practical no.1 of computer graphics programs to draw basic graphics objects : question- algorithm and flowchart
Answers
In any 2-Dimensional plane if we connect two points (x0, y0) and (x1, y1), we get a line segment. But in the case of computer graphics we can not directly join any two coordinate points, for that we should calculate intermediate point’s coordinate and put a pixel for each intermediate point, of the desired color with help of functions like putpixel(x, y, K) in C, where (x,y) is our co-ordinate and K denotes some color.
Examples:
Input: For line segment between (2, 2) and (6, 6) :
we need (3, 3) (4, 4) and (5, 5) as our intermediate
points.
Input: For line segment between (0, 2) and (0, 6) :
we need (0, 3) (0, 4) and (0, 5) as our intermediate
points.
For using graphics functions, our system output screen is treated as a coordinate system where the coordinate of the top-left corner is (0, 0) and as we move down our y-ordinate increases and as we move right our x-ordinate increases for any point (x, y).
Now, for generating any line segment we need intermediate points and for calculating them we have can use a basic algorithm called DDA(Digital differential analyzer) line generating algorithm.
DDA Algorithm :
Consider one point of the line as (X0,Y0) and the second point of the line as (X1,Y1).
// calculate dx , dy
dx = X1 - X0;
dy = Y1 - Y0;
Answer:
practical no.1 of computer graphics programs to draw basic graphics objects : question- algorithm and flowchart