qtbox.cpp Example File
demos/boxes/qtbox.cpp

 /****************************************************************************
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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 = dynamic_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 = dynamic_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 = dynamic_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 = dynamic_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 * exp(-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;
 }

 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][0] = (i & 1 ? 0.5f : -0.5f);
         m_vertices[i][1] = (i & 2 ? 0.5f : -0.5f);
         m_vertices[i][2] = (i & 4 ? 0.5f : -0.5f);
     }
     for (int i = 0; i < 4; ++i) {
         m_texCoords[i][0] = (i & 1 ? 1.0f : 0.0f);
         m_texCoords[i][1] = (i & 2 ? 1.0f : 0.0f);
     }
     memset(m_normals, 0, sizeof(m_normals));
     for (int i = 0; i < 3; ++i) {
         m_normals[2 * i + 0][i] = -1.0f;
         m_normals[2 * i + 1][i] = 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
     };

     glMatrixMode(GL_PROJECTION);
     glPushMatrix();
     glLoadMatrixf(moveToRectMatrix);
     gluPerspective(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(m_normals[2 * dir + 0].bits());
         for (int i = 0; i < 2; ++i) {
             for (int j = 0; j < 2; ++j) {
                 glTexCoord2fv(m_texCoords[(j << 1) | i].bits());
                 glVertex3fv(m_vertices[(i << ((dir + 2) % 3)) | (j << ((dir + 1) % 3))].bits());
             }
         }
         glEnd();

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

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