From 38ca6277880d89d8614fbd46fae28f5225950ffe Mon Sep 17 00:00:00 2001 From: Robby Findler Date: Sat, 25 Aug 2012 19:12:33 -0500 Subject: [PATCH] attempt to clarify the composition properties of empty-image --- collects/teachpack/2htdp/scribblings/image.scrbl | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/collects/teachpack/2htdp/scribblings/image.scrbl b/collects/teachpack/2htdp/scribblings/image.scrbl index 7d4f3356d1..90de5dfcd6 100644 --- a/collects/teachpack/2htdp/scribblings/image.scrbl +++ b/collects/teachpack/2htdp/scribblings/image.scrbl @@ -208,7 +208,20 @@ Unlike @racket[scene+curve], if the line passes outside of @racket[image], the i (rectangle 10 10 "solid" "red")) (beside empty-image (rectangle 10 10 "solid" "red")))] -} + + + In most cases, combining an image with @racket[empty-image] produces the + original image (as shown in the above example). In some situations, + however, the combination can cause the resulting pict to have a different + baseline (see @racket[image-baseline]) and thus not + be equal. + + @image-examples[(image-baseline (above (text "Hello" 24 "olive") empty-image)) + (image-baseline (text "Hello" 24 "olive")) + (equal? (above (text "Hello" 24 "olive") empty-image) + (text "Hello" 24 "olive"))] + + } @section{Polygons}