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Diffstat (limited to 'Client/ThirdParty/Box2D/src/collision/b2_edge_shape.cpp')
| -rw-r--r-- | Client/ThirdParty/Box2D/src/collision/b2_edge_shape.cpp | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/Client/ThirdParty/Box2D/src/collision/b2_edge_shape.cpp b/Client/ThirdParty/Box2D/src/collision/b2_edge_shape.cpp new file mode 100644 index 0000000..65f0606 --- /dev/null +++ b/Client/ThirdParty/Box2D/src/collision/b2_edge_shape.cpp @@ -0,0 +1,158 @@ +// MIT License + +// Copyright (c) 2019 Erin Catto + +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: + +// The above copyright notice and this permission notice shall be included in all +// copies or substantial portions of the Software. + +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +// SOFTWARE. + +#include "box2d/b2_edge_shape.h" +#include "box2d/b2_block_allocator.h" +#include <new> + +void b2EdgeShape::SetOneSided(const b2Vec2& v0, const b2Vec2& v1, const b2Vec2& v2, const b2Vec2& v3) +{ + m_vertex0 = v0; + m_vertex1 = v1; + m_vertex2 = v2; + m_vertex3 = v3; + m_oneSided = true; +} + +void b2EdgeShape::SetTwoSided(const b2Vec2& v1, const b2Vec2& v2) +{ + m_vertex1 = v1; + m_vertex2 = v2; + m_oneSided = false; +} + +b2Shape* b2EdgeShape::Clone(b2BlockAllocator* allocator) const +{ + void* mem = allocator->Allocate(sizeof(b2EdgeShape)); + b2EdgeShape* clone = new (mem) b2EdgeShape; + *clone = *this; + return clone; +} + +int32 b2EdgeShape::GetChildCount() const +{ + return 1; +} + +bool b2EdgeShape::TestPoint(const b2Transform& xf, const b2Vec2& p) const +{ + B2_NOT_USED(xf); + B2_NOT_USED(p); + return false; +} + +// p = p1 + t * d +// v = v1 + s * e +// p1 + t * d = v1 + s * e +// s * e - t * d = p1 - v1 +bool b2EdgeShape::RayCast(b2RayCastOutput* output, const b2RayCastInput& input, + const b2Transform& xf, int32 childIndex) const +{ + B2_NOT_USED(childIndex); + + // Put the ray into the edge's frame of reference. + b2Vec2 p1 = b2MulT(xf.q, input.p1 - xf.p); + b2Vec2 p2 = b2MulT(xf.q, input.p2 - xf.p); + b2Vec2 d = p2 - p1; + + b2Vec2 v1 = m_vertex1; + b2Vec2 v2 = m_vertex2; + b2Vec2 e = v2 - v1; + + // Normal points to the right, looking from v1 at v2 + b2Vec2 normal(e.y, -e.x); + normal.Normalize(); + + // q = p1 + t * d + // dot(normal, q - v1) = 0 + // dot(normal, p1 - v1) + t * dot(normal, d) = 0 + float numerator = b2Dot(normal, v1 - p1); + if (m_oneSided && numerator > 0.0f) + { + return false; + } + + float denominator = b2Dot(normal, d); + + if (denominator == 0.0f) + { + return false; + } + + float t = numerator / denominator; + if (t < 0.0f || input.maxFraction < t) + { + return false; + } + + b2Vec2 q = p1 + t * d; + + // q = v1 + s * r + // s = dot(q - v1, r) / dot(r, r) + b2Vec2 r = v2 - v1; + float rr = b2Dot(r, r); + if (rr == 0.0f) + { + return false; + } + + float s = b2Dot(q - v1, r) / rr; + if (s < 0.0f || 1.0f < s) + { + return false; + } + + output->fraction = t; + if (numerator > 0.0f) + { + output->normal = -b2Mul(xf.q, normal); + } + else + { + output->normal = b2Mul(xf.q, normal); + } + return true; +} + +void b2EdgeShape::ComputeAABB(b2AABB* aabb, const b2Transform& xf, int32 childIndex) const +{ + B2_NOT_USED(childIndex); + + b2Vec2 v1 = b2Mul(xf, m_vertex1); + b2Vec2 v2 = b2Mul(xf, m_vertex2); + + b2Vec2 lower = b2Min(v1, v2); + b2Vec2 upper = b2Max(v1, v2); + + b2Vec2 r(m_radius, m_radius); + aabb->lowerBound = lower - r; + aabb->upperBound = upper + r; +} + +void b2EdgeShape::ComputeMass(b2MassData* massData, float density) const +{ + B2_NOT_USED(density); + + massData->mass = 0.0f; + massData->center = 0.5f * (m_vertex1 + m_vertex2); + massData->I = 0.0f; +} |