From 7647e94eee4fe59ba62362c15445bf2feaae1e36 Mon Sep 17 00:00:00 2001
From: Robby Findler <robby@racket-lang.org>
Date: Wed, 22 Aug 2012 22:03:49 -0500
Subject: [PATCH] add scale-to-fit to slideshow/pict

---
 collects/scribblings/slideshow/picts.scrbl | 12 ++++++++++++
 collects/texpict/utils.rkt                 | 10 ++++++++++
 2 files changed, 22 insertions(+)

diff --git a/collects/scribblings/slideshow/picts.scrbl b/collects/scribblings/slideshow/picts.scrbl
index 7c45936192..c7091f0fca 100644
--- a/collects/scribblings/slideshow/picts.scrbl
+++ b/collects/scribblings/slideshow/picts.scrbl
@@ -543,6 +543,18 @@ Scales a pict drawing, as well as its @tech{bounding box}. The drawing
 is scaled by adjusting the destination @racket[dc<%>]'s scale while
 drawing the original @racket[pict].}
 
+@defproc*[([(scale-to-fit [pict pict?] [size-pict pict?]) pict?]
+           [(scale-to-fit [pict pict?] [width real?] [height real?]) pict?])]{
+  Scales @racket[pict] so that it fits within the bounding box of
+         @racket[size-pict] (if two arguments are supplied) or
+         into a box of size @racket[width] by @racket[height] 
+         (if three arguments are supplied).
+         
+         The aspect ratio of the pict is preserved, so the resulting pict
+         will have either the width or the height of the @racket[size-pict]
+         (or @racket[width] by @racket[height] box), but not necessarily
+         both.
+}
 
 @defproc[(rotate [pict pict?] [theta real?]) pict?]{
 
diff --git a/collects/texpict/utils.rkt b/collects/texpict/utils.rkt
index 965038c6e5..0347edc972 100644
--- a/collects/texpict/utils.rkt
+++ b/collects/texpict/utils.rkt
@@ -71,6 +71,8 @@
   (provide/contract 
    [scale (case-> (-> pict? number? number? pict?)
                   (-> pict? number? pict?))]
+   [scale-to-fit (case-> (-> pict? number? number? pict?)
+                         (-> pict? pict? pict?))]
    [rotate (case-> (-> pict? number? pict?))]
    [pin-line (->* (pict?
                    pict-path? (-> pict? pict-path? (values number? number?))
@@ -1068,6 +1070,14 @@
           (s (send c green))
           (s (send c blue))))))
   
+  (define scale-to-fit
+    (case-lambda
+      [(main-pict size-pict)
+       (scale-to-fit main-pict (pict-width size-pict) (pict-height size-pict))]
+      [(main-pict w h)
+       (scale main-pict (min (/ w (pict-width main-pict))
+                             (/ h (pict-height main-pict))))]))
+  
   (define scale
     (case-lambda
      [(p x-factor y-factor)