Multiple Definition errors in c

Multiple Definition errors in c 


Multiple Definition errors in c  
#ifndef SCREEN_H
#define SCREEN_H

#include <graphics.h>

class Screen
{
      private:
              int max_x,max_y,grid_size;
              int delta_x,delta_y;
              int origin_x,origin_y;
      public:
      // Default Constructor to Initialize the screen with the grid
      Screen(int xcoord=641, int ycoord=641, int grid=8)
      {
           //variable initialization
           max_x = xcoord;
           max_y = ycoord;
           grid_size = grid;

           delta_x = max_x / grid_size;
           delta_y = max_y / grid_size;

           origin_x = grid_size / 2 * delta_x;
           origin_y = grid_size / 2 * delta_y;

           //plotting the initial grid
           int gd,gm;
           initgraph(&gd,&gm,NULL);
            //draw the x component of the grid
             for(int i=0; i<max_x; i += delta_x)
             {
                     if( i != max_x / 2)
                         setcolor(GREEN);
                     else
                         setcolor(RED);
                    line(i,0,i,max_y);
             }
             //draw the y component of the grid
             for(int i=0; i<max_y; i += delta_y)
             {
                     if( i != max_y / 2)
                         setcolor(GREEN);
                     else
                         setcolor(RED);
                     line(0,i,max_x,i);
             }
             //mark the origin with a white dot to acertain its coordinates for future use
             putpixel(origin_x,origin_y,WHITE);
             std::cout<<origin_x<<"t"<<origin_y<<"n";
        }



      //Method prototypes
      void plot_pixel(int xcoord,int ycoord,int col=WHITE)
      {
        int l,t,r,b;
        l = origin_x + xcoord * delta_x;
        r = l + delta_x;
        b = origin_y - ycoord * delta_y;
        t = b - delta_y;
        setcolor(col);
        bar(l,t,r,b);
        setcolor(WHITE);
     }
};
#endif
#include<iostream>
#include<cmath>
#include "screen.h"
using namespace std;

  void draw_midpoint_circle(Screen ob,int radius); 
  void circlepointplot(Screen ob,int m,int n); 
  void trigonometric_circle(Screen ob, int radius);  

int main()
{
    Screen scr = Screen(641,641,16);
    int choice,rad;
    cout<<"Menun 1. Midpoint Circle Drawing Algorithmn 2. Bresenham's Circle Drawing Algorithm n 3. Trigonometric Methodn";
    cin>>choice;
    cout<<"Enter Radius t";
    cin>>rad;

    switch(choice)
    {
                  case 1:
                       draw_midpoint_circle(scr, rad);
                       break;
                  case 2:
                       draw_midpoint_circle(scr,rad);
                       break;
                  case 3:
                         trigonometric_circle(scr,rad);
                         break;   
                  default:
                          cout<<"Wrong Choicen";
                          break;       
    }

    getch();
    return 0;
}


void trigonometric_circle(Screen ob, int radius)
{
     double angle=0.0;
      while(angle<=360){
                        int dx = 641 / 16;
                             int x=int(radius*cos(angle));
                             int y=int(radius*sin(angle));
                             angle=angle+5;
                             ob.plot_pixel(x,y,0); 
                             cout<<"Point Plotted  "<<x<<"t"<<y<<endl;
                             char buffer[50];  
                             sprintf(buffer,"%d,%d",x,y);
                             outtextxy(320 + ((x+1)*dx),320 - ((y-1)*dx), buffer);
                             getch();
                          }                      
}


void draw_midpoint_circle(Screen ob,int radius)
{
     float dp;
     int x,y;
     x=0;
                          y=radius;                          
                          dp=1-radius;
                          while(x<y)
                          {
                                    circlepointplot(ob,x,y);
                                    if(dp<0)
                                            dp=dp+2*x+3;
                                    else{
                                         dp=dp+2*(x-y)+5;
                                         y--;
                                         }

                                   x++;
                                   circlepointplot(ob,x,y);      
                          }   
}


void circlepointplot(Screen ob,int m,int n){                                            
                                         ob.plot_pixel(m,n,0);     
                                         ob.plot_pixel(n,m,0); 
                                         ob.plot_pixel(m,-n,0); 
                                         ob.plot_pixel(n,-m,0);        
                                         ob.plot_pixel(-m,n,0);     
                                         ob.plot_pixel(-n,m,0); 
                                         ob.plot_pixel(-m,-n,0); 
                                         ob.plot_pixel(-n,-m,0); 

                                         cout<<"Point Plotted"<<m<<"t"<<n<<endl;
                                         cout<<"Point Plotted"<<n<<"t"<<m<<endl;
                                         cout<<"Point Plotted"<<m<<"t"<<-n<<endl;
                                         cout<<"Point Plotted"<<n<<"t"<<-m<<endl;
                                         cout<<"Point Plotted"<<-m<<"t"<<n<<endl;
                                         cout<<"Point Plotted"<<-n<<"t"<<m<<endl;
                                         cout<<"Point Plotted"<<-m<<"t"<<-n<<endl;
                                         cout<<"Point Plotted"<<-n<<"t"<<-m<<endl;
                                         int dx = 641 / 16;
                                         char buffer[50];  
                             sprintf(buffer,"%d,%d",m,n);
                             outtextxy(320 + ((m+1)*dx),320 - ((n-1)*dx), buffer);
                             getch();

                                       }
g++ -c screen.cpp -o screen.o
g++ -c circles.cpp -o circles.o
g++ screen.o circles.o -o "circle.exe" -lgraph
circles.o:(.bss+0x0): multiple definition of `screen'
screen.o:(.bss+0x0): first defined here
circles.o:(.bss+0x8): multiple definition of `Font_surface'
screen.o:(.bss+0x8): first defined here
circles.o:(.bss+0x10): multiple definition of `_fgcolor'
screen.o:(.bss+0x10): first defined here
circles.o:(.bss+0x14): multiple definition of `_bgcolor'
screen.o:(.bss+0x14): first defined here
circles.o:(.bss+0x18): multiple definition of `_fontcolor'
screen.o:(.bss+0x18): first defined here
circles.o:(.bss+0x1c): multiple definition of `_pid'
screen.o:(.bss+0x1c): first defined here
circles.o:(.bss+0x20): multiple definition of `CP'
screen.o:(.bss+0x20): first defined here
circles.o:(.bss+0x40): multiple definition of `InternalFont'
screen.o:(.bss+0x40): first defined here
circles.o:(.bss+0x850): multiple definition of `TP'
screen.o:(.bss+0x850): first defined here
circles.o:(.bss+0x860): multiple definition of `_last_arc'
screen.o:(.bss+0x860): first defined here
circles.o:(.bss+0x878): multiple definition of `_internal_linestyle'
screen.o:(.bss+0x878): first defined here
circles.o:(.bss+0x888): multiple definition of `_scanlist'
screen.o:(.bss+0x888): first defined here
collect2: ld returned 1 exit status
/tmp/ccB2RO2Q.o: In function `main':
circles.cpp:(.text+0x111): undefined reference to `grgetch'
/tmp/ccB2RO2Q.o: In function `trigonometric_circle(Screen, int)':
circles.cpp:(.text+0x242): undefined reference to `outtextxy'
circles.cpp:(.text+0x247): undefined reference to `grgetch'
/tmp/ccB2RO2Q.o: In function `circlepointplot(Screen, int, int)':
circles.cpp:(.text+0x6f2): undefined reference to `outtextxy'
circles.cpp:(.text+0x6f7): undefined reference to `grgetch'
/tmp/ccB2RO2Q.o: In function `Screen::Screen(int, int, int)':
circles.cpp:(.text._ZN6ScreenC2Eiii[_ZN6ScreenC5Eiii]+0xd0): undefined reference to `initgraph'
circles.cpp:(.text._ZN6ScreenC2Eiii[_ZN6ScreenC5Eiii]+0xf7): undefined reference to `setcolor'
circles.cpp:(.text._ZN6ScreenC2Eiii[_ZN6ScreenC5Eiii]+0x103): undefined reference to `setcolor'
circles.cpp:(.text._ZN6ScreenC2Eiii[_ZN6ScreenC5Eiii]+0x11c): undefined reference to `line'
circles.cpp:(.text._ZN6ScreenC2Eiii[_ZN6ScreenC5Eiii]+0x15e): undefined reference to `setcolor'
circles.cpp:(.text._ZN6ScreenC2Eiii[_ZN6ScreenC5Eiii]+0x16a): undefined reference to `setcolor'
circles.cpp:(.text._ZN6ScreenC2Eiii[_ZN6ScreenC5Eiii]+0x182): undefined reference to `line'
circles.cpp:(.text._ZN6ScreenC2Eiii[_ZN6ScreenC5Eiii]+0x1b9): undefined reference to `putpixel'
/tmp/ccB2RO2Q.o: In function `Screen::plot_pixel(int, int, int)':
circles.cpp:(.text._ZN6Screen10plot_pixelEiii[Screen::plot_pixel(int, int, int)]+0x6d): undefined reference to `setcolor'
circles.cpp:(.text._ZN6Screen10plot_pixelEiii[Screen::plot_pixel(int, int, int)]+0x80): undefined reference to `bar'
circles.cpp:(.text._ZN6Screen10plot_pixelEiii[Screen::plot_pixel(int, int, int)]+0x8a): undefined reference to `setcolor'
collect2: ld returned 1 exit status
/* libgraph - TurboC graphics API on GNU/Linux
 * graphics.h: Core initialization and configuration functions
 * 
 * Copyright (C) 2003  Faraz Shahbazker
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 *  MA 02111-1307, USA
 *
 * Author:  Faraz Shahbazker <faraz_ms@rediffmail.com>
 */

/* Graphic functions using SDL */

#ifndef GRAPHICS_H
#define GRAPHICS_H 1


#include <SDL/SDL.h>
#include <unistd.h>
#include <sys/types.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>


#ifdef __cplusplus
extern "C" 
{

#endif      /* __cplusplus */


/* graphic drivers */
enum _driver{DETECT=0, USER, VGA=9};
enum graphics_modes{VGALO=0, VGAMED, VGAHI, VGAMAX, VGA640, VGA800, VGA1024, USERMODE};


/* 16 colors */
enum _color{BLACK=0, BLUE, GREEN, CYAN, RED, MAGENTA, BROWN, LIGHTGRAY, DARKGRAY,LIGHTBLUE, LIGHTGREEN, LIGHTCYAN, LIGHTRED, LIGHTMAGENTA, YELLOW, WHITE};



/* global variables */
SDL_Surface *screen;        //main drawing screen
SDL_Surface *Font_surface;  //font screen 
Uint32 _fgcolor, _bgcolor, _fontcolor;  //global color numbers
pid_t _pid;         //Don't bother with this 



/* function prototypes */
void initgraph(int *graphdriver,int *graphmode,char *pathtodriver);
void closegraph(void);
void setgraphmode(int gmode);
int  getgraphmode(void);
void restorecrtmode(void);
int  getmaxx(void);
int  getmaxy(void);
void putpixel(int x, int y, int color);
int  getpixel(int, int);
void setbkcolor(int color);
int  getbkcolor(void);
void setcolor(int color);
int  getcolor(void);
int getmaxcolor(void);
char* getdrivername(void);
char* getmodename(int mode_number);
int getmaxmode(void);
void detectgraph(int* graphdriver, int* graphmode);
void getmoderange(int graphdriver, int* lomode, int* himode);
int delay(float);
void setfontcolor(int color);
int getfontcolor(void);





/*** library specific functions - not for users ***/
void initialize_settings (void);
void mappixel(int, int);     //marks a pixel without updating screen
void clippixel(int *, int *); /* Clip pixel (x,y) to current
                                 screen size*/
void mapword(int,int,int);
void mapvword(int,int,int);
int colorrev(const Uint8);   // maps 0..255 8-bit color to 0..15 TC color
Uint8 colortrans(const int); // maps 0..15 TC color to 0..255 8-bit color
void ctrlbreak(void);        // To detect user interrupt    
void inthandler(int);        // clean up on user interrupt
void safe_update(int top, int left, int right, int bottom);
    /* update screen within boundary */

#define CHECK_INITIALIZATION
    if (!getenv("LIBGRAPHICS_ACTIVE")) 
    { 
        fprintf(stderr, "*** The graphics system has not been initialized!n"); 
        fprintf(stderr, "*** Call initgraph() before trying to use graphics functions.n"); 
        exit(-1); 
    }

struct {int x;int y;}CP;

#include "grtext.h"
#include "shapes.h"
#include "polygon.h"

#ifdef __cplusplus
}
#endif      /* __cplusplus */


#endif      /* LIBGRAPH_H */
graphics.h


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