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| author | user <user@clank> | 2026-07-18 21:42:27 +0200 |
|---|---|---|
| committer | user <user@clank> | 2026-07-18 21:42:27 +0200 |
| commit | 554fd415d34235fda6c172fc09b19278764f00c3 (patch) | |
| tree | c97cfaa03a281d61d39820fbddbb3eef0705bcce /include | |
| parent | term: cache tile attrs in COL_BUF's spare stride bytes (3.5x scroll) (diff) | |
| download | gbos-554fd415d34235fda6c172fc09b19278764f00c3.tar.gz gbos-554fd415d34235fda6c172fc09b19278764f00c3.tar.xz gbos-554fd415d34235fda6c172fc09b19278764f00c3.zip | |
term: 3 more renderer wins - 10.9x scroll, 2.7x putc vs pre-cache
1. color_setup memoization: a call with the same (colL,colR) pair as
last time returns immediately (masks/attr still valid in WRAM).
Runs of same-colored cells - i.e. almost all text - hit this.
2. build_tile blank fast path: two spaces = bg-only planes, 8 constant
rows; term_scroll's cleared line and every blank region skip the
glyph pipeline entirely.
3. build_tile two-phase rewrite: combine both glyphs into wRowBuf with
pointers in registers (the old per-row 16-bit WRAM pointer walk was
most of the blit), then compose planes unrolled with plane-0 masks
in B/C.
4. term_write_tilemap attr pass: split each row at the pos-256 VRAM
bank boundary into two tight cache->tilemap copy runs - no per-tile
addressing or bank test.
Measured (emulator cycle counter, ANSI test screen):
term_scroll 857k -> 248k (attr cache) -> 78.5k T-cycles
term_write_tilemap 723k -> 114k -> 45.4k
term_putc 18.2k -> 6.7k
A scroll is now ~1.1 frames of guest CPU (was 12); a full 40-char line
prints in ~63ms of guest time (was ~173ms).
Diffstat (limited to '')
| -rw-r--r-- | include/gbos.inc | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/gbos.inc b/include/gbos.inc index e63d53f..be6009f 100644 --- a/include/gbos.inc +++ b/include/gbos.inc @@ -39,6 +39,9 @@ DEF wCSset EQU $D5AD ; color_setup scratch: 7-bit set of colors present DEF wCSpb EQU $D5AE ; color_setup scratch: palette*8 (SlotOf base) DEF wCStmp0 EQU $D5AF ; color_setup scratch: assembled plane-0 mask DEF wCStmp1 EQU $D5B0 ; color_setup scratch: assembled plane-1 mask +DEF wCSPL EQU $D5B1 ; color_setup memo: last (colL,colR) pair - a call +DEF wCSPR EQU $D5B2 ; with the same pair returns early (masks valid) +DEF wRowBuf EQU $D5B3 ; build_tile: 8 combined glyph rows (L=hi/R=lo nibble) DEF OSK_DOCK EQU 3 ; on-screen keyboard height in rows (dock at the bottom) DEF rKEY1 EQU $FF4D ; CGB speed switch DEF rSB EQU $FF01 ; serial data |