887a8a1 · vty · git.iko.soy

git.iko.soy/vty

translateX/Y: fix negative translations

This change makes it so that translating an image negatively will return an empty image if the negative translation completely hides the input image. Previously we'd just return an image with a negative height, which not only violates the requirement that all images have height no less than zero, but it caused downstream bugs in mutable vector accesses due to negative vector indices.

commit887a8a1e1008c9d1cec22c88d010f89badc2523c authorJonathan Daugherty <cygnus@foobox.com> dateSat 20 May 2017, 08:13 (9 years ago) parent60c0468

1 file changed+2

compare with master

unifiedsplit

src/Graphics/Vty/Image.hs+2

src/Graphics/Vty/Image.hs+2

@@ -242,6 +242,7 @@ translate x y i = translateX x (translateY y i)

242242-- | Translates an image by padding or cropping its left side.

243243translateX :: Int -> Image -> Image

244244translateX x i

245+ | x < 0 && (abs x > imageWidth i) = emptyImage

245246 | x < 0 = let s = abs x in CropLeft i s (imageWidth i - s) (imageHeight i)

246247 | x == 0 = i

247248 | otherwise = let h = imageHeight i in HorizJoin (BGFill x h) i (imageWidth i + x) h

@@ -249,6 +250,7 @@ translateX x i

249250-- | Translates an image by padding or cropping its top.

250251translateY :: Int -> Image -> Image

251252translateY y i

253+ | y < 0 && (abs y > imageHeight i) = emptyImage

252254 | y < 0 = let s = abs y in CropTop i s (imageWidth i) (imageHeight i - s)

253255 | y == 0 = i

254256 | otherwise = let w = imageWidth i in VertJoin (BGFill w y) i w (imageHeight i + y)