The code in imgui.cpp embeds a copy of 'ProggyClean.ttf' (by Tristan Grimmer),
a 13 pixels high, pixel-perfect font used by default. We embed it in the source code so you can use Dear ImGui without any file system access. ProggyClean does not scale smoothly, therefore it is recommended that you load your own file when using Dear ImGui in an application aiming to look nice and wanting to support multiple resolutions.
- All loaded fonts glyphs are rendered into a single texture atlas ahead of time. Calling either of `io.Fonts->GetTexDataAsAlpha8()`, `io.Fonts->GetTexDataAsRGBA32()` or `io.Fonts->Build()` will build the atlas.
- You can use the style editor `ImGui::ShowStyleEditor()` in the "Fonts" section to browse your fonts and understand what's going on if you have an issue. You can also reach it in `Demo->Tools->Style Editor->Fonts`:
If you get an assert stating "Could not load font file!", your font filename is likely incorrect. Read "[About filenames](#about-filenames)" carefully.
- If you have very large number of glyphs or multiple fonts, the texture may become too big for your graphics API. The typical result of failing to upload a texture is if every glyphs appears as white rectangles.
- Mind the fact that some graphics drivers have texture size limitation. If you are building a PC application, mind the fact that your users may use hardware with lower limitations than yours.
You can use the `ImFontGlyphRangesBuilder` for this purpose and rebuilding your atlas between frames when new characters are needed. This will be the biggest win!
6. To support the extended range of unicode beyond 0xFFFF (e.g. emoticons, dingbats, symbols, shapes, ancient languages, etc...) add `#define IMGUI_USE_WCHAR32`in your `imconfig.h`.
Using an icon font (such as [FontAwesome](http://fontawesome.io) or [OpenFontIcons](https://github.com/traverseda/OpenFontIcons)) is an easy and practical way to use icons in your Dear ImGui application.
A common pattern is to merge the icon font within your main font, so you can embed icons directly from your strings without having to change fonts back and forth.
To refer to the icon UTF-8 codepoints from your C++ code, you may use those headers files created by Juliette Foucaut: https://github.com/juliettef/IconFontCppHeaders.
So you can use `ICON_FA_SEARCH` as a string that will render as a "Search" icon.
- Dear ImGui uses imstb\_truetype.h to rasterize fonts (with optional oversampling). This technique and its implementation are not ideal for fonts rendered at small sizes, which may appear a little blurry or hard to read.
- There is an implementation of the ImFontAtlas builder using FreeType that you can use in the [misc/freetype/](https://github.com/ocornut/imgui/tree/master/misc/freetype) folder.
You can use the `ImFontGlyphRangesBuilder` helper to create glyph ranges based on text input. For example: for a game where your script is known, if you can feed your entire script to it and only build the characters the game needs.
- You can use the `ImFontAtlas::AddCustomRect()` and `ImFontAtlas::AddCustomRectFontGlyph()` api to register rectangles that will be packed into the font atlas texture. Register them before building the atlas, then call Build()`.
- You can then use `ImFontAtlas::GetCustomRectByIndex(int)` to query the position/size of your rectangle within the texture, and blit/copy any graphics data of your choice into those rectangles.
- This API is beta because it is likely to change in order to support multi-dpi (multiple viewports on multiple monitors with varying DPI scale).
- Compile and use [binary_to_compressed_c.cpp](https://github.com/ocornut/imgui/blob/master/misc/fonts/binary_to_compressed_c.cpp) to create a compressed C style array that you can embed in source code.
- See the documentation in [binary_to_compressed_c.cpp](https://github.com/ocornut/imgui/blob/master/misc/fonts/binary_to_compressed_c.cpp) for instruction on how to use the tool.
- You may find a precompiled version binary_to_compressed_c.exe for Windows instead of demo binaries package (see [README](https://github.com/ocornut/imgui/blob/master/docs/README.md)).
- The tool can optionally output Base85 encoding to reduce the size of _source code_ but the read-only arrays in the actual binary will be about 20% bigger.
**Please note that many new C/C++ users have issues their files _because the filename they provide is wrong_.**
Two things to watch for:
- Make sure your IDE/debugger settings starts your executable from the right working directory. In Visual Studio you can change your working directory in project `Properties > General > Debugging > Working Directory`. People assume that their execution will start from the root folder of the project, where by default it oftens start from the folder where object or executable files are stored.
```cpp
// Relative filename depends on your Working Directory when running your program!
- In C/C++ and most programming languages if you want to use a backslash `\` within a string literal, you need to write it double backslash `\\`. At it happens, Windows uses backslashes as a path separator, so be mindful.
```cpp
io.Fonts->AddFontFromFileTTF("MyFiles\MyImage01.jpg", ...); // This is INCORRECT!!
io.Fonts->AddFontFromFileTTF("MyFiles\\MyImage01.jpg", ...); // This is CORRECT
```
In some situations, you may also use `/` path separator under Windows.
##### [Return to Index](#index)
## Credits/Licenses For Fonts Included In Repository
Some fonts files are available in the `misc/fonts/` folder:
- Proggy Fonts, by Tristan Grimmer http://www.proggyfonts.net or http://upperbounds.net
- Sweet16, Sweet16 Mono, by Martin Sedlak (Latin + Supplemental + Extended A) https://github.com/kmar/Sweet16Font (also include an .inl file to use directly in dear imgui.)
