From 63c917fd8fefd1c8f381c1467fe751e3a64949df Mon Sep 17 00:00:00 2001
From: Robby Findler <robby@racket-lang.org>
Date: Mon, 4 Jan 2010 12:36:04 +0000
Subject: [PATCH] made the image sizing functions always return exact, positive
 integers

svn: r17476
---
 collects/2htdp/private/image-more.ss           |  4 ++--
 collects/2htdp/tests/test-image.ss             | 18 +++++++++---------
 .../teachpack/2htdp/scribblings/image-toc.ss   |  4 ++--
 .../teachpack/2htdp/scribblings/image.scrbl    |  6 +++---
 4 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/collects/2htdp/private/image-more.ss b/collects/2htdp/private/image-more.ss
index 70cebcd30e..16ed89f7d7 100644
--- a/collects/2htdp/private/image-more.ss
+++ b/collects/2htdp/private/image-more.ss
@@ -756,8 +756,8 @@
 ;; see pin-line in slideshow
 ;; the initial strings in the second instance of add-curve are like the strings in add-line
 
-(define/chk (image-width image) (image-right image))
-(define/chk (image-height image) (image-bottom image))
+(define/chk (image-width image) (inexact->exact (ceiling (image-right image))))
+(define/chk (image-height image) (inexact->exact (ceiling (image-bottom image))))
 
 (define-syntax (bitmap stx)
   (syntax-case stx ()
diff --git a/collects/2htdp/tests/test-image.ss b/collects/2htdp/tests/test-image.ss
index 513e7f0bae..83cc4da712 100644
--- a/collects/2htdp/tests/test-image.ss
+++ b/collects/2htdp/tests/test-image.ss
@@ -148,27 +148,27 @@
       0)
 
 (check-close (image-width (rotate 45 (rectangle 100 0 'solid 'blue)))
-             (* (sin (* pi 1/4)) 100))
+             (inexact->exact (ceiling (* (sin (* pi 1/4)) 100))))
 (check-close (image-height (rotate 45 (rectangle 100 0 'solid 'blue)))
-             (* (sin (* pi 1/4)) 100))
+             (inexact->exact (ceiling (* (sin (* pi 1/4)) 100))))
 (check-close (image-width (rotate 45 (rectangle 0 100 'solid 'blue)))
-             (* (sin (* pi 1/4)) 100))
+             (inexact->exact (ceiling (* (sin (* pi 1/4)) 100))))
 (check-close (image-height (rotate 45 (rectangle 0 100 'solid 'blue)))
-             (* (sin (* pi 1/4)) 100))
+             (inexact->exact (ceiling (* (sin (* pi 1/4)) 100))))
 
 (test (image-width (scale 4 (rectangle 10 10 'outline 'black)))
       =>
       40)
 (test (image-width (rotate 90 (scale 4 (rectangle 10 10 'outline 'black))))
       =>
-      40.0)
+      40)
 
 (test (image-width (scale 4 (rectangle 10 10 'solid 'black)))
       =>
       40)
 (test (image-width (rotate 90 (scale 4 (rectangle 10 10 'solid 'black))))
       =>
-      40.0)
+      40)
 
 
 (test (image-width (ellipse 10 20 'solid 'blue))
@@ -192,14 +192,14 @@
 
 (test (image-width (rotate 30 (ellipse 100 0 'solid 'blue)))
       =>
-      (* (cos (* pi 1/6)) 100))
+      (inexact->exact (ceiling (* (cos (* pi 1/6)) 100))))
 (test (image-height (rotate 30 (ellipse 100 0 'solid 'blue)))
       =>
-      (* (sin (* pi 1/6)) 100))
+      (inexact->exact (ceiling (* (sin (* pi 1/6)) 100))))
 (check-close (image-width (rotate 30 (ellipse 0 100 'solid 'blue)))
              (* (sin (* pi 1/6)) 100))
 (check-close (image-height (rotate 30 (ellipse 0 100 'solid 'blue)))
-             (* (cos (* pi 1/6)) 100))
+             (ceiling (* (cos (* pi 1/6)) 100)))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
diff --git a/collects/teachpack/2htdp/scribblings/image-toc.ss b/collects/teachpack/2htdp/scribblings/image-toc.ss
index b3bd0c0cda..b70120fdcf 100644
--- a/collects/teachpack/2htdp/scribblings/image-toc.ss
+++ b/collects/teachpack/2htdp/scribblings/image-toc.ss
@@ -8,8 +8,8 @@
   (list
    (list '(image-height (rectangle 100 100 "solid" "black")) 'val 100)
    (list '(image-baseline (rectangle 100 100 "solid" "black")) 'val 100)
-   (list '(image-height (text "Hello" 24 "black")) 'val 24.0)
-   (list '(image-baseline (text "Hello" 24 "black")) 'val 18.0)
+   (list '(image-height (text "Hello" 24 "black")) 'val 24)
+   (list '(image-baseline (text "Hello" 24 "black")) 'val 18)
    (list
     '(image-height
       (overlay (circle 20 "solid" "orange") (circle 30 "solid" "purple")))
diff --git a/collects/teachpack/2htdp/scribblings/image.scrbl b/collects/teachpack/2htdp/scribblings/image.scrbl
index 3e4a15ef98..594110a38a 100644
--- a/collects/teachpack/2htdp/scribblings/image.scrbl
+++ b/collects/teachpack/2htdp/scribblings/image.scrbl
@@ -527,7 +527,7 @@ other. The top and bottom pair of angles is @scheme[angle] and the left and righ
 
 @section{Image Properties}
 
-@defproc[(image-width [i image?]) (and/c number? positive?)]{
+@defproc[(image-width [i image?]) (and/c integer? positive? exact?)]{
   Returns the width of @scheme[i].
                        
   @image-examples[(image-width (ellipse 30 40 "solid" "orange"))
@@ -536,7 +536,7 @@ other. The top and bottom pair of angles is @scheme[angle] and the left and righ
                                        (circle 20 "solid" "purple")))]
 }
 
-@defproc[(image-height [i image?]) (and/c number? positive?)]{
+@defproc[(image-height [i image?]) (and/c integer? positive? exact?)]{
   Returns the height of @scheme[i].
   
   @image-examples[(image-height (ellipse 30 40 "solid" "orange"))
@@ -545,7 +545,7 @@ other. The top and bottom pair of angles is @scheme[angle] and the left and righ
                                          (circle 30 "solid" "purple")))]
   }
 
-@defproc[(image-baseline [i image?]) (and/c number? positive?)]{
+@defproc[(image-baseline [i image?]) (and/c integer? positive? exact?)]{
   Returns the distance from the top of the image to its baseline. 
   Unless the image was constructed with @scheme[text] or @scheme[text/font],
   this will be the same as its height.