Configure Fontconfig To Ignore Bitmaps In Scalable Fonts

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Introduction

Fontconfig is a powerful tool for managing fonts on Linux systems. It allows you to configure font settings, such as font paths, font aliases, and font filtering. In this article, we will explore how to configure fontconfig to ignore bitmaps in scalable fonts. This is particularly useful when you have a mix of bitmap and scalable fonts installed on your system, and you want to ensure that scalable fonts are used by default.

Understanding Bitmap and Scalable Fonts

Before we dive into the configuration, let's briefly discuss the difference between bitmap and scalable fonts.

  • Bitmap Fonts: Bitmap fonts are raster-based fonts that are composed of a grid of pixels. They are typically used for printing and are not suitable for on-screen display. Examples of bitmap fonts include Courier, Fixedsys, and the Microsoft C-Fonts.
  • Scalable Fonts: Scalable fonts, on the other hand, are vector-based fonts that can be scaled up or down without losing any quality. They are ideal for on-screen display and are widely used in modern operating systems. Examples of scalable fonts include Arial, Calibri, and Cambria.

The Problem with Calibri and Cambria

As you mentioned, Calibri and Cambria are wonderful fonts, but they can appear as bitmap fonts in certain sizes. This is because fontconfig may be using the bitmap version of these fonts instead of the scalable version. This can be frustrating, especially when you want to use these fonts for on-screen display.

Configuring Fontconfig to Ignore Bitmaps

To configure fontconfig to ignore bitmaps in scalable fonts, you need to create a font configuration file. This file will specify the font filtering rules that fontconfig should use.

Step 1: Create a Font Configuration File

Create a new file called fonts.conf in the /etc/fonts directory. This file will contain the font configuration settings.

sudo nano /etc/fonts/fonts.conf

Step 2: Add Font Filtering Rules

In the fonts.conf file, add the following lines to specify the font filtering rules:

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
  <match target="font">
    <test name="family" qual="any">
      <string>Calibri</string>
      <string>Cambria</string>
    </test>
    <edit name="embeddedbitmap" mode="assign">
      <bool>false</bool>
    </edit>
  </match>
</fontconfig>

In this example, we are specifying that Calibri and Cambria fonts should not use the bitmap version. The embeddedbitmap attribute is set to false, which tells fontconfig to use the scalable version of these fonts.

Step 3: Reload Fontconfig

After adding the font filtering rules, you need to reload fontconfig to apply the changes. You can do this by running the following command:

sudo fc-cache -f

Step 4: Verify the Changes

To verify that the changes have taken effect, you can use the fc-list command to list the fonts your system:

fc-list : family

This command will list all the fonts on your system, including the scalable and bitmap versions. You should see that Calibri and Cambria fonts are now using the scalable version.

Conclusion

In this article, we have explored how to configure fontconfig to ignore bitmaps in scalable fonts. We have created a font configuration file and added font filtering rules to specify that Calibri and Cambria fonts should not use the bitmap version. By following these steps, you can ensure that scalable fonts are used by default on your Linux system.

Additional Tips and Tricks

Here are some additional tips and tricks to help you configure fontconfig:

  • Font Aliases: You can create font aliases to map one font to another. For example, you can create an alias for Calibri to use the Arial font.
  • Font Paths: You can specify custom font paths to include additional fonts on your system.
  • Font Filtering: You can use font filtering rules to specify which fonts should be used for specific applications or use cases.

Introduction

Fontconfig is a powerful tool for managing fonts on Linux systems. In our previous article, we explored how to configure fontconfig to ignore bitmaps in scalable fonts. However, we know that you may have more questions about fontconfig and how to use it effectively. In this article, we will answer some of the most frequently asked questions about fontconfig.

Q: What is fontconfig?

A: Fontconfig is a font management system for Linux systems. It allows you to configure font settings, such as font paths, font aliases, and font filtering.

Q: Why do I need to configure fontconfig?

A: You need to configure fontconfig to ensure that your Linux system uses the fonts you want to use. By default, fontconfig may use the bitmap version of a font instead of the scalable version, which can lead to poor font rendering.

Q: How do I configure fontconfig?

A: To configure fontconfig, you need to create a font configuration file and add font filtering rules to specify which fonts should be used for specific applications or use cases.

Q: What is a font configuration file?

A: A font configuration file is a file that contains font configuration settings. You can create a font configuration file in the /etc/fonts directory.

Q: How do I create a font configuration file?

A: To create a font configuration file, you can use a text editor such as nano or vim. Create a new file called fonts.conf in the /etc/fonts directory and add the font configuration settings.

Q: What are font filtering rules?

A: Font filtering rules are used to specify which fonts should be used for specific applications or use cases. You can use font filtering rules to exclude bitmap fonts or to include specific fonts.

Q: How do I add font filtering rules?

A: To add font filtering rules, you need to add a <match> element to the font configuration file. Inside the <match> element, you can specify the font filtering rules using a <test> element.

Q: What is the difference between <test> and <edit> elements?

A: The <test> element is used to specify the font filtering rules, while the <edit> element is used to specify the font configuration settings.

Q: How do I reload fontconfig?

A: To reload fontconfig, you can use the fc-cache -f command.

Q: How do I verify that the changes have taken effect?

A: To verify that the changes have taken effect, you can use the fc-list command to list the fonts on your system.

Q: Can I use fontconfig to create font aliases?

A: Yes, you can use fontconfig to create font aliases. A font alias is a mapping of one font to another.

Q: How do I create a font alias?

A: To create a font alias, you need to add a <alias> element to the font configuration file. Inside the <alias> element, you can specify the font alias.

Q: Can I use fontconfig to specify custom font paths?

A: Yes, you can use fontconfig to specify custom font paths. You can add a <dir> element to the font configuration file to specify the font path.

Q: How do I specify a custom font path?

A: To specify a custom font path, you need to add a <dir> element to the font configuration file. Inside the <dir> element, you can specify the font path.

Conclusion

In this article, we have answered some of the most frequently asked questions about fontconfig. We hope that this article has provided you with a better understanding of fontconfig and how to use it effectively.