commit 73aec484df4b906e0c4e965a828ae7db52e364a8
Author: parovoz <andrey.android7890@gmail.com>
Date:   Thu Sep 12 23:12:19 2024 +0400

    init

diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..d771ba6
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,48 @@
+cmake_minimum_required(VERSION 3.5)
+
+project(fourier LANGUAGES C CXX)
+
+set(CMAKE_CXX_STANDARD 23)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+find_package(Wt REQUIRED
+    Wt
+    HTTP
+)
+
+include(GNUInstallDirs)
+
+include_directories("src")
+
+add_executable(${PROJECT_NAME}
+    src/main.cpp
+    src/MyApplication.h
+    src/MyApplication.cpp
+)
+
+target_link_libraries(${PROJECT_NAME}
+    Wt::Wt
+    Wt::HTTP
+)
+
+configure_file(
+    run.sh.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.wt
+)
+
+install( TARGETS ${PROJECT_NAME}
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+)
+
+install( FILES       wt_config.xml   DESTINATION ${CMAKE_INSTALL_SYSCONFDIR}/${PROJECT_NAME})
+
+install(
+    FILES       ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.wt
+    DESTINATION ${CMAKE_INSTALL_BINDIR}
+    PERMISSIONS
+        OWNER_READ OWNER_WRITE OWNER_EXECUTE
+        GROUP_READ             GROUP_EXECUTE
+        WORLD_READ             WORLD_EXECUTE
+)
+
diff --git a/run.sh.in b/run.sh.in
new file mode 100644
index 0000000..13f729c
--- /dev/null
+++ b/run.sh.in
@@ -0,0 +1,25 @@
+#!/bin/bash
+
+pid=''
+run=true
+
+start() {
+  @CMAKE_INSTALL_FULL_BINDIR@/@PROJECT_NAME@ \
+    --docroot=@CMAKE_INSTALL_FULL_DATADIR@/@PROJECT_NAME@/docroot \
+    --http-address 0.0.0.0 --http-port 8080 \
+    --config @CMAKE_INSTALL_FULL_SYSCONFDIR@/@PROJECT_NAME@/wt_config.xml \
+    --resources-dir /usr/share/Wt/resources &> >(logger --tag @PROJECT_NAME@) & pid="$!"
+}
+
+shutdown() {
+  run=false
+  (( $pid )) && kill "$pid"
+}
+
+trap shutdown EXIT
+
+start
+while $run
+do
+  wait "$pid" || { logger --tag @PROJECT_NAME@ -p 3 "restarting server after error"; start; }
+done
diff --git a/src/MyApplication.cpp b/src/MyApplication.cpp
new file mode 100644
index 0000000..1e2c18d
--- /dev/null
+++ b/src/MyApplication.cpp
@@ -0,0 +1,405 @@
+#include "MyApplication.h"
+
+#include <Wt/Chart/WAbstractChartModel.h>
+#include <cfloat>
+#include <ranges>
+#include <algorithm>
+
+class SinModel : public Chart::WAbstractChartModel
+{
+public:
+    SinModel(vector<Sin>& data, int rows)
+        : Chart::WAbstractChartModel{}
+        , sinuses{data}
+        , rows_{rows}
+    { }
+
+    virtual double data(int row, int column) const override {
+        double x = -M_PI + row * 2*M_PI / (rowCount() - 1);
+        switch ( column ) {
+        case 0: return x;
+        case 1:
+            return ranges::fold_left_first(
+                sinuses | views::transform([x](Sin s){return s.get(x);}),
+                std::plus<double>()
+            ).value_or(0);
+        default:
+            try { return sinuses.at(column-2).get(x); }
+            catch (out_of_range e){ return 0; }
+        }
+    }
+    virtual int columnCount() const override { return 2 + sinuses.size(); };
+    virtual int rowCount() const override { return rows_; }
+
+    void setRows(int rows) {
+        rows_ = rows;
+        changed().emit();
+    }
+
+private:
+    int rows_;
+    vector<Sin>& sinuses;
+};
+
+
+class FourierModel : public Chart::WAbstractChartModel
+{
+public:
+    FourierModel(shared_ptr<SinModel> dm)
+        : Chart::WAbstractChartModel{}
+        , discreteModel{dm}
+    {
+        dm->changed().connect([this](){
+            data_.clear();
+            data_.reserve(rowCount());
+
+            vector<double> vals;
+            vals.reserve( discreteModel->rowCount());
+
+            double first_positive = DBL_MAX;
+            for(int i = 0; i <  discreteModel->rowCount(); i++) {
+                auto v = discreteModel->data(i, 1);
+                vals.push_back(v);
+
+                if ( abs(vals[i]) > 0 && abs(vals[i]) < first_positive )
+                    first_positive = abs(vals[i]);
+            }
+
+            for ( int k = 0; k < rowCount(); k++ ) {
+                if ( first_positive > 0 ) {
+                    double x = 0,
+                           y = 0;
+                    for ( int n = 0; n < discreteModel->rowCount(); n++ ) {
+                        double e = 2*M_PI*k*n/discreteModel->rowCount();
+                        double x = vals[n] / first_positive;
+
+                        x+=x*cos(e);
+                        y-=x*sin(e);
+                    }
+
+                    data_[k] = {sqrt(x*x+y*y), atan2(y,x)};
+                } else data_[k] = {0,0};
+            }
+
+            changed().emit();
+        });
+    }
+
+    virtual double data(int row, int column) const override {
+        //double x = row/(2*M_PI);
+        switch ( column ) {
+        case 0: return row;
+        case 1: return data_[row].first;
+        case 2: return data_[row].second;
+
+        default: return 0;
+        }
+    }
+    virtual int columnCount() const override { return 3; };
+    virtual int rowCount() const override { return discreteModel->rowCount()/2; }
+
+private:
+    shared_ptr<SinModel> discreteModel;
+    vector<pair<double, double>> data_;
+};
+
+#include <Wt/WBootstrap5Theme.h>
+
+#include <Wt/Chart/WAbstractChartModel.h>
+#include <Wt/Chart/WAxisSliderWidget.h>
+#include <Wt/Chart/WCartesianChart.h>
+#include <Wt/Chart/WDataSeries.h>
+#include <Wt/WApplication.h>
+#include <Wt/WContainerWidget.h>
+#include <Wt/WObject.h>
+#include <Wt/WShadow.h>
+
+#include <Wt/WSpinBox.h>
+#include <Wt/WDoubleSpinBox.h>
+#include <Wt/WLabel.h>
+#include <Wt/WPushButton.h>
+#include <Wt/WColorPicker.h>
+#include <Wt/WCheckBox.h>
+#include <Wt/WStandardItemModel.h>
+
+
+MyApplication::MyApplication(const WEnvironment& env)
+    : WApplication{env}
+{
+    setTheme(make_shared<WBootstrap5Theme>());
+    styleSheet().addRule("html, body", "height: 100%");
+    root()->addStyleClass("d-flex h-100");
+
+    auto left = root()->addNew<WContainerWidget>();
+    left->addStyleClass("d-flex flex-column h-100");
+
+    { // график
+        auto chartContainer = left->addNew<WContainerWidget>();
+        chart = chartContainer->addNew<Chart::WCartesianChart>();
+        //chart->setBackground(WColor(220, 220, 220));
+        chart->setType(Chart::ChartType::Scatter);
+
+
+        roughModel = make_shared<SinModel>(sinuses, 100);
+        auto roughSeries = make_unique<Chart::WDataSeries>(1, Chart::SeriesType::Line);
+        auto roughSeries_ = roughSeries.get();
+        roughSeries_->setModel(roughModel);
+        roughSeries_->setXSeriesColumn(0);
+        roughSeries->setHidden(true);
+        chart->addSeries(std::move(roughSeries));
+
+
+
+        detailedModel = make_shared<SinModel>(sinuses, 10000);
+        auto seriesPtr = make_unique<Chart::WDataSeries>(1, Chart::SeriesType::Line);
+        auto series = seriesPtr.get();
+        series->setModel(detailedModel);
+        series->setXSeriesColumn(0);
+        series->setShadow(WShadow(3, 3, WColor(0, 0, 0, 127), 3));
+        chart->addSeries(std::move(seriesPtr));
+
+        chart->setFollowCurve(series);
+
+
+        discreteModel = make_shared<SinModel>(sinuses, 0);
+        auto pointsDSPtr = make_unique<Chart::WDataSeries>(1, Chart::SeriesType::Point);
+        pointsDS = pointsDSPtr.get();
+        pointsDS->setModel(discreteModel);
+        pointsDS->setXSeriesColumn(0);
+        pointsDS->setShadow(WShadow(3, 3, WColor(0, 0, 0, 127), 3));
+        pointsDS->setHidden(true);
+        pointsDS->setLabelsEnabled(Chart::Axis::Y);
+        pointsDS->setLabelColor(StandardColor::Black);
+        chart->addSeries(std::move(pointsDSPtr));
+
+
+        chart->axis(Chart::Axis::X).setMaximumZoomRange( 2*M_PI+1 );
+        chart->axis(Chart::Axis::X).setMinimumZoomRange( M_PI / 16.0 );
+        chart->axis(Chart::Axis::X).setMinimum( -M_PI );
+        chart->axis(Chart::Axis::X).setMaximum(  M_PI );
+
+        chart->axis(Chart::Axis::Y).setMinimumZoomRange(0.1);
+
+        chart->axis(Chart::Axis::X).setLocation(Chart::AxisValue::Zero);
+        chart->axis(Chart::Axis::Y).setLocation(Chart::AxisValue::Zero);
+
+        chart->axis(Chart::Axis::X).setGridLinesEnabled(true);
+        chart->axis(Chart::Axis::Y).setGridLinesEnabled(true);
+
+
+        chart->resize(800, 600);
+
+        chart->setPanEnabled(true);
+        chart->setZoomEnabled(true);
+        chart->setCrosshairEnabled(true);
+        chart->setOnDemandLoadingEnabled(true);
+
+        auto sliderWidget = chartContainer->addNew<Chart::WAxisSliderWidget>(roughSeries_);
+        sliderWidget->resize(800, 80);
+        sliderWidget->setSelectionAreaPadding(40, Side::Left | Side::Right);
+    }
+
+    auto controlsContainer = left->addNew<WContainerWidget>();
+    controlsContainer->addStyleClass("h-100 d-flex flex-column");
+    controlsContainer->setOverflow(Overflow::Hidden);
+
+    { // функции
+        auto form = controlsContainer->addNew<WContainerWidget>();
+        form->addStyleClass("d-flex flex-row align-items-center gap-1 p-3");
+
+        list = controlsContainer->addNew<WContainerWidget>();
+        list->addStyleClass("d-flex flex-column gap-1 p-2");
+        list->setOverflow(Overflow::Auto);
+
+        showAll = form->addNew<WCheckBox>();
+        showAll->setTristate();
+        showAll->clicked().connect([=,this](){
+            for ( auto s : sinuses ) {
+                ((WCheckBox*)s.el->children().at(0))
+                    ->setChecked(showAll->isChecked());
+                s.ds->setHidden(!showAll->isChecked());
+            }
+            checkCount = showAll->isChecked() ? sinuses.size() : 0;
+            chart->update();
+        });
+
+        form->addNew<WText>("a=");
+        auto a = form->addNew<WDoubleSpinBox>();
+        form->addNew<WText>("w=");
+        auto w = form->addNew<WDoubleSpinBox>();
+        form->addNew<WText>("f=");
+        auto f = form->addNew<WDoubleSpinBox>();
+
+        for ( auto i : {a,w,f} ) {
+            i->setWidth(100);
+            i->setRange(-1000, 1000);
+        }
+
+        auto addBtn = form->addNew<WPushButton>("+");
+
+        addBtn->clicked().connect([=,this](){
+            addSin({a->value(), w->value(), f->value()});
+        });
+    }
+
+
+    auto right = root()->addNew<WContainerWidget>();
+    right->addStyleClass("d-flex flex-column h-100 gap-1");
+    right->setOverflow(Overflow::Hidden, Orientation::Horizontal);
+    { // дискретизация
+        auto form = right->addNew<WContainerWidget>();
+        form->addStyleClass("d-flex flex-row gap-3");
+
+        auto show = form->addNew<WCheckBox>("дискретизация");
+        auto freq = form->addNew<WSpinBox>();
+        freq->setWidth(120);
+        freq->setRange(0, 1000);
+
+        show->clicked().connect([=,this](){
+            pointsDS->setHidden(!show->isChecked());
+            chart->update();
+        });
+
+
+        freq->changed().connect([=,this](){
+            discreteModel->setRows(freq->value());
+        });
+
+        discreteModel->changed().connect([this](){
+            vals->clear();
+
+            for ( int i = 0; i < discreteModel->rowCount(); i++ ) {
+                auto x = discreteModel->data(i,1);
+                vals->addNew<WText>(format("{:.2f}", x))
+                    ->addStyleClass("border rounded-3 p-1");
+            }
+        });
+    }
+
+    vals = right->addNew<WContainerWidget>();
+    vals->setOverflow(Overflow::Auto, Orientation::Horizontal);
+    vals->addStyleClass("d-flex gap-1 p-1 text-nowrap");
+
+    fourierChart = right->addNew<Chart::WCartesianChart>();
+    fourierChart->setPlotAreaPadding(100);
+    fourierChart->setType(Chart::ChartType::Scatter);
+    fourierModel = make_shared<FourierModel>(discreteModel);
+    fourierChart->setModel(static_pointer_cast<Chart::WAbstractChartModel>(fourierModel));
+
+    auto seriesPtr = make_unique<Chart::WDataSeries>(2, Chart::SeriesType::Point);
+    auto phaseSeries = seriesPtr.get();
+    phaseSeries->setModel(fourierChart->model());
+    phaseSeries->setXSeriesColumn(0);
+    phaseSeries->setShadow(WShadow(3, 3, WColor(0, 0, 0, 127), 3));
+    fourierChart->addSeries(std::move(seriesPtr));
+
+
+    seriesPtr = make_unique<Chart::WDataSeries>(1, Chart::SeriesType::Line);
+    auto ampSeries = seriesPtr.get();
+    ampSeries->setModel(fourierChart->model());
+    ampSeries->setXSeriesColumn(0);
+    ampSeries->setShadow(WShadow(3, 3, WColor(0, 0, 0, 127), 3));
+    fourierChart->addSeries(std::move(seriesPtr));
+    auto id = fourierChart->addYAxis(make_unique<Chart::WAxis>());
+    ampSeries->bindToYAxis(id);
+    fourierChart->setFollowCurve(ampSeries);
+
+    fourierChart->yAxis(0).setTitle("φ");
+    fourierChart->yAxis(0).setTextPen(phaseSeries->pen());
+    fourierChart->yAxis(id).setTitle("α");
+    fourierChart->yAxis(id).setTextPen(ampSeries->pen());
+
+    fourierChart->axis(Chart::Axis::X).setLabelAngle(-90);
+
+    fourierChart->setPanEnabled(true);
+    fourierChart->setZoomEnabled(true);
+    fourierChart->setCrosshairEnabled(true);
+
+    fourierChart->resize(800, 600);
+}
+
+void MyApplication::addSin(Sin s) {
+    if ( find(sinuses.cbegin(), sinuses.cend(), s) != sinuses.cend() ) return;
+
+    sinuses.push_back(s);
+    int index = sinuses.size()-1;
+    roughModel->changed().emit();
+    detailedModel->changed().emit();
+    discreteModel->changed().emit();
+
+    auto seriesPtr = make_unique<Chart::WDataSeries>(index+2, Chart::SeriesType::Line);
+    auto series = seriesPtr.get();
+    series->setModel(detailedModel);
+    series->setXSeriesColumn(0);
+    series->setShadow({3, 3, WColor{0, 0, 0, 127}, 3});
+    series->setPen({StandardColor::Green});
+    chart->addSeries(std::move(seriesPtr));
+    sinuses[index].ds = series;
+    series->setHidden(true);
+
+    auto el = list->addNew<WContainerWidget>();
+    {
+        el->addStyleClass("border rounded-3 p-3 d-flex justify-content-between align-items-center gap-3");
+
+        auto show = el->addNew<WCheckBox>();
+        show->clicked().connect([=,this](){
+            sinuses.at(series->modelColumn()-2).ds->setHidden(!show->isChecked());
+            chart->update();
+            checkCount+= show->isChecked() ? 1 : -1;
+            showAll->setCheckState(
+                checkCount == 0 ?               CheckState::Unchecked
+                : checkCount < sinuses.size() ? CheckState::PartiallyChecked
+                                              : CheckState::Checked
+            );
+        });
+
+        auto c = el->addNew<WColorPicker>(WColor{StandardColor::Black});
+        c->setColor(StandardColor::Green);
+        c->changed().connect([=,this](){
+            sinuses.at(series->modelColumn()-2).ds->setPen(WPen{c->color()});
+            chart->update();
+        });
+        c->setWidth(50);
+
+        el->addNew<WText>(WString{"{1} cos( {2}t + {3} )"}.arg(s.a).arg(s.w).arg(s.f));
+        auto del = el->addNew<WPushButton>("x");
+        del->setStyleClass("btn-danger");
+
+        del->clicked().connect([=,this](){
+            removeSin(series->modelColumn()-2);
+            el->removeFromParent();
+        });
+    }
+
+    sinuses[index].el = el;
+
+    int freq = 2*M_PI / ranges::max_element(sinuses, [](Sin a, Sin b){return abs(a.w) > abs(b.w);})->w * 4;
+    if ( detailedModel->rowCount() < freq ) detailedModel->setRows(freq);
+    else detailedModel->setRows(10000);
+
+    showAll->setCheckState(
+        checkCount == 0 ?               CheckState::Unchecked
+        : checkCount < sinuses.size() ? CheckState::PartiallyChecked
+                                      : CheckState::Checked
+    );
+}
+
+void MyApplication::removeSin(int index) {
+    auto& s = sinuses.at(index);
+
+    chart->removeSeries(s.ds);
+    sinuses.erase(next(sinuses.begin(), index));
+
+    for ( ; index < sinuses.size(); index++ )
+        sinuses[index].ds->setModelColumn(index+2);
+
+       roughModel->changed().emit();
+    detailedModel->changed().emit();
+    discreteModel->changed().emit();
+
+    showAll->setCheckState(
+        checkCount == 0 ?               CheckState::Unchecked
+        : checkCount < sinuses.size() ? CheckState::PartiallyChecked
+                                      : CheckState::Checked
+    );
+}
diff --git a/src/MyApplication.h b/src/MyApplication.h
new file mode 100644
index 0000000..2a53d3e
--- /dev/null
+++ b/src/MyApplication.h
@@ -0,0 +1,60 @@
+#pragma once
+
+#include <Wt/WApplication.h>
+#include <cmath>
+
+using namespace Wt;
+using namespace std;
+
+
+struct sin {
+    double a;
+    double w;
+    double f;
+
+    Chart::WDataSeries* ds;
+    WContainerWidget* el;
+
+    double get(double t) const
+    { return a*cos(w*t+f); }
+
+    bool operator ==(const sin& other) const {
+        return a == other.a && w == other.w && f == other.f;
+    }
+
+    bool operator <(const sin& other) const {
+        return (a+w+f) < (other.a + other.w + other.f);
+    }
+};
+typedef struct sin Sin;
+
+class SinModel;
+class FourierModel;
+
+class MyApplication : public WApplication
+{
+public:
+    MyApplication(const WEnvironment& env);
+
+private:
+    Chart::WCartesianChart* chart;
+    shared_ptr<SinModel> roughModel;
+    shared_ptr<SinModel> detailedModel;
+    shared_ptr<SinModel> discreteModel;
+    Chart::WDataSeries* pointsDS;
+
+    Chart::WCartesianChart* fourierChart;
+    shared_ptr<FourierModel> fourierModel;
+
+
+    WContainerWidget* list;
+    WCheckBox* showAll;
+    size_t checkCount = 0;
+
+    WContainerWidget* vals;
+
+    vector<Sin> sinuses;
+
+    void addSin(Sin s);
+    void removeSin(int index);
+};
diff --git a/src/main.cpp b/src/main.cpp
new file mode 100644
index 0000000..5db3ed5
--- /dev/null
+++ b/src/main.cpp
@@ -0,0 +1,28 @@
+#include <Wt/WServer.h>
+
+#include "MyApplication.h"
+
+using namespace std;
+using namespace Wt;
+
+
+int main(int argc, char *argv[]) {
+    int code = 0;
+
+    try {
+        WServer server(argc, argv, WTHTTP_CONFIGURATION);
+
+        using namespace placeholders;
+
+        server.addEntryPoint( EntryPointType::Application,
+            [](const WEnvironment& env){return make_unique<MyApplication>(env);},
+            "/"
+        );
+
+        server.run();
+    }
+    catch ( WServer::Exception& e ) { cerr <<                  e.what() << endl; code = -1; }
+    catch (     std::exception& e ) { cerr << "exception: " << e.what() << endl; code = -1; }
+
+    return code;
+}
diff --git a/wt_config.xml b/wt_config.xml
new file mode 100644
index 0000000..946dcc5
--- /dev/null
+++ b/wt_config.xml
@@ -0,0 +1,55 @@
+<!--
+    Wt Configuration File.
+
+    The Wt configuration file manages, for every Wt application, settings
+    for session management, debugging, directory for runtime information
+    such as session sockets, and some security settings.
+
+    Settings may be specified globally, or for a single application path.
+
+    The path should be as configured in the Wt build process, where it
+    defaults to /etc/wt/wt_config.xml. It can be overridden in the environment
+    variable WT_CONFIG_XML, or with the -c startup option of wthttp.
+
+    The values listed here are the default values, which are used when the
+    declaration is missing or no configuration file is used.
+  -->
+
+<server>
+    <application-settings location="*">
+        <web-sockets>true</web-sockets>
+        <progressive-bootstrap>false</progressive-bootstrap>
+        <head-matter user-agent=".*">
+            <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />
+        </head-matter>
+
+        <behind-reverse-proxy>true</behind-reverse-proxy>
+
+        <trusted-proxy-config>
+          <original-ip-header>X-Forwarded-For</original-ip-header>
+          <trusted-proxies>
+            <!-- loopback -->
+
+            <proxy>127.0.0.1/8</proxy>
+            <proxy>::1/128</proxy>
+
+            <!-- link local -->
+            <!--
+            <proxy>169.254.0.0/16</proxy>
+            <proxy>fe80::/10</proxy>
+            -->
+            <!-- local -->
+            <!--
+            <proxy>10.0.0.0/8</proxy>
+            <proxy>172.16.0.0/12</proxy>
+            <proxy>192.168.0.0/16</proxy>
+            <proxy>fc00::/7</proxy>
+            -->
+          </trusted-proxies>
+        </trusted-proxy-config>
+
+        <properties>
+        </properties>
+
+    </application-settings>
+</server>