diff options
Diffstat (limited to 'src/3rdparty/Box2D/Collision/Shapes/b2ChainShape.cpp')
| -rw-r--r-- | src/3rdparty/Box2D/Collision/Shapes/b2ChainShape.cpp | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/src/3rdparty/Box2D/Collision/Shapes/b2ChainShape.cpp b/src/3rdparty/Box2D/Collision/Shapes/b2ChainShape.cpp new file mode 100644 index 0000000..a709585 --- /dev/null +++ b/src/3rdparty/Box2D/Collision/Shapes/b2ChainShape.cpp @@ -0,0 +1,198 @@ +/* +* 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. +*/ + +#include "Box2D/Collision/Shapes/b2ChainShape.h" +#include "Box2D/Collision/Shapes/b2EdgeShape.h" +#include <new> +#include <string.h> + +b2ChainShape::~b2ChainShape() +{ + Clear(); +} + +void b2ChainShape::Clear() +{ + b2Free(m_vertices); + m_vertices = nullptr; + m_count = 0; +} + +void b2ChainShape::CreateLoop(const b2Vec2* vertices, int32 count) +{ + b2Assert(m_vertices == nullptr && m_count == 0); + b2Assert(count >= 3); + if (count < 3) + { + return; + } + + for (int32 i = 1; i < count; ++i) + { + b2Vec2 v1 = vertices[i-1]; + b2Vec2 v2 = vertices[i]; + // If the code crashes here, it means your vertices are too close together. + b2Assert(b2DistanceSquared(v1, v2) > b2_linearSlop * b2_linearSlop); + } + + m_count = count + 1; + m_vertices = (b2Vec2*)b2Alloc(m_count * sizeof(b2Vec2)); + memcpy(m_vertices, vertices, count * sizeof(b2Vec2)); + m_vertices[count] = m_vertices[0]; + m_prevVertex = m_vertices[m_count - 2]; + m_nextVertex = m_vertices[1]; + m_hasPrevVertex = true; + m_hasNextVertex = true; +} + +void b2ChainShape::CreateChain(const b2Vec2* vertices, int32 count) +{ + b2Assert(m_vertices == nullptr && m_count == 0); + b2Assert(count >= 2); + for (int32 i = 1; i < count; ++i) + { + // If the code crashes here, it means your vertices are too close together. + b2Assert(b2DistanceSquared(vertices[i-1], vertices[i]) > b2_linearSlop * b2_linearSlop); + } + + m_count = count; + m_vertices = (b2Vec2*)b2Alloc(count * sizeof(b2Vec2)); + memcpy(m_vertices, vertices, m_count * sizeof(b2Vec2)); + + m_hasPrevVertex = false; + m_hasNextVertex = false; + + m_prevVertex.SetZero(); + m_nextVertex.SetZero(); +} + +void b2ChainShape::SetPrevVertex(const b2Vec2& prevVertex) +{ + m_prevVertex = prevVertex; + m_hasPrevVertex = true; +} + +void b2ChainShape::SetNextVertex(const b2Vec2& nextVertex) +{ + m_nextVertex = nextVertex; + m_hasNextVertex = true; +} + +b2Shape* b2ChainShape::Clone(b2BlockAllocator* allocator) const +{ + void* mem = allocator->Allocate(sizeof(b2ChainShape)); + b2ChainShape* clone = new (mem) b2ChainShape; + clone->CreateChain(m_vertices, m_count); + clone->m_prevVertex = m_prevVertex; + clone->m_nextVertex = m_nextVertex; + clone->m_hasPrevVertex = m_hasPrevVertex; + clone->m_hasNextVertex = m_hasNextVertex; + return clone; +} + +int32 b2ChainShape::GetChildCount() const +{ + // edge count = vertex count - 1 + return m_count - 1; +} + +void b2ChainShape::GetChildEdge(b2EdgeShape* edge, int32 index) const +{ + b2Assert(0 <= index && index < m_count - 1); + edge->m_type = b2Shape::e_edge; + edge->m_radius = m_radius; + + edge->m_vertex1 = m_vertices[index + 0]; + edge->m_vertex2 = m_vertices[index + 1]; + + if (index > 0) + { + edge->m_vertex0 = m_vertices[index - 1]; + edge->m_hasVertex0 = true; + } + else + { + edge->m_vertex0 = m_prevVertex; + edge->m_hasVertex0 = m_hasPrevVertex; + } + + if (index < m_count - 2) + { + edge->m_vertex3 = m_vertices[index + 2]; + edge->m_hasVertex3 = true; + } + else + { + edge->m_vertex3 = m_nextVertex; + edge->m_hasVertex3 = m_hasNextVertex; + } +} + +bool b2ChainShape::TestPoint(const b2Transform& xf, const b2Vec2& p) const +{ + B2_NOT_USED(xf); + B2_NOT_USED(p); + return false; +} + +bool b2ChainShape::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 b2ChainShape::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 b2ChainShape::ComputeMass(b2MassData* massData, float32 density) const +{ + B2_NOT_USED(density); + + massData->mass = 0.0f; + massData->center.SetZero(); + massData->I = 0.0f; +} |