C++ library for Coordinate Transformation Matrices (CTM)?

Question

I'm looking for a C++ library which allows for easy integration of Coordinate Transformation Matrices (CTM) in my application. You might know CTMs from PDF or PostScript.

For one project we are using C++/Qt4 as a framework, which offers a QTransform class, which provides methods like .translate(double x, double y) or .rotate(double degrees).

After doing some transformations, it would allow me to get all 6 CTM values, which I could feed into a PDF library or use a transformation matrix in export files. Qt's API also allows for arbitrary mapping of polygons (QPolygon), rectangles (QRect) and other primitive data structures into transformed coordinate systems.

So basically I'm looking for something similar to what Qt provides, but without the need of using Qt.

I know I could do the matrix multiplications myself, but I'm not really interested in doing so, as I'm very sure that someone already solved this problem, so please no links to books or other guides on how to multiply matrices.

Thanks!

Answer 1

Why not just use Qt? It does what you want, is open source (LGPL I think) and you should be able to link just against the QTransform class.

Answer 2

Have you considered OpenGL? It can not only do the types of transforms you're looking for (linear transformations up to 4x4), but it can typically offload that work to your graphics card which will perform the computations on hardware specifically designed for such things (i.e. it's fast).