Basics of Graphics programming

-

 • We are going to see the basic syntax which must be followed while programming the graphics in turbo C++ 

1) By default are output screen or the terminal (Black screen were we get the output of programs) is in text mode.

2) So to initialize the terminal in graphic mode(x-axis and y-axis) we use initgraph function in our program.

3) Here the screen resolution is in text mode. X-direction is horizontally across the screen and y-direction is vertically down the screen. The top left corner is (0, 0) and the bottom right corner is (80, 25).

While executing the program, Turbo C opens the console in text mode only.


                  Terminal in Graphics mode 

4) In text mode the screen is divided into 80 columns and 25 rows. In case of graphic mode the total screen is divided into 640 pixels width and 480 pixels height. Latest displays are even rich in resolution.

5) This function is present in "graphics.h" header line in turbo C. 

Sample graphics program: 

#include<stdio.h>

#include<graphics.h>

#include<conio.h>

int main()

{

   int gd= DETECT,  gm;

  initgraph (&gd, &gm, "C:\\TC\\BCI");

  getch();

   closegraph();

    return 0;

}

OUTPUT: This program initialise graphic mode and then closes it after a key is pressed.

Explanation: 

• To begin with we have declared two variables of int type gd and gm for graphics driver and graphics mode respectively, you can choose any other variable name as well. 

• DETECT is a macro defined in "graphics.h" header file.

• we have passed three arguments to initgraph function:

1) First is the address of gd.

2) second is the address of gm.

3) Third is the path where your BGI files are present (you have to adjust this accordingly where you Turbo C compiler is installed). 

4) Initgraph function automatically decides an appropriate graphics driver and mode such that maximum screen resolution is set.

5) getch helps us to wait until a key is pressed, closegraph function closes the graphics mode, and finally return statement returns a value 0 to main indicating successful execution of the program.

• Once you have understood initgraph function then you can use functions to draw shapes such as circle, line , rectangle, etc.

Remember:

1) All the  programs that we are going to execute in are other post, work only in Turbo C platform because functions like gotoxy(), clrscr(), textcolor(), cprintf(), window(), rand(), kbhit() and delay() are not available in other platforms.


*You can leave a comment if you have doubt in it.





Comments

Post a Comment

Popular posts from this blog

Line Basic Concepts

-
Image
 • We are going to study about Line Basic Concepts on Raster Screen. • so we are going to discuss what are the different ways in which line can be represented on Raster Screen and some of there respective features. 1) Vertical and Horizontal Line  • They have same width. • Straight line.  • Effective spacing is less. • More brighter. 2) 45° Line  • Width is not a constraint.  • Straight line. • More effective spacing. • Less brighter. Explanation:  • Point to remember is when there is more spacing between the points of line less brighter it will be and vice versa.  • But more spacing leads to effectiness in orientation of line. 3) Line with other orientation • In both of the above image the lines are nethier straight nor of same width. • Here points of line that is Pixel is approximated because while drawing the single line at point we get two points one is above the line and another is below the line. • But here approximation doesn't make a wide diffe...
Read more

Sample programs

-
Image
 • We are going to discuss some simple programs in turbo C before going to graphics program that is terminal in graphic mode. • So simple programs in text mode. 1) Program to print Hello world on different line. #include<stdio.h> #include<conio.h> int main() {     int c= 5;      for(int i=0;i<12; i=i+2)     {     gotoxy(c,i);     printf("Hello world!");     c=c+2;     } getch(); return 0; } Explanation: • we have also discussed prior about text mode in Turbo C let's understand it in short. • So this is the image representation of text mode where: 1) screen is divided in Rows and Columns. 2) we have 80 rows and 25 columns 3) Here first coordinate is of column and another is row example: (80,25) • 80 is column and 25 is row only in turbo C text mode it's reverse as it is normally. 4)  program we did above is of Controlling the cursor with the help of function gotoxy( )  it's a functio...
Read more

Types of Computer Monitor

-
Image
 • We all use in are day to day life different types of Computer for instance different color, size, shape, and brand, we also have different types of monitor too. • So let's have a look on different types of monitor available in market • Different types of monitor 1) CRT (Cathode Ray tube) 2) LCD (Liquid Crystal Displays) 3) TFT (Thin Film Transistor) 4) LED (light Emitting Diodes) • There are two type of CRT display available: 1) Raster Scan Display 2) Vector Scan Display • We will discuss both the display one by one, but before that we will study how CRT works? in further post. * You can leave a comment if you have doubt in it.
Read more