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diff --git a/Source/3rdParty/Box2D/Collision/Shapes/b2PolygonShape.cpp b/Source/3rdParty/Box2D/Collision/Shapes/b2PolygonShape.cpp
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-/*
-* Copyright (c) 2006-2009 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/b2PolygonShape.h"
-#include <new>
-
-b2Shape* b2PolygonShape::Clone(b2BlockAllocator* allocator) const
-{
- void* mem = allocator->Allocate(sizeof(b2PolygonShape));
- b2PolygonShape* clone = new (mem) b2PolygonShape;
- *clone = *this;
- return clone;
-}
-
-void b2PolygonShape::SetAsBox(float32 hx, float32 hy)
-{
- m_count = 4;
- m_vertices[0].Set(-hx, -hy);
- m_vertices[1].Set( hx, -hy);
- m_vertices[2].Set( hx, hy);
- m_vertices[3].Set(-hx, hy);
- m_normals[0].Set(0.0f, -1.0f);
- m_normals[1].Set(1.0f, 0.0f);
- m_normals[2].Set(0.0f, 1.0f);
- m_normals[3].Set(-1.0f, 0.0f);
- m_centroid.SetZero();
-}
-
-void b2PolygonShape::SetAsBox(float32 hx, float32 hy, const b2Vec2& center, float32 angle)
-{
- m_count = 4;
- m_vertices[0].Set(-hx, -hy);
- m_vertices[1].Set( hx, -hy);
- m_vertices[2].Set( hx, hy);
- m_vertices[3].Set(-hx, hy);
- m_normals[0].Set(0.0f, -1.0f);
- m_normals[1].Set(1.0f, 0.0f);
- m_normals[2].Set(0.0f, 1.0f);
- m_normals[3].Set(-1.0f, 0.0f);
- m_centroid = center;
-
- b2Transform xf;
- xf.p = center;
- xf.q.Set(angle);
-
- // Transform vertices and normals.
- for (int32 i = 0; i < m_count; ++i)
- {
- m_vertices[i] = b2Mul(xf, m_vertices[i]);
- m_normals[i] = b2Mul(xf.q, m_normals[i]);
- }
-}
-
-int32 b2PolygonShape::GetChildCount() const
-{
- return 1;
-}
-
-static b2Vec2 ComputeCentroid(const b2Vec2* vs, int32 count)
-{
- b2Assert(count >= 3);
-
- b2Vec2 c; c.Set(0.0f, 0.0f);
- float32 area = 0.0f;
-
- // pRef is the reference point for forming triangles.
- // It's location doesn't change the result (except for rounding error).
- b2Vec2 pRef(0.0f, 0.0f);
-#if 0
- // This code would put the reference point inside the polygon.
- for (int32 i = 0; i < count; ++i)
- {
- pRef += vs[i];
- }
- pRef *= 1.0f / count;
-#endif
-
- const float32 inv3 = 1.0f / 3.0f;
-
- for (int32 i = 0; i < count; ++i)
- {
- // Triangle vertices.
- b2Vec2 p1 = pRef;
- b2Vec2 p2 = vs[i];
- b2Vec2 p3 = i + 1 < count ? vs[i+1] : vs[0];
-
- b2Vec2 e1 = p2 - p1;
- b2Vec2 e2 = p3 - p1;
-
- float32 D = b2Cross(e1, e2);
-
- float32 triangleArea = 0.5f * D;
- area += triangleArea;
-
- // Area weighted centroid
- c += triangleArea * inv3 * (p1 + p2 + p3);
- }
-
- // Centroid
- b2Assert(area > b2_epsilon);
- c *= 1.0f / area;
- return c;
-}
-
-void b2PolygonShape::Set(const b2Vec2* vertices, int32 count)
-{
- b2Assert(3 <= count && count <= b2_maxPolygonVertices);
- if (count < 3)
- {
- SetAsBox(1.0f, 1.0f);
- return;
- }
-
- int32 n = b2Min(count, b2_maxPolygonVertices);
-
- // Perform welding and copy vertices into local buffer.
- b2Vec2 ps[b2_maxPolygonVertices];
- int32 tempCount = 0;
- for (int32 i = 0; i < n; ++i)
- {
- b2Vec2 v = vertices[i];
-
- bool unique = true;
- for (int32 j = 0; j < tempCount; ++j)
- {
- if (b2DistanceSquared(v, ps[j]) < ((0.5f * b2_linearSlop) * (0.5f * b2_linearSlop)))
- {
- unique = false;
- break;
- }
- }
-
- if (unique)
- {
- ps[tempCount++] = v;
- }
- }
-
- n = tempCount;
- if (n < 3)
- {
- // Polygon is degenerate.
- b2Assert(false);
- SetAsBox(1.0f, 1.0f);
- return;
- }
-
- // Create the convex hull using the Gift wrapping algorithm
- // http://en.wikipedia.org/wiki/Gift_wrapping_algorithm
-
- // Find the right most point on the hull
- int32 i0 = 0;
- float32 x0 = ps[0].x;
- for (int32 i = 1; i < n; ++i)
- {
- float32 x = ps[i].x;
- if (x > x0 || (x == x0 && ps[i].y < ps[i0].y))
- {
- i0 = i;
- x0 = x;
- }
- }
-
- int32 hull[b2_maxPolygonVertices];
- int32 m = 0;
- int32 ih = i0;
-
- for (;;)
- {
- b2Assert(m < b2_maxPolygonVertices);
- hull[m] = ih;
-
- int32 ie = 0;
- for (int32 j = 1; j < n; ++j)
- {
- if (ie == ih)
- {
- ie = j;
- continue;
- }
-
- b2Vec2 r = ps[ie] - ps[hull[m]];
- b2Vec2 v = ps[j] - ps[hull[m]];
- float32 c = b2Cross(r, v);
- if (c < 0.0f)
- {
- ie = j;
- }
-
- // Collinearity check
- if (c == 0.0f && v.LengthSquared() > r.LengthSquared())
- {
- ie = j;
- }
- }
-
- ++m;
- ih = ie;
-
- if (ie == i0)
- {
- break;
- }
- }
-
- if (m < 3)
- {
- // Polygon is degenerate.
- b2Assert(false);
- SetAsBox(1.0f, 1.0f);
- return;
- }
-
- m_count = m;
-
- // Copy vertices.
- for (int32 i = 0; i < m; ++i)
- {
- m_vertices[i] = ps[hull[i]];
- }
-
- // Compute normals. Ensure the edges have non-zero length.
- for (int32 i = 0; i < m; ++i)
- {
- int32 i1 = i;
- int32 i2 = i + 1 < m ? i + 1 : 0;
- b2Vec2 edge = m_vertices[i2] - m_vertices[i1];
- b2Assert(edge.LengthSquared() > b2_epsilon * b2_epsilon);
- m_normals[i] = b2Cross(edge, 1.0f);
- m_normals[i].Normalize();
- }
-
- // Compute the polygon centroid.
- m_centroid = ComputeCentroid(m_vertices, m);
-}
-
-bool b2PolygonShape::TestPoint(const b2Transform& xf, const b2Vec2& p) const
-{
- b2Vec2 pLocal = b2MulT(xf.q, p - xf.p);
-
- for (int32 i = 0; i < m_count; ++i)
- {
- float32 dot = b2Dot(m_normals[i], pLocal - m_vertices[i]);
- if (dot > 0.0f)
- {
- return false;
- }
- }
-
- return true;
-}
-
-bool b2PolygonShape::RayCast(b2RayCastOutput* output, const b2RayCastInput& input,
- const b2Transform& xf, int32 childIndex) const
-{
- B2_NOT_USED(childIndex);
-
- // Put the ray into the polygon'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;
-
- float32 lower = 0.0f, upper = input.maxFraction;
-
- int32 index = -1;
-
- for (int32 i = 0; i < m_count; ++i)
- {
- // p = p1 + a * d
- // dot(normal, p - v) = 0
- // dot(normal, p1 - v) + a * dot(normal, d) = 0
- float32 numerator = b2Dot(m_normals[i], m_vertices[i] - p1);
- float32 denominator = b2Dot(m_normals[i], d);
-
- if (denominator == 0.0f)
- {
- if (numerator < 0.0f)
- {
- return false;
- }
- }
- else
- {
- // Note: we want this predicate without division:
- // lower < numerator / denominator, where denominator < 0
- // Since denominator < 0, we have to flip the inequality:
- // lower < numerator / denominator <==> denominator * lower > numerator.
- if (denominator < 0.0f && numerator < lower * denominator)
- {
- // Increase lower.
- // The segment enters this half-space.
- lower = numerator / denominator;
- index = i;
- }
- else if (denominator > 0.0f && numerator < upper * denominator)
- {
- // Decrease upper.
- // The segment exits this half-space.
- upper = numerator / denominator;
- }
- }
-
- // The use of epsilon here causes the assert on lower to trip
- // in some cases. Apparently the use of epsilon was to make edge
- // shapes work, but now those are handled separately.
- //if (upper < lower - b2_epsilon)
- if (upper < lower)
- {
- return false;
- }
- }
-
- b2Assert(0.0f <= lower && lower <= input.maxFraction);
-
- if (index >= 0)
- {
- output->fraction = lower;
- output->normal = b2Mul(xf.q, m_normals[index]);
- return true;
- }
-
- return false;
-}
-
-void b2PolygonShape::ComputeAABB(b2AABB* aabb, const b2Transform& xf, int32 childIndex) const
-{
- B2_NOT_USED(childIndex);
-
- b2Vec2 lower = b2Mul(xf, m_vertices[0]);
- b2Vec2 upper = lower;
-
- for (int32 i = 1; i < m_count; ++i)
- {
- b2Vec2 v = b2Mul(xf, m_vertices[i]);
- lower = b2Min(lower, v);
- upper = b2Max(upper, v);
- }
-
- b2Vec2 r(m_radius, m_radius);
- aabb->lowerBound = lower - r;
- aabb->upperBound = upper + r;
-}
-
-void b2PolygonShape::ComputeMass(b2MassData* massData, float32 density) const
-{
- // Polygon mass, centroid, and inertia.
- // Let rho be the polygon density in mass per unit area.
- // Then:
- // mass = rho * int(dA)
- // centroid.x = (1/mass) * rho * int(x * dA)
- // centroid.y = (1/mass) * rho * int(y * dA)
- // I = rho * int((x*x + y*y) * dA)
- //
- // We can compute these integrals by summing all the integrals
- // for each triangle of the polygon. To evaluate the integral
- // for a single triangle, we make a change of variables to
- // the (u,v) coordinates of the triangle:
- // x = x0 + e1x * u + e2x * v
- // y = y0 + e1y * u + e2y * v
- // where 0 <= u && 0 <= v && u + v <= 1.
- //
- // We integrate u from [0,1-v] and then v from [0,1].
- // We also need to use the Jacobian of the transformation:
- // D = cross(e1, e2)
- //
- // Simplification: triangle centroid = (1/3) * (p1 + p2 + p3)
- //
- // The rest of the derivation is handled by computer algebra.
-
- b2Assert(m_count >= 3);
-
- b2Vec2 center; center.Set(0.0f, 0.0f);
- float32 area = 0.0f;
- float32 I = 0.0f;
-
- // s is the reference point for forming triangles.
- // It's location doesn't change the result (except for rounding error).
- b2Vec2 s(0.0f, 0.0f);
-
- // This code would put the reference point inside the polygon.
- for (int32 i = 0; i < m_count; ++i)
- {
- s += m_vertices[i];
- }
- s *= 1.0f / m_count;
-
- const float32 k_inv3 = 1.0f / 3.0f;
-
- for (int32 i = 0; i < m_count; ++i)
- {
- // Triangle vertices.
- b2Vec2 e1 = m_vertices[i] - s;
- b2Vec2 e2 = i + 1 < m_count ? m_vertices[i+1] - s : m_vertices[0] - s;
-
- float32 D = b2Cross(e1, e2);
-
- float32 triangleArea = 0.5f * D;
- area += triangleArea;
-
- // Area weighted centroid
- center += triangleArea * k_inv3 * (e1 + e2);
-
- float32 ex1 = e1.x, ey1 = e1.y;
- float32 ex2 = e2.x, ey2 = e2.y;
-
- float32 intx2 = ex1*ex1 + ex2*ex1 + ex2*ex2;
- float32 inty2 = ey1*ey1 + ey2*ey1 + ey2*ey2;
-
- I += (0.25f * k_inv3 * D) * (intx2 + inty2);
- }
-
- // Total mass
- massData->mass = density * area;
-
- // Center of mass
- b2Assert(area > b2_epsilon);
- center *= 1.0f / area;
- massData->center = center + s;
-
- // Inertia tensor relative to the local origin (point s).
- massData->I = density * I;
-
- // Shift to center of mass then to original body origin.
- massData->I += massData->mass * (b2Dot(massData->center, massData->center) - b2Dot(center, center));
-}
-
-bool b2PolygonShape::Validate() const
-{
- for (int32 i = 0; i < m_count; ++i)
- {
- int32 i1 = i;
- int32 i2 = i < m_count - 1 ? i1 + 1 : 0;
- b2Vec2 p = m_vertices[i1];
- b2Vec2 e = m_vertices[i2] - p;
-
- for (int32 j = 0; j < m_count; ++j)
- {
- if (j == i1 || j == i2)
- {
- continue;
- }
-
- b2Vec2 v = m_vertices[j] - p;
- float32 c = b2Cross(e, v);
- if (c < 0.0f)
- {
- return false;
- }
- }
- }
-
- return true;
-}
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