A pixel-font rendering system for Unity (uGUI).
Texpix draws pixel fonts the way they were drawn — one font pixel, one screen block, never blurred, never half-covered. It replaces TextMesh Pro for pixel-art UI instead of fighting it into shape.
TextMesh Pro is built around SDF (signed distance field) text, which is designed to stay smooth at any size. Pixel fonts want the exact opposite.
- Pixel-perfect by default. No SDF, no anti-aliasing, no sampling settings to tune. Glyphs are rasterized once at the font's native pixel size and drawn with nearest-neighbor filtering, snapped to the pixel grid. Set the font's pixel size and an integer scale, and it just looks right — at any zoom level.
- Outlines that actually work. 4-neighbor and 8-neighbor pixel outlines — the classic 1px game-UI look — are a single dropdown. TMP's dilate-based outline is a distance-field effect and cannot produce a clean 1px neighbor outline. In Texpix, the outline costs no extra texture, no extra draw call, and no extra pass: it is already encoded in the atlas.
- Cheap atlases. Each glyph pixel needs only 4 states, so 4 font pixels are packed into one byte of an R8 texture. That's roughly 1/8 the memory of an equivalent RGBA atlas — and it holds the outline data too. Don't need outlines? Switch the font asset to Fill Only and it drops to 1 bit per pixel, 8 to a byte.
Use TMP for body text and free scaling. Use Texpix when the font is the art.
- Unity 6000.3 or newer
- uGUI (Canvas). UI Toolkit is not supported.
Package Manager → Add package from git URL…:
https://github.com/ruccho/Texpix.git?path=Packages/com.ruccho.texpix#release
- Import a pixel-font TTF into your project.
- Assets → Create → Texpix → Font Asset. Assign the TTF to Source Font, and set Pixel Size to the font's native size — the size at which the font was designed. Getting this number right is the whole trick; a wrong value is what makes pixel fonts look mushy.
- In a Canvas, GameObject → UI → Texpix Text.
- Assign the font asset, type your text, and set Pixel Scale to how many canvas units one font pixel should occupy. Use an integer (1, 2, 3, …).
That's it — the atlas is built on demand, so there is nothing to bake while you are iterating.
| Setting | What it does |
|---|---|
| Font | The TexpixFontAsset to render with. |
| Text | The string to display. Supports \n. |
| Pixel Scale | Canvas units per font pixel. Integers keep pixels square and sharp. |
| Horizontal / Vertical Alignment | Left / Center / Right × Top / Middle / Bottom (9-way). |
| Wrap Mode | NoWrap, or Wrap — word wrap for spaced text, per-character wrap for CJK with basic kinsoku (line-start/line-end prohibited characters). |
| Overflow | Overflow (draw past the rect), Truncate (drop what doesn't fit), Ellipsis (trim and append …). |
| Letter Spacing | Extra spacing between characters/sprites in font pixels; may be negative. Participates in wrapping and alignment like kerning. |
| Line Spacing | Added to the font's line height in font pixels; may be negative. |
| Snap To Pixel Grid | Rounds the layout origin to a multiple of Pixel Scale so glyph texels stay 1:1. Leave on. |
| Rich Text | Enables the tag set below. |
| Sprite Asset | TexpixSpriteAsset used by <sprite> tags. |
| Outline Mode | None, FourNeighbor, EightNeighbor. |
| Outline Color | Color of the outline pixels. |
The component is a MaskableGraphic, so Mask and RectMask2D work as usual.
A deliberately small tag set:
<color=#RRGGBB>/<color=red>…</color>(nestable)<sprite=name>/<sprite index=0>, withtint=1to tint by the current color<noparse>…</noparse><br>
Unknown tags are rendered literally rather than swallowed.
| Setting | What it does |
|---|---|
| Source Font | The TTF/OTF to rasterize. |
| Pixel Size | The font's native design size, in pixels. |
| Atlas Format | Outline (2 bits per font pixel, outline classes included) or Fill Only (1 bit per font pixel, roughly half the atlas memory — text using the font cannot draw an outline). |
| Atlas Mode | Dynamic (glyphs added on demand) or Static (baked in the editor). |
| Fallback Fonts | Other font assets searched, in order, for glyphs this font lacks. Chains are flattened depth-first and cycles are ignored. |
| Atlas Width / Max Height | Size bounds of the dynamic atlas. It starts small and doubles in height as needed. |
| Bake Character Set | Characters written into the static atlas by Bake. |
The inspector has Bake / Clear buttons and an atlas preview. Baking serializes the glyph table, kerning pairs, metrics, and the atlas texture as a sub-asset, and switches the asset to Static.
Assets → Create → Texpix → Sprite Asset: an RGBA texture plus named entries (pixel rect, bearing, advance). If the texture is imported with Sprite Mode Multiple, Import Entries From Texture Sprites fills the table for you. Inline sprites sit on the baseline and participate in layout and wrapping.
Runtime/Shaders/Texpix.hlsl is a public include exposing the atlas decode API (TexpixAtlasUV, TexpixSubPixel, TexpixExtractLevel, TexpixUnpackOutline, TexpixShade). Import the Custom Shader sample from Package Manager for a working example (hue-cycling fill with the full UI stencil/clip boilerplate). Vertices carry atlas font-pixel coordinates in uv0.xy and the packed outline color/mode plus atlas format in uv0.zw. Assign your material to the component's standard material slot; fallback sub-renderers inherit it.
The atlas is 2 bits per font pixel. When a glyph is rasterized, each of its pixels is classified into one of four levels: fill, 4-neighbor outline, diagonal-only outline, or outside — computed once, at ingest time, from a 1-pixel padding ring around the bitmap. Four such pixels are packed into one byte of an R8 texture.
The outline is a shader switch. Because both outline classes are already in the atlas, Outline Mode only changes which levels the shader treats as opaque: None draws level 3, FourNeighbor adds level 2, EightNeighbor adds level 1. No second pass, no dilation, no extra texture.
…and 1 bit if you opt out. A font asset set to Fill Only stores a single bit per font pixel — 8 to a byte — with no classification pass and no padding ring, which is about 40–55 % less atlas texture depending on the pixel size. The format is per font asset, travels to the shader in the vertex stream (so batching is unaffected), and is frozen into static assets at bake time. It is a rendering-time no-op otherwise: fill-only pixels decode to the same fill level, and Outline Mode simply has nothing to draw.
Vertices carry font-pixel coordinates. Quad UVs are integer atlas font-pixel positions, not normalized UVs; the shader decodes the sub-pixel within the texel itself. Layout likewise runs entirely in integer font-pixel space and is scaled by Pixel Scale at mesh build, which is why the result is exact rather than approximately aligned.
Glyphs come from Unity's FontEngine. Dynamic assets rasterize on demand (RASTER mode, thresholded to binary) and pack into a fixed cell grid with O(1) allocation. Static assets carry a baked glyph table and atlas and never touch FontEngine at runtime.
- Bake a static atlas for shipping. Static mode removes runtime rasterization, the FontEngine dependency, and any first-frame hitch when new text appears. Dynamic mode is for iteration; static is for release — unless the content is genuinely unbounded (user names, chat, localized text you don't know upfront).
- Size
Atlas Max Heightfor your working set. When a dynamic atlas fills up it is cleared and rebuilt, not evicted per glyph — cheap and predictable, but it costs a one-frame artifact and logs a warning. Seeing that warning repeatedly means the atlas is too small for the glyphs on screen at once. - Keep the fallback chain short. Each fallback font that actually contributes glyphs to a text adds a child renderer with its own atlas texture — that is an extra draw call per fallback, per text. Put the characters you use most in the primary font. The same applies to inline sprites: they draw from the sprite texture, in one extra renderer.
- Components batch by font, not by style. Outline color and mode travel in the vertex stream, so every
Texpix Texton the default material shares one material instance and uGUI batches them regardless of their outline settings. What still splits a batch is a different atlas texture: a different font asset, a fallback renderer, or an inline-sprite renderer. Assigning a custom material to some components splits them off as well. - Keep Pixel Scale an integer and let the canvas be pixel-perfect. Fractional scale, a non-integer canvas scale factor, or a rotated/scaled parent will reintroduce sampling error that no amount of snapping can fix.
- Changing
Textre-runs layout. The layout pass is integer-only and allocation-light, but it is still O(characters). Avoid rewriting long strings every frame; split volatile parts (counters, timers) into their own small components. - Atlas growth is deferred, not free. When a dynamic atlas doubles, its texture is recreated and every text using it refreshes on the next canvas update (one frame late). This is rare and self-correcting, but it is another reason to bake before shipping.
- uGUI only — no UI Toolkit, no TextMeshPro drop-in replacement.
- No justified alignment or line-height multiplier.
- One sprite asset per text component; sprite quads always draw above glyphs.
- Kerning never applies across a font-fallback boundary.
- Static atlases are not trimmed to content height.
MIT