This long-standing bug was caused by using blending when trying to
copy an image, though for some reason it was inconsistent. Thanks to
everyone on the SDL mailing list for helping me solve this one!
Release differences from 1.3:
* Fixed a case of division by zero, most notably when asteroids were
destroyed.
* Added Y as a fire button (for QWERTZ layout users).
* Changed 3-way and 4-way spread to the original behavior.
* Added fake difficulty to the Dorim mission.
The way it was previously, you always knew exactly where the WEAPCO
scientist was. I don't remember if this was the case in the original
game (I don't think it was), but regardless, this makes the mission
seem incredibly short and easy, and it ends up centering on the
secondary objective rather than the primary objective. Now, you have
to search through all the asteroids until you find the right one,
and you have to pay close attention to explosions. Collecting ore is
just something you do along the way.
It may be fake difficulty, but after all, tropes are not bad.
The bug in question caused the super charge to be stripped away when
you collected powerups; each powerup would limit that aspect of your
weapon to its maximum. This put a limit on how long you could keep the
super charge, so I've added it back in for "original" difficulty.
I don't know why it was changed, but the changed version caused
full spread rather than partial spread with the triple shot, and it
also caused the quaduple shot to be arguably worse than the triple
shot.
The plain int type is only guaranteed to be at least 16 bits, and
yet the flags variable was expecting at least 22 bits. This turns
out to be true for x86 and x86-64 systems, but to ensure compatibility,
the variable has been changed to an unsigned long int. Also added
the "L" suffix to flags that were more than 16 bits.
There. Together with spreading out the asteroids, this has the effect
of getting rid of the sort of boxed-in feel this mission originally
had, and preventing the mission from being beaten simply by going
up or down forever.
I noticed that in "original" difficulty, plasma upgrades are basically
prohibitively expensive, which is not at all like the original. To
fix this, I've given that difficulty the original prices for those.
I've also slightly reduced the normal cost of permanent upgrades.
In particular:
* The charge cannon in that difficulty now behaves as originally.
* Cash is now rare, not nonexistent, on interceptions in that difficulty.
onpon4