project page 3 - Dave's Blog

Encode-O-Matic Update: Compression, Hex View, Quick Show Output

I've just put up an update for Encode-O-Matic with the following improvements:

• Hex editor: the output and input views can now be switched between a UTF8 textbox view and a hex editor view. This is built using the free Be.HexEditor.
• Compression: I've added the .NET GZip, deflate, and inflate streams to the list of supported encodings.
• Quick Show Output: There are now 'Show Output' radio buttons next to each encoding in the encoding stack. Clicking on them changes the output view to show the output from that encoding in the stack. This lets you easily jump between different parts of your encoding process. Adding or removing an encoding to the stack resets the view.
• Minor visuals improvement: added app icon, changed buttons with one word symbols to command names.

WPAD Server Fiddler Extension

I've made a WPAD server Fiddler extension and in a fit of creativity I've named it: WPAD Server Fiddler Extension.

Of course you know about Fiddler, Eric's awesome HTTP debugger tool, the HTTP proxy that lets you inspect, visualize and modify the HTTP traffic that flows through it. And on the subject you've probably definitely heard of WPAD, the Web Proxy Auto Discovery protocol that allows web browsers like IE to use DHCP or DNS to automatically discover HTTP proxies on their network. While working on a particularly nasty WPAD bug towards the end of IE8 I really wished I had a way to see the WPAD requests and responses and modify PAC responses in Fiddler. Well the wishes of me of the past are now fulfilled by present day me as this Fiddler extension will respond to WPAD DHCP requests telling those clients (by default) that Fiddler is their proxy.

When I started working on this project I didn't really understand how DHCP worked especially with respect to WPAD. I won't bore you with my misconceptions: it works by having your one DHCP server on your network respond to regular DHCP requests as well as WPAD DHCP requests. And Windows I've found runs a DHCP client service (you can start/stop it via Start|Run|'services.msc', scroll to DHCP Client or via the command line with "net start/stop 'DHCP Client'") that caches DHCP server responses making it just slightly more difficult to test and debug my extension. If a Windows app uses the DHCP client APIs to ask for the WPAD option, this service will send out a DHCP request and take the first DHCP server response it gets. That means that if you're on a network with a DHCP server, my extension will be racing to respond to the client. If the DHCP server wins then the client ignores the WPAD response from my extension.

Various documents and tools I found useful while working on this:

• WPAD IETF draft document the never out of draft document describing WPAD
• DHCP RFC
• DHCP options RFC
• DHCP Wikipedia article which includes helpful byte layout tables for DHCP messages.
• Fiddler Wiki esp. the dev section but also the portion on the new preferences API.
• Fiddler Dev Docs and for those things not covered in the Fiddler docs, Visual Studio's name completion (or the .NET Reflector) usually served me well.
• Netmon a great network sniffing tool for all my non-HTTP network inspection needs.
• Tiny DHCP Server on CodeProject which implements a conventional DHCP server.

Cheap Multiplayer Tricks for New Super Mario Bros. Wii

The New Super Mario Bros. Wii is a great game. Its the fun of old school Mario with the addition of great graphics and the kind of multiplayer I've wanted for Mario since playing the original as a child: its got up to four player simultaneous cooperative multiplayer. I recommend it to anyone who has enjoyed Mario in the past. Watch this amazing video of level 1-3 you can unlock in the game.

As noted elsewhere, multiple players attempting to navigate platforms, grab power ups, and throw turtle shells creates new challenges but along with that there's new ways to be incredibly cheap.

Jumping Higher

A second player means a head one can jump on to reach higher locations. Jump on your friend's head at the apex of their jump while holding down the jump button yourself for maximum jumping. In the game you can also grab other players and hold them over your head. This is useful for reaching the top of the flagpole at the end of levels. On that same line, if the player you grab has a flying cap you can now use them to fly in the same manner you would use a flying block which makes it easy to get two players to the top of the finish flagpole if only one of you has a flying cap.

Power-Ups

Normal power-up blocks now spawn enough power-ups for everyone. A mushroom is spawned for each small player and full power-ups for the rest, except in the case everyone is small: then one of the power-ups is a full power-up. If there's two players and you're both small, the full power-up always jumps out of the block to the right. Some hidden power-up blocks only give out one power-up and in that case its a mushroom or not based on the player who hits the block - so be sure that a big player hits that if you have one.

Death & Bubbles

When a player dies but at least one other player lives the dead player comes back in a limbo bubble from which they must be released before they may play again. Because of this, in a tough spot you can send one player in and leave a second behind. If the first dies you don't lose your place in the level and the first comes back in a bubble ready to try again. For instance, if you're trying to get the last star coin in 2-1 which sits just above the abyss, one player can just jump to their death for it and as long as another player lives you've collected the coin. However you need not sacrifice your life to do this: you can press down and 'a' to force yourself into a bubble saving yourself from death. This is true in general as long as you have enough time to see your death coming. This is also useful if one player runs ahead to the right. The screen will expand a bit but then it will just move to the right following the player in the lead. Players left behind walls or now forced into lava pits will die unless they use the bubble.

Misc.

• If all players hit the ground at the same time from a ground pound it acts like hitting a pow block, killing the enemies on the screen.
• If you hold a player who has a projectile power over your head they can still use their power.
• Bubbles can be popped by hitting them with your fire or ice projectiles as well as thrown shells or blocks.
• All players get the extra lives from anyone collecting 100 coins or finishing a level with more than 7 enemies on the screen.

Creating Accelerators for Other People's Web Services

Before we shipped IE8 there were no Accelerators, so we had some fun making our own for our favorite web services. I've got a small set of tips for creating Accelerators for other people's web services. I was planning on writing this up as an IE blog post, but Jon wrote a post covering a similar area so rather than write a full and coherent blog post I'll just list a few points:

• The first thing to try is looking for developer help for the web service, specifically if there's a REST-ful URL based API. For example, Bing Maps has great URL API documentation that would be enough to create an Accelerator.
• The Accelerator XML is very similar to HTML forms. If you can find an HTML form for the web service for which you want to create an Accelerator, you can view the HTML source and create an Accelerator based on that.
• I created the FormToAccelerator extension based on the previous idea. You can use the extension to create an Accelerator from an HTML form, or just use it to create the start of one and edit it manually after.
• If the page doesn't use an HTML form, you can start up an HTTP debugger like Fiddler, use the web service from the normal web page, and then in Fiddler see if you can find a REST-ful looking URL you can use.
• When looking to create a preview for your Accelerator, see if the web page for the web service has a mobile version or a version that's intended to embed in other web pages via an iframe. On this same line, iPhone apps make great Accelerators usually with lovely previews.
• If there's no mobile or embeddable version and the only thing wrong with the normal web page for the web service is that the useful information doesn't fit in the preview window then see if you can find an HTML tag with a name or id near the useful information, and stick a '#' fragment pointing to that tag onto the preview URL template.
• Without a reasonable REST-ful API you can use a combination of Google's "site:" and "I'm Feeling Lucky" to find the most relevant page on a particular site.
• The value of a name and value pair need not consist of only a single Accelerator variable. You can get creative and put other text in there. For instance, I implemented a Google currency conversion by setting the query to "{selection} in US Dollars".

Infrared Paint Link Roundup

I like the idea of QR codes, encoding URLs and placing them on real world objects, but the QR codes themselves are kind of ugly. To make them less obvious I thought I could spray QR codes on to an object with an infrared reflective paint and shine infrared light on the QR codes, since most cameras, for instance the camera in my G1 phone, pick up infrared that our eyes do not.

In my search for infrared paint I've found a seller of IR ink (via programming forum) and an Infrared Paint Recipe (via IR FAQ).

In looking for this paint I've found that it comes up a lot in relation to the military for things like paint markers that are visible at night with proper equipment, and paint that absorbs IR light to make vehicles less obvious to night vision goggles. Even though the first reflects infrared light and the second absorbs it websites end up refering to both as infrared paint which made it difficult to search.

Additionally I found links to some other geeky infrared projects:

• Infrared goggles that block out all light except for the edge of infrared light that humans can perceive.
• A project to make infrared patterns and paint to screw with tourist video/photos.

New Home

Sarah and I have a new place in Redmond and we'll be moving there in a few weeks. Exciting! Incidentally, when researching the place on the Internet I found that the nearby park used to be a radar site for the Project Nike missile system in the fifties. Fun!