first commit

[blok] / Box2D / Source / Dynamics / Contacts / b2CircleContact.cpp

diff --git a/Box2D/Source/Dynamics/Contacts/b2CircleContact.cpp b/Box2D/Source/Dynamics/Contacts/b2CircleContact.cpp
new file mode 100644 (file)
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+++ b/Box2D/Source/Dynamics/Contacts/b2CircleContact.cpp
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+/*
+* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com
+*
+* This software is provided 'as-is', without any express or implied
+* warranty.  In no event will the authors be held liable for any damages
+* arising from the use of this software.
+* Permission is granted to anyone to use this software for any purpose,
+* including commercial applications, and to alter it and redistribute it
+* freely, subject to the following restrictions:
+* 1. The origin of this software must not be misrepresented; you must not
+* claim that you wrote the original software. If you use this software
+* in a product, an acknowledgment in the product documentation would be
+* appreciated but is not required.
+* 2. Altered source versions must be plainly marked as such, and must not be
+* misrepresented as being the original software.
+* 3. This notice may not be removed or altered from any source distribution.
+*/
+
+#include "b2CircleContact.h"
+#include "../b2Body.h"
+#include "../b2WorldCallbacks.h"
+#include "../../Common/b2BlockAllocator.h"
+
+#include <new>
+#include <string.h>
+
+b2Contact* b2CircleContact::Create(b2Shape* shape1, b2Shape* shape2, b2BlockAllocator* allocator)
+{
+       void* mem = allocator->Allocate(sizeof(b2CircleContact));
+       return new (mem) b2CircleContact(shape1, shape2);
+}
+
+void b2CircleContact::Destroy(b2Contact* contact, b2BlockAllocator* allocator)
+{
+       ((b2CircleContact*)contact)->~b2CircleContact();
+       allocator->Free(contact, sizeof(b2CircleContact));
+}
+
+b2CircleContact::b2CircleContact(b2Shape* s1, b2Shape* s2)
+: b2Contact(s1, s2)
+{
+       b2Assert(m_shape1->GetType() == e_circleShape);
+       b2Assert(m_shape2->GetType() == e_circleShape);
+       m_manifold.pointCount = 0;
+       m_manifold.points[0].normalImpulse = 0.0f;
+       m_manifold.points[0].tangentImpulse = 0.0f;
+}
+
+void b2CircleContact::Evaluate(b2ContactListener* listener)
+{
+       b2Body* b1 = m_shape1->GetBody();
+       b2Body* b2 = m_shape2->GetBody();
+
+       b2Manifold m0;
+       memcpy(&m0, &m_manifold, sizeof(b2Manifold));
+
+       b2CollideCircles(&m_manifold, (b2CircleShape*)m_shape1, b1->GetXForm(), (b2CircleShape*)m_shape2, b2->GetXForm());
+
+       b2ContactPoint cp;
+       cp.shape1 = m_shape1;
+       cp.shape2 = m_shape2;
+       cp.friction = m_friction;
+       cp.restitution = m_restitution;
+
+       if (m_manifold.pointCount > 0)
+       {
+               m_manifoldCount = 1;
+               b2ManifoldPoint* mp = m_manifold.points + 0;
+
+               if (m0.pointCount == 0)
+               {
+                       mp->normalImpulse = 0.0f;
+                       mp->tangentImpulse = 0.0f;
+
+                       if (listener)
+                       {
+                               cp.position = b1->GetWorldPoint(mp->localPoint1);
+                               b2Vec2 v1 = b1->GetLinearVelocityFromLocalPoint(mp->localPoint1);
+                               b2Vec2 v2 = b2->GetLinearVelocityFromLocalPoint(mp->localPoint2);
+                               cp.velocity = v2 - v1;
+                               cp.normal = m_manifold.normal;
+                               cp.separation = mp->separation;
+                               cp.id = mp->id;
+                               listener->Add(&cp);
+                       }
+               }
+               else
+               {
+                       b2ManifoldPoint* mp0 = m0.points + 0;
+                       mp->normalImpulse = mp0->normalImpulse;
+                       mp->tangentImpulse = mp0->tangentImpulse;
+
+                       if (listener)
+                       {
+                               cp.position = b1->GetWorldPoint(mp->localPoint1);
+                               b2Vec2 v1 = b1->GetLinearVelocityFromLocalPoint(mp->localPoint1);
+                               b2Vec2 v2 = b2->GetLinearVelocityFromLocalPoint(mp->localPoint2);
+                               cp.velocity = v2 - v1;
+                               cp.normal = m_manifold.normal;
+                               cp.separation = mp->separation;
+                               cp.id = mp->id;
+                               listener->Persist(&cp);
+                       }
+               }
+       }
+       else
+       {
+               m_manifoldCount = 0;
+               if (m0.pointCount > 0 && listener)
+               {
+                       b2ManifoldPoint* mp0 = m0.points + 0;
+                       cp.position = b1->GetWorldPoint(mp0->localPoint1);
+                       b2Vec2 v1 = b1->GetLinearVelocityFromLocalPoint(mp0->localPoint1);
+                       b2Vec2 v2 = b2->GetLinearVelocityFromLocalPoint(mp0->localPoint2);
+                       cp.velocity = v2 - v1;
+                       cp.normal = m0.normal;
+                       cp.separation = mp0->separation;
+                       cp.id = mp0->id;
+                       listener->Remove(&cp);
+               }
+       }
+}