gridnode.cpp Example File | Qt Quick 5.12.11

- Qt 5.12
- Qt Quick
- Scene Graph - Graph
- gridnode.cpp Example File
- Qt 5.12.11 Reference Documentation

# gridnode.cpp Example File

scenegraph/graph/gridnode.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2017 The Qt Company Ltd.
     ** Contact: https://www.qt.io/licensing/
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** Commercial License Usage
     ** Licensees holding valid commercial Qt licenses may use this file in
     ** accordance with the commercial license agreement provided with the
     ** Software or, alternatively, in accordance with the terms contained in
     ** a written agreement between you and The Qt Company. For licensing terms
     ** and conditions see https://www.qt.io/terms-conditions. For further
     ** information use the contact form at https://www.qt.io/contact-us.
     **
     ** BSD License Usage
     ** Alternatively, you may use this file under the terms of the BSD license
     ** as follows:
     **
     ** "Redistribution and use in source and binary forms, with or without
     ** modification, are permitted provided that the following conditions are
     ** met:
     **   * Redistributions of source code must retain the above copyright
     **     notice, this list of conditions and the following disclaimer.
     **   * Redistributions in binary form must reproduce the above copyright
     **     notice, this list of conditions and the following disclaimer in
     **     the documentation and/or other materials provided with the
     **     distribution.
     **   * Neither the name of The Qt Company Ltd nor the names of its
     **     contributors may be used to endorse or promote products derived
     **     from this software without specific prior written permission.
     **
     **
     ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
     **
     ** $QT_END_LICENSE$
     **
     ****************************************************************************/

     #include "gridnode.h"

     #include "qmath.h"

     #define GRID_SIZE 32

     GridNode::GridNode()
         : m_geometry(QSGGeometry::defaultAttributes_Point2D(), 0)
     {
         setGeometry(&m_geometry);
         m_geometry.setDrawingMode(GL_LINES);

         setMaterial(&m_material);
         m_material.setColor(Qt::gray);
     }

     /*
      * The function hardcodes a fixed set of grid lines and scales
      * those to the bounding rect.
      */
     void GridNode::setRect(const QRectF &rect)
     {
         int vCount = int((rect.width() - 1) / GRID_SIZE);
         int hCount = int((rect.height() - 1) / GRID_SIZE);

         int lineCount = vCount + hCount;

         QSGGeometry *g = geometry();

         g->allocate(lineCount * 2);

         float x = rect.x();
         float y = rect.y();
         float w = rect.width();
         float h = rect.height();

         QSGGeometry::Point2D *v = g->vertexDataAsPoint2D();

         // Then write the vertical lines
         for (int i=0; i<vCount; ++i)  {
             float dx = (i + 1) * GRID_SIZE;
             v[i*2].set(dx, y);
             v[i*2+1].set(dx, y + h);
         }
         v += vCount * 2;
         // Then write the horizontal lines
         for (int i=0; i<hCount; ++i)  {
             float dy = (i + 1) * GRID_SIZE;
             v[i*2].set(x, dy);
             v[i*2+1].set(x + w, dy);
         }

         // Tell the scenegraph we updated the geometry..
         markDirty(QSGNode::DirtyGeometry);
     }