A collection of coding snippets, tips, hints and random thoughts.
When using ImageMagick to convert an RGBA picture (e.g. an OS X window with shadows) to an RGB JPEG file, you should use the following command:
$ convert input.png -flatten +matte output.jpg
If you don’t do that, you will end up with a picture like this:
The right conversion leads to this result instead:
I just tried out my second game from the Humble Bundle 2. This one is called Braid. It is a 2D puzzle platform jump and run with a little twist. In the first world that I just started, you can let time run backwards, by hitting the shift key. Other than that, you only have the arrow keys for moving around your character and the space bar for jumping. The graphics are wonderful, in style akin to a aquarel or water colour painting. The music is some violins playing a melancholic soundtrack. The worlds seem to be designed with a lot of love, and it’s nice to see a jump and run game with more puzzles than fast action scenes. It’s somewhat of a change. Here’s a nice screenshot of one of the first levels:
MacPorts comes with a nice package for Doxygen, the source documentation tool. However, it is missing the doxywizard, to quickly create and edit the sometimes very long Doxygen configuration files. However, there is a page (even from the original Doxygen guy) hosting special OS X builds with a nice small bundle, that you can drop into your Applications folder and which looks like this:
There is a nice little blog entry which explains how to convince iTunes to take other media into your media library. The command is:
SetFile -t “MooV” -c “TVOD” some-movie.avi
When you’ve installed Perian, iTunes should then accept almost any movie, be it avi, mkv or xvid.
Some time back I reported on crashing the Macs here using a non-trivial GLSL shader program. This bug still exists to this day. Now we’ve got a small, brand new 21″ iMac, fresh out of the box. It exhibits a similar problem. This time, the UI does not lock up, but the rendering is totally borked. Compare the two screenshots. The first one shows the correct rendering, on a Linux PC using an NVIDIA GTX285 GPU, the other one is from the 21″ iMac using an ATI GPU. The trick between crashing and not crashing seems to be the ATI brand…
I do like the MagicMouse by Apple. But there are some limitations to it. Thus I installed MagicPrefs, and all is well. Check it out:
An absolutely cute 2D, very classic jump and run game is Frogatto and Friends. It is for free, comes even with source code. Only the iPhone version does cost a bit. But I guess that is a nice way to support the developers. The game is crossplatform, running on Linux, OS X, Windows and, as mentioned, iOS devices. I assume, if you take the source, you can make it run on several other platforms as well. The music is nice, the characters lovable, and the levels have a great amount of detail. Controls are simple: cursor keys, plus A and S is all you need. What surprised me was that the music is stored as .ogg files, although it sounds like tracker songs. Thus it makes up 90 MiB of the game data, the whole game being slightly over 100 MB in size. Anyway, download it and have fun!
Ok, so the combination of Truecrypt and ext2/3 is not optimal for sharing data between Linux and OS X. Truecrypt and fuse-ext2 on OS X cannot mount an ext2/3 partition read-write. So I will now go back to the lowest common denominator for all OSes: NTFS…
Update: Yes, it seems NTFS is a good alternative. With both OSes using NTFS-3G, I can use the Truecrypt file on both Linux and OS X — and even Windows, if I had one… Creation of a 200GB Truecrypt file takes time, though. And copying all the data to it, even more.
What a nice surprise. Apple has actually documented the Keynote file format. Sadly, as far as I can see, there is no import/export capability in either PowerPoint nor OpenOffice.org Impress. That would be a nice feature. But it’s good that Apple does document the format. Since it is XML, it is easy to parse. However the hard part is always the semantics, not the syntax…
The quit command C-g is pretty much standard in Emacs. It runs the interactive function keyboard-quit and also serves as the default quit-char. It aborts basically every running function, also it allows you to cancel operations in the minibuffer. The Emacs documentation describes current-input-mode, set-input-mode and set-quit-char for getting and setting the quit-char value. Also, global-set-key allows you to rebind keyboard-quit to another character. However, this does not work very well. The quit-char is not settable for non-tty Emacs versions, e.g. on OS X using Cocoa Emacs you get this:
So, basically nothing changes. On a tty it looks more promising:
After rebinding the keyboard quit as well, using (global-set-key (kbd “C-q”) ‘keyboard-quit), not much happens either. It seems the minibuffer assumes C-g to be the choice of the day. Running find-file with C-x C-f or interactively via M-x find-file, and then hitting C-q does nothing except printing “Quit”. Hitting C-g however quits the minibuffer. This seems to be documented in Bug #1218 of Emacs.