The Digital Differential Analyzer (DDA) algorithm is one of the simplest line-drawing algorithms in computer graphics. It is an incremental method that determines intermediate points between two given endpoints of a line. In this blog post, we will explore the DDA algorithm, understand its working, and implement it using C++.
What is the DDA Algorithm?
The DDA (Digital Differential Analyzer) algorithm is a rasterization algorithm used to draw lines on a pixel-based display. It works by calculating the intermediate points that form a straight line between two given points and plotting them sequentially. The algorithm uses floating-point arithmetic to incrementally determine the next pixel position.
Steps of the DDA Algorithm:
Calculate the change in x (dx) and y (dy) between the starting and ending points.
Determine the number of steps required for the line. This is the greater value between dx and dy.
Compute the increment values dx/steps and dy/steps to determine how much x and y should increase per step.
Start from the initial point and iteratively plot the next points by adding the increment values.
Stop when the endpoint is reached.
C++ Implementation of DDA Algorithm
Here is a simple C++ program to implement the DDA line drawing algorithm using the graphics.h library:
This post demonstrates how to sort an array of integers using inline assembly in C++. We use basic comparison and swap logic in assembly embedded within a C++ program.
#include<iostream.h>
#include<conio.h>
void main()
{
int a[5], x, y;
int i, j;
cout << "\n Enter 5 Numbers:";
for(i = 0; i < 5; i++)
{
cin >> a[i];
}
//Sorting
for(i = 0; i < 4; i++)
{
for(j = 0; j < 4; j++)
{
x = a[j];
y = a[j + 1];
asm {
mov ax, x
mov bx, y
cmp ax, bx
jge nxt
mov cx, ax
mov ax, bx
mov bx, cx
mov x, ax
mov y, bx
}
nxt:
a[j] = x;
a[j + 1] = y;
}
}
cout << "\n Sorted Array:";
for(i = 0; i < 5; i++)
cout << a[i] << " ";
getch();
}
Bresenham’s circle algorithm is an efficient way to draw a circle using only integer calculations. It eliminates the need for floating-point arithmetic and is widely used in computer graphics.
Below is the implementation of Bresenham’s circle drawing algorithm using C++ and the graphics.h library. This program takes user input for the circle’s center and radius, then uses the algorithm to plot the circle.
Bresenham’s line algorithm is an algorithm that determines the points of an n-dimensional raster that should be selected in order to form a close approximation to a straight line between two points. It is commonly used to draw lines on a computer screen, as it uses only integer addition, subtraction and bit shifting.
