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

 /*
 * Copyright (c) 2006-2009 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_SHAPE_H
 #define B2_SHAPE_H
 
 #include <Box2D/Common/b2BlockAllocator.h>
 #include <Box2D/Common/b2Math.h>
 #include <Box2D/Collision/b2Collision.h>
 
 /// This holds the mass data computed for a shape.
 struct b2MassData
 {
     /// The mass of the shape, usually in kilograms.
     float32 mass;
 
     /// The position of the shape's centroid relative to the shape's origin.
     b2Vec2 center;
 
     /// The rotational inertia of the shape about the local origin.
     float32 I;
 };
 
 /// A shape is used for collision detection. You can create a shape however you like.
 /// Shapes used for simulation in b2World are created automatically when a b2Fixture
 /// is created. Shapes may encapsulate a one or more child shapes.
 class b2Shape
 {
 public:
     
     enum Type
     {
         e_circle = 0,
         e_edge = 1,
         e_polygon = 2,
         e_chain = 3,
         e_typeCount = 4
     };
 
     virtual ~b2Shape() {}
 
     /// Clone the concrete shape using the provided allocator.
     virtual b2Shape* Clone(b2BlockAllocator* allocator) const = 0;
 
     /// Get the type of this shape. You can use this to down cast to the concrete shape.
     /// @return the shape type.
     Type GetType() const;
 
     /// Get the number of child primitives.
     virtual int32 GetChildCount() const = 0;
 
     /// Test a point for containment in this shape. This only works for convex shapes.
     /// @param xf the shape world transform.
     /// @param p a point in world coordinates.
     virtual bool TestPoint(const b2Transform& xf, const b2Vec2& p) const = 0;
 
     /// Cast a ray against a child shape.
     /// @param output the ray-cast results.
     /// @param input the ray-cast input parameters.
     /// @param transform the transform to be applied to the shape.
     /// @param childIndex the child shape index
     virtual bool RayCast(b2RayCastOutput* output, const b2RayCastInput& input,
                         const b2Transform& transform, int32 childIndex) const = 0;
 
     /// Given a transform, compute the associated axis aligned bounding box for a child shape.
     /// @param aabb returns the axis aligned box.
     /// @param xf the world transform of the shape.
     /// @param childIndex the child shape
     virtual void ComputeAABB(b2AABB* aabb, const b2Transform& xf, int32 childIndex) const = 0;
 
     /// Compute the mass properties of this shape using its dimensions and density.
     /// The inertia tensor is computed about the local origin.
     /// @param massData returns the mass data for this shape.
     /// @param density the density in kilograms per meter squared.
     virtual void ComputeMass(b2MassData* massData, float32 density) const = 0;
 
     Type m_type;
     float32 m_radius;
 };
 
 inline b2Shape::Type b2Shape::GetType() const
 {
     return m_type;
 }
 
 #endif