Torpedos now work.

There are some minor glitches, mainly that it should only take two torpedos to destroy a fighter on easy difficulty, not six, but that’s the only remaining issue with the torpedos themselves. I already know the cause (the damage factor is randomized twice, which produces completely wrong numbers) and I’ll fix it next.

I’d like to apologize for taking so long to get done with what may seem like a simple thing. There were two major issues that made torpedos so difficult:

1. There was an underlying graphical error across the entire game that had gone more or less unnoticed until now because torpedos were the first sprites to be severely affected by it. It seemed that OpenGL was doing linear filtering on textures when scaling them to the power-of-two rectangles per GL_TEXTURE_RECTANGLE_ARB instead of nearest neighbor. Problem: I was calling glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_NEAREST), ditto for GL_TEXTURE_MAG_FILTER. Why wasn’t this working? I tried a long list of solutions, including subpixel offset (glTranslated(0.375, 0.375, 0.0)), switching to ARB_non_power_of_two (which failed completely for reasons I still don’t understand), and texture padding. Finally, it dawned on a friend that I was calling glTexParameteri() only once, in -prepareOpenGL, instead of each time I did a glBindTexture(). The assumption was that texture parameters worked the same as the rest of OpenGL, such that state is sticky once set. Fail. Setting the parameters before each glTexImage2D() fixed the problem. That was a fun week of frustration.
2. I had not, until now, implemented collision detection. If you look carefully at Missions, you find that collision detection is actually only necessary in exactly two places:
   1. Torpedos (including standard player and enemy torpedos, antimatter torpedos, and the planet-busters fired by the battleship).
   2. Missiles (as fired by defense satellites)
   It took some time to implement collision detection, partly because I’d made some bad design decisions in the code much earlier on that had to be fixed to make it work in any reasonable way.

With torpedos working, we’re on the home stretch. Almost everything else is assembling components that already exist in the code. Stay tuned for further updates!