Vector graphics editing with interweaving and penetrating

Decorative patterns are common in traditional Chinese architectures as shown in Figure 1. However, scalable vector graphics (SVG) is not capable of representing interweaving and penetrating patterns. In this paper, we develop a web-based vector graphics interweaving and penetrating editing system. We propose a data structure to dealing with interweaving and penetrating, allowing users to assign depth value for each edge of a polygon. As a result, when we click on a polygon and move it to interweave with another one, the intersecting edge is calculated using linear interpolation of the depth values. In contrast, the conventional SVG format arranges layers to separate two polygons for interweaving and penetrating. In other words, users need to split a polygon into multiple polygons and assigning them to different layers to achieve interweaving and penetrating. As shown in Figure 2, the proposed system handles the interweaving and penetrating problem intuitively and maintains the topology of the polygons. After finish editing, the proposed system allows the user to save the drawing in both standard SVG format and the proposed augmented depth value format for future editing.