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Move tolerance calculation to its own class.

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This commit is contained in:
Hermann Kraus 2012-08-19 12:32:27 +02:00
parent accbc139a5
commit d4ef591a99
1 changed files with 55 additions and 14 deletions
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63
src/text/placement_finder_ng.cpp
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@ -42,6 +42,55 @@
namespace mapnik
{
class tolerance_iterator
{
public:
tolerance_iterator(double label_position_tolerance, double spacing)
: tolerance_(label_position_tolerance > 0 ?
label_position_tolerance : spacing/2.0),
tolerance_delta_(std::max(1.0, tolerance_/100.0)),
value_(0),
initialized_(false),
values_tried_(0)
{
}
~tolerance_iterator()
{
//std::cout << "values tried:" << values_tried_ << "\n";
}
double get() const
{
return value_;
}
bool next()
{
values_tried_ ++;
if (!initialized_)
{
initialized_ = true;
return true; //Always return value 0 as the first value.
}
if (value_ == 0)
{
value_ = tolerance_delta_;
return true;
}
value_ = -value_;
if (value_ > 0) value_ += tolerance_delta_;
if (value_ > tolerance_) return false;
return true;
}
private:
double tolerance_;
double tolerance_delta_;
double value_;
bool initialized_;
unsigned values_tried_;
};
placement_finder_ng::placement_finder_ng(Feature const& feature, DetectorType &detector, box2d<double> const& extent, text_placement_info_ptr placement_info, face_manager_freetype &font_manager, double scale_factor)
: feature_(feature), detector_(detector), extent_(extent), layout_(font_manager), info_(placement_info), valid_(true), scale_factor_(scale_factor), placements_(), has_marker_(false), marker_(), marker_box_()
{
@ -268,29 +317,21 @@ bool placement_finder_ng::find_line_placements(T & path)
double spacing = get_spacing(pp.length(), layout_.width());
double tolerance = info_->properties.label_position_tolerance > 0 ?
info_->properties.label_position_tolerance : spacing/2.0;
double tolerance_delta = std::max(1.0, tolerance/100.0);
// first label should be placed at half the spacing
pp.forward(spacing/2);
path_move_dx(pp);
do
{
tolerance_iterator tolerance_offset(info_->properties.label_position_tolerance, spacing);
vertex_cache::state state = pp.save_state();
for (double diff = 0; diff < tolerance; diff += tolerance_delta)
while (tolerance_offset.next())
{
for(int dir = -1; dir < 2; dir+=2) //-1, +1
{
if (pp.move(dir * diff) && single_line_placement(pp, info_->properties.upright))
if (pp.move(tolerance_offset.get()) && single_line_placement(pp, info_->properties.upright))
{
success = true;
diff = tolerance; // Break out of outer loop
break;
}
pp.restore_state(state);
if (diff == 0) continue;
}
}
} while (pp.forward(spacing));
}