Refine man-page w.r.t to optional parameters.

The optional parameters after `=` should be inside the [...] brackets.

`--title=[<format-string>]` -> `--title[=<format-string>]`

README.md

@@ -92,7 +92,8 @@ Options (most common first):
         -F<filelist>   : like -f, but relative filenames considered relative
                          to the directory containing the filelist.
         -b<str>        : Background color to use behind alpha channel. Format
-                         'yellow', '#rrggbb', 'auto' or 'none' (default 'auto').
+                         color name like 'yellow', '#rrggbb', 'auto' or 'none'.
+                        'auto' is terminal background color. (default 'auto').
         -B<str>        : Checkerboard pattern color to use on alpha.
         --pattern-size=<n> : Integer factor scale of the checkerboard pattern.
         --auto-crop[=<pre-crop>] : Crop away all same-color pixels around image.
@@ -105,8 +106,9 @@ Options (most common first):
         -U, --upscale[=i]: Allow Upscaling. If an image is smaller than the
                          available frame (e.g. an icon), enlarge it to fit.
                          Optional parameter 'i' only enlarges in integer steps.
-        --clear        : Clear screen first. Optional argument 'every' will
-                         clear before every image (useful with -w)
+        --clear[=every]: Clear draw area first. Optional argument 'every' will
+                         clear before every image (useful with -w/-wr,
+                         but not with --grid)
         -V             : Directly use Video subsystem. Don't probe image
                          decoding first (useful, if you stream video from stdin)
         -I             : Only  use Image subsystem. Don't attempt video decoding
@@ -125,13 +127,13 @@ Options (most common first):
                          (Default 3, 3/4 #cores on this machine)
         --color8       : Choose 8 bit color mode for -ph or -pq
         --version      : Print detailed version including used libraries.
-                         (v1.5.1+)
+                         (v1.5.3+)
         --verbose      : Print some stats after images shown.
         -h             : Print this help and exit.
         --help         : Page through detailed manpage-like help and exit.
 
   Scrolling
-        --scroll=[<ms>]       : Scroll horizontally (optionally: delay ms (60)).
+        --scroll[=<ms>]       : Scroll horizontally (optionally: delay ms (60)).
         --delta-move=<dx:dy>  : delta x and delta y when scrolling (default:1:0)
 
   For Animations, Scrolling, or Video

man/timg.1

@@ -1,6 +1,6 @@
-.\" Automatically generated by Pandoc 3.1.8
+.\" Automatically generated by Pandoc 3.1.9
 .\"
-.TH "timg" "1" "Jul 2023" "" ""
+.TH "timg" "1" "Dec 2023" "" ""
 .SH NAME
 timg - A terminal image and video viewer
 .SH SYNOPSIS
@@ -129,7 +129,7 @@ below).
 \f[B]-C\f[R], \f[B]--center\f[R]
 Center image(s) and title(s) horizontally in their alotted space.
 .TP
-\f[B]--title=[format-string]\f[R]
+\f[B]--title\f[R][=<\f[I]format-string\f[R]>]
 Print title above each image.
 It is possible to customize the title by giving a format string.
 In this string, the following format specifiers are expanded:
@@ -244,7 +244,7 @@ terminal, so might require scrolling to see the full picture.
 Default behavior is to fit within the allotted width \f[I]and\f[R]
 height.
 .TP
-\f[B]-U\f[R], \f[B]--upscale=[i]\f[R]
+\f[B]-U\f[R], \f[B]--upscale\f[R][=i]
 Allow Upscaling.
 If an image is smaller than the terminal size, scale it up to fit the
 terminal.
@@ -263,7 +263,7 @@ that forces the upscaling to be in integer increments to keep the
 `fuzzing'.
 .RE
 .TP
-\f[B]--clear\f[R]
+\f[B]--clear\f[R][=every]
 Clear screen before \f[I]first\f[R] image.
 This places the image at the top of the screen.
 .RS
@@ -498,7 +498,9 @@ connection that can\[cq]t keep up with playing videos.
 Or if you have a very slow CPU.
 .SH EXAMPLES
 Some example invocations including scrolling text or streaming an online
-video are put together at <https://timg.sh/#examples>
+video are put together at \c
+.UR https://timg.sh/#examples
+.UE \c
 .PP
 It might be useful to prepare some environment variables or aliases in
 the startup profile of your shell.
@@ -520,12 +522,16 @@ display images on some limited text console.
 The option \f[B]-V\f[R] should not be necessary for streaming video from
 stdin; timg should internally buffer bytes it uses for probing.
 .SH BUGS
-Report bugs at <http://github.com/hzeller/timg/issues>
+Report bugs at \c
+.UR http://github.com/hzeller/timg/issues
+.UE \c
 .SH COPYRIGHT
 Copyright (c) 2016..2023 Henner Zeller.
 This program is free software, provided under the GNU GPL version 2.0.
 .PP
-<https://gnu.org/licenses/gpl-2.0.html>
+\c
+.UR https://gnu.org/licenses/gpl-2.0.html
+.UE \c
 .SH SEE ALSO
 GraphicsMagick, ffmpeg(1), utf-8(7), unicode(7), kitty(1),
 https://en.wikipedia.org/wiki/Sixel

man/timg.1.md

@@ -1,6 +1,6 @@
 % timg(1)
 % Henner Zeller
-% Nov 2023
+% Dec 2023
 
 # NAME
 
@@ -113,7 +113,7 @@ Most likely commonly needed options first.
 **-C**, **-\-center**
 :    Center image(s) and title(s) horizontally in their alotted space.
 
-**-\-title=[format-string]**
+**-\-title**[=<*format-string*>]
 :    Print title above each image. It is possible to customize the
      title by giving a format string. In this string, the following format
      specifiers are expanded:
@@ -207,7 +207,7 @@ Most likely commonly needed options first.
      see the full picture.
      Default behavior is to fit within the allotted width *and* height.
 
-**-U**, **-\-upscale=[i]**
+**-U**, **-\-upscale**[=i]
 :   Allow Upscaling. If an image is smaller than the terminal size, scale
     it up to fit the terminal.
 
@@ -221,7 +221,7 @@ Most likely commonly needed options first.
     that forces the upscaling to be in integer increments to keep the 'blocky'
     appearance of an upscaled image without bilinear scale 'fuzzing'.
 
-**-\-clear**
+**-\-clear**[=every]
 :   Clear screen before *first* image. This places the image at the top of the
     screen.
 

src/svg-image-source.cc

@@ -82,6 +82,7 @@ bool SVGImageSource::LoadAndScale(const DisplayOptions &opts, int, int) {
     // the x-axis by 2 did not result in satisfactorial results, maybe due
     // to rounding on an already heavily quantized size ? Let's just render
     // in double resolution in both directions then manually scale down height.
+    // TODO: figure out how to get good low-res rendering without detour.
     const int render_width = target_width;
     const int render_height =
         needs_x_double_resolution ? target_height * 2 : target_height;