imgui/misc/fonts

The code in imgui.cpp embeds a copy of 'ProggyClean.ttf' (by Tristan Grimmer) that is used by default.
We embed the font in source code so you can use Dear ImGui without any file system access.
You may also load external .TTF/.OTF files. 
The files in this folder are suggested fonts, provided as a convenience.
(Note: .OTF support in stb_truetype.h currently doesn't appear to load every font)

Fonts are rasterized in a single texture at the time of calling either of io.Fonts->GetTexDataAsAlpha8()/GetTexDataAsRGBA32()/Build().
Also read dear imgui FAQ in imgui.cpp!

In this document:

- Readme First / FAQ
- Using Icons
- Fonts Loading Instructions
- FreeType rasterizer, Small font sizes
- Building Custom Glyph Ranges
- Remapping Codepoints
- Embedding Fonts in Source Code
- Credits/Licences for fonts included in this folder
- Links, Other fonts


---------------------------------------
 README FIRST / FAQ
---------------------------------------

 - You can use the style editor ImGui::ShowStyleEditor() to browse your fonts and understand what's going on if you have an issue.
 - Make sure your font ranges data are persistent (available during the call to GetTexDataAsAlpha8()/GetTexDataAsRGBA32()/Build().
 - Use C++11 u8"my text" syntax to encode literal strings as UTF-8. 
 - If you want to include a backslash \ character in your string literal, you need to double them e.g. "folder\\filename".


---------------------------------------
 USING ICONS
---------------------------------------

 Using an icon font (such as FontAwesome: http://fontawesome.io) is an easy and practical way to use icons in your 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

 The C++11 version of those files uses the u8"" utf-8 encoding syntax + \u
   #define ICON_FA_SEARCH  u8"\uf002"
 The pre-C++11 version has the values directly encoded as utf-8:
   #define ICON_FA_SEARCH  "\xEF\x80\x82"

 Example:

    // Merge icons into default tool font
   #include "IconsFontAwesome.h"
   ImGuiIO& io = ImGui::GetIO();
   io.Fonts->AddFontDefault();

   ImFontConfig config;
   config.MergeMode = true;
   static const ImWchar icon_ranges[] = { ICON_MIN_FA, ICON_MAX_FA, 0 };
   io.Fonts->AddFontFromFileTTF("fonts/fontawesome-webfont.ttf", 13.0f, &config, icon_ranges);

   // Usage, e.g.
   ImGui::Button(ICON_FA_SEARCH " Search");                     // C string literals can be concatenated at compilation time, this is the same as "A" "B" becoming "AB"
   ImGui::Text("%s among %d items", ICON_FA_SEARCH, count);
   
 See Links below for other icons fonts and related tools.


---------------------------------------
 FONTS LOADING INSTRUCTIONS
---------------------------------------

 Load default font:

   ImGuiIO& io = ImGui::GetIO();
   io.Fonts->AddFontDefault();

 Load .TTF/.OTF file with:

   ImGuiIO& io = ImGui::GetIO();
   ImFont* font1 = io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels);
   ImFont* font2 = io.Fonts->AddFontFromFileTTF("anotherfont.otf", size_pixels);
  
   // Select font at runtime
   ImGui::Text("Hello");	// use the default font (which is the first loaded font)
   ImGui::PushFont(font2);
   ImGui::Text("Hello with another font");
   ImGui::PopFont();

 For advanced options create a ImFontConfig structure and pass it to the AddFont function (it will be copied internally):

   ImFontConfig config;
   config.OversampleH = 3;
   config.OversampleV = 1;
   config.GlyphExtraSpacing.x = 1.0f;
   ImFont* font = io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels, &config);

 If you have very large number of glyphs or multiple fonts:

  - Mind the fact that some graphics drivers have texture size limitation.
  - Set io.Fonts.TexDesiredWidth to specify a texture width to minimize texture height (see comment in ImFontAtlas::Build function).
  - Set io.Fonts.Flags |= ImFontAtlasFlags_NoPowerOfTwoHeight; to disable rounding the texture height to the next power of two.
  - You may reduce oversampling, e.g. config.OversampleH = 1, this will largely reduce your textue size.
  - Reduce glyphs ranges, consider calculating them based on your source data if this is possible.

 Combine two fonts into one:

   // Load a first font
   ImFont* font = io.Fonts->AddFontDefault();

   // Add character ranges and merge into the previous font
   // The ranges array is not copied by the AddFont* functions and is used lazily
   // so ensure it is available for duration of font usage
   static const ImWchar icons_ranges[] = { 0xf000, 0xf3ff, 0 }; // will not be copied by AddFont* so keep in scope.
   ImFontConfig config;
   config.MergeMode = true;
   io.Fonts->AddFontFromFileTTF("DroidSans.ttf", 18.0f, &config, io.Fonts->GetGlyphRangesJapanese());
   io.Fonts->AddFontFromFileTTF("fontawesome-webfont.ttf", 18.0f, &config, icons_ranges);

 Add a fourth parameter to bake specific font ranges only:

   // Basic Latin, Extended Latin
   io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels, NULL, io.Fonts->GetGlyphRangesDefault());
   
   // Include full set of about 21000 CJK Unified Ideographs
   io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels, NULL, io.Fonts->GetGlyphRangesJapanese());
   
   // Default + Hiragana, Katakana, Half-Width, Selection of 1946 Ideographs
   io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels, NULL, io.Fonts->GetGlyphRangesChinese());

 Offset font vertically by altering the io.Font->DisplayOffset value:

   ImFont* font = io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels);
   font->DisplayOffset.y = 1;   // Render 1 pixel down


---------------------------------------
 FREETYPE RASTERIZER, SMALL FONT SIZES
---------------------------------------

 Dear Imgui uses stb_truetype.h to rasterize fonts (with optional oversampling).
 This technique and implementation are not ideal for fonts rendered at _small sizes_, which may appear a little blurry.
 There is an implementation of the ImFontAtlas builder using FreeType that you can use in the misc/freetype/ folder.

 FreeType supports auto-hinting which tends to improve the readability of small fonts.
 Note that this code currently creates textures that are unoptimally too large (could be fixed with some work)


---------------------------------------
 BUILDING CUSTOM GLYPH RANGES
---------------------------------------

 You can use the ImFontAtlas::GlyphRangesBuilder 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. 

   ImVector<ImWchar> ranges;
   ImFontAtlas::GlyphRangesBuilder builder;
   builder.AddText("Hello world");                        // Add a string (here "Hello world" contains 7 unique characters)
   builder.AddChar(0x7262);                               // Add a specific character
   builder.AddRanges(io.Fonts->GetGlyphRangesJapanese()); // Add one of the default ranges
   builder.BuildRanges(&ranges);                          // Build the final result (ordered ranges with all the unique characters submitted)
   io.Fonts->AddFontFromFileTTF("myfontfile.ttf", size_in_pixels, NULL, ranges.Data);


---------------------------------------
 REMAPPING CODEPOINTS
---------------------------------------

 All your strings needs to use UTF-8 encoding. Specifying literal in your source code using a local code page (such as CP-923 for Japanese, or CP-1251 for Cyrillic) will NOT work!
 In C++11 you can encode a string literal in UTF-8 by using the u8"hello" syntax. Otherwise you can convert yourself to UTF-8 or load text data from file already saved as UTF-8.
 e.g.
      u8"hello"
      u8"こんにちは"
 You may also try to remap your local codepage characters to their Unicode codepoint using font->AddRemapChar(), but international users may have problems reading/editing your source code.


---------------------------------------
 EMBEDDING FONTS IN SOURCE CODE
---------------------------------------

 Compile and use '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 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).
 The tool optionally used Base85 encoding to reduce the size of _source code_ but the read-only arrays will be about 20% bigger. 

 Then load the font with:
 
   ImFont* font = io.Fonts->AddFontFromMemoryCompressedTTF(compressed_data, compressed_data_size, size_pixels, ...);
   
 Or 
 
   ImFont* font = io.Fonts->AddFontFromMemoryCompressedBase85TTF(compressed_data_base85, size_pixels, ...);


---------------------------------------
 CREDITS/LICENSES FOR FONTS INCLUDED IN THIS FOLDER
---------------------------------------

 Roboto-Medium.ttf
   Apache License 2.0
   by Christian Robertson
   https://fonts.google.com/specimen/Roboto

 Cousine-Regular.ttf
   by Steve Matteson
   Digitized data copyright (c) 2010 Google Corporation.
   Licensed under the SIL Open Font License, Version 1.1
   https://fonts.google.com/specimen/Cousine 

 DroidSans.ttf
   Copyright (c) Steve Matteson
   Apache License, version 2.0
   https://www.fontsquirrel.com/fonts/droid-sans

 ProggyClean.ttf
   Copyright (c) 2004, 2005 Tristan Grimmer
   MIT License
   recommended loading setting in ImGui: Size = 13.0, DisplayOffset.Y = +1
   http://www.proggyfonts.net/

 ProggyTiny.ttf
   Copyright (c) 2004, 2005 Tristan Grimmer
   MIT License
   recommended loading setting in ImGui: Size = 10.0, DisplayOffset.Y = +1
   http://www.proggyfonts.net/

 Karla-Regular.ttf
   Copyright (c) 2012, Jonathan Pinhorn
   SIL OPEN FONT LICENSE Version 1.1


---------------------------------------
 LINKS, OTHER FONTS
---------------------------------------

 (Icons) Icon fonts
   https://fortawesome.github.io/Font-Awesome/
   https://github.com/SamBrishes/kenney-icon-font
   https://design.google.com/icons/
   You can use https://github.com/juliettef/IconFontCppHeaders for C/C++ header files with name #define to access icon codepoint in source code.

 (Icons) IcoMoon - Custom Icon font builder
   https://icomoon.io/app

 (Regular) Open Sans Fonts
   https://fonts.google.com/specimen/Open+Sans

 (Regular) Google Noto Fonts (worldwide languages)
   https://www.google.com/get/noto/
 
 (Monospace) Typefaces for source code beautification
   https://github.com/chrissimpkins/codeface

 (Monospace) Programmation fonts
   http://s9w.github.io/font_compare/

 (Monospace) Proggy Programming Fonts
   http://upperbounds.net
   
 (Monospace) Inconsolata
   http://www.levien.com/type/myfonts/inconsolata.html

 (Monospace) Adobe Source Code Pro: Monospaced font family for user interface and coding environments
   https://github.com/adobe-fonts/source-code-pro

 (Monospace) Monospace/Fixed Width Programmer's Fonts
   http://www.lowing.org/fonts/

 (Japanese) M+ fonts by Coji Morishita are free and include most useful Kanjis you would need.
   http://mplus-fonts.sourceforge.jp/mplus-outline-fonts/index-en.html

 Or use Arial Unicode or other Unicode fonts provided with Windows for full characters coverage (not sure of their licensing).