Computer Graphics BS 7 Semester/Term GCUF — Government College University Faisalabad 2022

GOVERNMENT COLLEGE UNIVERSITY,

FAISALABAD

External Semester Examination Fall 2022-23

BS(Computer Science) 7th Semester

Course Code: CS-603 Time: 02:30 Minutes

Course Title: Computer Graphics

Note: Attempt all questions. All questions carry equal marks.

Question 2: 2D Transformation

Computer graphics relies heavily on geometric transformations. Most common

are transformations such as rotations, translations, and scales. In the following,

T(dx,dy) refers to a translation by (dx, dy), R(0) refers to a rotation by 0-

degrees, and S(sx,sy) refers to a scaling by (sx, sy). For simplicity, assume all

transformations are 2D. The order of transformations may matter. Also,

sometimes the order may be rearranged, but the arguments will change. State

whether the following statements are True or False.

I T(1,0) S(2,2) = T(2,0) S(1,1)

I T(1,0) T(0,2) = T(0,1) T(1,1)

I R(50) S(2,1) = S(2,1) R(50)

I R(-90) T(1,0) = T(0,1) R(-90)

Question 3:

Develop a mid-point algorithm which scan-converts a circle start at pixel location: X=R, Y=0. Assume

you are scan-converting in the clockwise direction. Find equations along with what choices should be

made for the next pixel. [Hint : remember the algorithm and equations to find the next pixel in Mid point

algorithm]

Question 4: 2D Transformation

Suppose a triangle with points A(4,1), B(6,1), and C(4,3). Find the composite

transformation matrix to transform this triangle into A'(1,4), B'(1,2), and C'(5,4).

Question 5: Clipping

Suppose a rectangular window whose lower left-hand corner is at L(-3,1) and

upper right-hand corner is at R(2,6). Use the Liang-Barsky algorithm to clip

the following lines.

Line A: (1,1) to (2,3)

Line B: (-4,2) to (-1,7)

Line C: (-1,5) to (3,8)