generate contact when body type changes at runtime, decoupling, add first ray cast hit query to world query (more to add later such as sphere/box/convex casts), hotfix

src/bounce/dynamics/body.cpp

@@ -335,6 +335,41 @@ bool b3Body::ShouldCollide(const b3Body* other) const
 	return true;
 }
 
+void b3Body::SetType(b3BodyType type)
+{
+	if (m_type == type)
+	{
+		return;
+	}
+
+	m_type = type;
+
+	ResetMass();
+
+	m_force.SetZero();
+	m_torque.SetZero();
+
+	if (m_type == e_staticBody)
+	{
+		m_linearVelocity.SetZero();
+		m_angularVelocity.SetZero();
+		m_sweep.worldCenter0 = m_sweep.worldCenter;
+		m_sweep.orientation0 = m_sweep.orientation;
+		SynchronizeShapes();
+	}
+
+	SetAwake(true);
+
+	DestroyContacts();
+
+	// Move the shape proxies so new contacts can be created.
+	b3BroadPhase* phase = &m_world->m_contactMan.m_broadPhase;
+	for (b3Shape* s = m_shapeList.m_head; s; s = s->m_next)
+	{
+		phase->BufferMove(s->m_broadPhaseID);
+	}
+}
+
 void b3Body::Dump() const
 {
 	i32 bodyIndex = m_islandID;

src/bounce/dynamics/contacts/collide/collide_capsules.cpp

@@ -79,7 +79,7 @@ void b3CollideCapsuleAndCapsule(b3Manifold& manifold,
 			float32 d1 = b3Distance(clipEdgeA[0].position, cp1);
 			float32 d2 = b3Distance(clipEdgeA[1].position, cp2);
 
-			if (d1 <= totalRadius && d2 <= totalRadius)
+			if (d1 > B3_EPSILON && d1 <= totalRadius && d2 > B3_EPSILON && d2 <= totalRadius)
 			{
 				b3Vec3 n1 = (cp1 - clipEdgeA[0].position) / d1;
 				b3Vec3 n2 = (cp2 - clipEdgeA[1].position) / d2;
@@ -123,7 +123,7 @@ void b3CollideCapsuleAndCapsule(b3Manifold& manifold,
 
 	float32 distance = b3Distance(pointA, pointB);
 
-	if (distance > 0.0f)
+	if (distance > B3_EPSILON)
 	{
 		b3Vec3 normal = (pointB - pointA) / distance;
 		b3Vec3 center = 0.5f * (pointA + hullA.radius * normal + pointB - hullB.radius * normal);

src/bounce/dynamics/shapes/capsule_shape.cpp

@@ -17,6 +17,7 @@
 */
 
 #include <bounce/dynamics/shapes/capsule_shape.h>
+#include <bounce/dynamics/time_step.h>
 
 b3CapsuleShape::b3CapsuleShape() 
 {

src/bounce/dynamics/shapes/sphere_shape.cpp

@@ -17,6 +17,7 @@
 */
 
 #include <bounce/dynamics/shapes/sphere_shape.h>
+#include <bounce/dynamics/time_step.h>
 
 b3SphereShape::b3SphereShape() 
 {

src/bounce/dynamics/world.cpp

@@ -377,6 +377,68 @@ void b3World::RayCast(b3RayCastListener* listener, const b3Vec3& p1, const b3Vec
 	m_contactMan.m_broadPhase.RayCast(&callback, input);
 }
 
+struct b3RayCastFirstCallback
+{
+	float32 Report(const b3RayCastInput& input, i32 proxyId)
+	{
+		// Get shape associated with the proxy.
+		void* userData = broadPhase->GetUserData(proxyId);
+		b3Shape* shape = (b3Shape*)userData;
+
+		// Get map from shape local space to world space.
+		b3Transform xf = shape->GetBody()->GetTransform();
+
+		b3RayCastOutput output;
+		bool hit = shape->RayCast(&output, input, xf);
+		if (hit)
+		{
+			// Track minimum time of impact to require less memory.
+			if (output.fraction < output0.fraction)
+			{
+				shape0 = shape;
+				output0 = output;
+			}
+		}
+
+		// Continue the search from where we stopped.
+		return input.maxFraction;
+	}
+
+	b3Shape* shape0;
+	b3RayCastOutput output0; 
+	const b3BroadPhase* broadPhase;
+};
+
+void b3World::RayCastFirst(b3RayCastListener* listener, const b3Vec3& p1, const b3Vec3& p2) const
+{
+	b3RayCastInput input;
+	input.p1 = p1;
+	input.p2 = p2;
+	input.maxFraction = 1.0f;
+
+	b3RayCastFirstCallback callback;
+	callback.shape0 = NULL;
+	callback.output0.fraction = B3_MAX_FLOAT;
+	callback.broadPhase = &m_contactMan.m_broadPhase;
+	
+	// Perform the ray cast.
+	m_contactMan.m_broadPhase.RayCast(&callback, input);
+
+	if (callback.shape0)
+	{
+		// Ray hits closest shape.
+		float32 fraction = callback.output0.fraction;
+		float32 w1 = 1.0f - fraction;
+		float32 w2 = fraction;
+
+		b3Vec3 point = w1 * input.p1 + w2 * input.p2;
+		b3Vec3 normal = callback.output0.normal;
+
+		// Report the intersection to the user.
+		listener->ReportShape(callback.shape0, point, normal, fraction);
+	}
+}
+
 struct b3QueryAABBCallback
 {
 	bool Report(i32 proxyID)