Re: 4x4 matrices in Cairo
James Cloos <[email protected]>
| Newsgroups | gmane.comp.lib.cairo |
|---|---|
| Message-ID | <[email protected]> |
AD>> Is there a way to use 4x4 matrices in cairo? US> No. Cairo ... projective transformations ... A 4x4 matrix implies 3D. Perspective transforms for 2D require arbitrary 3x3 matrices and [x,y,z] vectors, as opposed to [ [a,b,0], [c,d,0], [dx,dy,1] ] 3x3 matrices and [x,y,1] vectors. The also, of course, require rational splines rather than polynomial. (Some authors of course put the dx,dy where I put the 0s, and the 0s where I put the dx and dy, depending on whether they prefer appending or prepending the matrix to the vector.) I always thought that support for rational splines would be a good point to increment the major version. -JimC -- James Cloos <[email protected]> OpenPGP: 1024D/ED7DAEA6 -- cairo mailing list [email protected] http://lists.cairographics.org/mailman/listinfo/cairo