Coordinate Spaces and Transformations

Applications use coordinate spaces and transformations to scale, rotate, translate, shear, and reflect graphics output. A coordinate space is a planar space that locates two-dimensional objects by using two reference axes that are perpendicular to each other. There are four coordinate spaces: world, page, device, and physical device (client area, desktop, or page of printer paper).

A transformation is an algorithm that alters ("transforms") the size, orientation, and shape of objects. Transformations also transfer a graphics object from one coordinate space to another. Ultimately, the object appears on the physical device, which is usually a screen or printer.

This chapter is divided into three topics: