5.1 Binary Format (.d3f - D3-TUI Font)

Header (16 bytes):
  - Magic: "D3TF" (4 bytes)
  - Version: 1 (2 bytes)
  - Texture width: uint16_t
  - Texture height: uint16_t
  - Cell width: uint8_t
  - Cell height: uint8_t
  - Reserved: 2 bytes

Glyph table (256 entries × 16 bytes = 4096 bytes):
  For each ASCII character (0-255):
  - tex_x: uint16_t
  - tex_y: uint16_t
  - tex_w: uint8_t
  - tex_h: uint8_t
  - bearing_x: int8_t
  - bearing_y: int8_t
  - advance: uint8_t
  - reserved: uint8_t

Texture data: Variable size (tex_width × tex_height × 2 bytes for ARGB1555)