port to linear

[jeffreyrosenbluth]

diagrams-canvas remains specialized to Float, as is the blank-canvas
package. As with rasterific and cairo, see diagrams/diagrams-cairo#54
for a discussion of why float only.

[jeffreyrosenbluth]

Some examples need updating for Direction.
Nothing to do with Linear.

[andygill]

Question: Should blank-canvas use Double everywhere?

[jeffreyrosenbluth]

From the diagrams perspective I don't think it makes a difference using Double or Float.
I'm sure your aware of this:
http://www.haskell.org/haskellwiki/Performance/Floating_point
but it's quite old and I don't know if its relevant anymore

[andygill]

No, I was not. I guessed that most of the advantage of Float went away when we had 64 bit buses, but this says to me we should change to Double, if we do an API bump (which it looks like we've done).