NOTE: THIS IS NOT FOR SOURCE CODE OPTIMIZATIONS, JUST THE FINAL EXECUTABLE!

This is a topic to share and comment on Axe optimizations. I'll start out with a very useful one that can decrease code size quite a bit:

Instead of
If A=B
do
!If A-B

And instead of
If A!=B
do
If A-B

This optimization takes advantage of the fact that the If statement checks for non-zero and !If checks for zero. No speed/space is wasted on the boolean expressions returning just a 0 or 1.

Since Goplat released the beta of his TI-Nspire emulator (as featured on ticalc), I decided I could start writing some code to eventually run on the TI-Nspire once it gets cracked. So, I've started a Game Boy emulator (again)

Not much runs at the moment - Link's Awakening in particular has some major issues (probably related to some mistake I made in the cpu emulation). Only the background tilemap is supported so far - no sprites or window.


Probably the next thing to do would be to get sprites working.

Alpha 0.0.3 has been released here!

The app builder works even better now, TI-Boy itself has some speedups, and I included a new homebrew ROM. Also, it shouldn't crash on the buggy hardware - instead it gives an error message. The readme also now has information on the hardware glitches and which ROM sizes will fit oncalc.

Here's a quick fix for how the appbuilding will be in v0.0.3 (the emulator itself isn't working right now for an actual release).

Download this batch file, save over the one you currently have: http://otbp.tifreakware.net/files/Drag your rom here!.bat
Then download this wabbitsign.exe and put it in the makeapp folder. Delete wabbit.exe if you want to. http://otbp.tifreakware.net/files/wabbitsign.exe

Now the builder will probably work much better. Yay!

Yeah, so on Sunday I'm leaving for a camp and won't be back until the beginning of August. This should explain inactivityishness. So basically I'm not disappearing from the community or anything like that.

I decided that Project M's code was getting way too messy and was heading in a direction I didn't want. So, I am starting again from scratch. Well, I actually have the old code on hand in case I want to borrow some stuff from it, plus I still have all of the graphics data.

And starting fresh isn't all bad... it can allow for things like nSpire support, or making it an APP. And yes, I think it should be an APP.

It can also let me do graphics upgrades which I rejected before, like so:


That would be the new tilemapper. Shiny, eh?
Just for the record, the screenshot is running at 15MHz.
It goes at about 26 FPS in 6MHz, and 65 FPS in 15MHz. I don't think frame rate will be too much of an issue in this game, anyway.

More updates aren't very likely this week because of finals and junk like that.

Indeed, I have been making a Game Boy emulator for the TI-83+SE, TI-84+, and TI-84+SE.

It currently supports two zoom levels, and another is planned as well. When zoomed in, you can configure the camera to follow any sprite (most often you will want this to be your character).
It also supports two out of the four Game Boy sound channels, so you can plug in your headphones and enjoy.
Only two games are known to work at the moment: Tetris and Link's Awakening. Tetris runs at almost full speed, while Link's Awakening is more at about half speed (but still very playable!)

I uploaded a Youtube video of Link's Awakening for your enjoyment. Beware, the video and sound aren't fully synchronized.

Next on the list for compatibility is the special rendering techniques which are employed by many games.

Here is a compilation of all the screenshots from the beginning of production (ripped unmercifully from the OTBP thread):

Infinite checkerboard! Very buggy, as you can see:

Less buggy checkerboard:

Finally reading from a 4x4 tilemap:

Reading from an 8x8 tilemap, decreased quality at this point to increase speed:

Reading from a 16x16 tilemap with much better textures:

Reading from 32x32 tilemap (final size), introduced "diagonal" tiles:

Demonstration of displaying a sprite in the world:

Rotating and moving sprite:

GRAYSCALE!

Multiple ships, changeable ship/camera height:

Acceleration, collisions:

Artificial intelligence with steering/acceleration:

Artificial intelligence that follows the track:

Splitscreen:

A better view:

32x32 has been redacted as final size, replaced by 64x64:

More flexible splitscreen, lap counter:

Turning sprites, larger render area at a small quality cost: