BASICS OF COMPUTER GRAPHICS

Computer graphics are any image media, usually movies and pictures, which are created through the use of hardware and software. They are often referred to as computer-generated imagery; more commonly known as CGI. An example of a computer graphic is the Computer Hope Guy (shown right), one of our various logos.

In general, a the term graphic refers to a design or visual image displayed on a variety of surfaces, including canvas, paper, a wall, a sign, or a computer monitor. They are created for the purposes of entertainment, branding or to inform.

Graphic may also be used to describe a phrase, gesture, or image that is considered obscene or offensive.

HEADER  FILE:-                      

#include<stdio.h> :- Stdio.h is a header file which contains the declarations (not the definitions) of standard I/O functions like print(), scanf(), etc.,. The header file just tells the compiler what types external functions and variables are, defines macros, types etc. Any functions and variables that get referenced in your source file will be linked in during the linker phase. If you include stdio.h and use print in your program, the compiler adds print as an "unresolved" symbol in the object file, and then the linker will try to find a function called printf either in the object files you explicitly link, or in the libraries it is configured to search.

#include<graphics.h> :- graphics.h. This interface provides access to a simple graphics library that makes it possible to draw lines, rectangles, ovals, arcs, polygons, images, and strings on a graphical window. Functions. ... Creates the graphics window on the screen. drawArc(bounds, start, sweep). There is a modern port for this Turbo C graphics interface, it's called WinBGIM, which emulates BGI graphics under MinGW/GCC.

#include<conio.h> :- Conio.h is a C header file used mostly by MS-DOS compilers to provide console input/output. It is not part of the C standard library or ISO C, nor is it defined by POSIX. This header declares several useful library functions for performing "console input and output" from a Program.

This header declares several useful library functions for performing "console input and output" from a program. Most C compilers that target DOS, Windows 3.x, Phar Lap (company)|Phar Lap, DOSX, OS/2, or Win32  have this header and supply the associated library functions in the default C library. Most C compilers that target UNIX and Linux do not have this header and do not supply the library functions. Some embedded systems are using a conio-compatible library 

The library functions declared by conio.h vary somewhat from compiler to compiler. As originally implemented in Lattice C, the various functions mapped directly to the first few DOS int 21h functions. But the library supplied with Borland's Turbo C did not use the DOS API but instead accessed video RAM directly for output and used BIOS interrupt calls; they also have additional functions inspired on the successful Turbo Pascal library.

#include<Iostream.h> :- In the C++ programming language, Input/output library refers to a family of class templates and supporting functions in the C++ Standard Library that implement stream-based input/output capabilities. It is an object-oriented alternative to C's FILE-based streams from the C standard library. iostream - header is used to access the input output built in functions of the language as it is the the “Standard input/output streams library”. Here input-output refers to the fact of taking input command and showing output result in the program. “cin>>” , “cout<<” - these are the member objects of the <iostream> header. The iostream library is an object-oriented library that provides input and output functionality using streams. A stream is an abstraction that represents a device in which input and ouput operations are performed.

#include<dos.h> :- Dos.h is one among the header files . It contains functions for handling interrupts, producing sound, date and time functions etc. It is a Borland specific and works in turbo c compiler. Dos is a header file of C language. this header file will helps you createor delete a directory or subdirectory and exit from the application etc it is more and more important header file for the developers. DOS.h is a header file used to handle DOS commands (DISK Operating system) in C/C++ programming environment.

#incule<math.h> math.h is a header file in the standard library of the C programming language designed for basic mathematical operations. Most of the functions involve the use of floating point number. “math.h” header file supports all the mathematical related functions in C language.  math.h ( cmath header in C++). The functions that operate on integers, such as abs , labs , div , and ldiv , are instead defined in the stdlib.h header ( cstdlib header in C++). Any functions that operate on angles use radians as the unit of angle.

#include<snap.h> :-  SNAP stands for Stanford Network Analysis Platform which is totally written in C++ and it can be embedded in your programs. If you looking for a toolbox or library in C++ , which allows you to perform general network analysis like calculating the shortest path or cluster coefficient then you can use snap.h.

Basic Structure of Computer Graphics Program

#Include<stdio.h>

#include<graphics.h> // must be included for every graphic program

#include<conio.h>

#include<dos.h> // For including delay function

Void main()

{

Int gd=DETECT,gm; // detect best available graphics driver,,,gm=graphics mode

Initgraph(&gd , &gm,”C\\TC\\BGI”); // For initializing graph mode

//above 2 steps are must for every graph program,

//declaration of any variable must be done before calling initgraph() function.

//next write code for producing requiring design or drawing object

Line(100,100,200,200); // draw a line segment

getch();

}