[cairo] 4x4 matrices in Cairo
cloos at jhcloos.com
Thu Nov 14 13:49:19 PST 2013
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
(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.
James Cloos <cloos at jhcloos.com> OpenPGP: 1024D/ED7DAEA6
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