fontconfig/conf.d/90-synthetic.conf

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
<!-- 
 Artificial oblique for fonts without an italic or oblique version
 -->
 
	<match target="font">
		<!-- check to see if the font is roman -->
		<test name="slant">
			<const>roman</const>
		</test>
		<!-- check to see if the pattern requested non-roman -->
		<test target="pattern" name="slant" compare="not_eq">
			<const>roman</const>
		</test>
		<!-- multiply the matrix to slant the font -->
		<edit name="matrix" mode="assign">
			<times>
				<name>matrix</name>
				<matrix><double>1</double><double>0.2</double>
					<double>0</double><double>1</double>
				</matrix>
			</times>
		</edit>
		<!-- pretend the font is oblique now -->
		<edit name="slant" mode="assign">
			<const>oblique</const>
		</edit>
                <!-- and disable embedded bitmaps for artificial oblique -->
                <edit name="embeddedbitmap" mode="assign">
                        <bool>false</bool>
                </edit>
	</match>

<!--
 Synthetic emboldening for fonts that do not have bold face available
 -->

	<match target="font">
		<!-- check to see if the font is just regular -->
		<test name="weight" compare="less_eq">
			<const>medium</const>
		</test>
		<!-- check to see if the pattern requests bold -->
		<test target="pattern" name="weight" compare="more">
			<const>medium</const>
		</test>
		<!--
		  set the embolden flag
		  needed for applications using cairo, e.g. gucharmap, gedit, ...
		-->
		<edit name="embolden" mode="assign">
			<bool>true</bool>
		</edit>
		<!--
		 set weight to bold
		 needed for applications using Xft directly, e.g. Firefox, ...
		-->
		<edit name="weight" mode="assign">
			<const>bold</const>
		</edit>
		<!--
		 Hinting will be done before Embolden in freetype2,
		 but in such case, Embolden will get wrong result
		 on some glyph contours after applying hinting.
		 Actually, hinting should be done after embolden, but we can't
		 fix it in current freetype2. So as a workaround, just turn off
		 hinting if we want to do embolden.
		-->
		<edit name="hintstyle" mode="assign">
			<const>hintnone</const>
		</edit>
	</match>
</fontconfig>