Implement straight flags in scheme

[hanwenn]

Reviewers: Reinhold,


http://codereview.appspot.com/11046/diff/8/11
File scm/flag-styles.scm (left):

http://codereview.appspot.com/11046/diff/8/11#oldcode17
Line 17: ;; (define-public (add-stroke-straight stencil dir
stroke-style)
drop commented stuff.

http://codereview.appspot.com/11046/diff/8/11
File scm/flag-styles.scm (right):

http://codereview.appspot.com/11046/diff/8/11#newcode18
Line 18: (let* ((udmult (if stem-up? 1 -1))
fix naming

http://codereview.appspot.com/11046/diff/8/11#newcode28
Line 28: (let* ((conversion-constant (/ (atan 1 1) 45))
define PI = 3.141.. somewhere and use that.

split this in a polar -> rect function and a degree -> radian function.

http://codereview.appspot.com/11046/diff/8/11#newcode36
Line 36: (define (buildflag flag-stencil remain curr-stencil spacing)
doc string

http://codereview.appspot.com/11046/diff/8/11#newcode57
Line 57: (factor (if (number? fs) (expt 1.12246 fs) 1))
look for magstep to unhardcoded this

http://codereview.appspot.com/11046/diff/8/11#newcode61
Line 61: (up-length (+ (* upflag-length factor) half-stem-thickness))
can you make the up/down distinction generic? Usually up=1, down= -1, so
usually you can just do (* direction thick) to have a direction
dependent value.

http://codereview.appspot.com/11046/diff/8/11#newcode80
Line 80: (if (null? stroke-style)
use explicit check

 (eq? stroke-style 'grace)

(or whatever)

Description:
Implement straight flags in scheme

Please review this at http://codereview.appspot.com/11046

Affected files:
  M Documentation/topdocs/NEWS.tely
  A input/regression/flags-straight.ly
  M scm/flag-styles.scm