File indexing completed on 2025-08-03 03:49:54

 /*
 * Copyright (c) 2006-2010 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 <Box2D/Collision/Shapes/b2LoopShape.h>
 #include <Box2D/Collision/Shapes/b2EdgeShape.h>
 #include <new>
 #include <cstring>
 using namespace std;
 
 b2LoopShape::~b2LoopShape()
 {
     b2Free(m_vertices);
     m_vertices = NULL;
     m_count = 0;
 }
 
 void b2LoopShape::Create(const b2Vec2* vertices, int32 count)
 {
     b2Assert(m_vertices == NULL && m_count == 0);
     b2Assert(count >= 2);
     m_count = count;
     m_vertices = (b2Vec2*)b2Alloc(count * sizeof(b2Vec2));
     memcpy(m_vertices, vertices, m_count * sizeof(b2Vec2));
 }
 
 b2Shape* b2LoopShape::Clone(b2BlockAllocator* allocator) const
 {
     void* mem = allocator->Allocate(sizeof(b2LoopShape));
     b2LoopShape* clone = new (mem) b2LoopShape;
     clone->Create(m_vertices, m_count);
     return clone;
 }
 
 int32 b2LoopShape::GetChildCount() const
 {
     return m_count;
 }
 
 void b2LoopShape::GetChildEdge(b2EdgeShape* edge, int32 index) const
 {
     b2Assert(2 <= m_count);
     b2Assert(0 <= index && index < m_count);
     edge->m_type = b2Shape::e_edge;
     edge->m_radius = m_radius;
     edge->m_hasVertex0 = true;
     edge->m_hasVertex3 = true;
 
     int32 i0 = index - 1 >= 0 ? index - 1 : m_count - 1;
     int32 i1 = index;
     int32 i2 = index + 1 < m_count ? index + 1 : 0;
     int32 i3 = index + 2;
     while (i3 >= m_count)
     {
         i3 -= m_count;
     }
 
     edge->m_vertex0 = m_vertices[i0];
     edge->m_vertex1 = m_vertices[i1];
     edge->m_vertex2 = m_vertices[i2];
     edge->m_vertex3 = m_vertices[i3];
 }
 
 bool b2LoopShape::TestPoint(const b2Transform& xf, const b2Vec2& p) const
 {
     B2_NOT_USED(xf);
     B2_NOT_USED(p);
     return false;
 }
 
 bool b2LoopShape::RayCast(b2RayCastOutput* output, const b2RayCastInput& input,
                             const b2Transform& xf, int32 childIndex) const
 {
     b2Assert(childIndex < m_count);
 
     b2EdgeShape edgeShape;
 
     int32 i1 = childIndex;
     int32 i2 = childIndex + 1;
     if (i2 == m_count)
     {
         i2 = 0;
     }
 
     edgeShape.m_vertex1 = m_vertices[i1];
     edgeShape.m_vertex2 = m_vertices[i2];
 
     return edgeShape.RayCast(output, input, xf, 0);
 }
 
 void b2LoopShape::ComputeAABB(b2AABB* aabb, const b2Transform& xf, int32 childIndex) const
 {
     b2Assert(childIndex < m_count);
 
     int32 i1 = childIndex;
     int32 i2 = childIndex + 1;
     if (i2 == m_count)
     {
         i2 = 0;
     }
 
     b2Vec2 v1 = b2Mul(xf, m_vertices[i1]);
     b2Vec2 v2 = b2Mul(xf, m_vertices[i2]);
 
     aabb->lowerBound = b2Min(v1, v2);
     aabb->upperBound = b2Max(v1, v2);
 }
 
 void b2LoopShape::ComputeMass(b2MassData* massData, qreal density) const
 {
     B2_NOT_USED(density);
 
     massData->mass = 0.0f;
     massData->center.SetZero();
     massData->I = 0.0f;
 }