Dialog font (proportional Latin) Confirmed

At a glance

In the game

The dialog box, pause menu, shop and battle text - every proportional line of Latin text

Where

Glyph sheet: a plain TIM at PROT.DAT file offset 0x7F40 (the unindexed head gap before entry 0), uploaded to VRAM (896, 0). Width table at SCUS 0x80073F1C; escape table at SCUS 0x80074050

Size

256×256 4bpp pixels = 16 × 14 cells of 16×16 (224 glyphs); 256-byte width table; 38 × 4-byte escape entries

Parser

crates/font - Font::from_disc_tim_and_scus, layout API, CLI font-extract

Confidence

Confirmed - tables and packet shape traced in the single-line renderer; the disc TIM byte-matches the save-state VRAM extraction (how we know)

Used by

MES dialog, field menu, save screen, translation packs

Three pieces of data

• The glyph sheet - 4bpp tiles in VRAM at (896, 0)..(960, 256), one 16×16 cell per character byte.
• The width table - 256 bytes in the executable, one advance per character byte.
• The escape table - 38 four-byte entries in the executable, selected by the byte after a 0xCE escape; they splice in names, icons and numbers.

Glyph sheet

The sheet is a 4bpp TIM (4 bits per pixel, 16 colours), 64 halfwords wide × 256 tall = 256×256 pixels, framebuffer destination (896, 0). Cell c for character byte c in 0x20..=0xFF:

U = (c & 0x0F) * 16
V = (c & 0xF0) - 0x20

The drawn region in each cell is 14 × 15 pixels; the remaining 2 × 1 pixels are guard space. Bytes 0x00..=0x1F are control codes and have no glyph. The TIM uses three palette indices: 0 transparent, 14 the (32,32,32) drop shadow, 15 the glyph fill.

The TIM sits in the unindexed head gap of PROT.DAT - after the table of contents, before the first numbered entry - which is why a per-entry walk never sees it. The font is therefore decodable straight from the disc, no save state required.

Palettes

Sixteen 16-colour palettes (CLUTs) sit end-to-end on VRAM row 510 from x = 96, one every 16 pixels. The colour-change escape 0xCF n sets the palette index; the CLUT word in each glyph packet is index + 0x7F86, and 0x7F86 decodes as (96, 510). Palette 0 is the white-on-transparent dialog palette; the others are the coloured variants for status text and system prompts.

Width table

256 bytes indexed by character byte. The advance for c is widths[c] + pad + 1, where pad is a per-string override (normally zero, reset after each render call) and +1 is the fixed inter-character gap. Every byte reaches the advance except the four control bytes; a space takes its advance without emitting a sprite. A line's pixel width is exactly the sum of its per-byte advances, with no per-line term - the save screen's memory-card warning line measures 164 px.

Entries 0x00..=0x1F overlap three short actor-name strings and are not advances. The full table is exported as extracted/font/dialog_font_widths.csv.

Control bytes and escapes

Escape table

Each entry is { i16 string_id; u8 advance_px; i8 y_offset }. A non-zero string_id draws a looked-up string at y + y_offset; a zero string_id formats one of four runtime numbers (HP / MP / gold / exp), with y_offset as the variable index. Authoring-time text writes escapes as ^X; a preprocessor turns them into 0xCE (X - 0x2D).

Rendering pipeline

[0x04 00 00 00]              // OT-list terminator
[0x64 80 80 80]              // cmd 0x64 + RGB shading
[i16 X][i16 Y]               // top-left in screen coords
[u8 U][u8 V][u16 CLUT]       // U,V within texture page; CLUT word
[u16 W=14][u16 H=15]         // sprite size in pixels

Adding accented or non-Latin glyphs

The translation pipeline writes only bytes the retail font can draw - printable ASCII 0x20..=0x7E - so the community language packs are ASCII-folded (e for é, ss for ß). Real accented glyphs are a font patch, needing three things:

1. A free byte slot - not a two-byte opcode (0x5E, 0xC0..=0xCF, 0xFF), not a control byte, not used by any string. Roughly a hundred slots in 0x80..=0xFF are free.
2. A glyph bitmap - a 14×15 drawing in the cell: a same-size in-place edit of the head-gap TIM through the TIM encoder.
3. A width entry - a one-byte poke into the executable's width table.

Accented Latin (~35 code points) and Cyrillic (~66) both fit. CJK does not: thousands of glyphs exceed the 224-cell sheet and the byte index space, and would need a second glyph bank plus a multi-byte encoding in the renderer.

How we know

Field dialogue has no dedicated opcode: an NPC's text is its inline interaction-script MES, shown by the per-frame actor-dialog state machine and the dialog pager, triggered by the field-interact op - see field script VM.

Deep dive

cargo run -p legaia-font --bin font-extract -- \
    --scus extracted/SCUS_942.54 \
    --save "$HOME/.mednafen/mcs/Legend of Legaia (USA).<hash>.mcN" \
    --out extracted/font

Source of record: docs/formats/dialog-font.md.

See also