qtbox.cpp Example File

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  #include "qtbox.h"

  const qreal ROTATE_SPEED_X = 30.0 / 1000.0;
  const qreal ROTATE_SPEED_Y = 20.0 / 1000.0;
  const qreal ROTATE_SPEED_Z = 40.0 / 1000.0;
  const int MAX_ITEM_SIZE = 512;
  const int MIN_ITEM_SIZE = 16;

  //============================================================================//
  //                                  ItemBase                                  //
  //============================================================================//

  ItemBase::ItemBase(int size, int x, int y) : m_size(size), m_isResizing(false)
  {
      setFlag(QGraphicsItem::ItemIsMovable, true);
      setFlag(QGraphicsItem::ItemIsSelectable, true);
      setFlag(QGraphicsItem::ItemIsFocusable, true);
      setAcceptHoverEvents(true);
      setPos(x, y);
      m_startTime = QTime::currentTime();
  }

  ItemBase::~ItemBase()
  {
  }

  QRectF ItemBase::boundingRect() const
  {
      return QRectF(-m_size / 2, -m_size / 2, m_size, m_size);
  }

  void ItemBase::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *)
  {
      if (option->state & QStyle::State_Selected) {
          painter->setRenderHint(QPainter::Antialiasing, true);
          if (option->state & QStyle::State_HasFocus)
              painter->setPen(Qt::yellow);
          else
              painter->setPen(Qt::white);
          painter->drawRect(boundingRect());

          painter->drawLine(m_size / 2 - 9, m_size / 2, m_size / 2, m_size / 2 - 9);
          painter->drawLine(m_size / 2 - 6, m_size / 2, m_size / 2, m_size / 2 - 6);
          painter->drawLine(m_size / 2 - 3, m_size / 2, m_size / 2, m_size / 2 - 3);

          painter->setRenderHint(QPainter::Antialiasing, false);
      }
  }

  void ItemBase::contextMenuEvent(QGraphicsSceneContextMenuEvent *event)
  {
      if (!isSelected() && scene()) {
          scene()->clearSelection();
          setSelected(true);
      }

      QMenu menu;
      QAction *delAction = menu.addAction("Delete");
      QAction *newAction = menu.addAction("New");
      QAction *growAction = menu.addAction("Grow");
      QAction *shrinkAction = menu.addAction("Shrink");

      QAction *selectedAction = menu.exec(event->screenPos());

      if (selectedAction == delAction)
          deleteSelectedItems(scene());
      else if (selectedAction == newAction)
          duplicateSelectedItems(scene());
      else if (selectedAction == growAction)
          growSelectedItems(scene());
      else if (selectedAction == shrinkAction)
          shrinkSelectedItems(scene());
  }

  void ItemBase::duplicateSelectedItems(QGraphicsScene *scene)
  {
      if (!scene)
          return;

      QList<QGraphicsItem *> selected;
      selected = scene->selectedItems();

      foreach (QGraphicsItem *item, selected) {
          ItemBase *itemBase = qgraphicsitem_cast<ItemBase *>(item);
          if (itemBase)
              scene->addItem(itemBase->createNew(itemBase->m_size, itemBase->pos().x() + itemBase->m_size, itemBase->pos().y()));
      }
  }

  void ItemBase::deleteSelectedItems(QGraphicsScene *scene)
  {
      if (!scene)
          return;

      QList<QGraphicsItem *> selected;
      selected = scene->selectedItems();

      foreach (QGraphicsItem *item, selected) {
          ItemBase *itemBase = qgraphicsitem_cast<ItemBase *>(item);
          if (itemBase)
              delete itemBase;
      }
  }

  void ItemBase::growSelectedItems(QGraphicsScene *scene)
  {
      if (!scene)
          return;

      QList<QGraphicsItem *> selected;
      selected = scene->selectedItems();

      foreach (QGraphicsItem *item, selected) {
          ItemBase *itemBase = qgraphicsitem_cast<ItemBase *>(item);
          if (itemBase) {
              itemBase->prepareGeometryChange();
              itemBase->m_size *= 2;
              if (itemBase->m_size > MAX_ITEM_SIZE)
                  itemBase->m_size = MAX_ITEM_SIZE;
          }
      }
  }

  void ItemBase::shrinkSelectedItems(QGraphicsScene *scene)
  {
      if (!scene)
          return;

      QList<QGraphicsItem *> selected;
      selected = scene->selectedItems();

      foreach (QGraphicsItem *item, selected) {
          ItemBase *itemBase = qgraphicsitem_cast<ItemBase *>(item);
          if (itemBase) {
              itemBase->prepareGeometryChange();
              itemBase->m_size /= 2;
              if (itemBase->m_size < MIN_ITEM_SIZE)
                  itemBase->m_size = MIN_ITEM_SIZE;
          }
      }
  }

  void ItemBase::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
  {
      if (m_isResizing) {
          int dx = int(2.0 * event->pos().x());
          int dy = int(2.0 * event->pos().y());
          prepareGeometryChange();
          m_size = (dx > dy ? dx : dy);
          if (m_size < MIN_ITEM_SIZE)
              m_size = MIN_ITEM_SIZE;
          else if (m_size > MAX_ITEM_SIZE)
              m_size = MAX_ITEM_SIZE;
      } else {
          QGraphicsItem::mouseMoveEvent(event);
      }
  }

  void ItemBase::hoverMoveEvent(QGraphicsSceneHoverEvent *event)
  {
      if (m_isResizing || (isInResizeArea(event->pos()) && isSelected()))
          setCursor(Qt::SizeFDiagCursor);
      else
          setCursor(Qt::ArrowCursor);
      QGraphicsItem::hoverMoveEvent(event);
  }

  void ItemBase::mousePressEvent(QGraphicsSceneMouseEvent *event)
  {
      static qreal z = 0.0;
      setZValue(z += 1.0);
      if (event->button() == Qt::LeftButton && isInResizeArea(event->pos())) {
          m_isResizing = true;
      } else {
          QGraphicsItem::mousePressEvent(event);
      }
  }

  void ItemBase::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
  {
      if (event->button() == Qt::LeftButton && m_isResizing) {
          m_isResizing = false;
      } else {
          QGraphicsItem::mouseReleaseEvent(event);
      }
  }

  void ItemBase::keyPressEvent(QKeyEvent *event)
  {
      switch (event->key()) {
      case Qt::Key_Delete:
          deleteSelectedItems(scene());
          break;
      case Qt::Key_Insert:
          duplicateSelectedItems(scene());
          break;
      case Qt::Key_Plus:
          growSelectedItems(scene());
          break;
      case Qt::Key_Minus:
          shrinkSelectedItems(scene());
          break;
      default:
          QGraphicsItem::keyPressEvent(event);
          break;
      }
  }

  void ItemBase::wheelEvent(QGraphicsSceneWheelEvent *event)
  {
      prepareGeometryChange();
      m_size = int(m_size * qExp(-event->delta() / 600.0));
      if (m_size > MAX_ITEM_SIZE)
          m_size = MAX_ITEM_SIZE;
      else if (m_size < MIN_ITEM_SIZE)
          m_size = MIN_ITEM_SIZE;
  }

  int ItemBase::type() const
  {
      return Type;
  }

  bool ItemBase::isInResizeArea(const QPointF &pos)
  {
      return (-pos.y() < pos.x() - m_size + 9);
  }

  //============================================================================//
  //                                    QtBox                                   //
  //============================================================================//

  QtBox::QtBox(int size, int x, int y) : ItemBase(size, x, y), m_texture(0)
  {
      for (int i = 0; i < 8; ++i) {
          m_vertices[i].setX(i & 1 ? 0.5f : -0.5f);
          m_vertices[i].setY(i & 2 ? 0.5f : -0.5f);
          m_vertices[i].setZ(i & 4 ? 0.5f : -0.5f);
      }
      for (int i = 0; i < 4; ++i) {
          m_texCoords[i].setX(i & 1 ? 1.0f : 0.0f);
          m_texCoords[i].setY(i & 2 ? 1.0f : 0.0f);
      }
      m_normals[0] = QVector3D(-1.0f, 0.0f, 0.0f);
      m_normals[1] = QVector3D(1.0f, 0.0f, 0.0f);
      m_normals[2] = QVector3D(0.0f, -1.0f, 0.0f);
      m_normals[3] = QVector3D(0.0f, 1.0f, 0.0f);
      m_normals[4] = QVector3D(0.0f, 0.0f, -1.0f);
      m_normals[5] = QVector3D(0.0f, 0.0f, 1.0f);
  }

  QtBox::~QtBox()
  {
      if (m_texture)
          delete m_texture;
  }

  ItemBase *QtBox::createNew(int size, int x, int y)
  {
      return new QtBox(size, x, y);
  }

  void QtBox::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
  {
      QRectF rect = boundingRect().translated(pos());
      float width = float(painter->device()->width());
      float height = float(painter->device()->height());

      float left = 2.0f * float(rect.left()) / width - 1.0f;
      float right = 2.0f * float(rect.right()) / width - 1.0f;
      float top = 1.0f - 2.0f * float(rect.top()) / height;
      float bottom = 1.0f - 2.0f * float(rect.bottom()) / height;
      float moveToRectMatrix[] = {
          0.5f * (right - left), 0.0f, 0.0f, 0.0f,
          0.0f, 0.5f * (bottom - top), 0.0f, 0.0f,
          0.0f, 0.0f, 1.0f, 0.0f,
          0.5f * (right + left), 0.5f * (bottom + top), 0.0f, 1.0f
      };

      painter->beginNativePainting();

      glMatrixMode(GL_PROJECTION);
      glPushMatrix();
      glLoadMatrixf(moveToRectMatrix);
      qgluPerspective(60.0, 1.0, 0.01, 10.0);

      glMatrixMode(GL_MODELVIEW);
      glPushMatrix();
      glLoadIdentity();

      //glEnable(GL_DEPTH_TEST);
      glEnable(GL_CULL_FACE);
      glEnable(GL_LIGHTING);
      glEnable(GL_COLOR_MATERIAL);
      glEnable(GL_NORMALIZE);

      if(m_texture == 0)
          m_texture = new GLTexture2D(":/res/boxes/qt-logo.jpg", 64, 64);
      m_texture->bind();
      glEnable(GL_TEXTURE_2D);

      glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
      float lightColour[] = {1.0f, 1.0f, 1.0f, 1.0f};
      float lightDir[] = {0.0f, 0.0f, 1.0f, 0.0f};
      glLightfv(GL_LIGHT0, GL_DIFFUSE, lightColour);
      glLightfv(GL_LIGHT0, GL_POSITION, lightDir);
      glEnable(GL_LIGHT0);

      glTranslatef(0.0f, 0.0f, -1.5f);
      glRotatef(ROTATE_SPEED_X * m_startTime.msecsTo(QTime::currentTime()), 1.0f, 0.0f, 0.0f);
      glRotatef(ROTATE_SPEED_Y * m_startTime.msecsTo(QTime::currentTime()), 0.0f, 1.0f, 0.0f);
      glRotatef(ROTATE_SPEED_Z * m_startTime.msecsTo(QTime::currentTime()), 0.0f, 0.0f, 1.0f);
      int dt = m_startTime.msecsTo(QTime::currentTime());
      if (dt < 500)
          glScalef(dt / 500.0f, dt / 500.0f, dt / 500.0f);

      for (int dir = 0; dir < 3; ++dir) {
          glColor4f(1.0f, 1.0f, 1.0f, 1.0);

          glBegin(GL_TRIANGLE_STRIP);
          glNormal3fv(reinterpret_cast<float *>(&m_normals[2 * dir + 0]));
          for (int i = 0; i < 2; ++i) {
              for (int j = 0; j < 2; ++j) {
                  glTexCoord2fv(reinterpret_cast<float *>(&m_texCoords[(j << 1) | i]));
                  glVertex3fv(reinterpret_cast<float *>(&m_vertices[(i << ((dir + 2) % 3)) | (j << ((dir + 1) % 3))]));
              }
          }
          glEnd();

          glBegin(GL_TRIANGLE_STRIP);
          glNormal3fv(reinterpret_cast<float *>(&m_normals[2 * dir + 1]));
          for (int i = 0; i < 2; ++i) {
              for (int j = 0; j < 2; ++j) {
                  glTexCoord2fv(reinterpret_cast<float *>(&m_texCoords[(j << 1) | i]));
                  glVertex3fv(reinterpret_cast<float *>(&m_vertices[(1 << dir) | (i << ((dir + 1) % 3)) | (j << ((dir + 2) % 3))]));
              }
          }
          glEnd();
      }
      m_texture->unbind();

      //glDisable(GL_DEPTH_TEST);
      glDisable(GL_CULL_FACE);
      glDisable(GL_LIGHTING);
      glDisable(GL_COLOR_MATERIAL);
      glDisable(GL_TEXTURE_2D);
      glDisable(GL_LIGHT0);
      glDisable(GL_NORMALIZE);

      glPopMatrix();

      glMatrixMode(GL_PROJECTION);
      glPopMatrix();

      painter->endNativePainting();

      ItemBase::paint(painter, option, widget);
  }

  //============================================================================//
  //                                 CircleItem                                 //
  //============================================================================//

  CircleItem::CircleItem(int size, int x, int y) : ItemBase(size, x, y)
  {
       m_color = QColor::fromHsv(rand() % 360, 255, 255);
  }

  void CircleItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
  {
      int dt = m_startTime.msecsTo(QTime::currentTime());

      qreal r0 = 0.5 * m_size * (1.0 - qExp(-0.001 * ((dt + 3800) % 4000)));
      qreal r1 = 0.5 * m_size * (1.0 - qExp(-0.001 * ((dt + 0) % 4000)));
      qreal r2 = 0.5 * m_size * (1.0 - qExp(-0.001 * ((dt + 1800) % 4000)));
      qreal r3 = 0.5 * m_size * (1.0 - qExp(-0.001 * ((dt + 2000) % 4000)));

      if (r0 > r1)
          r0 = 0.0;
      if (r2 > r3)
          r2 = 0.0;

      QPainterPath path;
      path.moveTo(r1, 0.0);
      path.arcTo(-r1, -r1, 2 * r1, 2 * r1, 0.0, 360.0);
      path.lineTo(r0, 0.0);
      path.arcTo(-r0, -r0, 2 * r0, 2 * r0, 0.0, -360.0);
      path.closeSubpath();
      path.moveTo(r3, 0.0);
      path.arcTo(-r3, -r3, 2 * r3, 2 * r3, 0.0, 360.0);
      path.lineTo(r0, 0.0);
      path.arcTo(-r2, -r2, 2 * r2, 2 * r2, 0.0, -360.0);
      path.closeSubpath();
      painter->setRenderHint(QPainter::Antialiasing, true);
      painter->setBrush(QBrush(m_color));
      painter->setPen(Qt::NoPen);
      painter->drawPath(path);
      painter->setBrush(Qt::NoBrush);
      painter->setPen(Qt::SolidLine);
      painter->setRenderHint(QPainter::Antialiasing, false);

      ItemBase::paint(painter, option, widget);
  }

  ItemBase *CircleItem::createNew(int size, int x, int y)
  {
      return new CircleItem(size, x, y);
  }

  //============================================================================//
  //                                 SquareItem                                 //
  //============================================================================//

  SquareItem::SquareItem(int size, int x, int y) : ItemBase(size, x, y)
  {
      m_image = QPixmap(":/res/boxes/square.jpg");
  }

  void SquareItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
  {
      int dt = m_startTime.msecsTo(QTime::currentTime());
      QTransform oldTransform = painter->worldTransform();
      int dtMod = dt % 2000;
      qreal amp = 0.002 * (dtMod < 1000 ? dtMod : 2000 - dtMod) - 1.0;

      qreal scale = 0.6 + 0.2 * amp * amp;
      painter->setWorldTransform(QTransform().rotate(15.0 * amp).scale(scale, scale), true);

      painter->drawPixmap(-m_size / 2, -m_size / 2, m_size, m_size, m_image);

      painter->setWorldTransform(oldTransform, false);
      ItemBase::paint(painter, option, widget);
  }

  ItemBase *SquareItem::createNew(int size, int x, int y)
  {
      return new SquareItem(size, x, y);
  }