1 files changed, 176 insertions, 0 deletions
diff --git a/Runtime/Physics2D/EdgeCollider2D.cpp b/Runtime/Physics2D/EdgeCollider2D.cpp
new file mode 100644
index 0000000..1c49f96
--- /dev/null
+++ b/Runtime/Physics2D/EdgeCollider2D.cpp
@@ -0,0 +1,176 @@
+#include "UnityPrefix.h"
+
+#if ENABLE_2D_PHYSICS
+
+#include "Runtime/Physics2D/EdgeCollider2D.h"
+#include "Runtime/Physics2D/RigidBody2D.h"
+#include "Runtime/Physics2D/Physics2DManager.h"
+#include "Runtime/Graphics/Transform.h"
+#include "Runtime/Graphics/SpriteFrame.h"
+#include "Runtime/Serialize/TransferFunctions/SerializeTransfer.h"
+#include "Runtime/Profiler/Profiler.h"
+#include "Runtime/Filters/AABBUtility.h"
+#include "Runtime/Filters/Mesh/SpriteRenderer.h"
+
+#include "External/Box2D/Box2D/Box2D.h"
+#include "External/libtess2/libtess2/tesselator.h"
+
+PROFILER_INFORMATION(gPhysics2DProfileEdgeColliderCreate, "Physics2D.EdgeColliderCreate", kProfilerPhysics)
+
+IMPLEMENT_CLASS (EdgeCollider2D)
+IMPLEMENT_OBJECT_SERIALIZE (EdgeCollider2D)
+
+#define EDGE_COLLIDER_2D_MIN_DISTANCE	(b2_linearSlop * b2_linearSlop * 2.01f)
+
+// --------------------------------------------------------------------------
+
+
+EdgeCollider2D::EdgeCollider2D (MemLabelId label, ObjectCreationMode mode)
+	: Super(label, mode)
+{
+}
+
+
+EdgeCollider2D::~EdgeCollider2D ()
+{
+}
+
+
+template<class TransferFunction>
+void EdgeCollider2D::Transfer (TransferFunction& transfer)
+{
+	Super::Transfer (transfer);
+
+	TRANSFER (m_Points);
+}
+
+
+void EdgeCollider2D::Reset ()
+{
+	Super::Reset ();
+
+	m_Points.clear ();
+	m_Points.push_back (Vector2f (-0.5f, 0.0f));
+	m_Points.push_back (Vector2f (0.5f, 0.0f));
+}
+
+
+void EdgeCollider2D::SmartReset ()
+{
+	Super::SmartReset ();
+
+	AABB aabb;
+	if (GetGameObjectPtr () && CalculateLocalAABB (GetGameObject (), &aabb))
+	{
+		if (aabb.GetExtent ().x < EDGE_COLLIDER_2D_MIN_DISTANCE)
+		{
+			m_Points.clear ();
+			m_Points.push_back (Vector2f (-0.5f, 0.0f));
+			m_Points.push_back (Vector2f (0.5f, 0.0f));
+			return;
+		}
+
+		const Vector3f min = aabb.GetMin();
+		const Vector3f max = aabb.GetMax();
+		const float y = (min.y + max.y) * 0.5f;
+		
+		Vector2f points[2] = { Vector2f(min.x, y), Vector2f(max.x, y) };
+		SetPoints (points, 2);
+	}
+}
+
+
+bool EdgeCollider2D::SetPoints (const Vector2f* points, size_t count)
+{
+	// Fail if point count is invalid.
+	if (count < 2)
+		return false;
+
+	m_Points.clear ();
+	while (count-- > 0)
+	{
+		m_Points.push_back (*points++);
+	}
+
+	// Create the points.
+	Create();
+
+	return true;
+}
+
+
+// --------------------------------------------------------------------------
+
+
+void EdgeCollider2D::Create (const Rigidbody2D* ignoreRigidbody)
+{
+	PROFILER_AUTO(gPhysics2DProfileEdgeColliderCreate, NULL);
+
+	// Ensure we're cleaned-up.
+	Cleanup ();
+
+	// Ignore if not active.
+	if (!IsActive() || m_Points.size () < 2)
+		return;
+
+	// Calculate collider transformation.
+	Matrix4x4f relativeTransform;
+	b2Body* body;
+	CalculateColliderTransformation (ignoreRigidbody, &body, relativeTransform);
+
+	// Fetch the collider scale.
+	const Vector3f scale = GetComponent(Transform).GetWorldScaleLossy();
+
+	// Transform the chain.
+	b2Vec2* transformedPoints;
+	ALLOC_TEMP(transformedPoints, b2Vec2, m_Points.size () + 1);	// We add an extra one in-case we need to extend.
+	const int validPointCount = TransformPoints (relativeTransform, scale, transformedPoints);
+	
+	// Invalid chain if a single edge doesn't exit.
+	if (validPointCount < 2)
+		return;
+
+	// Check vertex distances.
+	for (int i = 1; i < validPointCount; ++i)
+		if (b2DistanceSquared (transformedPoints[i-1], transformedPoints[i]) < EDGE_COLLIDER_2D_MIN_DISTANCE)
+			return;
+
+	// Generate the chain shape.
+	b2ChainShape chainShape;
+	chainShape.CreateChain (transformedPoints, validPointCount);
+
+	// Create the chain fixture.
+	dynamic_array<b2Shape*> chainShapes(kMemTempAlloc);
+	chainShapes.push_back (&chainShape);
+	b2FixtureDef def;
+	FinalizeCreate(def, body, &chainShapes);	
+}
+
+
+// --------------------------------------------------------------------------
+
+
+int EdgeCollider2D::TransformPoints(const Matrix4x4f& relativeTransform, const Vector3f& scale, b2Vec2* outPoints)
+{
+	const size_t inPointCount = m_Points.size ();
+	const Vector2f* edgePoint = m_Points.data ();
+	int outCount = 0;
+	for (size_t i = 0; i <inPointCount; ++i, ++edgePoint)
+	{
+		// Calculate transform points.
+		const Vector3f vertex3D = relativeTransform.MultiplyPoint3 (Vector3f(edgePoint->x * scale.x, edgePoint->y * scale.y, 0.0f));
+		const b2Vec2 vertex2D(vertex3D.x, vertex3D.y);		
+
+		// Skip point if they end up being too close. Box2d fires asserts if distance between neighbors is less than b2_linearSlop.
+		if (outCount > 0 && b2DistanceSquared(*(outPoints-1), vertex2D) <= EDGE_COLLIDER_2D_MIN_DISTANCE)
+			continue;
+
+		*outPoints++ = vertex2D;
+		++outCount;
+	}
+
+	return outCount;
+}
+
+
+#endif // #if ENABLE_2D_PHYSICS