VTKImageXXXSource: Gaussian/Noise/Grid/Mandelbrot

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <vector>
#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL2)
VTK_MODULE_INIT(vtkInteractionStyle)
#include <vtkSmartPointer.h>
#include <vtkImageActor.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>

namespace Ui {
    class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    std::vector<vtkSmartPointer<vtkRenderer>>   pRenderers;
    std::vector<vtkSmartPointer<vtkImageActor>> pImageActors;
private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <vtkImageGaussianSource.h>
#include <vtkImageCast.h>
#include <vtkImageNoiseSource.h>
#include <vtkImageMandelbrotSource.h>
#include <vtkImageGridSource.h>
#include <vtkImageData.h>
#include <vtkImageChangeInformation.h>

// create the source data
static vtkImageData *CreateData(const std::string& sourceName, const int scalarType, const int size[3])
{
    vtkImageData *output = nullptr;

    if (sourceName == "gaussian")
    {
        vtkSmartPointer<vtkImageGaussianSource> source = vtkSmartPointer<vtkImageGaussianSource>::New();
        source->SetWholeExtent(0, size[0]-1, 0, size[1]-1, 0, size[2]-1);
        source->SetCenter(0.5*(size[0]-1), 0.5*(size[1]-1), 0.5*(size[2]-1)); // 圖像中心
        int maxdim = (size[0] > size[1] ? size[0] : size[1]);
        maxdim = (maxdim > size[2] ? maxdim : size[2]);
        source->SetStandardDeviation(0.25*(maxdim-1)); // 設置標準差
        source->SetMaximum(255.0);

        vtkSmartPointer<vtkImageCast> cast = vtkSmartPointer<vtkImageCast>::New();
        cast->SetInputConnection(source->GetOutputPort());
        cast->SetOutputScalarType(scalarType);
        cast->Update();

        output = cast->GetOutput();
        output->Register(nullptr);
    }
    else if (sourceName == "noise")
    {
        vtkSmartPointer<vtkImageNoiseSource> source = vtkSmartPointer<vtkImageNoiseSource>::New();
        source->SetMinimum(0.0);
        source->SetMinimum(255.0);
        source->SetWholeExtent(0, size[0]-1, 0, size[1]-1, 0, size[2]-1);

        vtkSmartPointer<vtkImageCast> cast = vtkSmartPointer<vtkImageCast>::New();
        cast->SetInputConnection(source->GetOutputPort());
        cast->SetOutputScalarType(scalarType);
        cast->Update();

        output = cast->GetOutput();
        output->Register(nullptr);
    }
    else if (sourceName == "mandelbrot")
    {
        vtkSmartPointer<vtkImageMandelbrotSource> source = vtkSmartPointer<vtkImageMandelbrotSource>::New();
        source->SetWholeExtent(0, size[0]-1, 0, size[1]-1, 0, size[2]-1);

        vtkSmartPointer<vtkImageCast> cast = vtkSmartPointer<vtkImageCast>::New();
        cast->SetInputConnection(source->GetOutputPort());
        cast->SetOutputScalarType(scalarType);
        cast->Update();

        output = cast->GetOutput();
        output->Register(nullptr);
    }
    else if (sourceName == "grid")
    {
        vtkSmartPointer<vtkImageGridSource> source = vtkSmartPointer<vtkImageGridSource>::New();
        source->SetDataExtent(0, size[0]-1, 0, size[1]-1, 0, size[2]-1);
        source->SetLineValue(255.0);
        source->SetFillValue(0.0);
        source->SetDataScalarType(scalarType);
        source->Update();
        output = source->GetOutput();
        output->Register(nullptr);
    }
    else
    {
        cerr << "unrecognized option for --source\n";
        return nullptr;
    }

    // standardize the geometry of the output
    vtkSmartPointer<vtkImageChangeInformation> change = vtkSmartPointer<vtkImageChangeInformation>::New();
    change->SetInputData(output);
    change->SetOutputSpacing(1.0, 1.0, 1.0);
    change->CenterImageOn();
    change->Update();
    output->Delete();
    output = change->GetOutput();
    output->Register(nullptr);

    return output;
}

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    const std::vector<std::string> sourceTypes = {"gaussian",
                                                  "noise",
                                                  "mandelbrot",
                                                  "grid"};
    // 初始化render
    pImageActors.resize(sourceTypes.size());
    pRenderers.resize(sourceTypes.size());

    int imageSize[] = {256, 256};

    float viewOffset = 1.0 / sourceTypes.size();
    for(size_t i = 0; i < sourceTypes.size(); ++i)
    {
        pImageActors[i] = vtkSmartPointer<vtkImageActor>::New();
        vtkImageData* pImageData = CreateData(sourceTypes[i], VTK_UNSIGNED_CHAR, imageSize);
        if(pImageData == nullptr)
        {
            continue;
        }
        pImageActors[i]->SetInputData(pImageData);

        pRenderers[i] = vtkSmartPointer<vtkRenderer>::New();
        pRenderers[i]->SetViewport(i * viewOffset, 0, (i + 1) * viewOffset, 1.0);
        pRenderers[i]->AddActor(pImageActors[i]);

        ui->qvtkWidget->GetRenderWindow()->AddRenderer(pRenderers[i]);
    }
}


MainWindow::~MainWindow()
{
    delete ui;
}

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralWidget">
   <layout class="QHBoxLayout" name="horizontalLayout">
    <item>
     <widget class="QVTKWidget" name="qvtkWidget"/>
    </item>
   </layout>
  </widget>
  <widget class="QMenuBar" name="menuBar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>400</width>
     <height>22</height>
    </rect>
   </property>
  </widget>
  <widget class="QToolBar" name="mainToolBar">
   <attribute name="toolBarArea">
    <enum>TopToolBarArea</enum>
   </attribute>
   <attribute name="toolBarBreak">
    <bool>false</bool>
   </attribute>
  </widget>
  <widget class="QStatusBar" name="statusBar"/>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <customwidgets>
  <customwidget>
   <class>QVTKWidget</class>
   <extends>QWidget</extends>
   <header>QVTKWidget.h</header>
  </customwidget>
 </customwidgets>
 <resources/>
 <connections/>
</ui>