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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);
}
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