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-rw-r--r--src/3rdparty/Box2D/Collision/Shapes/b2EdgeShape.cpp138
1 files changed, 138 insertions, 0 deletions
diff --git a/src/3rdparty/Box2D/Collision/Shapes/b2EdgeShape.cpp b/src/3rdparty/Box2D/Collision/Shapes/b2EdgeShape.cpp
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+++ b/src/3rdparty/Box2D/Collision/Shapes/b2EdgeShape.cpp
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+/*
+* 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/b2EdgeShape.h"
+#include <new>
+
+void b2EdgeShape::Set(const b2Vec2& v1, const b2Vec2& v2)
+{
+ m_vertex1 = v1;
+ m_vertex2 = v2;
+ m_hasVertex0 = false;
+ m_hasVertex3 = 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;
+ 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
+ float32 numerator = b2Dot(normal, v1 - p1);
+ float32 denominator = b2Dot(normal, d);
+
+ if (denominator == 0.0f)
+ {
+ return false;
+ }
+
+ float32 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;
+ float32 rr = b2Dot(r, r);
+ if (rr == 0.0f)
+ {
+ return false;
+ }
+
+ float32 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, float32 density) const
+{
+ B2_NOT_USED(density);
+
+ massData->mass = 0.0f;
+ massData->center = 0.5f * (m_vertex1 + m_vertex2);
+ massData->I = 0.0f;
+}