2006/03/16
Objective-C and Amazon S3
Great, a new toy ! Amazon launched S3, a storage solution aimed at developers. Interesting new ideas here: a simple bucket / ID mechanism to identify storage, a simple access control mechanism, REST or SOAP APIs... and HTTP or BitTorrent for access. They also provide a bunch of sample code in ruby, php, java, C#... So of course, I started a port of the access code to Objective-C, with the idea of eventually having a simple framework to interact with S3. I'll post here as soon I have something ready.
2006/03/05
Google Sitemaps (and Carto)
Google added nice webmaster tools a few months ago. It is now possible to have reports of what Google sees from your site when crawling the page, and information about top search queries and clicks. Also, they defined a sitemap format with which a webmaster can give hints to the GoogleBot about what to crawl, how frequently, with which relative priority within the site, etc. It is also possible to setup separate sitemap files for regular and mobile web content. Quite cool.
So it was a good excuse to play with Core Data and build a small Mac application to edit sitemap files. It is -so- previsible: I wanted to add a sitemap file to my site, so instead of taking 5 minutes to write the file by hand, I took a couple of hours to hack a tool to generate it. So Carto is the result. It imports and exports sitemap files,
allows to drag-n-drop URL from a browser, handles live search and batch edits. Feel free to use it, and please send email to: olg+carto @ no-distance.net if you have any issue or suggestion. The source code is an example of Core Data use in a small application, giving for free persistence, batch editing, undo management, and validation. There is also some bits of low-level Web Kit usage, to obtain last-modified information, and NSXMLDocument to generate or parse the sitemap files.
2006/03/01
Quartz Musings: Recap
At first,
I just wanted to play again with multi-agent systems, and build a small simulator. But soon, it diverged and the project became an excuse to play with several areas of CoreGraphics (aka Quartz) and use it for a series of post explaining some (in my opinion) interesting aspects of the OS X graphics system, a humble mini Quartz tutorial.
- The first post was about basic CoreGraphics drawing: line and shape drawing, a bit of path handling, the recently added and powerful layer abstraction, and general Quartz discussion.
- The second episode was about graphics contexts in CoreGraphics. The PDF context is an important one, as the Quartz drawing model is directly inspired by PDF. This post described how to easily generate PDF data (post updated to include PDF rendering).
- The third part was again about graphics contexts, with the example of the more experimental Quartz GLContext.
- The fourth post showed how to integrate CoreGraphics with another graphic system: OpenGL. In the code example, the CoreGraphics rendering is drawn on an offscreen bitmap context, and then uploaded as a texture in OpenGL.
- The fifth post is also GPU-oriented, but stays in OS X API, with a bitmap rendering used as an image on which a realtime GPU zoom/blur effect is applied, through the Core Image framework.
Here is the compiled application, and a source archive. As I'm using CoreImage and CGLayer, this application is 10.4 only, although the source code is probably still interesting for the PDF, GLContext and raw CoreGraphics snippets for older systems. Note also that the Core Image, OpenGL, or GLContext might give bogus results on some graphic cards, as I'm playing with unusually big textures (I tested with a GeForce6800 - I know there are issues with a 4MX for instance, and it won't work with a Rage128). These examples are provided on an as-is basis, so use at your own risk. In some cases, the code has been simplified to be a better example, and is probably not of production quality. Please let me know if you find this useful or if you spot any error or omission!
