desktop-shell: new wallpaper mode scale-crop
Scale-crop mode scales the wallpaper to tightly fill the whole output,
but preserving wallpaper aspect ratio. If aspect ratio differs from the
output's, the wallpaper is centered cutting it from top/bottom or
left/right.
Add this to the weston.ini man page, and explain all three modes.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/man/weston.ini.man b/man/weston.ini.man
index d37654a..c3e5747 100644
--- a/man/weston.ini.man
+++ b/man/weston.ini.man
@@ -118,8 +118,13 @@
sets the path for the background image file (string).
.TP 7
.BI "background-type=" tile
-determines how the background image is drawn (string). Can be scale or
-tile (default).
+determines how the background image is drawn (string). Can be
+.BR scale ", " scale-crop " or " tile " (default)."
+Scale means scaled to fit the output precisely, not preserving aspect ratio.
+Scale-crop preserves aspect ratio, scales the background image just big
+enough to cover the output, and centers it. The image ends up cropped from
+left and right, or top and bottom, if the aspect ratio does not match the
+output. Tile repeats the background image to fill the output.
.TP 7
.BI "background-color=" 0xAARRGGBB
sets the color of the background (unsigned integer). The hexadecimal