jetpac.nes/src/bullets.s, branch mainPort to the NES/Famicom of "Jetpac" from Ashby Computers and Graphics Limited.
https://git.mssola.com/nes/jetpac.nes/atom?h=main2026-04-13T14:34:11ZAdd sound effects2026-04-13T14:34:11ZMiquel Sabaté Solàmssola@mssola.com2026-04-13T14:34:11Zurn:sha1:aef156ac6216ed157b06a2872ba051af43317e93
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Fix overwrite issues when adding scores2026-03-27T23:27:09ZMiquel Sabaté Solàmssola@mssola.com2026-03-27T23:27:09Zurn:sha1:a2411d86a504adbc027a93c8bddb1ba0e0f447fd
The add_to_player() function relied on parameters to be passed on the
'Globals::zp_tmpX' variables, but that's just plain stupid. First,
because these memory addresses are not meant for arguments; but most
importantly, because callers actually needed some of these values before
calling this function. Hence, everything went into chaos and sprites
began to act wrongly in all sorts of random ways.
Moreover, some of the callers also needed a guarantee on either the 'x'
or the 'y' registers. Since this wasn't always feasible, we needed to
store/load these registers' values case by case.
All in all, now add_to_player() accepts only one argument via the 'y'
register (which callers already knew it was going to be messed
with). The value on 'y' has to be set via some helper constants.
As a cherry on top, this not only fixes a nasty bug, but it also makes
things more performant and with less code.
Fixes: 63ef73de3bdd ("Update scores on screen")
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Update scores on screen2026-03-25T21:40:48ZMiquel Sabaté Solàmssola@mssola.com2026-03-25T21:40:48Zurn:sha1:63ef73de3bdd698ab250407354e24a6de7c9ef20
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Support reading from the second controller2026-03-08T21:14:15ZMiquel Sabaté Solàmssola@mssola.com2026-03-08T21:09:31Zurn:sha1:f1d1d0efee9faa3067f7b0fc8b9a2aebb17f1ccd
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Make bullet transitions in relation to HZ2026-03-06T23:29:07ZMiquel Sabaté Solàmssola@mssola.com2026-03-06T23:29:07Zurn:sha1:7ce50c89c93326bcd4029a2a4fbf488a41db3369
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Convert enemy vs bullet collision into a loop2026-03-06T22:40:02ZMiquel Sabaté Solàmssola@mssola.com2026-03-06T22:40:02Zurn:sha1:e602dd3707f2b6ad3198a62497ca6ee311997485
The fact that unrolling the loop was easier or faster was a plain lie
from my lazyness. Convert it into a proper loop just so we can
experiment with adding more enemies in one screen.
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Rename scoped variables without being redundant2026-03-06T20:38:32ZMiquel Sabaté Solàmssola@mssola.com2026-03-06T20:38:32Zurn:sha1:270d60d58d3ef206a11057d399e360976546e439
Some variables had the same name of the scope in their names as
well. Remove this redundancy everywhere.
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Let enemies die whenever they touch a bullet2026-03-03T22:19:53ZMiquel Sabaté Solàmssola@mssola.com2026-03-03T22:19:53Zurn:sha1:196f2ac744fa8e0b6ce2da555e01178d04bfb322
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Wrap around the saving of the last allocated bullet2026-03-02T21:43:57ZMiquel Sabaté Solàmssola@mssola.com2026-03-02T21:43:57Zurn:sha1:b7c41567892a7b3bd3782128926c6a223658a034
If we don't do this, then it's possible to incur into a buffer overflow
as the last allocated index is set to the next (out of buffer)
position. Whenever we start over on this function, then it will compare
for a good bullet on this position, and if it's not exactly $FF, then it
will allocate it without problems.
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Small optimization on bullet initialization2026-03-02T21:34:27ZMiquel Sabaté Solàmssola@mssola.com2026-03-02T21:34:27Zurn:sha1:8ffad74ae370c0125c62b56ba23d8d74d48a4b3d
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>