**Jack **Elton **Bresenham **(born 11 October 1937, Clovis, New Mexico) is a former professor of computer science. **Bresenham **He retired from 27 years of service at IBM as a Senior Technical Staff Member in 1987. He taught for 16 years at Winthrop University and has nine patents. He has three children: Janet, Linda, and David. **Bresenham**‘s line algorithm, developed in 1962, is his most well-known innovation. It determines which points on a 2-dimensional raster should be plotted in order to form a straight line between two given points, and is commonly used to draw lines on a computer screen. It is one of the earliest algorithms discovered in the field of computer graphics. The Midpoint circle algorithm shares some similarities to his line algorithm and is known as **Bresenham**‘s circle algorithm.

**Historical Note**

In November 2001 Jack E. Bresenham wrote, “I was working in the computation lab at IBM’s San Jose development lab. A Cal comp plotter had been attached to an IBM 1401 via the 1407 typewriter console. [The algorithm] was in production use by summer 1962, possibly a month or so earlier. Programs in those days were freely exchanged among corporations so Cal comp (Jim Newland and Calvin Hefted) had copies. When I returned to Stanford in fall 1962, I put a copy in the Stanford comp center library.

A description of the line drawing routine was accepted for presentation at the 1963 ACM national convention in Denver, Colorado. It was a year in which no proceedings were published, only the agenda of speakers and topics in an issue of Communications of the ACM. A person from the IBM Systems Journal asked me after I made my presentation if they could publish the paper. I happily agreed, and they printed it in 1965.”

The Bresenham line algorithm is an algorithm which determines which order to form a close approximation to a straight line between two given points. It is commonly used to draw lines on a computer screen, as it uses only integer addition, subtraction and bit shifting, all of which are very cheap operations in standard computer architectures. It is one of the earliest algorithms developed in the field of computer graphics. A minor extension to the original algorithm also deals with drawing circles.

While algorithms such as Wu’s algorithm are also frequently used in modern computer graphics because they can support ant aliasing, the speed and simplicity of Bresenham’s line algorithm means that it is still important. The algorithm is used in hardware such as plotters and in the graphics chips of modern graphics cards. It can also be found in many software graphics libraries. Because the algorithm is very simple, it is often implemented in either the firmware or the graphics hardware of modern graphics cards.

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