MATLAB Implementation of Scanline Conversion Algorithm for Simple Polygons Without Inner Rings

This document presents a MATLAB implementation of a scanline conversion algorithm for polygon filling, specifically designed for simple polygons without inner rings.

First, let's clarify what constitutes a simple polygon without inner rings. These are polygons that contain no islands or internal holes – fundamental shapes commonly used in computer graphics applications such as mapping systems, image processing, and computer-aided design (CAD).

The scanline algorithm converts polygons into a series of horizontal segments by processing each scanline to determine intersections with polygon edges. The algorithm typically involves maintaining an active edge list and calculating intersection points where scanlines cross polygon boundaries. At each intersection point, the algorithm toggles the fill state, creating segments that lie inside the polygon.

Our implementation leverages MATLAB's computational capabilities for matrix operations and its visualization tools for result display. The program utilizes MATLAB's graphical user interface (GUI) toolbox for interactive polygon input and employs built-in graphics functions to visualize the scanline conversion process. Key functions include edge table initialization, active edge management, and intersection point calculation using linear interpolation between vertices.

Below you can examine our MATLAB program that implements the scanline conversion algorithm for simple polygons without inner rings. The code demonstrates efficient edge processing and fill segment generation through systematic scanline traversal.