linjerasterisering

Linjerasterisering, often translated as line rasterization or line drawing, is a fundamental algorithm in computer graphics used to approximate a straight line on a raster display, such as a computer monitor or pixel grid. The goal is to determine which pixels on the screen should be illuminated to create the visual appearance of a continuous line. Since displays are made of discrete pixels, a perfect representation is impossible, necessitating an approximation.

The most common and efficient algorithm for line rasterization is Bresenham's line algorithm. This algorithm works by incrementally selecting pixels based on an error term. It starts at one endpoint of the line and iteratively decides whether to move to the next pixel horizontally, vertically, or diagonally based on which pixel is closest to the true mathematical line. Bresenham's algorithm is advantageous because it uses only integer arithmetic, avoiding the computationally expensive floating-point operations that were prevalent in earlier methods like DDA (Digital Differential Analyzer). This efficiency makes it a cornerstone of real-time graphics rendering.

Other line rasterization algorithms exist, but Bresenham's remains popular due to its speed and simplicity. The output of linjerasterisering is a set of pixel coordinates that, when rendered, form the visual representation of the line segment. This process is crucial for drawing all sorts of graphical elements, from simple lines to the edges of polygons and text characters.