The document describes features and algorithms of a sketchboard application. Key features include drawing basic shapes and lines, changing line thickness, clearing the drawing area, and filling shapes with color. Algorithms covered are Bresenham's line and circle drawing, rectangle and triangle construction, and boundary fill. Challenges discussed are interfacing with a PS2 controller and VGA display. Suggested improvements include removing PS2 limitations and adding full mouse functionality.
12. COMPARE LINE DRAWING ALGORITHMS BRESENHAM’S LINE DRAWING ALGORITHM :: Fast and Incremental algorithm. It involves only integer calculations in its point computing. It makes use of addition, subtraction and shifting only. DIGITAL DIFFERENTIAL ANALYZER ALGORITHM :: Round-off errors makes the computing pixel to drift away from the ideal line. Time consuming -Floating point arithmetic & rounding off process XIAOLIN WU’S LINE ALGORITHM :: Performs anti-aliasing. Draw pairs of pixels on both side of the computed pixel and are coloured in a way that they look alike. Slower than Bresenham’s Line Drawing algortihm.
13. BRESENHAM’S LINE DRAWING If(midpoint>ideal line) Next_pixel_to_be_plotted = Next_Lower_pixel; (po<0) Else Next_pixel_to_be_plotted = Next_Upper_pixel; (po>0) po= 2*dy(LOWER PIXEL) (Next Co-ordinates will be (xk+1,yk)). po= 2*dy – 2*dx (UPPER PIXEL) (Next Co-ordinates will be (xk+1,yk+1)).
![FEATURES OF SKETCH-BOARD ,[object Object]](https://image.slidesharecdn.com/prsentation-13082176956099-phpapp01-110616050635-phpapp01/85/FPGA-Sketch-Board-1-320.jpg)
