Spline/GeneratorDialog.hpp

#pragma once
#include <Process/Script/ScriptEditor.hpp>
 
#include <ossia/math/math_expression.hpp>
 
#include <QDialog>
#include <QDoubleSpinBox>
#include <QFormLayout>
#include <QHBoxLayout>
 
#include <cmath>
 
#include <Spline/Commands.hpp>
 
namespace Spline
{
class GeneratorDialog : public Process::ScriptDialog
{
public:
  GeneratorDialog(
      const ProcessModel& model, const score::DocumentContext& ctx, QWidget* parent)
      : Process::ScriptDialog{"exprtk", ctx, parent}
      , m_model{model}
  {
    auto step = new QDoubleSpinBox{this};
    step->setRange(0.0001, 0.3);
    step->setValue(m_step);
    step->setSingleStep(0.001);
    step->setDecimals(8);
    // step->setStepType(QSpinBox::AdaptiveDecimalStepType);
    auto lay = static_cast<QBoxLayout*>(this->layout());
    auto controls = new QFormLayout;
    controls->addRow("Step (smaller is more precise)", step);
    lay->insertLayout(2, controls);
    connect(
        step, qOverload<double>(&QDoubleSpinBox::valueChanged), this,
        [this](double step) { m_step = step; });
 
    expr.add_variable("t", t);
    expr.add_variable("x", x);
    expr.add_variable("y", y);
    expr.add_constants();
    expr.register_symbol_table();
 
    setText(R"_(x := cos(2 * pi * t);
y := sin(2 * pi * t);
)_");
  }
 
  void on_accepted() override
  {
    this->setError(0, QString{});
    auto txt = this->text().toStdString();
    bool ok = expr.set_expression(txt);
    if(!ok)
    {
      setError(0, QString::fromStdString(expr.error()));
      return;
    }
    else
    {
      ossia::spline_data data;
      QString error;
      auto add_point = [&] {
        expr.value();
        if(expr.interrupted())
          error = tr("The expression runs for too long (a loop does not end)");
        else if(!(std::isfinite(x) && std::isfinite(y)))
          error = tr("The expression gives an undefined point at t = %1").arg(t);
        else
          data.points.push_back({x, y});
        return error.isEmpty();
      };
      bool complete = true;
      for(t = 0.; t < 1. && complete; t += m_step)
        complete = add_point();
      if(complete)
      {
        t = 1.;
        complete = add_point();
      }
      if(!complete)
      {
        setError(0, error);
        return;
      }
 
      CommandDispatcher<>{m_context.commandStack}.submit<ChangeSpline>(
          m_model, std::move(data));
    }
  }
  double t{}, x{}, y{};
  double m_step{0.03};
  ossia::math_expression expr;
 
  const ProcessModel& m_model;
};
 
}