Use branchless min/max

This commit is contained in:
Philipp Möller 2015-11-20 13:39:25 +01:00 committed by Sébastien Loriot
parent a408a08ae7
commit 3f4d185b1d
2 changed files with 17 additions and 19 deletions

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@ -122,17 +122,16 @@ struct AABB_traits_base_2<GeomTraits,true>{
FT t_near = -DBL_MAX; // std::numeric_limits<FT>::lowest(); C++1903 FT t_near = -DBL_MAX; // std::numeric_limits<FT>::lowest(); C++1903
FT t_far = DBL_MAX; FT t_far = DBL_MAX;
Construct_cartesian_const_iterator_3 construct_cartesian_const_iterator_3 const Construct_cartesian_const_iterator_3 construct_cartesian_const_iterator_3
= GeomTraits().construct_cartesian_const_iterator_3_object(); = GeomTraits().construct_cartesian_const_iterator_3_object();
Construct_source_3 construct_source_3 = GeomTraits().construct_source_3_object(); const Construct_source_3 construct_source_3 = GeomTraits().construct_source_3_object();
Construct_vector_3 construct_vector_3 = GeomTraits().construct_vector_3_object(); const Construct_vector_3 construct_vector_3 = GeomTraits().construct_vector_3_object();
const Point_3 source = construct_source_3(ray); const Point_3 source = construct_source_3(ray);
const Vector_3 direction = construct_vector_3(ray); const Vector_3 direction = construct_vector_3(ray);
Cartesian_const_iterator_3 source_iter = construct_cartesian_const_iterator_3(source); Cartesian_const_iterator_3 source_iter = construct_cartesian_const_iterator_3(source);
Cartesian_const_iterator_3 direction_iter = construct_cartesian_const_iterator_3(direction); Cartesian_const_iterator_3 direction_iter = construct_cartesian_const_iterator_3(direction);
for(int i = 0; i < 3; ++i, ++source_iter, ++direction_iter) { for(int i = 0; i < 3; ++i, ++source_iter, ++direction_iter) {
// we only use i as invariant to safe some checks
if(*direction_iter == 0) { if(*direction_iter == 0) {
if((*source_iter < bbox.min(i)) || (*source_iter > bbox.max(i))) { if((*source_iter < bbox.min(i)) || (*source_iter > bbox.max(i))) {
return boost::none; return boost::none;
@ -141,17 +140,17 @@ struct AABB_traits_base_2<GeomTraits,true>{
FT t1 = (bbox.min(i) - *source_iter) / *direction_iter; FT t1 = (bbox.min(i) - *source_iter) / *direction_iter;
FT t2 = (bbox.max(i) - *source_iter) / *direction_iter; FT t2 = (bbox.max(i) - *source_iter) / *direction_iter;
t_near = (std::max)(t_near, (std::min)(t1, t2));
t_far = (std::min)(t_far, (std::max)(t1, t2));
if(t1 > t2) // if(t1 > t2)
std::swap(t1, t2); // std::swap(t1, t2);
if(t1 > t_near) // if(t1 > t_near)
t_near = t1; // t_near = t1;
if(t2 < t_far) // if(t2 < t_far)
t_far = t2; // t_far = t2;
if(t_near > t_far) if(t_near > t_far || t_far < FT(0.))
return boost::none;
if(t_far < 0)
return boost::none; return boost::none;
} }
} }

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@ -152,10 +152,10 @@ private:
struct Node_ptr_with_ft { struct Node_ptr_with_ft {
Node_ptr_with_ft(const Node* node, const FT& value, size_type nb_primitives) Node_ptr_with_ft(const Node* node, const FT& value, size_type nb_primitives)
: node(node), value(value), nb_primitives(nb_primitives) {} : node(node), nb_primitives(nb_primitives), value(value) {}
const Node* node; const Node* node;
FT value;
size_type nb_primitives; size_type nb_primitives;
FT value;
bool operator<(const Node_ptr_with_ft& other) const { return value < other.value; } bool operator<(const Node_ptr_with_ft& other) const { return value < other.value; }
bool operator>(const Node_ptr_with_ft& other) const { return value > other.value; } bool operator>(const Node_ptr_with_ft& other) const { return value > other.value; }
}; };
@ -171,14 +171,13 @@ private:
FT operator()(const Point& point) { FT operator()(const Point& point) {
typename AABB_traits::Geom_traits::Vector_3 x(ray->source(), point); typename AABB_traits::Geom_traits::Vector_3 x(ray->source(), point);
typename AABB_traits::Geom_traits::Vector_3 v = ray->to_vector(); typename AABB_traits::Geom_traits::Vector_3 v = ray->to_vector();
FT dist = 0;
for(int i = 0; i < 3; ++i) { for(int i = 0; i < 3; ++i) {
if(v[0] != 0) { if(v[0] != FT(0.)) {
dist = std::max(dist, x[0] / v[0]); return x[0] / v[0];
} }
} }
return dist; return FT(0.);
} }
const Ray* ray; const Ray* ray;