I have a problem with painting my squares are the wrong size

AI_Messiah

I made things bigger so they are easier to see. I want the space between filled in;

I have a widget promoted to a class for the painting.
header:

#ifndef RENDERER_H
#define RENDERER_H

#include <QWidget>
#include <QPaintEvent>
#include <QPainter>
class Renderer : public QWidget
{
    Q_OBJECT
public:
    explicit Renderer(QWidget *parent = nullptr);
    QSize minimumSizeHint() const Q_DECL_OVERRIDE;
    QSize sizeHint() const Q_DECL_OVERRIDE;
    bool isFill[400][400];
protected:
    void paintEvent(QPaintEvent *event) Q_DECL_OVERRIDE;
signals:

};

#endif // RENDERER_H

source:

#include "renderer.h"

Renderer::Renderer(QWidget *parent) : QWidget(parent)
{
    for (int y=0;y<400;y++){
        for (int x=0;x<400;x++) isFill[x][y] = false;
    }
    for (int i=40;i<60;i++) isFill[i][50] = true;
}

QSize Renderer::minimumSizeHint() const
{
    return QSize(100,100);
}

QSize Renderer::sizeHint() const
{
    return QSize(400,400);
}

void Renderer::paintEvent(QPaintEvent *event)
{
    QPainter paint(this);
    paint.setBrush(QColor(0, 0, 0, 255));
    //paint.setRenderHint(QPainter::Antialiasing, true);
    paint.drawRect(this->rect());
    paint.setBrush(QColor(255, 255, 255, 255));
    for (int y=0;y<100;y++){
        for (int x=0;x<100;x++) if(isFill[x][y]) paint.drawRect(x * 8, y * 8, 8, 8);
    }
}

AI_Messiah

I wanb\t the spaces filled in.

Chris Kawa

drawRect() uses a brush for the inside of the rectangle and a pen for the border. A pen is by default black so that's why you're seeing the borders. Either set a white pen on the painter or, better yet, use fillRect() instead of drawRect(), which only fills the rectangle with a brush and has no border.