GraphicsMagick PHP extension fails to render Google Fonts in SVG - php

Question

My Ubuntu 14.04 laptop has GraphicsMagick and the PHP extension (GMagick) installed. When I run the following from the command line,
gm convert -font /usr/share/fonts/truetype/google-fonts/RockSalt.ttf svg_file.svg jpeg_file.jpg
renders the JPEG with the font as desired. However, this PHP code
$gm = new Gmagick();
$draw = new GmagickDraw();
$draw->setfont("/usr/share/fonts/truetype/google-fonts/RockSalt.ttf");
$gm->readImageBlob($svg);
$gm->setImageFormat("jpeg");
$gm->drawimage($draw);
$gm->writeImage($jpgFile);
$gm->clear();
Fails to do the same and creates a JPEG with a default font. What could be the issue here?
This is the SVG:
<?xml version="1.0"?><svg xmlns="http://www.w3.org/2000/svg" xmlns:svg="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="737" height="521"><defs/> <g class="main"> <title>Main</title> <rect fill="#ffffff" stroke-width="0" x="27.24188" y="429.44421" width="682.51626" height="68.18413" id="svg_2" class="element" opacity="0.75" stroke="#000000"/> <g text-anchor="start" font-family="Rock Salt" fill="#000" font-size="20" class="element textarea" id="svg_3"> <rect opacity="0" stroke-width="0" x="27.24188" y="429.44421" width="682.51626" height="68.18413" id="svg_4"/> <g class="textGroup"> <text class="eol" y="470.98331" x="44.46314" xml:space="preserve">Your memories will last forever</text> </g> </g> </g></svg>

Answer 1

You need to edit GraphicMagick's type.mkg file so the font will load.
https://sourceforge.net/p/graphicsmagick/discussion/250738/thread/5c00e815/
Here is an example of the required format:
https://github.com/CliffsDover/graphicsmagick/blob/master/config/type-windows.mgk.in
<?xml version="1.0"?>
<typemap>
<type
name="Arial"
fullname="Arial"
family="Arial"
weight="400"
style="normal"
stretch="normal"
glyphs="#windows_font_dir#arial.ttf"
/>
<type
name="Arial-Black"
fullname="Arial Black"
family="Arial"
weight="900"
style="normal"
stretch="normal"
glyphs="#windows_font_dir#ariblk.ttf"
/>
<type
name="Arial-Bold"
fullname="Arial Bold"
family="Arial"
weight="700"
style="normal"
stretch="normal"
glyphs="#windows_font_dir#arialbd.ttf"
/>