C++ GRAPHICS

Graphics Tutorial

In this chapter you will learn about basics of C++ Graphics. Before getting more information about c++ graphics first we starting from the header file:graphics.h.  This header contains many graphics functions, if you will not declare this header file the graphics function will not work.
it means you will have to add #include<graphics.h>  in header file section in your program.

Note : the important thing is BGI Error in c++:

BGI Error: Graphics not initialized (use ‘initgraph’)

If you see the above error in your output screen, you have to use the following code in main() function

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

We are starting from line() function in C++ graphics:

line() Function

function line is used to draw a line between two specified points.

its format is:

line(int x1, int y1, int x2, int y2);

where int x1 and int y1 is starting point and int x2 and y2  is ending point of line, it will draw a line from x1, y1 to x2, y2;

Normally the maximum distance of x is 640, and y is 480.

Example to draw a line include<graphics.h> include<conio.h> void main() { int gd=DETECT,gm; initgraph(&gd,&gm,”c:\\tc\\bgi\\”); line(0,0,640,480); getch(); }

 Output

 

   

linerel()

The linerel function is used to draw a line up to x2 and y2 from the current position

Format:

linerel(int x2, int y2);

The int x2 and int y2 is ending point value of line,

e.g-

linerel(640,480);

C++ Graphics : setcolor()

setcolor function is used to set the drawing outline color.

format:

setcolor(int color);

int color is a value of color or the name of color, here is the chart of c++ graphic colors:

Color Name	Value	Background	Foreground
BLACK	0	YES	YES
BLUE	1	YES	YES
GREEN	2	YES	YES
CYAN	3	YES	YES
RED	4	YES	YES
MAGENTA	5	YES	YES
BROWN	6	YES	YES
LIGHTGRAY	7	YES	YES
DARKGRAY	8	NO	YES
LIGHTBLUE	9	NO	YES
LIGHTGREEN	10	NO	YES
LIGHTCYAN	11	NO	YES
LIGHTRED	12	NO	YES
LIGHTMAGENTA	13	NO	YES
YELLOW	14	NO	YES
WHITE	15	NO	YES

For example:

setcolor(14); line(0,0,640,480);

setbkcolor():

The function setbkcolor is used to set the background color.

format:

setbkcolor(int backgroundcolor);

For example:

setbkcolor(3); setcolor(14); line(0,0,640,480);

C++ Graphics : circle()

> 

circle function is used to draw a circle.

format:

circle(int x, int y, int radius);

Where int x and int y is center position of circle and int radius is length of radius of circle.

example:

include<graphics.h> include<conio.h> void main() { int gd=DETECT,gm; initgraph(&gd,&gm,”c:\\tc\\bgi\\”); setbkcolor(1); setcolor(14); circle(300,250,200); getch(); }

output:

C++ Graphics : ellipse ()

function ellipse is used to draw an ellipse.

Format:

ellipse(int x, int y, int stange, int endangle, int x radius, int yradius);

where:

x,y               Center of ellipse

stangle          starting angle

endangle       ending engle

xradius          Lenth of Horizontal radius.

yradius          lenth of Vertical radius.

If stangle=0 and endangle = 360, the ellipse draws a complete ellipse.

 

example: include<graphics.h> include<conio.h> void main() { int gd=DETECT,gm; initgraph(&gd,&gm,”c:\\tc\\bgi\\”); setbkcolor(1); setcolor(14); ellipse(300,250,0,360,150,30); getch(); }

Output:

You can draw a half ellipse by the following code:

ellipse(300,250,0,180,150,30);

fillellipse()

This function draws a ellipse with solid fill.

format:

fillellipse( int x, int y, int xradius, int y radius);

For Example:

fillellipse(300,250,150,30);

    

C++ Graphics : rectangle ()

The function rectangle draws a rectangle shape.

Format:

rectangle (int left, int top, int right, int bottom);

Example:

include<graphics.h> include<conio.h> void main() { int gd=DETECT,gm; initgraph(&gd,&gm,”c:\\tc\\bgi\\”); setbkcolor(1); setcolor(14); rectangle(200,150,400,300); getch(); }

  

Output

C++ Graphics : setfillstyle() and floodfill() function

setfillstyle(int pattern, int color) :

This function sets the fill pattern and color. pattern may be solid empty, linear etc. and value of pattern will be from 0 to 12 number.

eg-

setfillstyle(5,9)

the value 5 display thick line pattern( \\\\).

floodfill ():

floodfill fills the bounded area of drawing.

syntax :

floodfill(int x, int y, int border)

the border must be color which you set in drawing color.

if x and y will in under the bounded region the floodfill will fill the inside of bounded area, and if the x and y will in outside of bounded area the floodfill will fill outside area.

Graphics example:

include<graphics.h> include<conio.h> void main() { int gd=DETECT,gm; initgraph(&gd,&gm,”c:\\tc\\bgi\\”); setbkcolor(1); setcolor(14); circle(300,250,200); setfillstyle(3,4); floodfill(320,251,11); getch(); }

output

C++ Graphics : Text settextstyle() function

settextstyle() :

this function is used to set the text style and direction.

format:

settextstyle(int font, int direction, int charsize);

where int font is font name or value of font, int direction is font direction, it may be vertical or horizontal, int charsize is size of character.

here is the chart of font name, directions and size.

font name :

Value	Name	Description
0	DEFAULT_FONT	Bit Mapped font
1	TRIPLEX_FONT	Strocked triplex font
2	SMALL_FONT	Strocked small font
3	SANS_SERIF_FONT	Strocked Sans sarif font
4	GOTHIC_FONT	Strocked gothic font

font direction :       0 (for left to right)

                             1(for bottom to top)

charsize:

Value                      Description

0                      4*4 pixel

1                      8*8 pixel

2                      16*16 pixel

3                      24*24 pixel

...                     up to ten times of normal size..

Note : you have to use outtext or outtextxy function to print the text.

E.g.-

outtext(*char); outtextxy(int x, int y, char ch);

example:

include<graphics.h> include<conio.h> void main() { int gd=DETECT,gm; initgraph(&gd,&gm,”c:\\tc\\bgi\\”); setbkcolor(1); setcolor(14); settextstyle(1,0,4); outtext(“bitavoncpp.com”); outtextxy(“bitavoncpp.com”); getch(); }

output

bitavoncpp.com                bitavoncpp.com

Write a program in c++ for password

#include<conio.h>
#include<iostream.h>
void main()
{
//coding by Rameshwar Sahu
//http://bitavoncpp.com
clrscr();
char p1,p2,p3,p4,p5,p6,p7;
cout<<"Please enter Your 7 digits password : ";
p1=getch();
cout<<"*";
p2=getch();
cout<<"*";
p3=getch();
cout<<"*";
p4=getch();
cout<<"*";
p5=getch();
cout<<"*";
p6=getch();
cout<<"*";
p7=getch();
cout<<"*";
getch();
if(p1=='b'&&p2=='i'&&p3=='t'&&p4=='a'&&p5=='v'&&p6=='o'&&p7=='n')
{
clrscr();
cout<<"Welcome! password matched";
}
else
{
clrscr();
cout<<"password didnot matched";
}
getch();
}