BCFNT

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CTR Font Format[edit]

.bcfnt files are bitmap fonts made for the 3ds. The system font uses this format too except the header is changed from CFNT to CFNU and all file offsets are changed to absolute in memory offsets.

CFNT Header[edit]

Offset Size Description
0x00 0x04 Magic Header (either CFNT or CFNU or FFNT)
0x04 0x02 Endianness (0xFEFF = little, 0xFFFE = big)
0x06 0x02 Header Size
0x08 0x04 Version (observed to be 0x03000000)
0x0C 0x04 File size (the total)
0x10 0x04 Number of "blocks" to read

FINF Header[edit]

Version 3 (BCFNT)[edit]

Offset Size Description
0x00 0x04 Magic Header (FINF)
0x04 0x04 Section Size
0x08 0x01 Font Type
0x09 0x01 Line Feed
0x0A 0x02 Alter Char Index
0x0C 0x03 Default Width (3 bytes: Left, Glyph Width, Char Width)
0x0F 0x01 Encoding
0x10 0x04 TGLP Offset
0x14 0x04 CWDH Offset
0x18 0x04 CMAP Offset
0x1C 0x01 Height
0x1D 0x01 Width
0x1E 0x01 Ascent
0x1F 0x01 Reserved

Version 4 (BFFNT)[edit]

Offset Size Description
0x00 0x04 Magic Header (FINF)
0x04 0x04 Section Size
0x08 0x01 Font Type
0x09 0x01 Height
0x0A 0x01 Width
0x0B 0x01 Ascent
0x0C 0x02 Line Feed
0x0E 0x02 Alter Char Index
0x10 0x03 Default Width (3 bytes: Left, Glyph Width, Char Width)
0x13 0x01 Encoding
0x14 0x04 TGLP Offset
0x18 0x04 CWDH Offset
0x1C 0x04 CMAP Offset

TGLP Header[edit]

Version 3 (BCFNT)[edit]

Offset Size Description
0x00 0x04 Magic Header (TGLP)
0x04 0x04 Section Size
0x08 0x01 Cell Width
0x09 0x01 Cell Height
0x0A 0x01 Baseline Position
0x0B 0x01 Max Character Width
0x0C 0x04 Sheet Size
0x10 0x02 Number of Sheets
0x12 0x02 Sheet Image Format 0-13: (RGBA8, RGB8, RGBA5551, RGB565, RGBA4, LA8, HILO8, L8, A8, LA4, L4, A4, ETC1, ETC1A4)
0x14 0x02 Number of columns
0x16 0x02 Number of rows
0x18 0x02 Sheet Width
0x1A 0x02 Sheet Height
0x1C 0x04 Sheet Data Offset

Version 4 (BFFNT)[edit]

Offset Size Description
0x00 0x04 Magic Header (TGLP)
0x04 0x04 Section Size
0x08 0x01 Cell Width
0x09 0x01 Cell Height
0x0A 0x01 Number of Sheets
0x0B 0x01 Max Character Width
0x0C 0x04 Sheet Size
0x10 0x02 Baseline Position
0x12 0x02 Sheet Image Format 0-13: (RGBA8, RGB8, RGBA5551, RGB565, RGBA4, LA8, HILO8, L8, A8, LA4, L4, A4, ETC1, ETC1A4)
0x14 0x02 Number of Sheet columns
0x16 0x02 Number of Sheet rows
0x18 0x02 Sheet Width
0x1A 0x02 Sheet Height
0x1C 0x04 Sheet Data Offset

CMAP Header[edit]

Offset Size Description
0x00 0x04 Magic Header (CMAP)
0x04 0x04 Section Size
0x08 0x02 Code Begin
0x0A 0x02 Code End
0x0C 0x02 Mapping Method (0 = Direct, 1 = Table, 2 = Scan)
0x0E 0x02 Reserved?
0x10 0x04 Next CMAP Offset

Depending on the mapping method the next bytes are read like so:

Direct: IndexOffset = read uint16

Table: IndexTable = read uint16 array (CodeEnd - CodeBegin + 1)

Scan: Number of Scan Entries = read uint16 for every scan entry: read uint16 & read uint16

CWDH Header[edit]

Offset Size Description
0x00 0x04 Magic Header (CWDH)
0x04 0x04 Section Size
0x08 0x02 Start Index
0x0A 0x02 End Index
0x0C 0x04 Next CWDH Offset
0x10 3 * (EndIndex - StartIndex + 1) Char Widths (3 bytes: Left, Glyph Width, Char Width)

Tools[edit]

[1] - BFFNT Extractor/Creator. Creates PNG files from TGLP atlas data and a JSON manifest.