C:/Users/MMarcin/Documents/LGM/zad3/MyWidget.cpp:4: error: 'img' was not declared in this scope

C:/Users/MMarcin/Documents/LGM/zad3/MyWidget.cpp:5: error: 'czysc' was not declared in this scope

C:/Users/MMarcin/Documents/LGM/zad3/MyWidget.cpp:10: error: no 'void MyWidget::paintEvent(QPaintEvent*)' member function declared in class 'MyWidget'

C:/Users/MMarcin/Documents/LGM/zad3/MyWidget.cpp:22: error: no 'void MyWidget::mousePressEvent(QMouseEvent*)' member function declared in class 'MyWidget'

C:/Users/MMarcin/Documents/LGM/zad3/MyWidget.cpp:33: error: no 'void MyWidget::czysc()' member function declared in class 'MyWidget'

C:/Users/MMarcin/Documents/LGM/zad3/MyWidget.cpp:46: error: no 'void MyWidget::ustawpiksel(int, int)' member function declared in class 'MyWidget'

C:/Users/MMarcin/Documents/LGM/zad3/MyWidget.cpp:57: error: no 'void MyWidget::rysodc(int, int, int, int)' member function declared in class 'MyWidget'

#include <QPainter>
#include <QWidget>
#include <QMouseEvent>
#include <iostream>
#include <QPushButton>
#include <QLabel>
#include <QtGui>
#include <QPaintEvent>
#include <QApplication>

class MyWidget:QWidget{
 public:
  MyWidget();
 private:
  QPushButton *b1;
};

#include "MyWidget.h"

MyWidget::MyWidget(){
 img = new QImage(700,700,QImage::Format_RGB32); //format kolorow
 czysc();

}


void MyWidget::paintEvent(QPaintEvent*){        //rysowanie lini
  QPainter p(this);
  // p.drawLine(p1->x(),p1->y(),100,100);
  /*
   p.drawLine(100,0,100,100); //rysowanie lini od (100,0) do (100,100)
   p.drawLine(100,100,200,100);
     p.drawLine(200,0,200,100);
  */

  p.drawImage(0,0,*img);
  
}
   void MyWidget::mousePressEvent(QMouseEvent *event){ 
     
     if(event->button()==Qt::RightButton) // czy klikniecie ppm
       // p1=new QPoint(event->x(), event->y());
       ustawpiksel(event->y(), event->x());
     if(event->button()==Qt::LeftButton) // czy klikniecie lpm
       // p1=new QPoint(event->x(), event->y());
       rysodc(200,200,event->y(), event->x());
     update();
   }
       
void MyWidget::czysc(){         //ustawienia koloru
  unsigned char *ptr;
  ptr = img->bits();
  int i,j;
  for (i=0;i<700;i++){
    for (j=0;j<700;j++){
      ptr[700*4*i+4*j]=255;
      ptr[700*4*i+4*j+1]=0;
      ptr[700*4*i+4*j+2]=0;
    }
  }
}

void MyWidget::ustawpiksel(int x, int y){         //ustawia piksele
  unsigned char *ptr;
  ptr = img->bits();
  

      ptr[700*4*x+4*y]=100;
      ptr[700*4*x+4*y+1]=100;
      ptr[700*4*x+4*y+2]=100;
      update();
 }

void MyWidget::rysodc(int x0, int y0, int x1, int y1){             //rysuje odcinek
  double m,y,x;
  int i, tmp, tmp1;
  if (x0>x1){   //rysowanie tez na gorze
    tmp=y0;
    y0=y1;
    y1=tmp;
    tmp1=x0;
    x0=x1;
    x1=tmp1;
  }
  
  m=(double)(y1-y0)/(x1-x0);
  y=y0;
  if (abs(m)<=1){ 
    if(x0>x1){
    tmp=y0;
    y0=y1;
    y1=tmp;
    tmp1=x0;
    x0=x1;
    x1=tmp1;
    }
  for (i=x0; i<x1; i++){
    y+=m;
    MyWidget:: ustawpiksel(i , (int)y);
  }
  }
  else{if (y0>y1){  
    tmp=y0;
    y0=y1;
    y1=tmp;
    tmp1=x0;
    x0=x1;
    x1=tmp1;
  }
    m=1/m;
     for (i=y0; i<y1; i++){
       x+=m;
       MyWidget::ustawpiksel(i ,(int)x);
       
  }
}
}

#include "MyWidget.h"

 int main(int argc, char **argv){

  QApplication a(argc,argv);
  MyWidget m;
  
   m.show();  

   return a.exec();
}

 connect(button, SIGNAL(clicked()), this, SLOT(funkcja()));