Warning, file /education/gcompris/external/qml-box2d/Box2D/Collision/b2CollideCircle.cpp was not indexed or was modified since last indexation (in which case cross-reference links may be missing, inaccurate or erroneous).

 /*
 * Copyright (c) 2007-2009 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/b2Collision.h>
 #include <Box2D/Collision/Shapes/b2CircleShape.h>
 #include <Box2D/Collision/Shapes/b2PolygonShape.h>
 
 void b2CollideCircles(
     b2Manifold* manifold,
     const b2CircleShape* circleA, const b2Transform& xfA,
     const b2CircleShape* circleB, const b2Transform& xfB)
 {
     manifold->pointCount = 0;
 
     b2Vec2 pA = b2Mul(xfA, circleA->m_p);
     b2Vec2 pB = b2Mul(xfB, circleB->m_p);
 
     b2Vec2 d = pB - pA;
     float32 distSqr = b2Dot(d, d);
     float32 rA = circleA->m_radius, rB = circleB->m_radius;
     float32 radius = rA + rB;
     if (distSqr > radius * radius)
     {
         return;
     }
 
     manifold->type = b2Manifold::e_circles;
     manifold->localPoint = circleA->m_p;
     manifold->localNormal.SetZero();
     manifold->pointCount = 1;
 
     manifold->points[0].localPoint = circleB->m_p;
     manifold->points[0].id.key = 0;
 }
 
 void b2CollidePolygonAndCircle(
     b2Manifold* manifold,
     const b2PolygonShape* polygonA, const b2Transform& xfA,
     const b2CircleShape* circleB, const b2Transform& xfB)
 {
     manifold->pointCount = 0;
 
     // Compute circle position in the frame of the polygon.
     b2Vec2 c = b2Mul(xfB, circleB->m_p);
     b2Vec2 cLocal = b2MulT(xfA, c);
 
     // Find the min separating edge.
     int32 normalIndex = 0;
     float32 separation = -b2_maxFloat;
     float32 radius = polygonA->m_radius + circleB->m_radius;
     int32 vertexCount = polygonA->m_count;
     const b2Vec2* vertices = polygonA->m_vertices;
     const b2Vec2* normals = polygonA->m_normals;
 
     for (int32 i = 0; i < vertexCount; ++i)
     {
         float32 s = b2Dot(normals[i], cLocal - vertices[i]);
 
         if (s > radius)
         {
             // Early out.
             return;
         }
 
         if (s > separation)
         {
             separation = s;
             normalIndex = i;
         }
     }
 
     // Vertices that subtend the incident face.
     int32 vertIndex1 = normalIndex;
     int32 vertIndex2 = vertIndex1 + 1 < vertexCount ? vertIndex1 + 1 : 0;
     b2Vec2 v1 = vertices[vertIndex1];
     b2Vec2 v2 = vertices[vertIndex2];
 
     // If the center is inside the polygon ...
     if (separation < b2_epsilon)
     {
         manifold->pointCount = 1;
         manifold->type = b2Manifold::e_faceA;
         manifold->localNormal = normals[normalIndex];
         manifold->localPoint = 0.5f * (v1 + v2);
         manifold->points[0].localPoint = circleB->m_p;
         manifold->points[0].id.key = 0;
         return;
     }
 
     // Compute barycentric coordinates
     float32 u1 = b2Dot(cLocal - v1, v2 - v1);
     float32 u2 = b2Dot(cLocal - v2, v1 - v2);
     if (u1 <= 0.0f)
     {
         if (b2DistanceSquared(cLocal, v1) > radius * radius)
         {
             return;
         }
 
         manifold->pointCount = 1;
         manifold->type = b2Manifold::e_faceA;
         manifold->localNormal = cLocal - v1;
         manifold->localNormal.Normalize();
         manifold->localPoint = v1;
         manifold->points[0].localPoint = circleB->m_p;
         manifold->points[0].id.key = 0;
     }
     else if (u2 <= 0.0f)
     {
         if (b2DistanceSquared(cLocal, v2) > radius * radius)
         {
             return;
         }
 
         manifold->pointCount = 1;
         manifold->type = b2Manifold::e_faceA;
         manifold->localNormal = cLocal - v2;
         manifold->localNormal.Normalize();
         manifold->localPoint = v2;
         manifold->points[0].localPoint = circleB->m_p;
         manifold->points[0].id.key = 0;
     }
     else
     {
         b2Vec2 faceCenter = 0.5f * (v1 + v2);
         float32 separation = b2Dot(cLocal - faceCenter, normals[vertIndex1]);
         if (separation > radius)
         {
             return;
         }
 
         manifold->pointCount = 1;
         manifold->type = b2Manifold::e_faceA;
         manifold->localNormal = normals[vertIndex1];
         manifold->localPoint = faceCenter;
         manifold->points[0].localPoint = circleB->m_p;
         manifold->points[0].id.key = 0;
     }
 }