Qt/C++ による GUI ソフトウェア作成の練習 6：ピッキング

#include <Qt3DCore>
#include <Qt3DExtras>
#include <Qt3DRender>

class Draw_Obj : public QObject {
 private:
  Qt3DExtras::Qt3DWindow *DrawWindow;
  Qt3DCore::QEntity *RootEntity;
  Qt3DCore::QEntity *Sphere;

  bool Picked;  //ピック済みかどうかを示すフラグ

 private slots:
  void slot_clicked(int i);  //このコードでは球をクリックしたときに呼び出される，引数付きのスロット関数

 public:
  Draw_Obj();
  ~Draw_Obj() {}

  Qt3DExtras::Qt3DWindow *get_draw_window()
        { return DrawWindow; }
  void init();
  void add_obj();
};

#include "draw_obj.h"
#include <iostream>

Draw_Obj::Draw_Obj()
 : DrawWindow(nullptr),
   RootEntity(nullptr),
   Sphere(nullptr),
   Picked(false)  //最初はピックされていない
{
 RootEntity = new Qt3DCore::QEntity();
 DrawWindow = new Qt3DExtras::Qt3DWindow();
 DrawWindow->setRootEntity(RootEntity);
}

void Draw_Obj::init() {
 if(Sphere) {
  delete Sphere;
  Sphere = nullptr;
 }

 if(RootEntity) {
  delete RootEntity;
  RootEntity = new Qt3DCore::QEntity();
 }

 if(DrawWindow) {
  delete DrawWindow;
  DrawWindow = new Qt3DExtras::Qt3DWindow();
 }

 DrawWindow->setRootEntity(RootEntity);

 Qt3DRender::QCamera *CameraEntity
        = DrawWindow->camera();
 CameraEntity->lens()->setPerspectiveProjection(
        45.0f, 1.0f, 10.f, 30.0f);
 CameraEntity->setPosition(QVector3D(0, 0, 20.0f));
 CameraEntity->setUpVector(QVector3D(0, 1, 0));
 CameraEntity->setViewCenter(QVector3D(0, 0, 0));

 Qt3DCore::QEntity *light_entity
        = new Qt3DCore::QEntity(RootEntity);
 Qt3DRender::QPointLight *light
        = new Qt3DRender::QPointLight(light_entity);
 light->setColor("white");
 light->setIntensity(1);
 light_entity->addComponent(light);
 Qt3DCore::QTransform *light_pos
        = new Qt3DCore::QTransform(light_entity);
 light_pos->setTranslation(
        CameraEntity->position());
 light_entity->addComponent(light_pos);
}

void Draw_Obj::add_obj() {
 if(Sphere) return;

 Sphere = new Qt3DCore::QEntity(RootEntity);

 Qt3DExtras::QSphereMesh *mesh
        = new Qt3DExtras::QSphereMesh();
 mesh->setRings(20);
 mesh->setSlices(20);
 mesh->setRadius(2.5);
 Sphere->addComponent(mesh);

 Qt3DExtras::QPhongMaterial *material
        = new Qt3DExtras::QPhongMaterial();
 material->setDiffuse(QColor(QRgb(0xFF0000)));
 Sphere->addComponent(material);

 Qt3DCore::QTransform *transform
        = new Qt3DCore::QTransform();
 transform->setTranslation(
        QVector3D(1.0f, 1.0f, 1.0f));
 Sphere->addComponent(transform);

 //ピッカーを Sphere のコンポーネントとして，識別番号を付けて作成する
 int id = 123;  //識別番号．ここでは値はてきとうでよい
 Qt3DRender::QObjectPicker *picker =
        new Qt3DRender::QObjectPicker(Sphere);
 connect(
        picker,
        &Qt3DRender::QObjectPicker::clicked,
        [this, id]() { slot_clicked(id); } );  //引数付きのスロット関数と接続するときは，ラムダ式を使えばよい
 Sphere->addComponent(picker);
}

//connect() を使って接続したので， 上で作成した Sphere がクリックされるとこの関数が呼び出される．引数は識別番号
void Draw_Obj::slot_clicked(int i) {
 //確認のため，識別番号を出力
 std::cout << "id : " << i << std::endl;

 //ピックされたら色を変える．これだと，ピックのたびにコンポーネントが増える一方のような気がする．何かうまい方法があるのかもしれない
 Qt3DExtras::QPhongMaterial *material
        = new Qt3DExtras::QPhongMaterial();
 if(!Picked)
  material->setDiffuse(QColor(QRgb(0x0000FF)));
 else
  material->setDiffuse(QColor(QRgb(0xFF0000)));

 Sphere->addComponent(material);

 //フラグを反転
 Picked = !Picked;
}

#include <QMainWindow>
#include <QMenuBar>
#include <QHBoxLayout>
#include "draw_obj.h"

class Main_Window : public QMainWindow {
 private:
  Q_OBJECT

  QMenuBar *MenuBar;

  QHBoxLayout *CentralLayout;
  QWidget *Container;
  Draw_Obj DrawObj;
  Qt3DExtras::Qt3DWindow *DrawWindow;

  private slots:
  void slot_draw();
  void slot_clear() { DrawObj.init(); }

 public:
  Main_Window(QWidget *parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags());
};

#include "main_window.h"

Main_Window::Main_Window(QWidget *parent, Qt::WindowFlags f)
 : QMainWindow(parent, f),
   MenuBar(menuBar()),
   CentralLayout(nullptr),
   Container(nullptr),
   DrawWindow(nullptr)
{
 QAction *action_quit = new QAction("終了(&Q)", this);
 connect(action_quit, SIGNAL(triggered()), this, SLOT(close()));

 QMenu *file_menu = new QMenu("ファイル(&F)", this);
 file_menu->addAction(action_quit);
 MenuBar->addMenu(file_menu);

 QAction *action_draw
        = new QAction(tr("描画(&D)"), this);
 connect(action_draw, SIGNAL(triggered()), this,
        SLOT(slot_draw()));

 QAction *action_clear
        = new QAction(tr("クリア(&C)"), this);
 connect(action_clear, SIGNAL(triggered()), this,
        SLOT(slot_clear()));

 QMenu *view_menu = new QMenu(tr("表示(&V)"), this);
 view_menu->addAction(action_draw);
 view_menu->addAction(action_clear);
 MenuBar->addMenu(view_menu);

 QWidget *central_widget = new QWidget(this);
 setCentralWidget(central_widget);
 CentralLayout = new QHBoxLayout(central_widget);

 DrawWindow = DrawObj.get_draw_window();
 Container = createWindowContainer(DrawWindow);
 CentralLayout->addWidget(Container);

 QSize screenSize = screen()->size();
 setMaximumSize(screenSize);

 setMinimumWidth(600);
 setMinimumHeight(600);
}

void Main_Window::slot_draw() {
 DrawObj.init();

 CentralLayout->removeWidget(Container);
 delete Container;
 DrawWindow = DrawObj.get_draw_window();
 Container = createWindowContainer(DrawWindow);
 CentralLayout->addWidget(Container);

 DrawObj.add_obj();
}

#include <QMainWindow>
#include <QApplication>
#include "main_window.h"

int main(int argc, char *argv[]) {
 QApplication app(argc, argv);

 Main_Window window(nullptr, Qt::Window);

 window.show();

 return app.exec();
}

TEMPLATE = app
TARGET = window
QT += widgets
INCLUDEPATH += .
HEADERS += main_window.h draw_obj.h
SOURCES += main.cc main_window.cc draw_obj.cc

QT += 3dcore
QT += 3dextras
#QT += 3drender
#QT += 3dinput

id : 123