Change Font ImGui

To change the font in ImGui library in C++, you can follow these steps:

Step 1: Load the font file

First, you need to load the font file that you want to use in your ImGui application. ImGui supports several font file formats such as TrueType (.ttf) or OpenType (.otf). You can load the font file using the ImFontAtlas class provided by ImGui. The ImFontAtlas class allows you to manage multiple fonts in your application.

Step 2: Add the font to the atlas

After loading the font file, you need to add the font to the font atlas using the AddFontFromFileTTF() or AddFontFromMemoryTTF() function. These functions take the path to the font file or a pointer to the loaded font data, respectively. The functions return an ImFont* pointer that you can use to specify the font in ImGui functions.

Step 3: Set the font in ImGui style

Once you have added the font to the font atlas, you can set it as the default font in the ImGui style. The ImGui style contains various settings that control the appearance of ImGui widgets. You can access the style using the GetStyle() function. To set the font, you need to assign the ImFont* pointer to the FontDefault field of the style.

Step 4: Render ImGui with the new font

Finally, you need to render ImGui with the new font. This can be done by calling the Render() function of the ImFontAtlas class. The Render() function generates the texture data for the fonts added to the atlas. You need to call this function every frame before rendering ImGui.

Here is an example code snippet that demonstrates how to change the font in ImGui:

// Step 1: Load the font file
ImFontAtlas fontAtlas;
ImFont* font = fontAtlas.AddFontFromFileTTF("path/to/font.ttf", 16.0f);

// Step 2: Add the font to the atlas
ImGuiIO& io = ImGui::GetIO();
io.Fonts->AddFontFromFileTTF("path/to/font.ttf", 16.0f);

// Step 3: Set the font in ImGui style
ImGuiStyle& style = ImGui::GetStyle();
style.FontDefault = font;

// Step 4: Render ImGui with the new font

By following these steps, you should be able to change the font used by ImGui in your C++ application.