DDA vs Bresenham: Fastest Line Drawing Algorithm Comparison
DDA (Digital Differential Analyzer) uses floating-point math to advance pixel by pixel along a line; Bresenham keeps everything integer, stepping only when the error crosses a threshold, making it the faster classic.
Beginners often see both names in textbooks and assume the older DDA must be quicker. In reality, Bresenham’s integer-only loop wins every time on modern CPUs, so game engines and renderers quietly drop DDA.
Key Differences
DDA needs float adds and a costly round() per pixel. Bresenham replaces floats with a single integer increment and a sign test, cutting CPU cycles and cache misses. On GPUs, Bresenham’s logic even maps to shader ALUs.
Which One Should You Choose?
Choose Bresenham for any raster line—2D games, embedded displays, or software renderers. Use DDA only when teaching concepts or when the hardware already provides floating-point vector units and rounding is free.
Is DDA ever faster than Bresenham?
Almost never; only on exotic vector machines where float adds are cheaper than integer branches.
Can Bresenham draw thick or anti-aliased lines?
Not directly—extend it with Wu’s algorithm for smooth, wide lines.