bool CircleCollider::IntersectsLine(const Vector2& start, const Vector2& end, float lineRadius, CollisionData *collisionData)
{
//Algorithm stolen from: http://www.gamedev.net/topic/304578-finite-line-circle-intersection/page__view__findpost__p__2938618
Vector2 ePos = GetEntityPosition();
Vector2 dir = end - start;
Vector2 diff = (ePos + offset) - start;
float t = diff.Dot(dir) / dir.GetSquaredMagnitude();
if (t < 0.0f)
t = 0.0f;
if (t > 1.0f)
t = 1.0f;
Vector2 closest = (t * dir) + start;
Vector2 d = (ePos + offset) - closest;
if (collisionData)
{
collisionData->hitPoint = closest;
}
return d.GetSquaredMagnitude() <= (radius + lineRadius) * (radius + lineRadius);
}
Entity* Scene::GetNearestEntityWithTag(const Vector2 &position, const std::string &tag)
{
float smallestSqrMag = -1.0f;
Entity *nearestEntity = NULL;
for (std::list<Entity*>::iterator i = tagMap[tag].begin(); i != tagMap[tag].end(); ++i)
{
Vector2 diff = (*i)->position - position;
float sqrMag = diff.GetSquaredMagnitude();
if (smallestSqrMag <= -1 || sqrMag < smallestSqrMag)
{
nearestEntity = (*i);
}
}
return nearestEntity;
}
Entity* Scene::GetNearestEntityByControlPoint(const Vector2 &position, const std::string &tag, Entity *ignoreEntity)
{
float smallestSqrMag = -1.0f;
Entity *nearestEntity = NULL;
std::list<Entity*> *entities = &this->entities;
if (tag != "")
{
entities = GetAllTag(tag);
}
if (entities != NULL)
{
for (std::list<Entity*>::iterator i = entities->begin(); i != entities->end(); ++i)
{
if ((*i) != ignoreEntity)
{
Vector2 diff = (*i)->GetWorldPosition() - position;
if (diff.IsInRange(ENTITY_CONTROLPOINT_SIZE))
{
float sqrMag = diff.GetSquaredMagnitude();
if (smallestSqrMag == -1 || sqrMag < smallestSqrMag)
{
smallestSqrMag = sqrMag;
nearestEntity = (*i);
}
}
}
//Entity *nearestChild = (*i)->GetNearestEntityByControlPoint(position, tag, ignoreEntity, smallestSqrMag);
//if (nearestChild)
//{
// nearestEntity = nearestChild;
//}
}
}
return nearestEntity;
}
Entity* Scene::GetNearestEntity(const Vector2 &position, Entity *ignoreEntity)
{
float smallestSqrMag = -1.0f;
Entity *nearestEntity = NULL;
for (std::list<Entity*>::iterator i = entities.begin(); i != entities.end(); ++i)
{
if ((*i) != ignoreEntity)
{
Vector2 diff = (*i)->position - position;
float sqrMag = diff.GetSquaredMagnitude();
if (smallestSqrMag <= -1 || sqrMag < smallestSqrMag)
{
nearestEntity = (*i);
}
}
}
return nearestEntity;
}