From b2ae4264e3c227330e4cfcae4eceb431abbbf289 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Tue, 24 Feb 2009 17:47:24 +0000
Subject: [PATCH] change pin-line pull to a ratio

svn: r13821
---
 collects/scribblings/slideshow/picts.scrbl | 16 +++++++---------
 collects/slideshow/pict.ss                 |  4 ++--
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/collects/scribblings/slideshow/picts.scrbl b/collects/scribblings/slideshow/picts.scrbl
index 72d8a03d26..cae5e309f1 100644
--- a/collects/scribblings/slideshow/picts.scrbl
+++ b/collects/scribblings/slideshow/picts.scrbl
@@ -287,8 +287,8 @@ argument for consistency with the other functions.}
                       [find-dest (pict? pict-path? . -> . (values real? real?))]
                       [#:start-angle start-angle (or/c real? #f) #f]
                       [#:end-angle end-angle (or/c real? #f) #f]
-                      [#:start-pull start-pull (or/c real? #f) #f]
-                      [#:end-pull end-pull (or/c real? #f) #f]
+                      [#:start-pull start-pull real? 1/4]
+                      [#:end-pull end-pull real? 1/4]
                       [#:line-width line-width (or/c #f real?) #f]
                       [#:color color (or/c #f string? (is-a/c? color%)) #f]
                       [#:under? under? any/c #f])
@@ -300,8 +300,8 @@ argument for consistency with the other functions.}
                       [find-dest (pict? pict-path? . -> . (values real? real?))]
                       [#:start-angle start-angle (or/c real? #f) #f]
                       [#:end-angle end-angle (or/c real? #f) #f]
-                      [#:start-pull start-pull (or/c real? #f) #f]
-                      [#:end-pull end-pull (or/c real? #f) #f]
+                      [#:start-pull start-pull real? 1/4]
+                      [#:end-pull end-pull real? 1/4]
                       [#:line-width line-width (or/c #f real?) #f]
                       [#:color color (or/c #f string? (is-a/c? color%)) #f]
                       [#:under? under? any/c #f]
@@ -314,8 +314,8 @@ argument for consistency with the other functions.}
                       [find-dest (pict? pict-path? . -> . (values real? real?))]
                       [#:start-angle start-angle (or/c real? #f) #f]
                       [#:end-angle end-angle (or/c real? #f) #f]
-                      [#:start-pull start-pull (or/c real? #f) #f]
-                      [#:end-pull end-pull (or/c real? #f) #f]
+                      [#:start-pull start-pull real? 1/4]
+                      [#:end-pull end-pull real? 1/4]
                       [#:line-width line-width (or/c #f real?) #f]
                       [#:color color (or/c #f string? (is-a/c? color%)) #f]
                       [#:under? under? any/c #f]
@@ -343,9 +343,7 @@ The @scheme[start-angle], @scheme[end-angle], @scheme[start-pull], and
 
  @item{The @scheme[start-pull] and @scheme[end-pull] arguments specify
        a kind of momentum for the starting and ending angles; larger
-       values preserve the angle longer. If @scheme[start-pull] or
-       @scheme[end-pull] is @scheme[#f], then it is replaced with
-       one-fourth of the distance between the start and end points.}
+       values preserve the angle longer.}
 
 ]
 
diff --git a/collects/slideshow/pict.ss b/collects/slideshow/pict.ss
index aac07f9fb0..adc304e0d8 100644
--- a/collects/slideshow/pict.ss
+++ b/collects/slideshow/pict.ss
@@ -108,8 +108,8 @@
              [ea (or ea
                      (atan (- sy0 dy0) (- dx0 sx0)))]
              [d (sqrt (+ (* (- dy0 sy0) (- dy0 sy0)) (* (- dx0 sx0) (- dx0 sx0))))]
-             [sp (or sp (* 1/4 d))]
-             [ep (or ep (* 1/4 d))])
+             [sp (* (or sp 1/4) d)]
+             [ep (* (or ep 1/4) d)])
         (let ([dx (if end-arrow? (- dx0 (* sz (cos ea))) dx0)]
               [dy (if end-arrow? (+ dy0 (* sz (sin ea))) dy0)]
               [sx (if start-arrow? (+ sx0 (* sz (cos sa))) sx0)]