		b3Vec3 n = c->n;
 		float32 u = s->GetFriction();
 		float32 normalForce = c0.Fn;
 		float32 maxFrictionForce = u * normalForce;
 
-		// Relative velocity
-		b3Vec3 dv = p->m_velocity;
+		// Relative velocity at contact point
+		b3Vec3 v1 = b->GetPointVelocity(c->p);
+		b3Vec3 v2 = p->m_velocity;
+		b3Vec3 dv = v2 - v1;
 
 		b3Vec3 t1 = dv - b3Dot(dv, n) * n;
 		if (b3Dot(t1, t1) > B3_EPSILON * B3_EPSILON)
@@ -637,11 +628,6 @@ void b3Cloth::UpdateContacts()
 
 			c->t1 = t1;
 			c->t2 = t2;
-
-			//c->f_active = true;
-			//c->f.m_type = e_frictionForce;
-			//c->f.m_p = p;
-			//c->f.m_kd = 10.0f;
 		}
 
 		b3Vec3 ts[2];
@@ -676,6 +662,22 @@ void b3Cloth::UpdateContacts()
 
 		c->t1_active = t_active[0];
 		c->t2_active = t_active[1];
+
+		if (c0.t1_active == true)
+		{
+			if (c0.Ft1 > maxFrictionForce)
+			{
+				c->t1_active = false;
+			}
+		}
+
+		if (c0.t2_active == true)
+		{
+			if (c0.Ft2 > maxFrictionForce)
+			{
+				c->t2_active = false;
+			}
+		}
 	}
 }