# BRESENHAM CIRCLE DRAWING ALGORITHM PDF

So during the while loop, y increments by 1 each iteration, and x decrements by 1 on occasion, never exceeding 1 in one iteration. The second part of the problem, the determinant, is far trickier. This determines when to decrement x. It usually comes after drawing the pixels in each iteration, because it never goes below the radius on the first pixel.

 Author: Yozshubar Mam Country: Swaziland Language: English (Spanish) Genre: Business Published (Last): 21 May 2019 Pages: 264 PDF File Size: 1.47 Mb ePub File Size: 10.40 Mb ISBN: 509-2-75944-209-3 Downloads: 4057 Price: Free* [*Free Regsitration Required] Uploader: Molkis

For starters, notice that all multiplications are by 2. This can be performed with a simple shift left instruction Shl in Pascal, [lessthan][lessthan] in C. Next notice that the values you add to the decision variable do not change throughout the loop, so they can be precalculated beforehand.

One property of lines is that they are symmetrical about their mid-points, and we can use this property to speed up the algorithm. Store two x and y values, xa, ya and xb, yb. Have each pair start on either end of the line. For each pass through the loop you draw the pixel at both points, add 1 to xa and subtract one from xb. You might be able to speed the algorithm up by keeping an array of how y has been modified and then use this array if the line starts repeating itself.

Above all remember that these optimizations will only significantly speed up the line drawing algorithm if the whole thing is done in assembly. There are many algorithms which use this equation.

One good use for the Bresenham line algorithm is for quickly drawing filled concave polygons eg triangles. You can set up an array of minimum and maximum x values for every horizontal line on the screen. This method involves taking a string of bitmap pixels and stretching them out or squashing them in to a line of pixels on the screen. Circle Algorithm Circles have the property of being highly symmetrical, which is handy when it comes to drawing them on a display screen.

It assumes that the circle is centered on the origin.

IEC 60906-2 PDF

## Bresenham's Line and Circle Algorithms

For starters, notice that all multiplications are by 2. This can be performed with a simple shift left instruction Shl in Pascal, [lessthan][lessthan] in C. Next notice that the values you add to the decision variable do not change throughout the loop, so they can be precalculated beforehand. One property of lines is that they are symmetrical about their mid-points, and we can use this property to speed up the algorithm. Store two x and y values, xa, ya and xb, yb. Have each pair start on either end of the line. For each pass through the loop you draw the pixel at both points, add 1 to xa and subtract one from xb.

LBOAVO BW 2010 PDF

.

FLUKE 8810A PDF

.

AUK R315A PDF

.