Your code works with me, although I did not use a fullscreen picture (32*32).
When pushing enter only a 10*10 square is cleared.

Edit:
Also, you can expect improvement in the next OS release.
TI did not create Lua for game programming, so its not hard to understand that its not optimized for games.
Anyway, I don't have any problem with TI.Image.

Actually I tried it on the official emulator, maybe the behavior is different on the actual hardware. Once I return home I'll try it on the calculator, so hopefully that was the reason why it didn't seem to work. Thanks for clearing that up anyway.
Hopefully they will indeed improve it in the next OS!

This is not the case if you only invalidate a certain spot (by giving arguments to invalidate() ).
I've made some stuff with it (smooth scrolling) and it works very good.

I'd like to see how you do that, as this simple example does clear the whole screen whenever I press the enter key:
sprite = image.new("some 318*212 ti image")
drawn = false

function on.enterKey()
    platform.window:invalidate(10, 10, 10, 10)
end

function on.paint(gc)
    if not drawn then
        gc:drawImage(sprite, 0, 0)
        drawn = true
    end
end

Looks quite nice so far. By the way although smooth scrolling cannot be implemented, have you tried 8 pixel scrolling or even 4 pixel scrolling?

No but I have tried some sort of smooth scrolling in the past. Way too slow for what it gives back, not worth the pain of implementing it. Well, at least not a this point, maybe if Lua gets a bit faster in the future, then why not.

Anyway joking aside, this looks nice. I will definitively have to give this a try when I have time. Will it support full screen or will it always just use a small portion of the screen due to limitations or something else?

Oh no, of course not. It's that small just to show off the scrolling (didn't bother to make a bigger map, maybe I should for the sake of a nicer demo). As I said it'll be a very flexible library, no restrictions.

EDIT: I updated the demo to a full screen one.

I've been working on a tile engine I named Owl. I had tried it before, but it was generally quite slow and a pain in the butt to use and adapt. I tried it again, but this time a lot more seriously, and it's been progressing nicely. My goal is to make a fast (fast as in TI-Nspire Lua fast), clean, flexible and lightweight tile map engine that anyone can use. The engine currently supports arbitrary-sized maps with scrolling, easy tile, object (anything that can change state during the game), and event (detonate the nuke when Link reads that sign) management. To keep the games responsive, playable and frustration-free, scrolling and movement is blocky, i.e. no smooth scrolling or fancy walking animations (although there will be basic animation management).

As mentioned up there, graphics-heavy TI-Nspire Lua programs (read: programs that use the TI.Image format to draw images a lot) are usually rather slow. But because sprites with a lot of transparent pixels and primitive shapes can be drawn relatively quickly, to tackle the issue of slowness I decided that every tile is defined by an optional background color and and a (hopefully) partially transparent sprite that comes on top of it. That in most cases improves the speed quite a bit. Also I'm working on a map format that will increase the FPS by a good 10%—40%.

All I can give you right now is the current source code, which is kept and updated whenever I commit a change on github (I repeat, it's not ready for public use): https://github.com/Hoffa/Owl

I'll at some point write some sort of documentation and release a public version (when I feel it works and am generally pleased with it, might take some time), but until then you can play around with the code on github if you wish.

EDIT: on hold while I work on the SDL port.

Classic Pong



http://www.omnimaga.org/index.php?action=downloads;sa=view;down=756

This is the classic Pong game on the TI-Nspire. You can either play against a friend or against an opponent that adjusts its skill according to yours.

Controls:
1/0: move left paddle up/down
3/(-): move right paddle up/down
8: toggle game mode (i.e., one or two players)
i: invert colors
r: reset the game

Voilà, there's 0.2 with a few fixes and stuff. I fixed many small things and added some basic things that were missing, so the changelog is really a lot of text for not that much. The better updates will come in the following versions (A* pathfinding for unit moves (and the range thing for shooting), saves, maybe some basic AI for single player, etc.).

Amazing game Hoffa! I know that the code to show where the units are able to move to must have been a nightmare. (I once tried to remake a fire emblem game and I tried to understand that part. It's what killed the project before I even started)

Don't tell anybody, but it actually uses a very dumb way of detecting where a unit can move or not. Actually a unit can magically jump over water and shoot through a mountain, but it rarely happens in the game as the range of the units is fairly small. I'm working on it though, there will be a real algorithm for finding the positions a unit can move to soon.