Qt Yin Yang Painting with Changeable Size

Filename: main.cpp
Source code:

#include <QApplication> 

#include <QGraphicsScene>

#include <QGraphicsView>

#include <QGraphicsEllipseItem>

int main(int argc, char *argv[])

{

    QApplication app(argc, argv);

    const int size = 500;

    QGraphicsScene scene;

    scene.setSceneRect( 0.0, 0.0, size+100, size+100 );

    QPen penWhite(Qt::white);

    QBrush brushWhite(Qt::white); //QBrush to fill-up shape with the color

    QPen penBlack(Qt::black);

    QBrush brushBlack(Qt::black); //QBrush to fill-up shape with the color

    //draw white big circle

    QPainterPath whiteBigCirlePainter;

    QPoint pointCircleCenter;

    pointCircleCenter.setX((size+100)/2);

    pointCircleCenter.setY((size+100)/2);

    whiteBigCirlePainter.addEllipse(pointCircleCenter, size/2, size/2);

    scene.addPath(whiteBigCirlePainter, penWhite, brushWhite);

    //draw black big semicircle to the right

    QPainterPath rightBlackSemicirclePath;

    rightBlackSemicirclePath.arcMoveTo((size+100)/2.0 - (size/2.0),

                                       (size+100)/2.0 - (size/2.0),

                                       size, size, 270);

    rightBlackSemicirclePath.arcTo((size+100)/2.0 - (size/2.0),

                                   (size+100)/2.0 - (size/2.0),

                                   size, size, 270, 180);

    scene.addPath(rightBlackSemicirclePath, penBlack, brushBlack);

    //draw black circle bottom

    QPainterPath blackCircleBottomPainter;

    QPoint pointCircleBottomCenter;

    pointCircleBottomCenter.setX((size+100)/2.0);

    pointCircleBottomCenter.setY((size+100)/2.0 + size/4.0);

    blackCircleBottomPainter.addEllipse(pointCircleBottomCenter, size/2/2, size/2/2);

    scene.addPath(blackCircleBottomPainter, penBlack, brushBlack);

    //draw white circle top

    QPainterPath whiteCircleTopPainter;

    QPoint pointCircleTopCenter;

    pointCircleTopCenter.setX((size+100)/2.0);

    pointCircleTopCenter.setY((size+100)/2.0 - size/4.0);

    whiteCircleTopPainter.addEllipse(pointCircleTopCenter, size/2/2, size/2/2);

    scene.addPath(whiteCircleTopPainter, penWhite, brushWhite);

    //draw white circle bottom eye

    QPainterPath whiteCircleBottomEyePainter;

    QPoint pointCircleBottomEyeCenter;

    pointCircleBottomEyeCenter.setX((size+100)/2.0);

    pointCircleBottomEyeCenter.setY((size+100)/2.0 + size/4.0);

    whiteCircleBottomEyePainter.addEllipse(pointCircleBottomEyeCenter, size/2/2/2/2, size/2/2/2/2);

    scene.addPath(whiteCircleBottomEyePainter, penWhite, brushWhite);

    //draw black circle top eye

    QPainterPath blackCircleTopEyePainter;

    QPoint pointCircleTopEyeCenter;

    pointCircleTopEyeCenter.setX((size+100)/2.0);

    pointCircleTopEyeCenter.setY((size+100)/2.0 - size/4.0);

    blackCircleTopEyePainter.addEllipse(pointCircleTopEyeCenter, size/2/2/2/2, size/2/2/2/2);

    scene.addPath(blackCircleTopEyePainter, penBlack, brushBlack);

    //draw big circle black outline

    QPainterPath bigCircleBlackOutlinePainter;

    bigCircleBlackOutlinePainter.addEllipse(pointCircleCenter, size/2, size/2);

    scene.addPath(bigCircleBlackOutlinePainter, penBlack, Qt::NoBrush);

    QGraphicsView view( &scene );

    view.setRenderHint(QPainter::Antialiasing); //antialias edges of primitives if possible

    view.setRenderHint(QPainter::HighQualityAntialiasing); //an OpenGL-specific rendering hint

    view.setWindowTitle("My Yin Yang Painting");

    view.show();

    return app.exec();

}
 

Project Output: ☯