[librsvg: 32/35] rsvg-convert.1: Document how --width and --height limit the --zoom.

[Marge Bot <marge-bot src gnome org>]

commit 217f3eb0405268d9ba101709b9943585c3ada09b
Author: Federico Mena Quintero <federico gnome org>
Date:   Thu Jun 17 13:51:00 2021 -0500

    rsvg-convert.1: Document how --width and --height limit the --zoom.
    
    Part-of: <https://gitlab.gnome.org/GNOME/librsvg/-/merge_requests/547>

 rsvg-convert.1 | 42 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)
---
diff --git a/rsvg-convert.1 b/rsvg-convert.1
index 55d72d41..36b2fe02 100644
--- a/rsvg-convert.1
+++ b/rsvg-convert.1
@@ -82,7 +82,7 @@ as part of a pipeline; without an argument for the input filename it will read t
 .I output.png
 .RE
 .P
-.SS SPECIFYING DIMENSIONS
+.SS SPECIFYING THE RENDERED SIZE
 You can use the
 .B --width
 and
@@ -193,6 +193,46 @@ placing it with its top-left corner 5\ cm away from the top and 8\ cm from the l
 .RE
 .P
 
+.SS SPECIFYING A SCALE FACTOR INSTEAD OF A RENDERED SIZE
+The
+.B --zoom
+option lets you scale the natural size of an SVG document.  For example, if
+.I input.svg
+is a document with a declared size of 100*200\ pixels, then the following command will render it at 250*500\ 
pixels (zoom\ 2.5):
+.P
+.RS
+.B rsvg-convert
+.BI --zoom=2.5
+.I input.svg
+.B >
+.I output.png
+.RE
+.P
+You can limit the maximum scaled size by specifying the
+.B --width
+and
+.B --height
+options together with
+.BR --zoom.
+Here, the image will be scaled 10x, but limited to 1000*1000\ pixels at the most:
+.P
+.RS
+.B rsvg-convert
+.BI --zoom=10
+.BI --width=1000
+.BI --height=1000
+.I input.svg
+.B >
+.I output.png
+.RE
+.P
+If you need different scale factors for the horizontal and vertical dimensions, use the
+.B --x-zoom
+and
+.B --y-zoom
+options instead of
+.BR --zoom.
+
 .SS CONVERSION OF PIXELS BASED ON THE DOTS-PER-INCH
 .B rsvg-convert
 uses the