This tutorial covers many topics in VGA programming in the C programming language. Tutorial assumes that the programmers have a comprehensive understanding of C and should also have a familiarity with DOS and BIOS function calls and interrupts. Knowledge of trigonometry and geometry would also be helpful.
A union in C programming is a user defined data type which may hold members of different sizes and type. Union uses a single memory location to hold more than one variables. However, only one of its members can be accessed at a time and all other members will contain garbage values. A structure is a convenient tool for handling a group of logically related data items. Structure help to organize complex data is a more meaningful way. It is powerful concept that we may after need to use in our program Design.
This article is about file handling using C programming language. File stores information for many purposes and retrieve whenever required by our C programs. A file represents a sequence of bytes on the disk where a group of related data is stored. File is created for permanent storage of data. C programming language can handle files as Stream-oriented data (Text) files and System oriented data (Binary) files.
In a C program, first step is to initialize the graphics drivers on the computer. This is done using the initgraph() method provided in graphics.h library. In the next few pages we will discuss graphics.h library in more details. Important functions in graphic.h library will be discussed in details and samples programs will be provided to show the power of C programming language especially for graphic programming developing graphical user interfaces.
A pointer is a variable that represents the location of a data item, such as a variable or an array element. Pointers are used frequently in C, as they have a number of useful applications. For example, pointers can be used to pass information back and forth between a function and its reference point. Pointers provide a way to return multiple data items from a function via function arguments to
be specified as arguments to a given function.
In C Programming, an array can be defined as number of memory locations, each of which can store the same data type and which can be referenced through the same variable name. Arrays can be of two types i.e. One Dimensional Array (such as lists) and Multidimensional Arrays (such as tables or matrices).
The standard way of handling all input and output is done with streams in C programming regardless of where input is coming from or where output is going to. This approach has definite advantages for the programmer. A library package has been evolved which is known as known as the Standard I/O Library which is used in any C program by using stdio.h header. First, however, we need to understand exactly what the terms input and output mean in context of C.
C programs are executed in a sequence, but we can control the execution of program by using any control mechanism by which we can compare things and come to a decision. This involves using some operations called Relational Operators, conditional statements called if-else and loops. We have fundamental operators to compare two values.
