Embers Text API

2.9.0

Added

• MSDF font rendering — Complete rewrite of the SDF font rendering pipeline from single-channel EDT (Euclidean Distance Transform) to Multi-Channel Signed Distance Fields (MSDF). Eliminates stray pixel artifacts and rounded corners that plagued the old approach. Key improvements:
  • Analytical Bézier distance computation — Distance to glyph edges is computed directly from vector outlines using Newton-Raphson refinement on quadratic and cubic Bézier curves, replacing the old bitmap→EDT approximation pipeline.
  • Multi-channel encoding — Distance information is encoded in three color channels (RGB) with edge coloring, enabling the shader to reconstruct sharp corners that monochrome SDF fundamentally cannot represent.
  • Cross-product sign determination — Inside/outside is determined by the cross product of the curve tangent at the closest point, eliminating winding-number ray casting errors.
  • Pseudo-distance — Uses perpendicular distance to the tangent line at the closest point instead of true Euclidean distance, preventing "bleeding" around segment endpoints.
  • Error correction — Post-generation pass detects and corrects false-color artifacts at edge intersection points.
  • Degenerate segment filtering — Tiny segments produced by bold fonts at stroke junctions are filtered out during outline extraction.
• New bundled MSDF fonts — Almendra, Almendra Bold, Cardo, Cardo Bold, Cinzel, Cinzel Bold, Norse, Norse Bold (in addition to existing Metamorphous).
• Font alias system — FontAliasRegistry maps short names to full ResourceLocations, so markup can use <font name=cinzel> instead of <font id=emberstextapi:cinzel>. All bundled fonts have aliases registered at mod init.
• New MSDF configuration options in font JSON:
  • px_range (default 8.0) — Pixel range controlling anti-aliasing width. Replaces the deprecated spread parameter.
  • angle_threshold (default 3.0 radians) — Corner detection threshold for edge coloring. Lower values detect more corners for sharper reproduction.
• Configurable anvil rename length — New anvilNameMaxLength config option (default 50) allows servers to increase the character limit when renaming items in an anvil. Three mixins (AnvilMenuMixin, AnvilRenameMixin, AnvilScreenMixin) patch the vanilla hardcoded limit.
• Server-side message limits — ServerMessageLimiter enforces configurable limits on messages sent to clients: maxServerMessageDuration, maxServerActiveMessages, maxQueueSize, and allowedEffects.
• Reduce motion support — New reduceMotion config option disables motion-based effects (wave, shake, bounce, etc.) for accessibility. isEffectDisabled() now checks both the explicit disable list and the reduce-motion flag.
• SDF debug texture dump — Launch with -Deta.sdf.debug=true to dump each MSDF glyph texture as an RGB PNG to debug-sdf/ in the game directory.
• Emojiful compatibility layer — ETA effects now work alongside Emojiful's emoji rendering. Regular characters get full effects while emoji sprites render normally through Emojiful's pipeline.
• EffectApplicator utility class — Shared effect-application logic extracted from StringRenderOutputMixin.

Fixed

• SDF text fringe on MC 1.20.1 — Fixed a visible anti-aliasing halo around MSDF-rendered text on all 1.20.1 loaders. MC 1.20.1's blit-to-screen reads framebuffer alpha, so semi-transparent SDF edge fragments caused a fringe artifact. Fixed by defining alpha-preserving blend state (srcalpha=0, dstalpha=1) in the shader JSON, which is applied inside ShaderInstance.apply() immediately before the draw call.

Changed

• Fragment shaders rewritten for MSDF — rendertype_eta_sdf_text.fsh and rendertype_eta_sdf_text_see_through.fsh now sample all three RGB channels and take the median for distance reconstruction, with fwidth-based screen-space anti-aliasing and alpha squaring for edge sharpening.
• Font JSON files updated — All bundled font definitions now use px_range and angle_threshold instead of the deprecated spread field. Old spread values are still accepted for backward compatibility (px_range = spread × 2).
• Emojiful is no longer declared as incompatible. The previous hard block has been replaced with automatic compatibility mode detection.

Removed

• SDFGenerator.java — Old single-channel SDF generator using bitmap→EDT pipeline. Replaced by MSDFGenerator.java.
• Bitmap rendering path in FreeTypeManager — renderGlyphSDF(), computeSDFFromBitmap(), and all EDT code removed. Only outline extraction via FT_Outline_Decompose remains.
• FT_Set_Pixel_Sizes and FT_Render_Glyph from NativeFreeType (1.20.1) — No longer needed since bitmap rendering was eliminated.

Internal

• New class MSDFGenerator — Analytical distance computation engine with 3-channel MSDF texture generation, error correction, and pseudo-distance support.
• New class EdgeColoring — Chlumsky's simple edge coloring heuristic with corner detection and CYAN/MAGENTA/YELLOW color cycling.
• SDFConfig record extended with pxRange and angleThreshold fields, backward-compatible constructor mapping spread → pxRange.
• SDFGlyphInfo.bake() rewired to: extract outline → edge color → generate MSDF → upload 3-channel data.
• SDFSheetGlyphInfo.upload() now writes independent R, G, B channels to the RGBA atlas instead of duplicating a monochrome value.
• MC 1.20.1 SDF shader JSONs now include a blend section with alpha-preserving factors; SDFRenderTypes.java uses standard TRANSLUCENT_TRANSPARENCY on both versions.
• New SDF pipeline mixins: FontManagerMixin, FontSetMixin (1.21.1), FontTextureMixin, GlyphRenderTypesMixin, BakedGlyphAccessor.
• 40 unit tests across 3 test classes: MSDFGeneratorTest (20), EdgeColoringTest (13), MSDFGenerationTest (7).
• Added @Pseudo mixin EmojiCharacterRendererMixin for Emojiful compatibility with require = 0 for graceful absence.
• Refactored StringRenderOutputMixin to delegate effect building, application, and character rendering to EffectApplicator.