From 5342361a5dab35d32aee3fe5cb032bb463f9bc29 Mon Sep 17 00:00:00 2001
From: Irlan <->
Date: Sun, 8 Apr 2018 00:13:29 -0300
Subject: [PATCH] use gravity

---
 include/bounce/dynamics/cloth/spring_cloth.h | 8 ++++----
 src/bounce/dynamics/cloth/spring_cloth.cpp   | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/bounce/dynamics/cloth/spring_cloth.h b/include/bounce/dynamics/cloth/spring_cloth.h
index cb82170..02e36e3 100644
--- a/include/bounce/dynamics/cloth/spring_cloth.h
+++ b/include/bounce/dynamics/cloth/spring_cloth.h
@@ -65,7 +65,7 @@ struct b3SpringClothDef
 	// Mass radius
 	float32 r;
 	
-	// Force due to gravity
+	// Acceleration due to gravity (m/s^2)
 	b3Vec3 gravity;
 };
 
@@ -136,11 +136,11 @@ public:
 	// Return the cloth mesh used to initialize this cloth.
 	b3Mesh* GetMesh() const;
 
-	// Set the gravitational force applied to this cloth.
-	// This force is applied at each time step.
+	// Set the gravitational acceleration applied to this cloth.
+	// Units are m/s^2.
 	void SetGravity(const b3Vec3& gravity);
 
-	// Return the gravitational force applied to this cloth.
+	// Return the gravitational acceleration applied to this cloth.
 	const b3Vec3& GetGravity() const;
 
 	// Set the type of a given point mass.
diff --git a/src/bounce/dynamics/cloth/spring_cloth.cpp b/src/bounce/dynamics/cloth/spring_cloth.cpp
index 060f796..90edbf8 100644
--- a/src/bounce/dynamics/cloth/spring_cloth.cpp
+++ b/src/bounce/dynamics/cloth/spring_cloth.cpp
@@ -485,12 +485,12 @@ void b3SpringCloth::Step(float32 dt)
 	// Update contacts
 	UpdateContacts();
 
-	// Apply gravity
+	// Apply gravity forces
 	for (u32 i = 0; i < m_massCount; ++i)
 	{
 		if (m_types[i] == b3MassType::e_dynamicMass)
 		{
-			m_f[i] += m_gravity;
+			m_f[i] += m_m[i] * m_gravity;
 		}
 	}