This project has been completed. See this topic for the download of the completed project and the full description.

Cemetech has posted a number of interesting articles on TI's STEM Behind Hollywood initiative, starting with when they first announced the project, and continuing with the overwhelmingly positive reception at T^3 and the newish Zombie activity. For Cemetech Contest #12, Lorenzo "Ordelore" Orders planned to port the Earth Impact! activity, as detailed in his contest topic. Unfortunately, after learning about the gravitational force equation that governs cosmological movement, he was forced to drop out of the contest. I was inspired by his code, and ended up starting from scratch to create a TI-84 Plus C Silver Edition version of Earth Impact!

Over the last few days, I have put together the framework for the STEM Behind Hollywood program Earth Impact using TI-BASIC and xLIBC. I started with a basic text-display engine that could scroll through individual pages of text, and flip backwards and forwards through pages of content. I then transcribed about six thousand characters of text from the original TI-Nspire version of Earth Impact and manually added line-breaks following the 20-character-wide text output that xLIBC can perform. Finally, I found a way to pack xLIBC background images into the end of a Celtic II CSE text file, using a custom Python script that I wrote to concatenate AppVars with a single correct header and checksum.

You can see a few sample screenshots of my work below. The remaining tasks are several:

1. Add some kind of busy indicator for when pages are rendering. Done
   
2. Implement the Help menu. Done
   
3. Implement the asteroid simulator for pages 10 and 32. Done
   
4. Implement setting the parameters for page 32. Done
   
5. Implement the graphs for pages 13, 16, and 17. Done
   
6. Set variable to fix degree/radian mode at end. Done
   
7. Write a TI-84+CSE-specific readme document for teachers and students, and produce a modified version of the existing documentation with updated screenshots. Done.
   
8. Package and (talk to the powers that be?) and release. Partially done

[Beta] Earth Impact! Activity for the TI-84 Plus C Silver Edition

This already looks very impressive good sir. Will you be releasing that little appvar combiner to the wild, or will it be implemented as a function of SourceCoder 3? Looking forward to more progress on this project!

I doubt I'll add it to SourceCoder 3, as it is very specific to my use case. It takes the contents of each of the AppVars, and concatenates them with newlines (0x3F characters) in between. This means that I can fetch out blobs of xLIBC background/image/sprite data as though they were lines in Celtic II CSE text files. I will certainly post it up in the Archives if it would be useful for people like you.

I added the busy indicator, and I started writing the simulator:

Nice! This is looking to be yet another pretty sweet program!

Oh my gosh! I am so excited. The great Kerm Martian returns with another brilliant TI-84 PCSE program!
Those graphics doe

Wow looks fantastic! So this is the project you were working on!

Id love the see how you've managed to pack the image/sprite data etc, that is VERY useful.

I eagerly await updates to this project .

It's pretty straightforward; I just pack the data together as "lines" of a longer AppVar, and then use the Celtic ReadLine function to pull lines out into separate xLIBC appvars. I got lucky that none of my images contain 0x3F (newline) characters.

Wow, Kerm, this looks great!

Thank you! I'm aiming to finish writing and testing the program and updating TI's documentation by the end of this weekend, so I've been working hard to whip it into shape. Also, I have been finishing off the simulator, and I accidentally made asteroids able to bounce off the Earth:



Edit: Also, my remaining to-do list:

1. Add some kind of busy indicator for when pages are rendering. Done
   
2. Implement the Help menu. Done
   
3. Implement the asteroid simulator for pages 10 and 32. Done
   
4. Implement setting the parameters for page 32. Done
   
5. Implement the graphs for pages 13, 16, and 17.
   
6. Set variable to fix degree/radian mode at end. Done
   
7. Write a TI-84+CSE-specific readme document for teachers and students, and produce a modified version of the existing documentation with updated screenshots.
   
8. Package and (talk to the powers that be?) and release

This is impossible! It had only been one day! Kerm you must have worked very hard on this, congrats

Nice work for sure KermM! I'm especially impressed by how fast you seem to be putting this together at. Great work.
I saw your twitter post about the bouncing asteroids, that made me chuckle. Good job so far!

I started serious development on this on Sunday, so this is actually my fourth day working on it. I've been at an important conference in my field, though, so I've only put a few hours of work into this each day.

Yeah, that was an amusing error with an incorrect use of tan^-1(). I'm glad I gave you a chuckle.

I have finished the code to display the graphs, including using xLIBC tricks to add labels and text outside of the graph area. Please excuse jsTIfied's occasional screenshotting glitches:

1. Add some kind of busy indicator for when pages are rendering. Done
   
2. Implement the Help menu. Done
   
3. Implement the asteroid simulator for pages 10 and 32. Done
   
4. Implement setting the parameters for page 32. Done
   
5. Implement the graphs for pages 13, 16, and 17. Done
   
6. Set variable to fix degree/radian mode at end. Done
   
7. Write a TI-84+CSE-specific readme document for teachers and students, and produce a modified version of the existing documentation with updated screenshots. Done.
   
8. Package and (talk to the powers that be?) and release. Partially done

That looks simply amazing, glad you took on this project, I'm sure others will greatly appreciate the work you've put in to this as well!

I hope so! In fact, on my flight home today, I put together version of the student handout and teacher notes that were packaged with the original activity, modified for my TI-84+CSE port. I'm slightly concerned about the legality of my close modification, but I made it very clear that Texas Instruments was the creator of the original material everywhere I could.

On that note, please test the beta I have released. This involves the following:

1. Testing out the program page-by-page, checking if any of the text is wrong or contains garbage characters
   
2. Playing with and trying to break the simulation
   
3. Please use the student handout along with the program and try answering the questions as you go, then check against the answers in the teacher sheet. Do you get the same answers as me?

Many thanks to any and all of you that do this; I greatly, greatly appreciate it. This can only help our beloved TI-84 Plus line remain relevant and supported for longer.

[Beta] Earth Impact! Activity for the TI-84 Plus C Silver Edition

Given how much they want us to make educational programs instead of games, I'll be a little bit surprised if they hound you for doing just that.

I suspect so too; it also helps them if the TI-84+CSE-using teachers can use these activities in the classroom, which I'm sure they're aware of. I look forward to bug reports from you guys, especially if anything is unclear or incorrect in the handouts. I took another run through the activity this morning to try to verify the math, and so far everything looks good. The only change I've made from the released Beta is to set Ans in the calculator tool after every calculation.

Wow so much progress in such little time! Glad that xLIBC is able to help, I like the text routine hack btw, it actually looks rather nice .

I'm guessing that you have a variable set when it does the vvv to indicate more information, right? I'd recommend disabling the down arrow key when it doesn't display vvv, if that's possible.

Otherwise, so far, I'm nearly at the graphs.

Looks good although I only tested in an emu for now (will test on calc when i get home).

The only thing i noticed was the missing 'o':



Aside from that awesome work, its really great that you managed to pack all that data into 1 appvar.

I was wondering if you had considered the 32-colour images? They take up more room (12kb) but offer a better resolution. The images do look good however.

I believe it doesn't do anything, correct? It will accept every key, but if it functionally does nothing (like the down key in that circumstance), it will just leave you right back where you were.

Thank you!

Fixed; nice catch on that.

No, it didn't occur to me to try that. Perhaps I'll use that for one/some/all of the other STEM Behind Hollywood activities if I need more detail. Thanks!