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The Dark · Oct 27th, 2006, 7:35 PM

Some of your rectangles are outside of the bounds of screen, which cause the program to write outside the bounds of the array. Note that the rectangle takes its parameters as hieght then width, which is the opposite order to the x,y that point takes.

The values you are passing in for Paint are not printable - char value 1 2 3 and 4 are control characters and will display oddly on your screen. Try using '1', '2', etc.

Inside the loop in the rectangle draw function the point to set is in i and j, not x1 and y1 (my example code is wrong too).

brad sue · Oct 28th, 2006, 1:33 AM

You're right I made all changes and it is ok.
How did you see that the order of the coordinates were inversed?
Now I am working now on another function
Thank You

The Dark · Oct 28th, 2006, 3:30 AM

I only found out that the order was reversed when I ran it and the output looked wrong (and caused an exception when it went out of bounds).

brad sue · Oct 30th, 2006, 3:58 AM

I have separeted my file into file headers and I have an error I can't get rid of :
these ar all my headers files:

(Toggle Plain Text)

// Point.h
#ifndef Point_H
#define Point_H
#include "Rectangle.h"
#include<iostream>
#include"Screen.h"

class Rectangle;
class Point{
      private:
              int x;
              int y;
      public:
             Point();
             Point(int,int);
             ~Point();
             void setPoint(int,int);
             int getX(void) const;
             int getY(void) const;
             };
#endif

(Toggle Plain Text)

//Screen.h
#ifndef Screen_H
#define Screen_H
#include "Rectangle.h"
#include "Point.h"
#include<iostream>


    class Rectangle;
    class Point;
   class Screen
   {
         private:
                 char pixels[20][30];
         public:
                Screen(void);
                ~Screen(void);
                void setPoint(const Point&,char);
                void resetPoint(const Point&);
                void clear(void);
                void draw(void)const;
   };
#endif

(Toggle Plain Text)

// Rectangle.h
#ifndef Rectangle_H
#define Rectangle_H
#include "Point.h"
#include "Screen.h"
#include<iostream>
#include<iomanip>

class Screen;
class Point;
class Rectangle{

          private:
                  int height;
                  int width;
                  Point upLeft;
                  char Paint;
          public:
                 Rectangle(void);
                 Rectangle(const Point&,int,int,char);
                 ~Rectangle();
                 void set(const Point&,int,int,char);rectangle
                 void setPaint(char);
                 void setPoint(const Point&);
                 void setPoint(int, int);
                 void setSize(int,int);
                 int getX(void);
                 int getY(void);
                 int getWidth(void);
                 int getHeight(void);
                 char getPaint(void);
                 void setIntersection( Rectangle,  Rectangle);
                 void setUnion(Rectangle, Rectangle);
                 bool containsPoint( Point);
                 bool containsPoint(int,int);
                 void draw(Screen&);
};                
   #endif

(Toggle Plain Text)

#include<iostream>
#include "Point.h"
#include "Rectangle.h"
#include "Screen.h"
using namespace std;

void check( const Point& pt , char c ,Rectangle r[6]);

int main()
{
   //...

I have this compile error:
compilation: cxx main.cpp Rectangle.cpp Point.cpp Screen.cpp -o main

(Toggle Plain Text)

main.cpp:
cxx: Error: Rectangle.h, line 15: incomplete type is not allowed
                  Point upLeft;
------------------------^
cxx: Info: 1 error detected in the compilation of "main.cpp".
Rectangle.cpp:
Point.cpp:
cxx: Error: Rectangle.h, line 15: incomplete type is not allowed
                  Point upLeft;
------------------------^
cxx: Info: 1 error detected in the compilation of "Point.cpp".
Screen.cpp:

First I would the to fix the error in Rectangle.h

Does someone see what is the problem?
thank you for the help

The Dark · Oct 30th, 2006, 4:11 AM

Don't include Screen.h, Rectangle.h or iostream.h inside point.h
You also don't need to forward declare Rectangle inside point.h, as it doesn't use it.

Screen.h doesn't need to include Point.h, Rectangle.h or iostream.h, it just needs the forward declare of Point (or you could just leave the Point.h include in there, but you don't need the include and the forward declare).

Rectangle just needs to include Point.h and have the forward declare of Screen. All the other includes should be removed.

As a rule of thumb, the fewer nested includes you have the better. If the header doesn't need the include, then don't put it in the header.

grumpy · Oct 30th, 2006, 4:12 AM

The reason for your error is that a forward declaration of a class is insufficient to allow declaration of an instance. So;

(Toggle Plain Text)

class Point;

class Rectangle
{
    // other stuff
    Point upLeft;
};

will fail. The way to eliminate it is to ensure that the complete declaration of class Point is seen by the compiler before it reaches the declaration of class Rectangle.

Partially related to your problem is that Point.h #include's Rectangle.h which #include's Point.h ..... That will not loop forever because you have employed #include guards, but is an issue because you will get different behaviour for other source files, depending on whether they #include Point.h or Rectangle.h first.

The Dark · Oct 30th, 2006, 4:17 AM

Bah, if you are quick editting and someone puts an extra post in, you lose all your changes.

What I was trying to add was pretty much what grumpy said. In this case, only Rectangle needs another actual class (Point) defined for the header to compile.

brad sue · Oct 30th, 2006, 5:12 PM

Thank you, it works!
Thanks for the tip

brad sue · Nov 1st, 2006, 5:29 AM

I am modifying my program now and I want the screen to be a dynamic allocated 2D array.
The code I made compiles well but gives me a run time error:
this is my class

(Toggle Plain Text)

class Screen
   {
         private:
                 char* pixels;
                 int height;//rows
                 int width;//columns
         public: 
                friend ostream& operator<<(ostream & out, const Screen & TV);
                Screen(int=10, int=10);
                ~Screen(void);
                void setH(int );
                int getH(void)const;
                void setW(int);
                int getW() const;
                void setPoint(const Point&,char);
                void resetPoint(const Point&);
                void clear(void);
                void draw(void)const;
   };

// implementation of screen class

   Screen::Screen(int r,int c)
   {
         int size;
         size=r*c;
         pixels=new char[size];
         for(int i=0;i<r;i++)
            {
              for(int j=0;j<c;j++)
                 {
                  *(pixels+(i*c)+j)='.';
                  }
            }
   }             
      
      
   Screen::~Screen(){delete []pixels;}
   
   void Screen::setPoint(const Point & object, char c)
   {
        int i=object.getX();
        int j=object.getY();        
        *(pixels+(i*width)+j)=c;
   }          
                 
   void Screen::draw()const
   {
        for( int i=0;i<height;i++)
            {for( int j=0;j<width;j++)
                 {cout<<*(pixels+(i*width)+j);}
                 cout<<endl;
                 }
   }    
   
   void Screen::resetPoint(const Point& object)
   {
        int x_del,y_del;
        x_del=object.getX();
        y_del=object.getY();
        *(pixels+(x_del*width)+y_del)='.';
   }   
   
   void Screen::clear()
   { int i,j;
         for(i=0;i<height;i++){
             for(j=0;j<width;j++){
                 *(pixels+(i*width)+j)='.';}}
   }
    
    void Screen::setH(int row)
    {height=row;}
    
    int Screen::getH()const{ return height;}
    
    void Screen::setW(int col)
    {         width=col;}
    
    int Screen::getW() const{ return width;}
    
         
    ostream& operator<<(ostream & out, const Screen & TV)
    { 
             for(int i=0;i<TV.height;i++)
                 for(int j=0;j<TV.width;j++)
                    out<<*(TV.pixels+(i*TV.width)+j);
                    out<<endl;
    }
    
int main()
{
    Screen ecran(20,30);
    cout<<"\n\nPrinting a blank Screen"<<endl;
    ecran.draw();// or cout ecran; still gives error

class Screen
   {
         private:
                 char* pixels;
                 int height;//rows
                 int width;//columns
         public: 
                friend ostream& operator<<(ostream & out, const Screen & TV);
                Screen(int=10, int=10);
                ~Screen(void);
                void setH(int );
                int getH(void)const;
                void setW(int);
                int getW() const;
                void setPoint(const Point&,char);
                void resetPoint(const Point&);
                void clear(void);
                void draw(void)const;
   };

// implementation of screen class

   Screen::Screen(int r,int c)
   {
         int size;
         size=r*c;
         pixels=new char[size];
         for(int i=0;i<r;i++)
            {
              for(int j=0;j<c;j++)
                 {
                  *(pixels+(i*c)+j)='.';
                  }
            }
   }             
      
      
   Screen::~Screen(){delete []pixels;}
   
   void Screen::setPoint(const Point & object, char c)
   {
        int i=object.getX();
        int j=object.getY();        
        *(pixels+(i*width)+j)=c;
   }          
                 
   void Screen::draw()const
   {
        for( int i=0;i<height;i++)
            {for( int j=0;j<width;j++)
                 {cout<<*(pixels+(i*width)+j);}
                 cout<<endl;
                 }
   }    
   
   void Screen::resetPoint(const Point& object)
   {
        int x_del,y_del;
        x_del=object.getX();
        y_del=object.getY();
        *(pixels+(x_del*width)+y_del)='.';
   }   
   
   void Screen::clear()
   { int i,j;
         for(i=0;i<height;i++){
             for(j=0;j<width;j++){
                 *(pixels+(i*width)+j)='.';}}
   }
    
    void Screen::setH(int row)
    {height=row;}
    
    int Screen::getH()const{ return height;}
    
    void Screen::setW(int col)
    {         width=col;}
    
    int Screen::getW() const{ return width;}
    
         
    ostream& operator<<(ostream & out, const Screen & TV)
    { 
             for(int i=0;i<TV.height;i++)
                 for(int j=0;j<TV.width;j++)
                    out<<*(TV.pixels+(i*TV.width)+j);
                    out<<endl;
    }
    
int main()
{
    Screen ecran(20,30);
    cout<<"\n\nPrinting a blank Screen"<<endl;
    ecran.draw();// or cout ecran; still gives error

I am supposed to have a 20X30 table but what is displayed is more like:

(Toggle Plain Text)

..............................................
...............................................
...............................................
..............................................
(8 lines only!)

and the error message
Please, can some help me to debug it?
Thank you.

The Dark · Nov 1st, 2006, 6:33 AM

You are not setting the values of height and width in your constructor.

Oct 30th, 2006, 3:58 AM	#24
brad sue Hobbyist Programmer Join Date: Mar 2006 Posts: 120 Rep Power: 3	I have separeted my file into file headers and I have an error I can't get rid of : these ar all my headers files: (Toggle Plain Text) // Point.h #ifndef Point_H #define Point_H #include "Rectangle.h" #include<iostream> #include"Screen.h" class Rectangle; class Point{ private: int x; int y; public: Point(); Point(int,int); ~Point(); void setPoint(int,int); int getX(void) const; int getY(void) const; }; #endif // Point.h #ifndef Point_H #define Point_H #include "Rectangle.h" #include<iostream> #include"Screen.h" class Rectangle; class Point{ private: int x; int y; public: Point(); Point(int,int); ~Point(); void setPoint(int,int); int getX(void) const; int getY(void) const; }; #endif (Toggle Plain Text) //Screen.h #ifndef Screen_H #define Screen_H #include "Rectangle.h" #include "Point.h" #include<iostream> class Rectangle; class Point; class Screen { private: char pixels[20][30]; public: Screen(void); ~Screen(void); void setPoint(const Point&,char); void resetPoint(const Point&); void clear(void); void draw(void)const; }; #endif //Screen.h #ifndef Screen_H #define Screen_H #include "Rectangle.h" #include "Point.h" #include<iostream> class Rectangle; class Point; class Screen { private: char pixels[20][30]; public: Screen(void); ~Screen(void); void setPoint(const Point&,char); void resetPoint(const Point&); void clear(void); void draw(void)const; }; #endif (Toggle Plain Text) // Rectangle.h #ifndef Rectangle_H #define Rectangle_H #include "Point.h" #include "Screen.h" #include<iostream> #include<iomanip> class Screen; class Point; class Rectangle{ private: int height; int width; Point upLeft; char Paint; public: Rectangle(void); Rectangle(const Point&,int,int,char); ~Rectangle(); void set(const Point&,int,int,char);rectangle void setPaint(char); void setPoint(const Point&); void setPoint(int, int); void setSize(int,int); int getX(void); int getY(void); int getWidth(void); int getHeight(void); char getPaint(void); void setIntersection( Rectangle, Rectangle); void setUnion(Rectangle, Rectangle); bool containsPoint( Point); bool containsPoint(int,int); void draw(Screen&); }; #endif // Rectangle.h #ifndef Rectangle_H #define Rectangle_H #include "Point.h" #include "Screen.h" #include<iostream> #include<iomanip> class Screen; class Point; class Rectangle{ private: int height; int width; Point upLeft; char Paint; public: Rectangle(void); Rectangle(const Point&,int,int,char); ~Rectangle(); void set(const Point&,int,int,char);rectangle void setPaint(char); void setPoint(const Point&); void setPoint(int, int); void setSize(int,int); int getX(void); int getY(void); int getWidth(void); int getHeight(void); char getPaint(void); void setIntersection( Rectangle, Rectangle); void setUnion(Rectangle, Rectangle); bool containsPoint( Point); bool containsPoint(int,int); void draw(Screen&); }; #endif (Toggle Plain Text) #include<iostream> #include "Point.h" #include "Rectangle.h" #include "Screen.h" using namespace std; void check( const Point& pt , char c ,Rectangle r[6]); int main() { //... #include<iostream> #include "Point.h" #include "Rectangle.h" #include "Screen.h" using namespace std; void check( const Point& pt , char c ,Rectangle r[6]); int main() { //... I have this compile error: compilation: cxx main.cpp Rectangle.cpp Point.cpp Screen.cpp -o main (Toggle Plain Text) main.cpp: cxx: Error: Rectangle.h, line 15: incomplete type is not allowed Point upLeft; ------------------------^ cxx: Info: 1 error detected in the compilation of "main.cpp". Rectangle.cpp: Point.cpp: cxx: Error: Rectangle.h, line 15: incomplete type is not allowed Point upLeft; ------------------------^ cxx: Info: 1 error detected in the compilation of "Point.cpp". Screen.cpp: main.cpp: cxx: Error: Rectangle.h, line 15: incomplete type is not allowed Point upLeft; ------------------------^ cxx: Info: 1 error detected in the compilation of "main.cpp". Rectangle.cpp: Point.cpp: cxx: Error: Rectangle.h, line 15: incomplete type is not allowed Point upLeft; ------------------------^ cxx: Info: 1 error detected in the compilation of "Point.cpp". Screen.cpp: First I would the to fix the error in Rectangle.h Does someone see what is the problem? thank you for the help

Oct 30th, 2006, 4:12 AM	#26
grumpy Programming Guru Join Date: Jun 2005 Location: Adelaide, South Australia Posts: 1,260 Rep Power: 5	The reason for your error is that a forward declaration of a class is insufficient to allow declaration of an instance. So; (Toggle Plain Text) class Point; class Rectangle { // other stuff Point upLeft; }; class Point; class Rectangle { // other stuff Point upLeft; }; will fail. The way to eliminate it is to ensure that the complete declaration of class Point is seen by the compiler before it reaches the declaration of class Rectangle. Partially related to your problem is that Point.h #include's Rectangle.h which #include's Point.h ..... That will not loop forever because you have employed #include guards, but is an issue because you will get different behaviour for other source files, depending on whether they #include Point.h or Rectangle.h first.

Nov 1st, 2006, 5:29 AM	#29
brad sue Hobbyist Programmer Join Date: Mar 2006 Posts: 120 Rep Power: 3	I am modifying my program now and I want the screen to be a dynamic allocated 2D array. The code I made compiles well but gives me a run time error: this is my class (Toggle Plain Text) class Screen { private: char* pixels; int height;//rows int width;//columns public: friend ostream& operator<<(ostream & out, const Screen & TV); Screen(int=10, int=10); ~Screen(void); void setH(int ); int getH(void)const; void setW(int); int getW() const; void setPoint(const Point&,char); void resetPoint(const Point&); void clear(void); void draw(void)const; }; // implementation of screen class Screen::Screen(int r,int c) { int size; size=rc; pixels=new char[size]; for(int i=0;i<r;i++) { for(int j=0;j<c;j++) { (pixels+(ic)+j)='.'; } } } Screen::~Screen(){delete []pixels;} void Screen::setPoint(const Point & object, char c) { int i=object.getX(); int j=object.getY(); (pixels+(iwidth)+j)=c; } void Screen::draw()const { for( int i=0;i<height;i++) {for( int j=0;j<width;j++) {cout<<(pixels+(iwidth)+j);} cout<<endl; } } void Screen::resetPoint(const Point& object) { int x_del,y_del; x_del=object.getX(); y_del=object.getY(); (pixels+(x_delwidth)+y_del)='.'; } void Screen::clear() { int i,j; for(i=0;i<height;i++){ for(j=0;j<width;j++){ (pixels+(iwidth)+j)='.';}} } void Screen::setH(int row) {height=row;} int Screen::getH()const{ return height;} void Screen::setW(int col) { width=col;} int Screen::getW() const{ return width;} ostream& operator<<(ostream & out, const Screen & TV) { for(int i=0;i<TV.height;i++) for(int j=0;j<TV.width;j++) out<<(TV.pixels+(iTV.width)+j); out<<endl; } int main() { Screen ecran(20,30); cout<<"\n\nPrinting a blank Screen"<<endl; ecran.draw();// or cout ecran; still gives error class Screen { private: char pixels; int height;//rows int width;//columns public: friend ostream& operator<<(ostream & out, const Screen & TV); Screen(int=10, int=10); ~Screen(void); void setH(int ); int getH(void)const; void setW(int); int getW() const; void setPoint(const Point&,char); void resetPoint(const Point&); void clear(void); void draw(void)const; }; // implementation of screen class Screen::Screen(int r,int c) { int size; size=rc; pixels=new char[size]; for(int i=0;i<r;i++) { for(int j=0;j<c;j++) { (pixels+(ic)+j)='.'; } } } Screen::~Screen(){delete []pixels;} void Screen::setPoint(const Point & object, char c) { int i=object.getX(); int j=object.getY(); (pixels+(iwidth)+j)=c; } void Screen::draw()const { for( int i=0;i<height;i++) {for( int j=0;j<width;j++) {cout<<(pixels+(iwidth)+j);} cout<<endl; } } void Screen::resetPoint(const Point& object) { int x_del,y_del; x_del=object.getX(); y_del=object.getY(); (pixels+(x_delwidth)+y_del)='.'; } void Screen::clear() { int i,j; for(i=0;i<height;i++){ for(j=0;j<width;j++){ (pixels+(iwidth)+j)='.';}} } void Screen::setH(int row) {height=row;} int Screen::getH()const{ return height;} void Screen::setW(int col) { width=col;} int Screen::getW() const{ return width;} ostream& operator<<(ostream & out, const Screen & TV) { for(int i=0;i<TV.height;i++) for(int j=0;j<TV.width;j++) out<<(TV.pixels+(i*TV.width)+j); out<<endl; } int main() { Screen ecran(20,30); cout<<"\n\nPrinting a blank Screen"<<endl; ecran.draw();// or cout ecran; still gives error I am supposed to have a 20X30 table but what is displayed is more like: (Toggle Plain Text) .............................................. ............................................... ............................................... .............................................. (8 lines only!) .............................................. ............................................... ............................................... .............................................. (8 lines only!) and the error message Please, can some help me to debug it? Thank you.

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Oct 27th, 2006, 7:35 PM	#21
The Dark Expert Programmer Join Date: Jun 2005 Posts: 894 Rep Power: 4	Some of your rectangles are outside of the bounds of screen, which cause the program to write outside the bounds of the array. Note that the rectangle takes its parameters as hieght then width, which is the opposite order to the x,y that point takes. The values you are passing in for Paint are not printable - char value 1 2 3 and 4 are control characters and will display oddly on your screen. Try using '1', '2', etc. Inside the loop in the rectangle draw function the point to set is in i and j, not x1 and y1 (my example code is wrong too).

Oct 28th, 2006, 1:33 AM	#22
brad sue Hobbyist Programmer Join Date: Mar 2006 Posts: 120 Rep Power: 3	You're right I made all changes and it is ok. How did you see that the order of the coordinates were inversed? Now I am working now on another function Thank You

Oct 28th, 2006, 3:30 AM	#23
The Dark Expert Programmer Join Date: Jun 2005 Posts: 894 Rep Power: 4	I only found out that the order was reversed when I ran it and the output looked wrong (and caused an exception when it went out of bounds).

Oct 30th, 2006, 4:11 AM	#25
The Dark Expert Programmer Join Date: Jun 2005 Posts: 894 Rep Power: 4	Don't include Screen.h, Rectangle.h or iostream.h inside point.h You also don't need to forward declare Rectangle inside point.h, as it doesn't use it. Screen.h doesn't need to include Point.h, Rectangle.h or iostream.h, it just needs the forward declare of Point (or you could just leave the Point.h include in there, but you don't need the include and the forward declare). Rectangle just needs to include Point.h and have the forward declare of Screen. All the other includes should be removed. As a rule of thumb, the fewer nested includes you have the better. If the header doesn't need the include, then don't put it in the header.

Oct 30th, 2006, 4:17 AM	#27
The Dark Expert Programmer Join Date: Jun 2005 Posts: 894 Rep Power: 4	Bah, if you are quick editting and someone puts an extra post in, you lose all your changes. What I was trying to add was pretty much what grumpy said. In this case, only Rectangle needs another actual class (Point) defined for the header to compile.

Oct 30th, 2006, 5:12 PM	#28
brad sue Hobbyist Programmer Join Date: Mar 2006 Posts: 120 Rep Power: 3	Thank you, it works! Thanks for the tip

Nov 1st, 2006, 6:33 AM	#30
The Dark Expert Programmer Join Date: Jun 2005 Posts: 894 Rep Power: 4	You are not setting the values of height and width in your constructor.

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