psemek/libs/ui/source/impl/move_base.cpp

85 lines
1.9 KiB
C++

#include <psemek/ui/impl/move_base.hpp>
#include <psemek/react/join.hpp>
#include <psemek/react/map.hpp>
namespace psemek::ui::impl
{
namespace
{
geom::box<float, 2> compute_child_shape(geom::box<float, 2> const & shape, geom::vector<float, 2> const & offset)
{
return shape + offset;
}
}
move_base::move_base()
: offset_({0.f, 0.f})
, animation_speed_(0.f)
, child_size_constraints_(size_constraints::max())
, size_constraints_(react::join(child_size_constraints_))
, current_offset_{0.f, 0.f}
{}
void move_base::reshape(geom::box<float, 2> const & new_shape)
{
single_container::reshape(new_shape);
if (auto child = this->child())
child->reshape(compute_child_shape(new_shape, current_offset_));
}
react::value<struct size_constraints> move_base::size_constraints() const
{
return size_constraints_;
}
void move_base::set_child(std::unique_ptr<component> child)
{
if (child)
child_size_constraints_.set(child->size_constraints());
else
child_size_constraints_.set(size_constraints::max());
single_container::set_child(std::move(child));
}
std::unique_ptr<component> move_base::release_child()
{
child_size_constraints_.set(size_constraints::max());
return single_container::release_child();
}
void move_base::animate(float dt)
{
if (*animation_speed_ == 0.f)
{
if (current_offset_ != *offset_)
{
current_offset_ = *offset_;
reshape(shape());
}
}
else
{
auto factor = - std::expm1(- dt * (*animation_speed_));
auto new_offset = geom::lerp(current_offset_, *offset_, factor);
if (geom::length(current_offset_ - new_offset) < 1.f / 16.f)
new_offset = *offset_;
if (current_offset_ != *offset_)
{
current_offset_ = new_offset;
reshape(shape());
}
}
}
void move_base::update(move const & value)
{
offset_ = value.offset;
animation_speed_ = value.animation_speed;
}
}