Implementation of polygon filling algorithm

1. #include<iostream.h>
2. #include<conio.h>
3. #include<graphics.h>
4. #include<stdio.h>
5. #include<dos.h>
6. void fill_right(int x,int y); void fill_left(int x,int y); void main()
7. {
8. 
   
9. int x,y,a[10][10]; int gd,gm,n,i; detectgraph(&gd,&gm);
10. initgraph(&gd,&gm,"C:\\TC\\BGI"); cout<<"Enter no of edges of polygon:"; cin>>n;
11. cout<<"\n Enter the coordinates of polygon"; for(i=0;i<n;i++)
12. {
13. cin>>a[i][0]>>a[i][1];
14. }
15. a[n][0]=a[0][0];
16. a[n][1]=a[0][1];
17. cout<<"\n Enter the seed point"; cin>>x>>y;
18. cleardevice(); setcolor(WHITE); for(i=0;i<n;i++)
19. {
20. 
    
21.  
22.  
23. line(a[i][0],a[i][1],a[i+1][0],a[i+1][1]);
24. }
25. fill_right(x,y); fill_left(x-1,y); getch();
26. }
27. void fill_right(int x,int y)    //Right fill
28. {
29. if((getpixel(x,y) != WHITE) && (getpixel(x,y) != RED))
30. {
31. delay(1); putpixel(x,y,RED); fill_right(++x,y); x=x-1; fill_right(x,y+1); fill_right(x,y-1);
32. }
33. }
34. void fill_left(int x,int y) //left fill
35. {
36. if((getpixel(x,y) != WHITE) && (getpixel(x,y) != RED))
37. {
38. putpixel(x,y,RED); delay(1); fill_left(--x,y); x=x+1; fill_left(x,y-1); fill_left(x,y+1);
39. }
40. }

Output:

Implementation of curve drawing using Bezier algorithm

1. #include<dos.h>
2. #include<stdio.h>
3. #include<iostream.h>
4. #include<graphics.h>
5. #include<conio.h>
6. int a[150],b[150],m,n=0,j,d; float bx[5000],by[5000],u; union REGS i,o;
7. initmouse()
8. {
9. i.x.ax=0; int86(0x33,&i,&o); return(o.x.ax);
10. }
11. void showmouseptr()
12. {
13. i.x.ax=1; int86(0x33,&i,&o);
14. }
15. void getmousepos(int *button,int *x,int *y)
16. {
17. i.x.ax=3; int86(0x33,&i,&o);
18. *button=o.x.bx;
19. *x=o.x.cx;
20. *y=o.x.dx; i.h.ah=0x02; i.h.dh=0;
21.  
22. 
    
23. 
    
24. i.h.dl=0;  int86(0x10,&i,&o);  cout<<"X: "<<*x<<" Y: "<<*y; i.h.ah=0x02; int86(0x10,&i,&o);
25. }
26. void hidemouseptr()
27. {
28. i.x.ax=2; int86(0x33,&i,&o);
29. }
30. int compco()
31. {
32. int k,coeff=1;
33. for(k=d+1;k<=n;k++) coeff=coeff*k; for(k=2;k<=n-d;k++) coeff=coeff/k; return coeff;
34. }
35. float blenval()
36. {
37. int k;
38. float blend; blend=compco();
39. for(k=1;k<=d;k++) blend=blend*u; for(k=1;k<=n-d;k++) blend=blend*(1.0-u); return blend;
40. }
41. void bezier()
42. {
43. float blend1;
44.  
45. 
    
46. 
    
47. bx[j]=0;by[j]=0; for(d=0;d<=n;d++)
48. {
49. blend1=blenval(); bx[j]+=a[d]*blend1; by[j]+=b[d]*blend1;
50. }
51. }
52. void curve()
53. {
54. for(j=0;j<m;j++) putpixel(bx[j],by[j],GREEN);
55. }
56. void drawi()
57. {
58. for(j=0;j<=m;j++)
59. {
60. u=(float)j/m; bezier();
61. }
62. curve();
63. }
64. void main()
65. {
66. int gd=DETECT,gm; int button,tx,ty; clrscr();  m=4990;
67. flushall(); initgraph(&gd,&gm,"c:\\tc\\bgi"); cleardevice();
68.  
69. 
    
70. 
    
71. showmouseptr(); while(!kbhit())
72. {
73. getmousepos(&button,&tx,&ty); if((button & 1) == 1)
74. {
75. hidemouseptr(); setcolor(WHITE); a[n]=tx;
76. b[n]=ty; putpixel(tx,ty,WHITE); circle(tx,ty,2);
77. n++;
78. delay(50); showmouseptr();
79. }
80. }
81. n--;
82. drawi();
83. getch();
84. }

Output:

Implementation of ellipse drawing algorithm

1. #include<iostream.h>
2. #include<conio.h>
3. #include<graphics.h>
4. #include<dos.h>
5. 
   
6. void main()
7. {
8. clrscr();
9. float rx=0,ry=0,x=0,y=0,dx=0,dy=0,d1=0,d2=0; 
10. float rxSqr=0,rySqr=0,rx2Sqr=0,ry2Sqr=0;
11. int x1=0,y1=0; int gd,gm;
12. 
    
13. detectgraph(&gd,&gm); initgraph(&gd,&gm,"c:\\tc\\bgi");
14. 
    
15. //textbackground(15);
16. //textcolor(8);
17. //setbkcolor(15);
18. //setcolor(8);
19. 
    
20. 
    
21. cout<<"Enter pixels for centre of an ellipse (x,y): "; cin>>x1>>y1;
22. 
    
23. cout<<"Enter rx radius: "; cin>>rx;
24. cout<<"Enter ry radius: "; cin>>ry;
25.  
26. line(0,getmaxy()/2,getmaxx(),getmaxy()/2); line(getmaxx()/2,0,getmaxx()/2,getmaxy());
27. 
    
28. x=0;
29. y=ry;
30. 
    
31. rxSqr=rx*rx; rx2Sqr=2*rxSqr; rySqr=ry*ry; ry2Sqr=2*rySqr; dx=ry2Sqr*x; dy=rx2Sqr*y;
32. d1=rySqr-rxSqr*ry+(.25*rxSqr);
33. do
34. {
35. putpixel(getmaxx()/2+(x1+x),getmaxy()/2-(y1+y),8); 
36. putpixel(getmaxx()/2+(x1-x),getmaxy()/2-(y1+y),8); 
37. putpixel(getmaxx()/2+(x1+x),getmaxy()/2-(y1-y),8); 
38. putpixel(getmaxx()/2+(x1-x),getmaxy()/2-(y1-y),8); 
39. if(d1<0)
40. {
41. x+=1;
42. y=y; dx+=ry2Sqr; d1+=dx+rySqr;
43. }
44. else
45. {
46. x+=1;
47. y-=1;
48. dx+=ry2Sqr; dy-=rx2Sqr;
49. d1+=dx-dy+rySqr;
50. }
51. delay(30);
52. }while(dx<dy);
53. d2=rySqr*((x+(.5))*(x+(.5)))+rxSqr*((y-1)*(y-1))-rxSqr*rySqr; do
54. {
55. putpixel(getmaxx()/2+(x1+x),getmaxy()/2-(y1+y),8); 
56. putpixel(getmaxx()/2+(x1-x),getmaxy()/2-(y1+y),8);
57.  putpixel(getmaxx()/2+(x1+x),getmaxy()/2-(y1-y),8); 
58. putpixel(getmaxx()/2+(x1-x),getmaxy()/2-(y1-y),8); 
59. if(d2>0)
60. {
61. x=x; y-=1;
62. dy-=rx2Sqr; d2-=dy+rxSqr;
63. }
64. else
65. {
66. x+=1; y-=1;
67. dy-=rx2Sqr; dx+=ry2Sqr; d2+=dx-dy+rxSqr;
68. }
69. delay(10);
70. }while(y>0);
71. getch();
72. }

Output:

Implementation of circle drawing algorithm

1. #include<iostream.h>
2. #include<conio.h>
3. #include<graphics.h>
4. #include<dos.h> 
5. void main()
6. {
7. int gm,gd=DETECT; initgraph(&gd,&gm,"c:\\tc\\bgi"); 
8. int x1,y1;
9. int x=0,y=0,r=0; float d;
10. //textbackground(15);
11. //textcolor(8);
12. //setbkcolor(15);
13. //setcolor(8);
14. cout<<"Enter pixels for centre of a circle (x,y): "; cin>>x1>>y1;
15. cout<<"\nEnter radius of circle: "; cin>>r;
16. x=0;
17. y=r; d=1.25-r;
18. line(0,getmaxy()/2,getmaxx(),getmaxy()/2); line(getmaxx()/2,0,getmaxx()/2,getmaxy()); 
19. do
20. {
21. putpixel(getmaxx()/2+(x1+x),getmaxy()/2-(y1+y),8); 
22. putpixel(getmaxx()/2+(x1-x),getmaxy()/2-(y1+y),8);
23. putpixel(getmaxx()/2+(x1-x),getmaxy()/2-(y1-y),8); 
24. 
    
25. putpixel(getmaxx()/2+(x1+x),getmaxy()/2-(y1-y),8); 
26. 
    
27. putpixel(getmaxx()/2+(x1+y),getmaxy()/2-(y1+x),8); 
28. 
    
29. putpixel(getmaxx()/2+(x1+y),getmaxy()/2-(y1-x),8); 
30. 
    
31. putpixel(getmaxx()/2+(x1-y),getmaxy()/2-(y1-x),8); 
32. 
    
33. putpixel(getmaxx()/2+(x1-y),getmaxy()/2-(y1+x),8); 
34. 
    
35. if(d<0)
36. {
37. x+=1;
38. y=y; 
39. d+=2*x+1;}
40. else
41. {
42.              x+=1; 
43.              y-=1;
44. d+=2*(x-y)+1;
45. }
46. delay(50);
47. }while(x<y);
48. getch();
49. }

Bresenham's algorithm

1. 
   
2. #include<iostream.h>
3. #include<conio.h>
4. #include<graphics.h>
5. #include<math.h>
6. #include<dos.h>
7. 
   
8. void main()
9. {
10. clrscr();
11. int gm,gd;
12. int x1,y1,x2,y2,i; 
13. float x,y,dx,dy,len,e;
14. detectgraph(&gd,&gm); 
15. initgraph(&gd,&gm,"c:\\tc\\bgi"); 
16. //textbackground(15);
17. //textcolor(8);
18. //setbkcolor(15);
19.           //setcolor(8);
20.                        
21.                        cout<<"Enter starting pixels for point (x1,y1): "; cin>>x1>>y1;
22. cout<<"\nEnter ending pixels for point (x2,y2): "; cin>>x2>>y2;
23. line(0,getmaxy()/2,getmaxx(),getmaxy()/2); line(getmaxx()/2,0,getmaxx()/2,getmaxy());dx=abs(x2-x1);
24. dy=abs(y2-y1);
25. x=x1; 
26. y=y1; 
27. e=2*dy-dx;
28.                     for(i=1;i<=dx;i++)
29. {
30. putpixel(getmaxx()/2+x,getmaxy()/2-y,8); while(e>=0)
31. {
32. y++;
33. e-=2*dx; 
34. delay(20)
35. }
36. x++;
37. e+=2*dy;
38. }
39. getch();
40. }

DDA algorithm (Implementation of line drawing algorithm)

1. #include<iostream.h>
2. #include<conio.h>
3. #include<graphics.h>
4. #include<math.h>
5. #include<dos.h>
6. 
   
7. void main()
8. {
9. clrscr(); 
10. int x1,y1,x2,y2,i=1; float x,y,dx,dy,len;
11. 
    
12. detectgraph(&gd,&gm); initgraph(&gd,&gm,"c:\\tc\\bgi");
13. 
    
14. textbackground(15); textcolor(15); setbkcolor(15); setcolor(8);
15. 
    
16. cout<<"Enter starting pixels for point (x1,y1):"; cin>>x1>>y1;
17. cout<<"\nEnter ending pixels for point (x2,y2):"; cin>>x2>>y2; line(0,getmaxy()/2,getmaxx(),getmaxy()/2); line(getmaxx()/2,0,getmaxx()/2,getmaxy());
18. 
    
19. dx=abs(x2-x1); 
20. dy=abs(y2-y1);
21. 
    
22.          if(dy>dx)len=dy;
23.           else len=dx;
24.            dx=((x2-x1)/len);
25. dy=((y2-y1)/len);
26. x=x1+0.5*dx; y=y1+0.5*dy; while(i<=len)
27. { 
28. putpixel(getmaxx()/2+x,getmaxy()/2-y,8);
29. }
30. x+=dx; y+=dy; i++;
31. 
    
32. delay(20);
33. }
34. getch();

Introduction to graphics libraries in c++

#include<stdio.h>

#include<conio.h>

#include<malloc.h>

#include<graphics.h> void main()

{

int gd=DETECT,gm; initgraph(&gd,&gm,"c:\\tc\\bgi");

//setbkcolor(15);

//setcolor(1); setfillstyle(HATCH_FILL,5);

circle(100,100,50); outtextxy(75,170,"circle");

line(100,250,540,250);

outtextxy(300,260,"line");

ellipse(500,100,0,360,100,50);

outtextxy(480,170,"ellipse");

sector(150,400,30,300,100,50);

outtextxy(120,460,"sector");

int poly[]={350,450,350,410,430,400,350,350,300,430,350,450};

fillpoly(6,poly); outtextxy(340,460,"polygon");

rectangle(200,50,350,150); outtextxy(530,460,"arc");

pieslice(120,320,45,120,40);

outtextxy(110,325,"pieslice");

bar(320,280,350,315);

outtextxy(320,325,"bar");

bar3d(480,280,520,320,10,15);

outtextxy(490,325,"bar3d");

getch(); closegraph();

}