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++ // Copyright (C) 2017 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ #include "gridnode.h"
++
++ #include "qmath.h"
++
++ #define GRID_SIZE 32
++
++ GridNode::GridNode()
++ : m_geometry(QSGGeometry::defaultAttributes_Point2D(), 0)
++ {
++ setGeometry(&m_geometry);
++ m_geometry.setDrawingMode(QSGGeometry::DrawLines);
++
++ 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);
++ }