File indexing completed on 2024-05-19 15:09:25

 /*
     This file is part of the KDE project
 
     SPDX-FileCopyrightText: 2014 Fredrik Höglund <fredrik@kde.org>
     SPDX-FileCopyrightText: 2014 Marco Martin <mart@kde.org>
     SPDX-FileCopyrightText: 2015 David Edmundson <davidedmundson@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "plotter.h"
 
 #include <QOpenGLContext>
 #include <QOpenGLShaderProgram>
 
 #include <QPainterPath>
 #include <QPolygonF>
 
 #include <QMatrix4x4>
 #include <QVector2D>
 
 #include <QSGSimpleTextureNode>
 #include <QSGTexture>
 
 #include <QDebug>
 
 #include <math.h>
 
 // completely arbitrary
 static int s_defaultSampleSize = 40;
 
 PlotData::PlotData(QObject *parent)
     : QObject(parent)
     , m_min(std::numeric_limits<qreal>::max())
     , m_max(std::numeric_limits<qreal>::min())
     , m_sampleSize(s_defaultSampleSize)
 {
     m_values.reserve(s_defaultSampleSize);
     for (int i = 0; i < s_defaultSampleSize; ++i) {
         m_values << 0.0;
     }
 }
 
 void PlotData::setColor(const QColor &color)
 {
     if (m_color == color) {
         return;
     }
 
     m_color = color;
 
     Q_EMIT colorChanged();
 }
 
 QColor PlotData::color() const
 {
     return m_color;
 }
 
 qreal PlotData::max() const
 {
     return m_max;
 }
 
 qreal PlotData::min() const
 {
     return m_min;
 }
 
 void PlotData::setSampleSize(int size)
 {
     if (m_sampleSize == size) {
         return;
     }
 
     m_values.reserve(size);
     if (m_values.size() > size) {
         const int numberToRemove = (m_values.size() - size);
         for (int i = 0; i < numberToRemove; ++i) {
             m_values.removeFirst();
         }
     } else if (m_values.size() < size) {
         const int numberToAdd = (size - m_values.size());
         for (int i = 0; i < numberToAdd; ++i) {
             m_values.prepend(0.0);
         }
     }
 
     m_sampleSize = size;
 }
 
 QString PlotData::label() const
 {
     return m_label;
 }
 
 void PlotData::setLabel(const QString &label)
 {
     if (m_label == label) {
         return;
     }
 
     m_label = label;
     Q_EMIT labelChanged();
 }
 
 void PlotData::addSample(qreal value)
 {
     // assume at this point we'll have to pop a single time to stay in size
     if (m_values.size() >= m_sampleSize) {
         m_values.removeFirst();
     }
 
     m_values.push_back(value);
 
     m_max = std::numeric_limits<qreal>::min();
     m_min = std::numeric_limits<qreal>::max();
     for (auto v : std::as_const(m_values)) {
         if (v > m_max) {
             m_max = v;
         } else if (v < m_min) {
             m_min = v;
         }
     }
 
     Q_EMIT valuesChanged();
 }
 
 QList<qreal> PlotData::values() const
 {
     return m_values;
 }
 
 const char *vs_source =
     "attribute vec4 vertex;\n"
     "varying float gradient;\n"
 
     "uniform mat4 matrix;\n"
     "uniform float yMin;\n"
     "uniform float yMax;\n"
 
     "void main(void) {\n"
     "    gradient = (vertex.y - yMin) / (yMax - yMin);"
     "    gl_Position = matrix * vertex;\n"
     "}";
 
 const char *fs_source =
     "uniform vec4 color1;\n"
     "uniform vec4 color2;\n"
 
     "varying float gradient;\n"
 
     "void main(void) {\n"
     "    gl_FragColor = mix(color1, color2, gradient);\n"
     "}";
 
 // --------------------------------------------------
 
 class PlotTexture : public QSGTexture
 {
 public:
     PlotTexture(QOpenGLContext *ctx);
     ~PlotTexture() override;
 
     void bind() override final;
     bool hasAlphaChannel() const override final
     {
         return true;
     }
     bool hasMipmaps() const override final
     {
         return false;
     }
     int textureId() const override final
     {
         return m_texture;
     }
     QSize textureSize() const override final
     {
         return m_size;
     }
 
     void recreate(const QSize &size);
     GLuint fbo() const
     {
         return m_fbo;
     }
 
 private:
     GLuint m_texture = 0;
     GLuint m_fbo = 0;
     GLenum m_internalFormat;
     bool m_haveTexStorage;
     QSize m_size;
 };
 
 PlotTexture::PlotTexture(QOpenGLContext *ctx)
     : QSGTexture()
 {
     QPair<int, int> version = ctx->format().version();
 
     if (ctx->isOpenGLES()) {
         m_haveTexStorage = version >= qMakePair(3, 0) || ctx->hasExtension("GL_EXT_texture_storage");
         m_internalFormat = m_haveTexStorage ? GL_RGBA8 : GL_RGBA;
     } else {
         m_haveTexStorage = version >= qMakePair(4, 2) || ctx->hasExtension("GL_ARB_texture_storage");
         m_internalFormat = GL_RGBA8;
     }
 
     glGenFramebuffers(1, &m_fbo);
 }
 
 PlotTexture::~PlotTexture()
 {
     if (m_texture) {
         glDeleteTextures(1, &m_texture);
     }
 
     glDeleteFramebuffers(1, &m_fbo);
 }
 
 void PlotTexture::bind()
 {
     glBindTexture(GL_TEXTURE_2D, m_texture);
 }
 
 void PlotTexture::recreate(const QSize &size)
 {
     if (m_texture) {
         glDeleteTextures(1, &m_texture);
     }
 
     glGenTextures(1, &m_texture);
     glBindTexture(GL_TEXTURE_2D, m_texture);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
 
     if (m_haveTexStorage) {
         glTexStorage2D(GL_TEXTURE_2D, 1, m_internalFormat, size.width(), size.height());
     } else {
         glTexImage2D(GL_TEXTURE_2D, 0, m_internalFormat, size.width(), size.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
     }
 
     glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
     glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_texture, 0);
 
     m_size = size;
 }
 
 class PlotSGNode : public QSGSimpleTextureNode
 {
 public:
     PlotSGNode();
     void bind()
     {
         m_program->bind();
     }
     void setMatrix(const QMatrix4x4 &matrix)
     {
         m_program->setUniformValue(u_matrix, matrix);
     }
     void setColor1(const QColor &color)
     {
         m_program->setUniformValue(u_color1, color);
     }
     void setColor2(const QColor &color)
     {
         m_program->setUniformValue(u_color2, color);
     }
     void setYMin(float min)
     {
         m_program->setUniformValue(u_yMin, min);
     }
     void setYMax(float max)
     {
         m_program->setUniformValue(u_yMax, max);
     }
     ~PlotSGNode() override = default;
 
 private:
     std::unique_ptr<QOpenGLShaderProgram> m_program;
     int u_matrix;
     int u_color1;
     int u_color2;
     int u_yMin;
     int u_yMax;
 };
 
 PlotSGNode::PlotSGNode()
     : m_program(std::make_unique<QOpenGLShaderProgram>())
 {
     setOwnsTexture(true);
     m_program->addCacheableShaderFromSourceCode(QOpenGLShader::Vertex, vs_source);
     m_program->addCacheableShaderFromSourceCode(QOpenGLShader::Fragment, fs_source);
     m_program->bindAttributeLocation("vertex", 0);
     m_program->link();
 
     u_yMin = m_program->uniformLocation("yMin");
     u_yMax = m_program->uniformLocation("yMax");
     u_color1 = m_program->uniformLocation("color1");
     u_color2 = m_program->uniformLocation("color2");
     u_matrix = m_program->uniformLocation("matrix");
 }
 
 // ----------------------
 
 Plotter::Plotter(QQuickItem *parent)
     : QQuickItem(parent)
     , m_min(0)
     , m_max(0)
     , m_rangeMax(0)
     , m_rangeMin(0)
     , m_sampleSize(s_defaultSampleSize)
     , m_horizontalLineCount(5)
     , m_stacked(true)
     , m_autoRange(true)
 {
     setFlag(ItemHasContents);
     connect(this, &Plotter::windowChanged, this, [this]() {
         if (m_window) {
             disconnect(m_window.data(), &QQuickWindow::beforeRendering, this, &Plotter::render);
         }
         m_window.clear();
         // when the window changes, the node gets deleted
         m_node = nullptr;
     });
 }
 
 Plotter::~Plotter()
 {
 }
 
 qreal Plotter::max() const
 {
     return m_max;
 }
 
 qreal Plotter::min() const
 {
     return m_min;
 }
 
 int Plotter::sampleSize() const
 {
     return m_sampleSize;
 }
 
 void Plotter::setSampleSize(int size)
 {
     if (m_sampleSize == size) {
         return;
     }
 
     m_sampleSize = size;
 
     m_mutex.lock();
     for (auto data : std::as_const(m_plotData)) {
         data->setSampleSize(size);
     }
     m_mutex.unlock();
 
     update();
     Q_EMIT sampleSizeChanged();
 }
 
 bool Plotter::isStacked() const
 {
     return m_stacked;
 }
 
 void Plotter::setStacked(bool stacked)
 {
     if (m_stacked == stacked) {
         return;
     }
 
     m_stacked = stacked;
 
     Q_EMIT stackedChanged();
     update();
 }
 
 bool Plotter::isAutoRange() const
 {
     return m_autoRange;
 }
 
 void Plotter::setAutoRange(bool autoRange)
 {
     if (m_autoRange == autoRange) {
         return;
     }
 
     m_autoRange = autoRange;
 
     Q_EMIT autoRangeChanged();
     normalizeData();
     update();
 }
 
 qreal Plotter::rangeMax() const
 {
     if (m_autoRange) {
         return m_max;
     } else {
         return m_rangeMax;
     }
 }
 
 void Plotter::setRangeMax(qreal max)
 {
     if (m_rangeMax == max) {
         return;
     }
 
     m_rangeMax = max;
 
     Q_EMIT rangeMaxChanged();
     normalizeData();
     update();
 }
 
 qreal Plotter::rangeMin() const
 {
     if (m_autoRange) {
         return m_min;
     } else {
         return m_rangeMin;
     }
 }
 
 void Plotter::setRangeMin(qreal min)
 {
     if (m_rangeMin == min) {
         return;
     }
 
     m_rangeMin = min;
 
     Q_EMIT rangeMinChanged();
     normalizeData();
     update();
 }
 
 void Plotter::setGridColor(const QColor &color)
 {
     if (m_gridColor == color) {
         return;
     }
 
     m_gridColor = color;
 
     Q_EMIT gridColorChanged();
 }
 
 QColor Plotter::gridColor() const
 {
     return m_gridColor;
 }
 
 int Plotter::horizontalGridLineCount()
 {
     return m_horizontalLineCount;
 }
 
 void Plotter::setHorizontalGridLineCount(int count)
 {
     if (m_horizontalLineCount == count) {
         return;
     }
 
     m_horizontalLineCount = count;
     Q_EMIT horizontalGridLineCountChanged();
 }
 
 void Plotter::addSample(qreal value)
 {
     if (m_plotData.count() != 1) {
         qWarning() << "Must add a new value per data set, pass an array of values instead";
         return;
     }
 
     addSample(QList<qreal>() << value);
 }
 
 void Plotter::addSample(const QList<qreal> &value)
 {
     if (value.count() != m_plotData.count()) {
         qWarning() << "Must add a new value per data set";
         return;
     }
 
     int i = 0;
     m_mutex.lock();
     for (auto data : std::as_const(m_plotData)) {
         data->addSample(value.value(i));
         ++i;
     }
     m_mutex.unlock();
 
     normalizeData();
 
     update();
 }
 
 void Plotter::dataSet_append(QQmlListProperty<PlotData> *list, PlotData *item)
 {
     // encase all m_plotData access in a mutex, since rendering is usually done in another thread
     Plotter *p = static_cast<Plotter *>(list->object);
     p->m_mutex.lock();
     p->m_plotData.append(item);
     p->m_mutex.unlock();
 }
 
 int Plotter::dataSet_count(QQmlListProperty<PlotData> *list)
 {
     Plotter *p = static_cast<Plotter *>(list->object);
     return p->m_plotData.count();
 }
 
 PlotData *Plotter::dataSet_at(QQmlListProperty<PlotData> *list, int index)
 {
     Plotter *p = static_cast<Plotter *>(list->object);
     p->m_mutex.lock();
     PlotData *d = p->m_plotData.at(index);
     p->m_mutex.unlock();
     return d;
 }
 
 void Plotter::dataSet_clear(QQmlListProperty<PlotData> *list)
 {
     Plotter *p = static_cast<Plotter *>(list->object);
 
     p->m_mutex.lock();
     p->m_plotData.clear();
     p->m_mutex.unlock();
 }
 
 QQmlListProperty<PlotData> Plotter::dataSets()
 {
     return QQmlListProperty<PlotData>(this, nullptr, Plotter::dataSet_append, Plotter::dataSet_count, Plotter::dataSet_at, Plotter::dataSet_clear);
 }
 
 // Catmull-Rom interpolation
 QPainterPath Plotter::interpolate(const QVector<qreal> &p, qreal x0, qreal x1) const
 {
     QPainterPath path;
 
     /* clang-format off */
     const QMatrix4x4 matrix( 0,    1,    0,     0,
                             -1/6., 1,    1/6.,  0,
                              0,    1/6., 1,    -1/6.,
                              0,    0,    1,     0);
     /* clang-format on */
 
     const qreal xDelta = (x1 - x0) / (p.count() - 3);
     qreal x = x0 - xDelta;
 
     path.moveTo(x0, p[0]);
 
     for (int i = 1; i < p.count() - 2; i++) {
         /* clang-format off */
         const QMatrix4x4 points(x,              p[i-1], 0, 0,
                                 x + xDelta * 1, p[i+0], 0, 0,
                                 x + xDelta * 2, p[i+1], 0, 0,
                                 x + xDelta * 3, p[i+2], 0, 0);
 
         const QMatrix4x4 res = matrix * points;
 
         path.cubicTo(res(1, 0), res(1, 1),
                      res(2, 0), res(2, 1),
                      res(3, 0), res(3, 1));
         /* clang-format on */
 
         x += xDelta;
     }
 
     return path;
 }
 
 void Plotter::render()
 {
     if (!window() || !m_node || !m_node->texture()) {
         return;
     }
 
     GLuint rb;
 
     if (m_haveMSAA && m_haveFramebufferBlit) {
         // Allocate a temporary MSAA renderbuffer
         glGenRenderbuffers(1, &rb);
         glBindRenderbuffer(GL_RENDERBUFFER, rb);
         glRenderbufferStorageMultisample(GL_RENDERBUFFER, m_samples, m_internalFormat, width(), height());
 
         // Attach it to the framebuffer object
         glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
         glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, rb);
     } else {
         // If we don't have MSAA support we render directly into the texture
         glBindFramebuffer(GL_FRAMEBUFFER, static_cast<PlotTexture *>(m_node->texture())->fbo());
     }
 
     glViewport(0, 0, width(), height());
 
     // Clear the color buffer
     glClearColor(0.0, 0.0, 0.0, 0.0);
     glClear(GL_COLOR_BUFFER_BIT);
 
     // Add horizontal lines
     qreal lineSpacing = height() / m_horizontalLineCount;
 
     QVector<QVector2D> vertices;
 
     // don't draw the bottom line that will come later
     for (int i = 0; i < m_horizontalLineCount; i++) {
         int lineY = ceil(i * lineSpacing) + 1; // floor +1 makes the entry at point 0 on pixel 1
         vertices << QVector2D(0, lineY) << QVector2D(width(), lineY);
     }
     // bottom line
     vertices << QVector2D(0, height() - 1) << QVector2D(width(), height() - 1);
 
     // Tessellate
     float min = height();
     float max = height();
 
     QHash<PlotData *, QPair<int, int>> verticesCounts;
 
     // encase all m_plotData access in a mutex, since rendering is usually done in another thread
     m_mutex.lock();
     int roundedHeight = qRound(height());
     int roundedWidth = qRound(width());
 
     for (auto data : std::as_const(m_plotData)) {
         // Interpolate the data set
         const QPainterPath path = interpolate(data->m_normalizedValues, 0, roundedWidth);
 
         // Flatten the path
         const QList<QPolygonF> polygons = path.toSubpathPolygons();
 
         for (const QPolygonF &p : polygons) {
             verticesCounts[data].first = 0;
             vertices << QVector2D(p.first().x(), roundedHeight);
 
             for (int i = 0; i < p.count() - 1; i++) {
                 min = qMin<float>(min, roundedHeight - p[i].y());
                 vertices << QVector2D(p[i].x(), roundedHeight - p[i].y());
                 vertices << QVector2D((p[i].x() + p[i + 1].x()) / 2.0, roundedHeight);
                 verticesCounts[data].first += 2;
             }
 
             min = qMin<float>(min, roundedHeight - p.last().y());
             vertices << QVector2D(p.last().x(), roundedHeight - p.last().y());
             vertices << QVector2D(p.last().x(), roundedHeight);
             verticesCounts[data].first += 3;
         }
 
         for (const QPolygonF &p : polygons) {
             verticesCounts[data].second = 0;
 
             for (int i = 0; i < p.count() - 1; i++) {
                 min = qMin<float>(min, roundedHeight - p[i].y());
                 vertices << QVector2D(p[i].x(), roundedHeight - p[i].y());
                 verticesCounts[data].second += 1;
             }
 
             vertices << QVector2D(p.last().x(), roundedHeight - p.last().y());
             verticesCounts[data].second += 1;
             min = qMin<float>(min, roundedHeight - p.last().y());
         }
     }
     m_mutex.unlock();
 
     // Upload vertices
     GLuint vbo;
     glGenBuffers(1, &vbo);
 
     glBindBuffer(GL_ARRAY_BUFFER, vbo);
     glBufferData(GL_ARRAY_BUFFER, vertices.count() * sizeof(QVector2D), vertices.constData(), GL_STATIC_DRAW);
 
     // Set up the array
     glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(QVector2D), nullptr);
     glEnableVertexAttribArray(0);
 
     // Bind the shader program
     m_node->bind();
     m_node->setMatrix(m_matrix);
 
     // Draw the lines
     QColor color1 = m_gridColor;
     QColor color2 = m_gridColor;
     color1.setAlphaF(0.10);
     color2.setAlphaF(0.40);
     m_node->setYMin((float)0.0);
     m_node->setYMax((float)height());
     m_node->setColor1(color1);
     m_node->setColor2(color2);
 
     glDrawArrays(GL_LINES, 0, (m_horizontalLineCount + 1) * 2);
 
     // Enable alpha blending
     glEnable(GL_BLEND);
     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
     QPair<int, int> oldCount;
     m_mutex.lock();
     for (auto data : std::as_const(m_plotData)) {
         color2 = data->color();
         color2.setAlphaF(0.60);
         // Draw the graph
         m_node->setYMin(min);
         m_node->setYMax(max);
         m_node->setColor1(data->color());
         m_node->setColor2(color2);
 
         //+2 is for the bottom line
         glDrawArrays(GL_TRIANGLE_STRIP, m_horizontalLineCount * 2 + 2 + oldCount.first + oldCount.second, verticesCounts[data].first);
 
         oldCount.first += verticesCounts[data].first;
 
         m_node->setColor1(data->color());
         m_node->setColor2(data->color());
         glDrawArrays(GL_LINE_STRIP, m_horizontalLineCount * 2 + 2 + oldCount.first + oldCount.second, verticesCounts[data].second);
 
         oldCount.second += verticesCounts[data].second;
     }
     m_mutex.unlock();
 
     glDisable(GL_BLEND);
 
     m_node->setColor1(m_gridColor);
     m_node->setColor2(m_gridColor);
     glDrawArrays(GL_LINES, vertices.count() - 2, 2);
 
     if (m_haveMSAA && m_haveFramebufferBlit) {
         // Resolve the MSAA buffer
         glBindFramebuffer(GL_READ_FRAMEBUFFER, m_fbo);
         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, static_cast<PlotTexture *>(m_node->texture())->fbo());
         glBlitFramebuffer(0, 0, width(), height(), 0, 0, width(), height(), GL_COLOR_BUFFER_BIT, GL_NEAREST);
 
         // Delete the render buffer
         glDeleteRenderbuffers(1, &rb);
     }
 
     // Delete the VBO
     glDeleteBuffers(1, &vbo);
 }
 
 QSGNode *Plotter::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *updatePaintNodeData)
 {
     Q_UNUSED(updatePaintNodeData)
     if (!window()->openglContext()) {
         delete oldNode;
         return nullptr;
     }
 
     PlotSGNode *n = static_cast<PlotSGNode *>(oldNode);
 
     if (width() == 0 && height() == 0) {
         delete oldNode;
         return nullptr;
     }
 
     if (!n) {
         n = new PlotSGNode();
         n->setTexture(new PlotTexture(window()->openglContext()));
         n->setFiltering(QSGTexture::Linear);
 
         m_node = n;
         if (m_window) {
             disconnect(m_window.data(), &QQuickWindow::beforeRendering, this, &Plotter::render);
         }
         connect(window(), &QQuickWindow::beforeRendering, this, &Plotter::render, Qt::DirectConnection);
         m_window = window();
     }
 
     if (!m_initialized) {
         glGenFramebuffers(1, &m_fbo);
 
         QOpenGLContext *ctx = window()->openglContext();
         QPair<int, int> version = ctx->format().version();
 
         if (ctx->isOpenGLES()) {
             m_haveMSAA = version >= qMakePair(3, 0) || ctx->hasExtension("GL_NV_framebuffer_multisample");
             m_haveFramebufferBlit = version >= qMakePair(3, 0) || ctx->hasExtension("GL_NV_framebuffer_blit");
             m_haveInternalFormatQuery = version >= qMakePair(3, 0);
             m_internalFormat = version >= qMakePair(3, 0) ? GL_RGBA8 : GL_RGBA;
         } else {
             /* clang-format off */
             m_haveMSAA = version >= qMakePair(3, 2)
                          || ctx->hasExtension("GL_ARB_framebuffer_object")
                          || ctx->hasExtension("GL_EXT_framebuffer_multisample");
 
             m_haveFramebufferBlit = version >= qMakePair(3, 0)
                                     || ctx->hasExtension("GL_ARB_framebuffer_object")
                                     || ctx->hasExtension("GL_EXT_framebuffer_blit");
             /* clang-format on */
 
             m_haveInternalFormatQuery = version >= qMakePair(4, 2) || ctx->hasExtension("GL_ARB_internalformat_query");
             m_internalFormat = GL_RGBA8;
         }
 
         // Query the maximum sample count for the internal format
         if (m_haveInternalFormatQuery) {
             int count = 0;
             glGetInternalformativ(GL_RENDERBUFFER, m_internalFormat, GL_NUM_SAMPLE_COUNTS, 1, &count);
 
             if (count > 0) {
                 QVector<int> samples(count);
                 glGetInternalformativ(GL_RENDERBUFFER, m_internalFormat, GL_SAMPLES, count, samples.data());
 
                 // The samples are returned in descending order. Choose the highest value.
                 m_samples = samples.at(0);
             } else {
                 m_samples = 0;
             }
         } else if (m_haveMSAA) {
             glGetIntegerv(GL_MAX_SAMPLES, &m_samples);
         } else {
             m_samples = 0;
         }
 
         m_initialized = true;
     }
 
     // we need a size always equal or smaller, size.toSize() won't do
     const QSize targetTextureSize(qRound(boundingRect().size().width()), qRound(boundingRect().size().height()));
     if (n->texture()->textureSize() != targetTextureSize) {
         static_cast<PlotTexture *>(n->texture())->recreate(targetTextureSize);
         m_matrix = QMatrix4x4();
         m_matrix.ortho(0, targetTextureSize.width(), 0, targetTextureSize.height(), -1, 1);
     }
 
     n->setRect(QRect(QPoint(0, 0), targetTextureSize));
     return n;
 }
 
 void Plotter::geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry)
 {
     QQuickItem::geometryChanged(newGeometry, oldGeometry);
     normalizeData();
 }
 
 void Plotter::normalizeData()
 {
     if (m_plotData.isEmpty()) {
         return;
     }
     // normalize data
     m_max = std::numeric_limits<qreal>::min();
     m_min = std::numeric_limits<qreal>::max();
     qreal adjustedMax = m_max;
     qreal adjustedMin = m_min;
     m_mutex.lock();
     if (m_stacked) {
         PlotData *previousData = nullptr;
         auto i = m_plotData.constEnd();
         do {
             --i;
             PlotData *data = *i;
             data->m_normalizedValues.clear();
             data->m_normalizedValues.resize(data->values().count());
             if (previousData) {
                 for (int i = 0; i < data->values().count(); ++i) {
                     data->m_normalizedValues[i] = data->values().value(i) + previousData->m_normalizedValues.value(i);
 
                     if (data->m_normalizedValues[i] > adjustedMax) {
                         adjustedMax = data->m_normalizedValues[i];
                     }
                     if (data->m_normalizedValues[i] < adjustedMin) {
                         adjustedMin = data->m_normalizedValues[i];
                     }
                 }
             } else {
                 data->m_normalizedValues = data->values().toVector();
                 if (data->max() > adjustedMax) {
                     adjustedMax = data->max();
                 }
                 if (data->min() < adjustedMin) {
                     adjustedMin = data->min();
                 }
             }
             previousData = data;
 
             // global max and global min
             if (data->max() > m_max) {
                 m_max = data->max();
             }
             if (data->min() < m_min) {
                 m_min = data->min();
             }
         } while (i != m_plotData.constBegin());
 
     } else {
         for (auto data : std::as_const(m_plotData)) {
             data->m_normalizedValues.clear();
             data->m_normalizedValues = data->values().toVector();
             // global max and global min
             if (data->max() > m_max) {
                 adjustedMax = m_max = data->max();
             }
             if (data->min() < m_min) {
                 adjustedMin = m_min = data->min();
             }
         }
     }
     m_mutex.unlock();
 
     if (adjustedMin > 0.0 && adjustedMax > 0.0) {
         adjustedMin = 0.0;
     }
 
     if (adjustedMin < 0.0 && adjustedMax < 0.0) {
         adjustedMax = 0.0;
     }
 
     if (m_autoRange || m_rangeMax > m_rangeMin) {
         if (!m_autoRange) {
             adjustedMax = m_rangeMax;
             adjustedMin = m_rangeMin;
         }
 
         qreal adjust;
         // this should never happen, remove?
         if (qFuzzyCompare(adjustedMax - adjustedMin, std::numeric_limits<qreal>::min())) {
             adjust = 1;
         } else {
             adjust = (height() / (adjustedMax - adjustedMin));
         }
 
         // normalizebased on global max and min
         m_mutex.lock();
         for (auto data : std::as_const(m_plotData)) {
             for (int i = 0; i < data->values().count(); ++i) {
                 data->m_normalizedValues[i] = (data->m_normalizedValues.value(i) - adjustedMin) * adjust;
             }
         }
         m_mutex.unlock();
     }
 }
 
 #include "moc_plotter.cpp"