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| author | Juan J. Martinez <jjm@usebox.net> | 2023-05-05 21:39:32 +0100 |
|---|---|---|
| committer | Juan J. Martinez <jjm@usebox.net> | 2023-05-05 21:40:34 +0100 |
| commit | ca551c1700cf982fe96388491a096b515365894f (patch) | |
| tree | e40b9a95cb1f0169c553c19da4ff52c16e73035a /example.asm | |
| parent | f10e1ea20cbadd151b20175f48ac902eac4ee0d7 (diff) | |
| download | tr8vm-ca551c1700cf982fe96388491a096b515365894f.tar.gz tr8vm-ca551c1700cf982fe96388491a096b515365894f.zip | |
Use the MSB of the index to mark a transparent color
Because we use 1 byte to store 4bpp, we don't need a mask and we can
encode a "transparent" color in the bits we don't use.
Diffstat (limited to 'example.asm')
| -rw-r--r-- | example.asm | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/example.asm b/example.asm index 73aa9a5..2ab0ee7 100644 --- a/example.asm +++ b/example.asm @@ -75,7 +75,16 @@ draw_sprite: line: push x ld x, [a : x] + + ; any color with index > 15 + ; is transparent + cmp x, 16 + bnc + jmp transparent + ld [b : y], x + +transparent: pop x inc x |