Core API >=26.1

AnvilLibFont

Main mod class, @Mod entry point. Client-side only (Dist.CLIENT), modid "anvillib_font".

@Mod(value = "anvillib_font", dist = Dist.CLIENT)
public class AnvilLibFont {
    // Get the currently configured AWT Font
    public static Font getSelectFont();
}

getSelectFont() reads the user-selected font family and font name from AnvilLibFontConfig and resolves it to an AWT java.awt.Font instance via FontManager.

ALFont

Wrapper around java.awt.Font providing text measurement and layout utilities. Internally delegates to SdfGlyphAtlas for glyph metrics.

ALFont alf = new ALFont(AnvilLibFont.getSelectFont());

// Text width measurement
int w = alf.width("Hello World");
int w2 = alf.width(Component.literal("Hello"));

// Substring by pixel width (forward/reverse)
String head = alf.plainSubstrByWidth("Hello World", 50);
String tail = alf.plainSubstrByWidth("Hello World", 50, true);

// Word wrapping
List<FormattedCharSequence> lines = alf.split(FormattedText.of(text), 200);
int totalHeight = alf.wordWrapHeight(FormattedText.of(text), 200);

// Underlying AWT font
Font awt = alf.awtFont();

Method	Description
alf.font()	Returns the wrapped AWT Font
width(String) / width(FormattedText) / width(FormattedCharSequence)	Text pixel width
plainSubstrByWidth(str, maxW)	Forward substring by width
plainSubstrByWidth(str, maxW, true)	Reverse substring by width
split(FormattedText, maxW)	Word-wrap line splitting
wordWrapHeight(FormattedText, maxW)	Total height after wrapping

System font discovery and management singleton.

public class FontManager {
    // Get the singleton instance
    public static FontManager getInstance();

    // Create a Font by name (default 16px)
    public Font getFont(@Nullable String name);

    // Create a Font by name and size
    public Font getFont(String name, float size);

    // Get all font family names
    public String[] getFamilyNames();

    // Get all font names within a given family
    public String[] getFamilyFontNames(String familyName);
}

Internal Mechanisms

• Discovers all system fonts via AWT GraphicsEnvironment.getLocalGraphicsEnvironment().getAvailableFontFamilyNames()
• Builds a font family Trie (FontTrie) for efficient family name grouping and prefix lookup
• getFont(String name) returns a 16px Font.PLAIN font, falls back to a default font if the name is not found

AnvilLibFontConfig

JSON configuration file manager. Config file path: config/anvillib/anvillib-font-client.json.

public class AnvilLibFontConfig {
    public String fontFamily; // Selected font family
    public String font;       // Selected font name

    // Read config from file
    public static AnvilLibFontConfig read();

    // Write config to file
    public void write();
}

Uses Gson for JSON serialization/deserialization. read() returns a default config when the file does not exist.

SdfTextRenderer

Main SDF text renderer supporting multiple draw modes.

public class SdfTextRenderer {
    // Draw plain text string
    public void drawString(
        GuiGraphicsExtractor graphics,
        Font font,
        String text,
        float x, float y,
        int color,
        boolean dropShadow
    );

    // Draw formatted text sequence
    public void drawFormatted(
        GuiGraphicsExtractor graphics,
        Font font,
        FormattedCharSequence text,
        float x, float y,
        int color,
        boolean dropShadow
    );

    // Draw a Component (auto-resolves styles)
    public void drawComponent(GuiGraphics graphics, Component component);

    // Draw a centered Component
    public void drawCentered(GuiGraphics graphics, Component component);

    // Draw formatted text with word wrap
    public void drawWrapped(
        GuiGraphics graphics,
        FormattedText text,
        int width
    );
}

Style Support

The renderer supports the following text styles, automatically applied in drawFormatted and drawComponent:

Style	Effect
Bold	Renders text with increased weight
Italic	Renders text with slant
Underline	Draws a line below the text
Strikethrough	Draws a line through the text
Obfuscated	Random character replacement animation

SdfGlyphAtlas

CPU-side multi-page SDF glyph atlas, responsible for glyph rasterization and SDF computation.

public class SdfGlyphAtlas {
    // Get or create atlas (cached by font name + style + size)
    public static SdfGlyphAtlas getAtlas(Font font);

    // Atlas page size (1024x1024 per page)
    public static final int PAGE_SIZE = 1024;

    // Get glyph info for a codepoint (includes UV coordinates and page index)
    public GlyphInfo getGlyph(int codePoint);

    // Get current page count
    public int getPageCount();
}

Internal Mechanisms

• Pre-warms glyphs in the ASCII 32-126 range (space through tilde)
• Other codepoints are lazy-rendered on demand
• Uses the Dead Reckoning EDT (Euclidean Distance Transform) algorithm for SDF field computation
• Static cache: atlases with the same font name + style + size reuse a static cache

SdfTextLayout

CPU-side glyph layout engine that computes glyph positions and groups them by atlas page.

public class SdfTextLayout {
    // Layout text and return quad data grouped by atlas page
    public static PageQuads layout(
        Font font,
        CharSequence text,
        float x, float y,
        Style style
    );

    // PageQuads contains glyph quad lists with UV coordinates per atlas page
    public static class PageQuads {
        public int pageIndex;
        public List<GlyphQuad> quads;
    }
}

Layout automatically handles kerning and line height.

SdfAtlasTexture

Uploads SdfGlyphAtlas CPU-side data to GPU textures.

public class SdfAtlasTexture {
    // Upload an atlas page to GPU (RED8 format, LINEAR filter, CLAMP wrap)
    public void upload(int pageIndex, SdfGlyphAtlas atlas);

    // Get the GPU texture handle
    public Texture getTexture(int pageIndex);
}

Texture format is RED8 (single channel, 8 bits), using LINEAR filtering for smooth scaling and CLAMP wrapping to prevent edge bleeding.

SdfTextRenderState

Implements LibGuiElementRenderState, building GPU render state for SDF text rendering.

public class SdfTextRenderState implements LibGuiElementRenderState {
    // Build vertex buffer from glyph quad data
    public void buildVertices(PageQuads quads, int color);

    // Submit rendering via ALFPipelines.SDF_TEXT pipeline
    @Override
    public void render();
}

GUI Extension Methods

Injected into Minecraft's GuiGraphics via the GuiGraphicsExtractorExtension interface and GuiGraphicsExtractorMixin Mixin.

public interface GuiGraphicsExtractorExtension {
    // Draw text
    void anvillib$text(Font font, String text, float x, float y, int color);

    // Draw text with drop shadow
    void anvillib$text(Font font, String text, float x, float y, int color, boolean dropShadow);

    // Draw centered text (Component)
    void anvillib$centeredText(Font font, Component component, int x, int y, int color);

    // Draw text with word wrap
    void anvillib$textWithWordWrap(Font font, FormattedText text, int x, int y, int width, int color);

    // Draw text with backdrop color outline
    void anvillib$textWithBackdrop(Font font, String text, int x, int y, int color, int backdropColor);
}

All extension methods use the anvillib$ prefix and require an AWT java.awt.Font parameter.

Screens

FontConfigScreen

Configuration screen allowing users to select a font family and specific font.

• Font family dropdown: Lists all available font families (via FontManager.getFamilyNames())
• Font dropdown: Lists all fonts within the selected family (via FontManager.getFamilyFontNames())
• Test button: Opens FontTestScreen to preview the currently selected font

FontTestScreen

Font testing screen showing sample text rendered in various styles and multiple languages with the selected font.

Dropdown

Custom dropdown widget with the following features:

• Scrollbar support for large option lists
• Auto-close on outside click (shielding)
• Accessibility narration support

ALFPipelines

Vulkan/OpenGL pipeline definition for SDF text rendering.

public class ALFPipelines {
    // SDF_TEXT pipeline config:
    // - Vertex format: QUADS
    // - Blend mode: TRANSLUCENT
    // - Uniforms: DynamicTransforms + Projection
    // - Sampler: DiffuseSampler
    // - Face culling: None (NO_CULL)
    public static final RenderingPipeline SDF_TEXT;
}

AnvilLibFontData

Data generation class responsible for generating the en_us.json language file.

@DataGen
public class AnvilLibFontData {
    // Generate en_us.json translation file
}