A line connects two points. It is a basic element in graphics. To draw a line, you need two points between which you can draw a line. In the following three algorithms, we refer the one point of line as X0,Y0X0,Y0 and the second point of line as X1,Y1X1,Y1.

## DDA Algorithm

Digital Differential Analyzer (DDA) algorithm is the simple line generation algorithm which is explained step by step here.

**Step 1** − Get the input of two end points (X0,Y0)(X0,Y0) and (X1,Y1)(X1,Y1).

**Step 2** − Calculate the difference between two end points.

dx = X_{1}- X_{0}dy = Y_{1}- Y_{0}

**Step 3** − Based on the calculated difference in step-2, you need to identify the number of steps to put pixel. If dx > dy, then you need more steps in x coordinate; otherwise in y coordinate.

if (absolute(dx) > absolute(dy)) Steps = absolute(dx); else Steps = absolute(dy);

**Step 4** − Calculate the increment in x coordinate and y coordinate.

Xincrement = dx / (float) steps; Yincrement = dy / (float) steps;

**Step 5** − Put the pixel by successfully incrementing x and y coordinates accordingly and complete the drawing of the line.

for(int v=0; v < Steps; v++) { x = x + Xincrement; y = y + Yincrement; putpixel(Round(x), Round(y)); } know more at : https://www.tutorialspoint.com