Raspbian 2 player chess game

Quantum1982 · 25 Dec 2021, 12:32

Hi

I am making a 2 player chess game for the Raspberry Pi.

I am getting a strange error with Qt creator :

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QImage>
#include "newstandardgame.h"
#include <QPainter>
#include <QRect>

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);

QPainter * ChessPiece = new QPainter();
QImage * Image = new QImage("C:\Users\User\Desktop\WhiteQueen.jpg");
//Image->

QRect Source;
QRect Dest;

Source.setCoords(0,0,30,30);
Dest.setCoords(0,0,30,30);

ChessPiece->drawImage((const RectF)Dest,Image,(const RectF)Source);

MainWindow::~MainWindow()
{
delete ui;
}

void MainWindow::on_NewStandardGame_clicked()
{
//NewStandardGame::show();
}

C:\Desktop\ChessRaspbian\mainwindow.cpp:15: warning: C4129: 'D': unrecognized character escape sequence

JonB · wrote on 25 Dec 2021, 12:32

@Quantum1982 said in Raspbian 2 player chess game:

I am getting a strange error with Qt creator

It's not strange, and it's a C++ compilation error, nothing to do with Qt or Creator.

"C:\Users\User\Desktop\WhiteQueen.jpg"

How does one put literal \s into C/C++ string literals?

Quantum1982 · wrote on 25 Dec 2021, 12:34

Hi
Thanks for your reply

What formatting am I missing here ?

Quantum1982 · wrote on 25 Dec 2021, 12:51

Ok thanks

But now there is a different error :

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QImage>
#include "newstandardgame.h"
#include <QPainter>
#include <QRect>

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);

QPainter * ChessPiece = new QPainter();
QImage * Image = new QImage("C:/Users/User/Desktop/WhiteQueen.jpg");
//Image->

QRect Source;
QRect Dest;

Source.setCoords(0,0,30,30);
Dest.setCoords(0,0,30,30);

ChessPiece->drawImage(Dest,Image,Source);

MainWindow::~MainWindow()
{
delete ui;
}

void MainWindow::on_NewStandardGame_clicked()
{
//NewStandardGame::show();
}

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QImage>
#include "newstandardgame.h"
#include <QPainter>
#include <QRect>

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);

QPainter * ChessPiece = new QPainter();
QImage * Image = new QImage("C:/Users/User/Desktop/WhiteQueen.jpg");
//Image->

QRect Source;
QRect Dest;

Source.setCoords(0,0,30,30);
Dest.setCoords(0,0,30,30);

ChessPiece->drawImage(Dest,Image,Source);

MainWindow::~MainWindow()
{
delete ui;
}

void MainWindow::on_NewStandardGame_clicked()
{
//NewStandardGame::show();
}
C:\Desktop\ChessRaspbian\mainwindow.cpp:24: error: C2664: 'void QPainter::drawImage(int,int,const QImage &,int,int,int,int,Qt::ImageConversionFlags)': cannot convert argument 2 from 'QImage *' to 'const QImage &'
..\ChessRaspbian\mainwindow.cpp(24): note: Reason: cannot convert from 'QImage *' to 'const QImage'
..\ChessRaspbian\mainwindow.cpp(24): note: No constructor could take the source type, or constructor overload resolution was ambiguous

Quantum1982 · 25 Dec 2021, 19:21

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QImage>
#include "newstandardgame.h"
#include <QPainter>
#include <QRect>
#include <QString>

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);

QString ChessPieces[12];

ChessPieces[0] = "C:/Users/User/Desktop/WhitePawn.jpg";
ChessPieces[1] = "C:/Users/User/Desktop/WhiteRook.jpg";
ChessPieces[2] = "C:/Users/User/Desktop/WhiteKnight.jpg";
ChessPieces[3] = "C:/Users/User/Desktop/WhiteBishop.jpg";
ChessPieces[4] = "C:/Users/User/Desktop/WhiteQueen.jpg";
ChessPieces[5] = "C:/Users/User/Desktop/WhiteKing.jpg";
ChessPieces[6] = "C:/Users/User/Desktop/BlackPawn.jpg";
ChessPieces[7] = "C:/Users/User/Desktop/BlackRook.jpg";
ChessPieces[8] = "C:/Users/User/Desktop/BlackKnight.jpg";
ChessPieces[9] = "C:/Users/User/Desktop/BlackBishop.jpg";
ChessPieces[10] = "C:/Users/User/Desktop/BlackQueen.jpg";
ChessPieces[11] = "C:/Users/User/Desktop/BlackKing.jpg";



QPainter * ChessPiece = new QPainter();
QImage * Image = new QImage("C:/Users/User/Desktop/WhiteQueen.jpg");
//Image->

QRect Source;
QRect Dest;

Source.setCoords(0,0,30,30);
Dest.setCoords(0,0,30,30);

//QPainter *Painter = new QPainter();
//Painter->drawImage(Dest,Image,Source);

//const QPixmap Pixmap;

//ChessPiece->drawImage(Dest,Image,Source);

// ChessPiece->drawPixmap(0,0,30,30,Pixmap);

}

MainWindow::~MainWindow()
{
delete ui;
}
moc_mainwindow.obj:-1: error: LNK2019: unresolved external symbol "private: void __cdecl MainWindow::on_NewStandardGame_clicked(void)" (?on_NewStandardGame_clicked@MainWindow@@AEAAXXZ) referenced in function "private: static void __cdecl MainWindow::qt_static_metacall(class QObject *,enum QMetaObject::Call,int,void * *)" (?qt_static_metacall@MainWindow@@CAXPEAVQObject@@W4Call@QMetaObject@@HPEAPEAX@Z)

JonB · wrote on 25 Dec 2021, 19:21

@Quantum1982
At a guess: you used to have a slot method void MainWindow::on_NewStandardGame_clicked(). You seem to have removed its definition in your latest code. Has its declaration been removed from the class declaration in the .h file? Is there still a connect() referencing it? Maybe search your source files for on_NewStandardGame_clicked. Have you re-run qmake and done a full rebuild?

Quantum1982 · wrote on 26 Dec 2021, 11:36

Thanks I fixed it.

My newest problem is this :

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QImage>
#include "newstandardgame.h"
#include <QPainter>
#include <QRect>
#include <QString>

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);

QString ChessPieces[12];

ChessPieces[0] = "C:/Users/User/Desktop/WhitePawn.jpg";
ChessPieces[1] = "C:/Users/User/Desktop/WhiteRook.jpg";
ChessPieces[2] = "C:/Users/User/Desktop/WhiteKnight.jpg";
ChessPieces[3] = "C:/Users/User/Desktop/WhiteBishop.jpg";
ChessPieces[4] = "C:/Users/User/Desktop/WhiteQueen.jpg";
ChessPieces[5] = "C:/Users/User/Desktop/WhiteKing.jpg";
ChessPieces[6] = "C:/Users/User/Desktop/BlackPawn.jpg";
ChessPieces[7] = "C:/Users/User/Desktop/BlackRook.jpg";
ChessPieces[8] = "C:/Users/User/Desktop/BlackKnight.jpg";
ChessPieces[9] = "C:/Users/User/Desktop/BlackBishop.jpg";
ChessPieces[10] = "C:/Users/User/Desktop/BlackQueen.jpg";
ChessPieces[11] = "C:/Users/User/Desktop/BlackKing.jpg";



QPainter * ChessPiece = new QPainter();
QImage * Image = new QImage("C:/Users/User/Desktop/WhiteQueen.jpg");
//Image->

QRect Source;
QRect Dest;

Source.setCoords(0,0,30,30);
Dest.setCoords(100,100,200,200);

QPainter *Painter = new QPainter();
Painter->drawImage(Dest,*Image,Source);

//const QPixmap Pixmap;

//ChessPiece->drawImage(Dest,Image,Source);

// ChessPiece->drawPixmap(0,0,30,30,Pixmap);

}

MainWindow::~MainWindow()
{
delete ui;
}

The chess piece is not drawn for some reason ?

SGaist · wrote on 26 Dec 2021, 19:42

Hi,

How do you determine they are not drawn ?

Quantum1982 · wrote on 28 Dec 2021, 13:31

I mean that the chess piece is not showing on the screen ?

SGaist · wrote on 28 Dec 2021, 16:23

The code you posted does not include anything that would bring the QImage on screen.

Quantum1982 · wrote on 30 Dec 2021, 15:57

@Quantum1982 said in Raspbian 2 player chess game:

Painter->drawImage(Dest,*Image,Source);

But what about the line :

Painter->drawImage(Dest,*Image,Source); ?

SGaist · wrote on 30 Dec 2021, 19:57

That painter does in fact not paint on anything.

Please re-read the class documentation.

Quantum1982 · wrote on 31 Dec 2021, 14:57

Ok

I changed it to this :

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QPainter>
#include <QImage>
#include <QRectF>

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);

QRectF target(10.0,10.0,50.0,50.0);
QRectF source(0.0,0.0,50.0,50.0);

// QImage Image("C:/Users/User/Desktop/WhiteQueen.jpg");

QPixmap Pixmap("C:/Users/User/Desktop/WhiteQueen.jpg");
QPainter Painter;

Painter.drawPixmap(target,Pixmap,source);

}

MainWindow::~MainWindow()
{
delete ui;
}

Still no chess piece on the screen ?

SGaist · wrote on 31 Dec 2021, 19:51

Because you are still using QPainter incorrectly. A bit less than before but still incorrectly.

You should paint what you want on a QPixmap that you will set on a QLabel if you want to show it.

Quantum1982 · wrote on 31 Dec 2021, 20:42

Ok, but now I am getting this error

C:\Users\User\Documents\Chess\main.cpp:-1: error: C1041: cannot open program database 'C:\Users\User\Documents\build-Chess-Desktop_Qt_5_12_12_MSVC2015_64bit-Debug\debug\Chess.vc.pdb'; if multiple CL.EXE write to the same .PDB file, please use /FS

Quantum1982 · 31 Dec 2021, 20:59

Ok I fixed it.

Now I am trying this :

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <QImage>
#include <QLabel>

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);

QPixmap Pixmap("C:/Users/User/Desktop/WhiteQueen.jpg");
QLabel WhiteQueen;
WhiteQueen.setGeometry(50,50,100,100);
WhiteQueen.setPixmap(Pixmap);

}

MainWindow::~MainWindow()
{
delete ui;
}

Still nothing appears ?

JonB · wrote on 31 Dec 2021, 20:59

@Quantum1982
QLabel WhiteQueen; is a local variable. It goes out of scope at the end of the constructor. And you never added the QLabel to the MainWindow anyway.

I would take some time to look at some basic Qt widgets examples.

Quantum1982 · 31 Dec 2021, 21:31

Ok, so where should I declare the label then for it to be drawn ?

JonB · wrote on 31 Dec 2021, 21:31

@Quantum1982
This is not a longterm design plan. But from where you are now:

Move the variable out to be a member of the MainWindow class.
Change it to be a pointer.
Set it to a newed instance back in the constructor, with the MainWindow as its parent: WhiteQueen = new QLabel(this).

At least you should then be able to see it.

I'm not sure I would do this whole chess UI with widgets, probably a graphics scene with QGraphicsPixmapItems instead, but that's a whole different matter.

Quantum1982 · 1 Jan 2022, 12:28

I am not sure how to do that.
This is what I have so far :
#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <QImage>
#include <QLabel>

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);

QString ChessPieces[12];

ChessPieces[0] = "C:/Users/User/Desktop/WhitePawn.jpg";
ChessPieces[1] = "C:/Users/User/Desktop/WhiteRook.jpg";
ChessPieces[2] = "C:/Users/User/Desktop/WhiteKnight.jpg";
ChessPieces[3] = "C:/Users/User/Desktop/WhiteBishop.jpg";
ChessPieces[4] = "C:/Users/User/Desktop/WhiteQueen.jpg";
ChessPieces[5] = "C:/Users/User/Desktop/WhiteKing.jpg";
ChessPieces[6] = "C:/Users/User/Desktop/BlackPawn.jpg";
ChessPieces[7] = "C:/Users/User/Desktop/BlackRook.jpg";
ChessPieces[8] = "C:/Users/User/Desktop/BlackKnight.jpg";
ChessPieces[9] = "C:/Users/User/Desktop/BlackBishop.jpg";
ChessPieces[10] = "C:/Users/User/Desktop/BlackQueen.jpg";
ChessPieces[11] = "C:/Users/User/Desktop/BlackKing.jpg";

QPixmap Pixmap("C:/Users/User/Desktop/WhiteQueen.jpg");
WhiteQueen.setGeometry(50,50,100,100);
WhiteQueen.setPixmap(Pixmap);

}

MainWindow::~MainWindow()
{
delete ui;
}
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QLabel>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
QLabel WhiteQueen;
MainWindow(QWidget *parent = nullptr);
~MainWindow();

private:
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H

Then there is still no chess piece displayed ?