[PATCH app/xrandr] man: Document the new --filter option

[Aaron Plattner]

Signed-off-by: Aaron Plattner <aplattner at nvidia.com>
---
I noticed elsewhere that in PDF versions of the man pages, \- expands as U+2212
MINUS SIGN and - expands to U+002D HYPHEN-MINUS. So I think our use of - and \-
is backwards. I didn't try to fix that here.

 man/xrandr.man | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/man/xrandr.man b/man/xrandr.man
index 55ea5dd9b6f4..65ccc2a2f9c6 100644
--- a/man/xrandr.man
+++ b/man/xrandr.man
@@ -155,7 +155,9 @@ parameters specify the border and default to 0. A width or height set to zero
 disables panning on the according axis. You typically have to set the screen
 size with \fI--fb\fP simultaneously.
 .IP "\-\-transform \fIa\fP,\fIb\fP,\fIc\fP,\fId\fP,\fIe\fP,\fIf\fP,\fIg\fP,\fIh\fP,\fIi\fP"
-Specifies a transformation matrix to apply on the output. Automatically a bilinear filter is selected.
+Specifies a transformation matrix to apply on the output.
+A bilinear filter is selected automatically unless the \-\-filter parameter is
+also specified.
 The mathematical form corresponds to:
 .RS
 .RS
@@ -201,6 +203,10 @@ As a special argument, instead of
 passing a matrix, one can pass the string \fInone\fP, in which case the default
 values are used (a unit matrix without filter).
 .RE
+.IP "\-\-filter \fIfiltermode\fP"
+Chooses the scaling filter method to be applied when the screen is scaled or
+transformed.
+Can be either 'bilinear' or 'nearest'.
 .IP "\-\-scale \fIx\fPx\fIy\fP"
 Changes the dimensions of the output picture. Values superior to 1 will lead to
 a compressed screen (screen dimension bigger than the dimension of the output
-- 
2.13.0