Rename Box2D folder to box2d

src/libraries/box2d/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;
+}