The five world-to-page transformations can be combined into a single 3-by-3 matrix. The CombineTransform function can be used to combine two world-space to page-space transformations. The combined transformations can be used to alter output associated with a particular device context (DC) by calling the SetWorldTransform function and supplying the elements for this matrix. When an application calls SetWorldTransform, it stores the elements of the 3-by-3 matrix in an XFORM structure. The members of this structure correspond to the first two columns of a 3-by-3 matrix; the last column of the matrix is not required because its values are constant.
The elements of the current world transformation matrix can be revived by calling the GetWorldTransform function and supplying a pointer to an XFORM structure.