QDMGraphicsScene.cpp

#include "GraphicsScene.hpp"
#include <QtCore>
#include <QtGui>

QDMGraphicsScene::QDMGraphicsScene(QWidget* pobj)
    : QGraphicsScene(pobj)
{
    setSceneRect(-(scnWidth / 2), -(scnHeight / 2), scnWidth, scnHeight);
    setBackgroundBrush(QColor("#393939"));
}

// Virtual:
void QDMGraphicsScene::drawBackground(QPainter *painter, const QRectF &rect)
{
    // Problem was here:
    // Adding this and it'll work:
    QGraphicsScene::drawBackground(painter, rect);

    QPen ppLight(QColor("#2f2f2f"));
    ppLight.setWidth(1);

    int32_t left   = static_cast<int32_t>(rect.left());
    int32_t right  = static_cast<int32_t>(rect.right());
    int32_t top    = static_cast<int32_t>(rect.top());
    int32_t bottom = static_cast<int32_t>(rect.bottom());

    int32_t first_left = left - (left % grdSize);

    QVector<QLine> gridVector;

    for (int32_t x = first_left; x < right; x += grdSize)
    {
        gridVector.push_back(QLine(x, top, x, bottom));
    }

    painter->setPen(ppLight);
    painter->drawLines(gridVector);
}