File indexing completed on 2025-02-16 03:29:32

 /*
 * Copyright (c) 2006-2010 Erin Catto http://www.box2d.org
 *
 * 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.
 */
 
 #ifndef B2_CHAIN_SHAPE_H
 #define B2_CHAIN_SHAPE_H
 
 #include <Box2D/Collision/Shapes/b2Shape.h>
 
 class b2EdgeShape;
 
 /// A chain shape is a free form sequence of line segments.
 /// The chain has two-sided collision, so you can use inside and outside collision.
 /// Therefore, you may use any winding order.
 /// Since there may be many vertices, they are allocated using b2Alloc.
 /// Connectivity information is used to create smooth collisions.
 /// WARNING: The chain will not collide properly if there are self-intersections.
 class b2ChainShape : public b2Shape
 {
 public:
     b2ChainShape();
 
     /// The destructor frees the vertices using b2Free.
     ~b2ChainShape();
 
     /// Clear all data.
     void Clear();
 
     /// Create a loop. This automatically adjusts connectivity.
     /// @param vertices an array of vertices, these are copied
     /// @param count the vertex count
     void CreateLoop(const b2Vec2* vertices, int32 count);
 
     /// Create a chain with isolated end vertices.
     /// @param vertices an array of vertices, these are copied
     /// @param count the vertex count
     void CreateChain(const b2Vec2* vertices, int32 count);
 
     /// Establish connectivity to a vertex that precedes the first vertex.
     /// Don't call this for loops.
     void SetPrevVertex(const b2Vec2& prevVertex);
 
     /// Establish connectivity to a vertex that follows the last vertex.
     /// Don't call this for loops.
     void SetNextVertex(const b2Vec2& nextVertex);
 
     /// Implement b2Shape. Vertices are cloned using b2Alloc.
     b2Shape* Clone(b2BlockAllocator* allocator) const;
 
     /// @see b2Shape::GetChildCount
     int32 GetChildCount() const;
 
     /// Get a child edge.
     void GetChildEdge(b2EdgeShape* edge, int32 index) const;
 
     /// This always return false.
     /// @see b2Shape::TestPoint
     bool TestPoint(const b2Transform& transform, const b2Vec2& p) const;
 
     /// Implement b2Shape.
     bool RayCast(b2RayCastOutput* output, const b2RayCastInput& input,
                     const b2Transform& transform, int32 childIndex) const;
 
     /// @see b2Shape::ComputeAABB
     void ComputeAABB(b2AABB* aabb, const b2Transform& transform, int32 childIndex) const;
 
     /// Chains have zero mass.
     /// @see b2Shape::ComputeMass
     void ComputeMass(b2MassData* massData, float32 density) const;
 
     /// The vertices. Owned by this class.
     b2Vec2* m_vertices;
 
     /// The vertex count.
     int32 m_count;
 
     b2Vec2 m_prevVertex, m_nextVertex;
     bool m_hasPrevVertex, m_hasNextVertex;
 };
 
 inline b2ChainShape::b2ChainShape()
 {
     m_type = e_chain;
     m_radius = b2_polygonRadius;
     m_vertices = NULL;
     m_count = 0;
     m_hasPrevVertex = false;
     m_hasNextVertex = false;
 }
 
 #endif