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| author | user <user@clank> | 2026-07-16 13:54:23 +0200 |
|---|---|---|
| committer | user <user@clank> | 2026-07-16 13:54:23 +0200 |
| commit | 4656a1003226709e9b3c804ec32b4913fca4c7f4 (patch) | |
| tree | 516185fb1827495f0fe747b6365eb963ad5cf031 /src/font.asm | |
| parent | fs: reject open()/read() on a directory (EISDIR) (diff) | |
| download | gbos-4656a1003226709e9b3c804ec32b4913fca4c7f4.tar.gz gbos-4656a1003226709e9b3c804ec32b4913fca4c7f4.tar.xz gbos-4656a1003226709e9b3c804ec32b4913fca4c7f4.zip | |
term: 40-column text terminal on the CGB LCD (4x8 dynamic tiles)
Add a background-tile text terminal that packs TWO 4px-wide characters
into each 8x8 tile, giving a 40x18 grid instead of the 20x18 you'd get
from an 8x8 font. The tilemap is static (one dedicated VRAM tile per
screen position); we rebuild a tile's 16 bytes from two glyphs whenever
a character changes. 360 tiles exceed the 256 a single tilemap can
address, so positions 256-359 live in VRAM bank 1 via the CGB tilemap
attribute bank-bit -- hence CGB-only.
- Switch the ROM to CGB (rgbfix -C). Safe for the FS: every process has
PROC_WRAMB=1, so SVBK stays on bank 1 and the WRAMX FS caches don't move.
- CGB BG palette 0 = white bg / black text via BCPS/BCPD.
- src/term.asm: term_init (palette + static tilemap + clear buffer),
build_tile (combine two 4px glyphs -> one 8x8 tile, correct VRAM bank),
term_redraw (rebuild all tiles), term_puts, term_show, term_test.
- src/font.asm: 96-glyph 3x5-in-4x8 font, generated by tools/genfont.py.
- 40x18 text buffer at $D600 (WRAMX, above the FS caches).
- tools/ppmview.py: render a --shot PPM as ASCII so the LCD is inspectable
from the shell during development.
Verified via emulator screenshot: "GBOS TERMINAL", the alphabet, and a
bank-1 row all render legibly at 40 columns. Serial shell + filesystem
still work unchanged.
Note: a full term_redraw builds 360 tiles and takes ~8 frames; fine for
incremental single-char updates, but scrolling needs a smarter path
(next milestone). Input (no keyboard) is also still TODO.
Diffstat (limited to 'src/font.asm')
| -rw-r--r-- | src/font.asm | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/src/font.asm b/src/font.asm new file mode 100644 index 0000000..a6ff7d9 --- /dev/null +++ b/src/font.asm @@ -0,0 +1,99 @@ +; auto-generated by tools/genfont.py - 4x8 font (3x5 glyphs), 96 glyphs +SECTION "font", ROM0 +FontData:: + db $00,$00,$00,$00,$00,$00,$00,$00 ; ' ' + db $04,$04,$04,$00,$04,$00,$00,$00 ; '!' + db $0A,$0A,$00,$00,$00,$00,$00,$00 ; '"' + db $0A,$0E,$0A,$0E,$0A,$00,$00,$00 ; '#' + db $04,$06,$0C,$06,$0C,$00,$00,$00 ; '$' + db $0A,$02,$04,$08,$0A,$00,$00,$00 ; '%' + db $04,$0A,$04,$0A,$06,$00,$00,$00 ; '&' + db $04,$04,$00,$00,$00,$00,$00,$00 ; ''' + db $02,$04,$04,$04,$02,$00,$00,$00 ; '(' + db $08,$04,$04,$04,$08,$00,$00,$00 ; ')' + db $0A,$04,$0E,$04,$0A,$00,$00,$00 ; '*' + db $00,$04,$0E,$04,$00,$00,$00,$00 ; '+' + db $00,$00,$00,$04,$08,$00,$00,$00 ; ',' + db $00,$00,$0E,$00,$00,$00,$00,$00 ; '-' + db $00,$00,$00,$00,$04,$00,$00,$00 ; '.' + db $02,$02,$04,$08,$08,$00,$00,$00 ; '/' + db $04,$0A,$0A,$0A,$04,$00,$00,$00 ; '0' + db $04,$0C,$04,$04,$0E,$00,$00,$00 ; '1' + db $0C,$02,$04,$08,$0E,$00,$00,$00 ; '2' + db $0C,$02,$04,$02,$0C,$00,$00,$00 ; '3' + db $0A,$0A,$0E,$02,$02,$00,$00,$00 ; '4' + db $0E,$08,$0C,$02,$0C,$00,$00,$00 ; '5' + db $06,$08,$0C,$0A,$04,$00,$00,$00 ; '6' + db $0E,$02,$04,$04,$04,$00,$00,$00 ; '7' + db $04,$0A,$04,$0A,$04,$00,$00,$00 ; '8' + db $04,$0A,$06,$02,$0C,$00,$00,$00 ; '9' + db $00,$04,$00,$04,$00,$00,$00,$00 ; ':' + db $00,$04,$00,$04,$08,$00,$00,$00 ; ';' + db $02,$04,$08,$04,$02,$00,$00,$00 ; '<' + db $00,$0E,$00,$0E,$00,$00,$00,$00 ; '=' + db $08,$04,$02,$04,$08,$00,$00,$00 ; '>' + db $0C,$02,$04,$00,$04,$00,$00,$00 ; '?' + db $04,$0A,$0E,$08,$06,$00,$00,$00 ; '@' + db $0C,$0A,$0E,$0A,$0A,$00,$00,$00 ; 'A' + db $0C,$0A,$0C,$0A,$0C,$00,$00,$00 ; 'B' + db $06,$08,$08,$08,$06,$00,$00,$00 ; 'C' + db $0C,$0A,$0A,$0A,$0C,$00,$00,$00 ; 'D' + db $0E,$08,$0C,$08,$0E,$00,$00,$00 ; 'E' + db $0E,$08,$0C,$08,$08,$00,$00,$00 ; 'F' + db $06,$08,$0A,$0A,$06,$00,$00,$00 ; 'G' + db $0A,$0A,$0E,$0A,$0A,$00,$00,$00 ; 'H' + db $0E,$04,$04,$04,$0E,$00,$00,$00 ; 'I' + db $02,$02,$02,$0A,$04,$00,$00,$00 ; 'J' + db $0A,$0A,$0C,$0A,$0A,$00,$00,$00 ; 'K' + db $08,$08,$08,$08,$0E,$00,$00,$00 ; 'L' + db $0A,$0E,$0E,$0A,$0A,$00,$00,$00 ; 'M' + db $0A,$0E,$0E,$0E,$0A,$00,$00,$00 ; 'N' + db $04,$0A,$0A,$0A,$04,$00,$00,$00 ; 'O' + db $0C,$0A,$0C,$08,$08,$00,$00,$00 ; 'P' + db $04,$0A,$0A,$04,$02,$00,$00,$00 ; 'Q' + db $0C,$0A,$0C,$0A,$0A,$00,$00,$00 ; 'R' + db $06,$08,$04,$02,$0C,$00,$00,$00 ; 'S' + db $0E,$04,$04,$04,$04,$00,$00,$00 ; 'T' + db $0A,$0A,$0A,$0A,$06,$00,$00,$00 ; 'U' + db $0A,$0A,$0A,$04,$04,$00,$00,$00 ; 'V' + db $0A,$0A,$0E,$0E,$0A,$00,$00,$00 ; 'W' + db $0A,$0A,$04,$0A,$0A,$00,$00,$00 ; 'X' + db $0A,$0A,$04,$04,$04,$00,$00,$00 ; 'Y' + db $0E,$02,$04,$08,$0E,$00,$00,$00 ; 'Z' + db $0C,$08,$08,$08,$0C,$00,$00,$00 ; '[' + db $08,$08,$04,$02,$02,$00,$00,$00 ; '?' + db $06,$02,$02,$02,$06,$00,$00,$00 ; ']' + db $04,$0A,$00,$00,$00,$00,$00,$00 ; '^' + db $00,$00,$00,$00,$0E,$00,$00,$00 ; '_' + db $08,$04,$00,$00,$00,$00,$00,$00 ; '`' + db $0C,$0A,$0E,$0A,$0A,$00,$00,$00 ; 'a' + db $0C,$0A,$0C,$0A,$0C,$00,$00,$00 ; 'b' + db $06,$08,$08,$08,$06,$00,$00,$00 ; 'c' + db $0C,$0A,$0A,$0A,$0C,$00,$00,$00 ; 'd' + db $0E,$08,$0C,$08,$0E,$00,$00,$00 ; 'e' + db $0E,$08,$0C,$08,$08,$00,$00,$00 ; 'f' + db $06,$08,$0A,$0A,$06,$00,$00,$00 ; 'g' + db $0A,$0A,$0E,$0A,$0A,$00,$00,$00 ; 'h' + db $0E,$04,$04,$04,$0E,$00,$00,$00 ; 'i' + db $02,$02,$02,$0A,$04,$00,$00,$00 ; 'j' + db $0A,$0A,$0C,$0A,$0A,$00,$00,$00 ; 'k' + db $08,$08,$08,$08,$0E,$00,$00,$00 ; 'l' + db $0A,$0E,$0E,$0A,$0A,$00,$00,$00 ; 'm' + db $0A,$0E,$0E,$0E,$0A,$00,$00,$00 ; 'n' + db $04,$0A,$0A,$0A,$04,$00,$00,$00 ; 'o' + db $0C,$0A,$0C,$08,$08,$00,$00,$00 ; 'p' + db $04,$0A,$0A,$04,$02,$00,$00,$00 ; 'q' + db $0C,$0A,$0C,$0A,$0A,$00,$00,$00 ; 'r' + db $06,$08,$04,$02,$0C,$00,$00,$00 ; 's' + db $0E,$04,$04,$04,$04,$00,$00,$00 ; 't' + db $0A,$0A,$0A,$0A,$06,$00,$00,$00 ; 'u' + db $0A,$0A,$0A,$04,$04,$00,$00,$00 ; 'v' + db $0A,$0A,$0E,$0E,$0A,$00,$00,$00 ; 'w' + db $0A,$0A,$04,$0A,$0A,$00,$00,$00 ; 'x' + db $0A,$0A,$04,$04,$04,$00,$00,$00 ; 'y' + db $0E,$02,$04,$08,$0E,$00,$00,$00 ; 'z' + db $02,$04,$0C,$04,$02,$00,$00,$00 ; '{' + db $04,$04,$04,$04,$04,$00,$00,$00 ; '|' + db $08,$04,$06,$04,$08,$00,$00,$00 ; '}' + db $00,$06,$0C,$00,$00,$00,$00,$00 ; '~' + db $0E,$0A,$0A,$0A,$0E,$00,$00,$00 ; '?' |