HG_REPOSITORIES/LPP/INSTRUMENTATION/USERS/JEANDET/qtcharts Commit - r429:cbe57d7d97d6

Fixed a bug with last two control points calculation

Marek Rosa -

r429:cbe57d7d97d6

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r429:cbe57d7d97d6

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example/splinechart/splinewidget.cpp +13 -3

             #include "splinewidget.h"
             #include "qchartview.h"
             #include "qsplineseries.h"
             #include "qlineseries.h"
             #include <QGridLayout>
             QTCOMMERCIALCHART_USE_NAMESPACE
             SplineWidget::SplineWidget(QWidget *parent)
                 : QWidget(parent)
             {
                 //create QSplineSeries
                 QSplineSeries* series = new QSplineSeries(this);
             //    series->add(QPointF(150, 100));
             //    series->add(QPointF(200, 130));
             //    series->add(QPointF(250, 120));
             //    series->add(QPointF(300, 140));
             //    series->add(QPointF(350, 100));
             //    series->add(QPointF(400, 120));
             //    series->add(QPointF(450, 150));
             ////    series->add(QPointF(600, 150));
             //    series->add(QPointF(500, 145));
             //    series->add(QPointF(550, 170));
             //    series->add(QPointF(600, 190));
             //    series->add(QPointF(650, 210));
             //    series->add(QPointF(700, 190));
             //    series->add(QPointF(750, 180));
             //    series->add(QPointF(800, 170));
-                qsrand(time(NULL));
+            //    qsrand(time(NULL));
-                for (int i = 0; i < 100; i++)
+            //    for (int i = 0; i < 100; i++)
+            //    {
+            //        series->add(QPointF(i*7, qrand()%600));
+            //    }
+                int k = 10;
+                for (int i = 0; i < 25; i++)
                 {
-                    series->add(QPointF(i*7, qrand()%600));
+                    if (k > 60)
+                    {
+                        k = 10;
+                    }
+                    series->add(QPointF(i*50, k));
+                    k +=10;
                 }
                 series->calculateControlPoints();
             //    QLineSeries* lineSeries = new QLineSeries;
             //    for (int i = 0; i < series->count() - 1; i++)
             //    {
             //        lineSeries->add(series->at(i).x(), series->at(i).y());
             //        lineSeries->add(series->controlPoint(2*i).x(), series->controlPoint(2*i).y());
             //        lineSeries->add(series->controlPoint(2*i + 1).x(), series->controlPoint(2*i + 1).y());
             //    }
             //    QLineChartSeries* lineSeries2 = new QLineChartSeries;
             //    lineSeries2->add(10, 50);
             //    lineSeries2->add(30, 15);
             //    lineSeries2->add(60, 40);
             //    lineSeries2->add(90, 70);
             //    lineSeries2->add(100, 20);
                 //create chart view
                 QChartView* chart = new QChartView;
                 chart->setMinimumSize(800,600);
             //    chart->setGeometry(50, 50, 400, 300);
                 chart->addSeries(series);
                 QGridLayout* mainLayout = new QGridLayout;
                 mainLayout->addWidget(chart);
                 setLayout(mainLayout);
             }
             SplineWidget::~SplineWidget()
             {
             }

src/splinechart/qsplineseries.cpp +3 -3

             #include "qsplineseries.h"
             QTCOMMERCIALCHART_BEGIN_NAMESPACE
             QSplineSeries::QSplineSeries(QObject *parent) :
                 QLineSeries(parent)
             {
             }
             //QSplineSeries& QSplineSeries::operator << (const QPointF &value)
             //{
             ////    d->m_data.append(value);
             //    m_data.append(value);
             ////    emit changed();
             //    return *this;
             //}
             //void QSplineSeries::addData(QPointF value)
             //{
             //    m_data.append(value);
             //}
             void QSplineSeries::calculateControlPoints()
             {
                 // Based on http://www.codeproject.com/Articles/31859/Draw-a-Smooth-Curve-through-a-Set-of-2D-Points-wit
                 // CPOL Licence
                 int n = m_x.size() - 1;
                 if (n == 1)
                 { // Special case: Bezier curve should be a straight line.
                     //            firstControlPoints = new Point[1];
                     // 3P1 = 2P0 + P3
                     m_controlPoints.append(QPointF((2 * m_x[0] + m_x[1]) / 3, (2 * m_y[0] + m_y[1]) / 3));
                     // P2 = 2P1  P0
                     m_controlPoints.append(QPointF(2 * m_controlPoints[0].x() - m_x[0], 2 * m_controlPoints[0].y() - m_y[0]));
                     return;
                 }
                 // Calculate first Bezier control points
                 // Right hand side vector
                 //  Set of equations for P0 to Pn points.
                 //
                 //  |   2   1   0   0   ... 0   0   0   ... 0   0   0   |   |   P1_1    |   |   P0 + 2 * P1             |
                 //  |   1   4   1   0   ... 0   0   0   ... 0   0   0   |   |   P1_2    |   |   4 * P1 + 2 * P2         |
                 //  |   0   1   4   1   ... 0   0   0   ... 0   0   0   |   |   P1_3    |   |   4 * P2 + 2 * P3         |
                 //  |   .   .   .   .   .   .   .   .   .   .   .   .   |   |   ...     |   |   ...                     |
                 //  |   0   0   0   0   ... 1   4   1   ... 0   0   0   | * |   P1_i    | = |   4 * P(i-1) + 2 * Pi     |
                 //  |   .   .   .   .   .   .   .   .   .   .   .   .   |   |   ...     |   |   ...                     |
                 //  |   0   0   0   0   0   0   0   0   ... 1   4   1   |   |   P1_(n-1)|   |   4 * P(n-2) + 2 * P(n-1) |
                 //  |   0   0   0   0   0   0   0   0   ... 0   2   7   |   |   P1_n    |   |   8 * P(n-1) + Pn         |
                 //
                 QList<qreal> rhs;
                 rhs.append(m_x[0] + 2 * m_x[1]);
                 // Set right hand side X values
-                for (int i = 1; i < m_x.size() - 1; ++i)
+                for (int i = 1; i < n - 1; ++i)
                     rhs.append(4 * m_x[i] + 2 * m_x[i + 1]);
                 rhs.append((8 * m_x[n - 1] + m_x[n]) / 2.0);
                 // Get first control points X-values
                 QList<qreal> x = getFirstControlPoints(rhs);
                 rhs[0] = m_y[0] + 2 * m_y[1];
                 // Set right hand side Y values
-                for (int i = 1; i < m_y.size() - 1; ++i)
+                for (int i = 1; i < n - 1; ++i)
                     rhs[i] = 4 * m_y[i] + 2 * m_y[i + 1];
                 rhs[n - 1] = (8 * m_y[n - 1] + m_y[n]) / 2.0;
                 // Get first control points Y-values
                 QList<qreal> y = getFirstControlPoints(rhs);
                 // Fill output arrays.
                 //        firstControlPoints = new Point[n];
                 //        secondControlPoints = new Point[n];
-                for (int i = 0; i < m_x.size(); ++i)
+                for (int i = 0; i < n; ++i)
                 {
                     // First control point
                     m_controlPoints.append(QPointF(x[i], y[i]));
                     // Second control point
                     if (i < n - 1)
                         m_controlPoints.append(QPointF(2 * m_x[i + 1] - x[i + 1], 2 * m_y[i + 1] - y[i + 1]));
                     else
                         m_controlPoints.append(QPointF((m_x[n] + x[n - 1]) / 2, (m_y[n] + y[n - 1]) / 2));
                 }
             }
             QList<qreal> QSplineSeries::getFirstControlPoints(QList<qreal> rhs)
             {
                 QList<qreal> x; // Solution vector.
                 QList<qreal> tmp; // Temp workspace.
                 qreal b = 2.0;
                 x.append(rhs[0] / b);
                 tmp.append(0);
                 for (int i = 1; i < rhs.size(); i++) // Decomposition and forward substitution.
                 {
                     tmp.append(1 / b);
                     b = (i < rhs.size() - 1 ? 4.0 : 3.5) - tmp[i];
                     x.append((rhs[i] - x[i - 1]) / b);
                 }
                 for (int i = 1; i < rhs.size(); i++)
                     x[rhs.size() - i - 1] -= tmp[rhs.size() - i] * x[rhs.size() - i]; // Backsubstitution.
                 return x;
             }
             #include "moc_qsplineseries.cpp"
             QTCOMMERCIALCHART_END_NAMESPACE

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