WallSource* * Drawing in wall is achieved by intersecting a simple, infinite image with a * shape. * * This image is described by a 'a Paint.t value and is simple by nature: * - a single color, * - a few different kinds of gradients, * - some user-defined pattern or textures, as determined by 'a. * * The 'a depends on the renderer and in practice it will be a * Wall_texture.t, an abstraction over OpenGL texture. * * The shapes are made from a Path.t that is filled or stroked. * The path is list of points that are connected by straight or curved (bezier) * lines. * When filled, the path is interpreted as the contour of a surface and the * resulting image is this surface. * When stroked, the path is interpreted as one or more lines: an Outline.t * that describe the style of line rendering (thickness, square or round ends, * etc) is used transform the abstract lines into a surface.