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• Spritebatch node animation appears to be broken in cocos2d-x 2.0.3

  - by George Host

  Hi I have spent aprox 2 days trying to get this to work doing a google searches left and right and I did get it working except for sprite batch nodes. So in my class I am able to load kuwalio_stand.png and I tested kuwalio_walk1.png and 2 and 3 from the FrameCache(). They work for sure 100%. I run this code and it does not animate does anyone else have the same issue with sprite batch nodes? cocos2d::CCSprite * player = Player::create(); player->setPosition(cocos2d::CCPointMake(0.0f,0.0f)); player->setDisplayFrame(cocos2d::CCSpriteFrameCache::sharedSpriteFrameCache()->spriteFrameByName("kuwalio_stand.png")); player->setTag(PlayerTag); cocos2d::CCAnimation * walk = cocos2d::CCAnimation::create(); cocos2d::CCSpriteFrame * walk1 = cocos2d::CCSpriteFrameCache::sharedSpriteFrameCache()->spriteFrameByName("kuwalio_walk1.png"); cocos2d::CCSpriteFrame * walk2 = cocos2d::CCSpriteFrameCache::sharedSpriteFrameCache()->spriteFrameByName("kuwalio_walk2.png"); cocos2d::CCSpriteFrame * walk3 = cocos2d::CCSpriteFrameCache::sharedSpriteFrameCache()->spriteFrameByName("kuwalio_walk3.png"); walk->addSpriteFrame(walk1); walk->addSpriteFrame(walk2); walk->addSpriteFrame(walk3); cocos2d::CCAnimate * actionWalk = cocos2d::CCAnimate::create(walk); cocos2d::CCRepeatForever * actionRepeat = cocos2d::CCRepeatForever::create(actionWalk); walk->setDelayPerUnit(0.1f); actionWalk->setDuration(10.1f); player->runAction(actionRepeat); // Change camera to a soft follow camera. this->runAction(cocos2d::CCFollow::create(player)); mSceneSpriteBatchNode->addChild(player); // Have the CCNode object run its virtual update function as fast as possible. // Every frame for this layer. this-scheduleUpdate(); Counter example without the sprite batch node... cocos2d::CCSprite * sprite = cocos2d::CCSprite::create("kuwalio_walk1.png"); this->addChild(sprite,0); sprite->setPosition(cocos2d::CCPointMake(60,60)); sprite->retain(); cocos2d::CCAnimation * actionAnimation = cocos2d::CCAnimation::create(); actionAnimation->setDelayPerUnit(0.01f); actionAnimation->retain(); actionAnimation->addSpriteFrameWithFileName("kuwalio_walk1.png"); actionAnimation->addSpriteFrameWithFileName("kuwalio_walk2.png"); actionAnimation->addSpriteFrameWithFileName("kuwalio_walk3.png"); cocos2d::CCAnimate * a = cocos2d::CCAnimate::create(actionAnimation); a->setDuration(0.10f); cocos2d::CCRepeatForever * actionRepeat = cocos2d::CCRepeatForever::create(a); sprite->runAction(actionRepeat);

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• The Loneliest Road in America and the OTN Garage

  - by rickramsey

  Source I never told anyone how the image of the OTN Garage on Facebook came to be. I took the Facebook picture on Route 50 in Nevada, USA, in October of 2010. I was riding from Colorado to Oracle OpenWorld in San Francisco, so it was probably October. Route 50 is known as "The Loneliest Road in America." There are roads across Nevada that have even LESS traffic, but Route 50 still one. desolate. road. Although I have seen stranger things while riding along Nevada's Extraterrestrial Highway, I still run across notable oddities every time I ride Route 50. Like the old man with a bandolero of water bottles jogging along the side of the highway in the middle of the day, 50 miles from the closest town. First ultra-marathoner I'd seen in action. He waved at me. Or the dozen Corvettes with California license plates driving toward me, all doing the speed limit in the middle of nowhere because they were being tailed by half a dozen Nevada state troopers. #fail. I don't remember which town I was in, but I noticed the building when I stopped at the gas station. While standing there pouring fuel into the Harley, the store caught my eye. So I pulled the bike in front and walked inside. The owner is a little old lady, about 100 years old. Most of the goods she had on the shelves looked like they had been placed there during WWII. She was itty bitty and could barely see over the counter, but she was so happy when I bought a bar of Hershey's chocolate that she gave me a five cent discount. I took a few pictures and, when I got back, Kemer Thomson, who sometimes blogs here, photoshopped the OTN Garage and Oil Change signs onto it. The bike is a 2009 Road King Classic with a Bob Dron fairing and a Corbin heated seat. The seat came in handy when I rode home over Tioga Pass. The Road King is a very comfy touring bike with a great Harley rumble. I'm kinda sorry I sold it. When I stopped for fuel about 75 miles down the road at the next town, I peeled back the chocolate bar. I had turned into powder. Probably 50 years ago. - Rick Website Newsletter Facebook Twitter

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• Thread placement policies on NUMA systems - update

  - by Dave

  In a prior blog entry I noted that Solaris used a "maximum dispersal" placement policy to assign nascent threads to their initial processors. The general idea is that threads should be placed as far away from each other as possible in the resource topology in order to reduce resource contention between concurrently running threads. This policy assumes that resource contention -- pipelines, memory channel contention, destructive interference in the shared caches, etc -- will likely outweigh (a) any potential communication benefits we might achieve by packing our threads more densely onto a subset of the NUMA nodes, and (b) benefits of NUMA affinity between memory allocated by one thread and accessed by other threads. We want our threads spread widely over the system and not packed together. Conceptually, when placing a new thread, the kernel picks the least loaded node NUMA node (the node with lowest aggregate load average), and then the least loaded core on that node, etc. Furthermore, the kernel places threads onto resources -- sockets, cores, pipelines, etc -- without regard to the thread's process membership. That is, initial placement is process-agnostic. Keep reading, though. This description is incorrect. On Solaris 10 on a SPARC T5440 with 4 x T2+ NUMA nodes, if the system is otherwise unloaded and we launch a process that creates 20 compute-bound concurrent threads, then typically we'll see a perfect balance with 5 threads on each node. We see similar behavior on an 8-node x86 x4800 system, where each node has 8 cores and each core is 2-way hyperthreaded. So far so good; this behavior seems in agreement with the policy I described in the 1st paragraph. I recently tried the same experiment on a 4-node T4-4 running Solaris 11. Both the T5440 and T4-4 are 4-node systems that expose 256 logical thread contexts. To my surprise, all 20 threads were placed onto just one NUMA node while the other 3 nodes remained completely idle. I checked the usual suspects such as processor sets inadvertently left around by colleagues, processors left offline, and power management policies, but the system was configured normally. I then launched multiple concurrent instances of the process, and, interestingly, all the threads from the 1st process landed on one node, all the threads from the 2nd process landed on another node, and so on. This happened even if I interleaved thread creating between the processes, so I was relatively sure the effect didn't related to thread creation time, but rather that placement was a function of process membership. I this point I consulted the Solaris sources and talked with folks in the Solaris group. The new Solaris 11 behavior is intentional. The kernel is no longer using a simple maximum dispersal policy, and thread placement is process membership-aware. Now, even if other nodes are completely unloaded, the kernel will still try to pack new threads onto the home lgroup (socket) of the primordial thread until the load average of that node reaches 50%, after which it will pick the next least loaded node as the process's new favorite node for placement. On the T4-4 we have 64 logical thread contexts (strands) per socket (lgroup), so if we launch 48 concurrent threads we will find 32 placed on one node and 16 on some other node. If we launch 64 threads we'll find 32 and 32. That means we can end up with our threads clustered on a small subset of the nodes in a way that's quite different that what we've seen on Solaris 10. So we have a policy that allows process-aware packing but reverts to spreading threads onto other nodes if a node becomes too saturated. It turns out this policy was enabled in Solaris 10, but certain bugs suppressed the mixed packing/spreading behavior. There are configuration variables in /etc/system that allow us to dial the affinity between nascent threads and their primordial thread up and down: see lgrp_expand_proc_thresh, specifically. In the OpenSolaris source code the key routine is mpo_update_tunables(). This method reads the /etc/system variables and sets up some global variables that will subsequently be used by the dispatcher, which calls lgrp_choose() in lgrp.c to place nascent threads. Lgrp_expand_proc_thresh controls how loaded an lgroup must be before we'll consider homing a process's threads to another lgroup. Tune this value lower to have it spread your process's threads out more. To recap, the 'new' policy is as follows. Threads from the same process are packed onto a subset of the strands of a socket (50% for T-series). Once that socket reaches the 50% threshold the kernel then picks another preferred socket for that process. Threads from unrelated processes are spread across sockets. More precisely, different processes may have different preferred sockets (lgroups). Beware that I've simplified and elided details for the purposes of explication. The truth is in the code. Remarks: It's worth noting that initial thread placement is just that. If there's a gross imbalance between the load on different nodes then the kernel will migrate threads to achieve a better and more even distribution over the set of available nodes. Once a thread runs and gains some affinity for a node, however, it becomes "stickier" under the assumption that the thread has residual cache residency on that node, and that memory allocated by that thread resides on that node given the default "first-touch" page-level NUMA allocation policy. Exactly how the various policies interact and which have precedence under what circumstances could the topic of a future blog entry. The scheduler is work-conserving. The x4800 mentioned above is an interesting system. Each of the 8 sockets houses an Intel 7500-series processor. Each processor has 3 coherent QPI links and the system is arranged as a glueless 8-socket twisted ladder "mobius" topology. Nodes are either 1 or 2 hops distant over the QPI links. As an aside the mapping of logical CPUIDs to physical resources is rather interesting on Solaris/x4800. On SPARC/Solaris the CPUID layout is strictly geographic, with the highest order bits identifying the socket, the next lower bits identifying the core within that socket, following by the pipeline (if present) and finally the logical thread context ("strand") on the core. But on Solaris on the x4800 the CPUID layout is as follows. [6:6] identifies the hyperthread on a core; bits [5:3] identify the socket, or package in Intel terminology; bits [2:0] identify the core within a socket. Such low-level details should be of interest only if you're binding threads -- a bad idea, the kernel typically handles placement best -- or if you're writing NUMA-aware code that's aware of the ambient placement and makes decisions accordingly. Solaris introduced the so-called critical-threads mechanism, which is expressed by putting a thread into the FX scheduling class at priority 60. The critical-threads mechanism applies to placement on cores, not on sockets, however. That is, it's an intra-socket policy, not an inter-socket policy. Solaris 11 introduces the Power Aware Dispatcher (PAD) which packs threads instead of spreading them out in an attempt to be able to keep sockets or cores at lower power levels. Maximum dispersal may be good for performance but is anathema to power management. PAD is off by default, but power management polices constitute yet another confounding factor with respect to scheduling and dispatching. If your threads communicate heavily -- one thread reads cache lines last written by some other thread -- then the new dense packing policy may improve performance by reducing traffic on the coherent interconnect. On the other hand if your threads in your process communicate rarely, then it's possible the new packing policy might result on contention on shared computing resources. Unfortunately there's no simple litmus test that says whether packing or spreading is optimal in a given situation. The answer varies by system load, application, number of threads, and platform hardware characteristics. Currently we don't have the necessary tools and sensoria to decide at runtime, so we're reduced to an empirical approach where we run trials and try to decide on a placement policy. The situation is quite frustrating. Relatedly, it's often hard to determine just the right level of concurrency to optimize throughput. (Understanding constructive vs destructive interference in the shared caches would be a good start. We could augment the lines with a small tag field indicating which strand last installed or accessed a line. Given that, we could augment the CPU with performance counters for misses where a thread evicts a line it installed vs misses where a thread displaces a line installed by some other thread.)

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• Responding to Invites

  - by Daniel Moth

  Following up from my post about Sending Outlook Invites here is a shorter one on how to respond. Whatever your choice (ACCEPT, TENTATIVE, DECLINE), if the sender has not unchecked the "Request Response" option, then send your response. Always send your response. Even if you think the sender made a mistake in keeping it on, send your response. Seriously, not responding is plain rude. If you knew about the meeting, and you are happy investing your time in it, and the time and location work for you, and there is an implicit/explicit agenda, then ACCEPT and send it. If one or more of those things don't work for you then you have a few options. Send a DECLINE explaining why. Reply with email to ask for further details or for a change to be made. If you don’t receive a response to your email, send a DECLINE when you've waited enough. Send a TENTATIVE if you haven't made up your mind yet. Hint: if they really require you there, they'll respond asking "why tentative" and you have a discussion about it. When you deem appropriate, instead of the options above, you can also use the counter propose feature of Outlook but IMO that feature has questionable interaction model and UI (on both sender and recipient) so many people get confused by it. BTW, two of my outlook rules are relevant to invites. The first one auto-marks as read the ACCEPT responses if there is no comment in the body of the accept (I check later who has accepted and who hasn't via the "Tracking" button of the invite). I don’t have a rule for the DECLINE and TENTATIVE cause typically I follow up with folks that send those.   The second rule ensures that all Invites go to a specific folder. That is the first folder I see when I triage email. It is also the only folder which I have configured to show a count of all items inside it, rather than the unread count - when sending a response to an invite the item disappears from the folder and hence it is empty and not nagging me. Comments about this post by Daniel Moth welcome at the original blog.

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• Just another web startup - platform comparison

  - by Holland

  I'm looking to do a web startup which involves something along the lines of an ecommerce site, yet a little more in depth than that. While it's something that I would rather not go into detail with in terms of the initial idea, I can specify (on a basic level) what would be required of the website. If you have any observations or opinions derived from personal experience, which relate to what you see here, I'd appreciate it if you could share these. Paypal's API interaction (definitely). From what I've read about their API, integration with it into their website is VERY expensive, so I'd probably hold off on that until I've (hopefully) generated money and write my own simple credit-card interaction system. SQL Backend (obviously) PostgreSQL seems like a pretty good choice, as from what I've read, it's structure is a bit more "object-oriented" than, say, MySQL. Then again, I've used MySQL before and haven't had much problem with it whatsoever. Would it be worth learning PostgreSQL for this purpose? Java or .Net implementation (Preferably Mono, so I can use .Net while hosting the website using Apache). The reason for this is because, frankly, while I know PHP is a great platform to develop websites with, I hate developing with it. Before someone chimes in and flames me for saying that, note that I have nothing against the language, I just don't like it for my purposes. While Mono may be good to go with, I'm aware that ASP.Net MVC 3 hasn't been released for Mono yet, which may be a pain to work with, without their Razor syntax. Ontop of that, it seems Java is completely FULL of class libraries which deal with web development, that can be downloaded from the web. If anyone has any experience with these, I'd appreciate if that were posted. From what I've read about Spring and Struts2, they seem to be the best out there - especially since they're (AFAIK) MVC. I've considered Python and Django, which do seem REALLY nice, but I don't know much Python, and I'd rather start with something that I already know (language-wise; not framework-wise) than dive into learning a language AND a new framework. I'd REALLY like to be able to host my website via Apache, rather than using Windows Server or anything like that, as, frankly, I hate their setup. I'm not dissing it in any way, shape, or form, I'm just saying I dislike it. <3 terminal config. If there is a good reason to with Windows Server, however, I'd be willing to learn it. C# has a lot of things that Java appears not to have, including Delegates, unsigned types, and LINQ. Is there anything that Java has which can counter these?

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• How to free up space on /boot? [closed]

  - by Phrogz

  Possible Duplicate: Free up more space on /boot I logged onto my server today to find the message: => /boot is using 98.9% of 91MB When I look at /boot I see that it is indeed very low on space, and has old-kernel files in it: phrogz@planar:~$ df -h /boot Filesystem Size Used Avail Use% Mounted on /dev/sda1 92M 54M 33M 63% /boot phrogz@planar:~$ la /boot total 81880 drwxr-xr-x 4 root root 3072 2011-12-02 06:26 ./ drwxr-xr-x 22 root root 4096 2011-09-29 06:37 ../ -rw-r--r-- 1 root root 646419 2011-03-01 19:02 abi-2.6.32-30-server -rw-r--r-- 1 root root 646419 2011-04-08 17:07 abi-2.6.32-31-server -rw-r--r-- 1 root root 646454 2011-04-20 16:53 abi-2.6.32-32-server -rw-r--r-- 1 root root 646454 2011-07-29 16:07 abi-2.6.32-33-server -rw-r--r-- 1 root root 646710 2011-09-13 18:00 abi-2.6.32-34-server -rw-r--r-- 1 root root 646820 2011-10-11 11:10 abi-2.6.32-35-server -rw-r--r-- 1 root root 110687 2011-03-01 19:02 config-2.6.32-30-server -rw-r--r-- 1 root root 110676 2011-04-08 17:07 config-2.6.32-31-server -rw-r--r-- 1 root root 110687 2011-04-20 16:53 config-2.6.32-32-server -rw-r--r-- 1 root root 110687 2011-07-29 16:07 config-2.6.32-33-server -rw-r--r-- 1 root root 110687 2011-09-13 18:00 config-2.6.32-34-server -rw-r--r-- 1 root root 110687 2011-10-11 11:10 config-2.6.32-35-server drwxr-xr-x 3 root root 6144 2011-12-02 06:26 grub/ -rw-r--r-- 1 root root 8258196 2011-05-18 11:58 initrd.img-2.6.32-30-server -rw-r--r-- 1 root root 8259568 2011-05-23 20:24 initrd.img-2.6.32-31-server -rw-r--r-- 1 root root 8257374 2011-05-30 07:47 initrd.img-2.6.32-32-server -rw-r--r-- 1 root root 8287489 2011-08-10 06:37 initrd.img-2.6.32-33-server -rw-r--r-- 1 root root 8288075 2011-09-29 06:37 initrd.img-2.6.32-34-server drwx------ 2 root root 12288 2011-05-18 11:46 lost+found/ -rw-r--r-- 1 root root 160280 2010-03-23 03:40 memtest86+.bin -rw-r--r-- 1 root root 2179117 2011-03-01 19:02 System.map-2.6.32-30-server -rw-r--r-- 1 root root 2179628 2011-04-08 17:07 System.map-2.6.32-31-server -rw-r--r-- 1 root root 2178240 2011-04-20 16:53 System.map-2.6.32-32-server -rw-r--r-- 1 root root 2178382 2011-07-29 16:07 System.map-2.6.32-33-server -rw-r--r-- 1 root root 2178952 2011-09-13 18:00 System.map-2.6.32-34-server -rw-r--r-- 1 root root 2179333 2011-10-11 11:10 System.map-2.6.32-35-server -rw-r--r-- 1 root root 1336 2011-03-01 19:08 vmcoreinfo-2.6.32-30-server -rw-r--r-- 1 root root 1336 2011-04-08 17:13 vmcoreinfo-2.6.32-31-server -rw-r--r-- 1 root root 1336 2011-04-20 16:54 vmcoreinfo-2.6.32-32-server -rw-r--r-- 1 root root 1336 2011-07-29 16:08 vmcoreinfo-2.6.32-33-server -rw-r--r-- 1 root root 1336 2011-09-13 18:03 vmcoreinfo-2.6.32-34-server -rw-r--r-- 1 root root 1336 2011-10-11 11:11 vmcoreinfo-2.6.32-35-server -rw-r--r-- 1 root root 4111552 2011-03-01 19:02 vmlinuz-2.6.32-30-server -rw-r--r-- 1 root root 4113344 2011-04-08 17:07 vmlinuz-2.6.32-31-server -rw-r--r-- 1 root root 4106528 2011-04-20 16:53 vmlinuz-2.6.32-32-server -rw-r--r-- 1 root root 4107648 2011-07-29 16:07 vmlinuz-2.6.32-33-server -rw-r--r-- 1 root root 4108960 2011-09-13 18:00 vmlinuz-2.6.32-34-server -rw-r--r-- 1 root root 4111040 2011-10-11 11:10 vmlinuz-2.6.32-35-server I was able to find the old kernel packages like so: phrogz@planar:/boot$ dpkg -l | grep linux-image ii linux-image-2.6.32-30-server 2.6.32-30.59 Linux kernel image for version 2.6.32 on x86 ii linux-image-2.6.32-31-server 2.6.32-31.61 Linux kernel image for version 2.6.32 on x86 ii linux-image-2.6.32-32-server 2.6.32-32.62 Linux kernel image for version 2.6.32 on x86 ii linux-image-2.6.32-33-server 2.6.32-33.72 Linux kernel image for version 2.6.32 on x86 ii linux-image-2.6.32-34-server 2.6.32-34.77 Linux kernel image for version 2.6.32 on x86 iF linux-image-2.6.32-35-server 2.6.32-35.78 Linux kernel image for version 2.6.32 on x86 iU linux-image-server 2.6.32.36.42 Linux kernel image on Server Equipment. …and I can see that many of them are older than my current image: phrogz@planar:/boot$ uname -a Linux planar 2.6.32-34-server #77-Ubuntu SMP Tue Sep 13 20:54:38 UTC 2011 x86_64 GNU/Linux However, I can't actually remove them due to an unmet dependency: phrogz@planar:/boot$ sudo apt-get --purge remove linux-image-2.6.32-30-server Reading package lists... Done Building dependency tree Reading state information... Done You might want to run `apt-get -f install' to correct these: The following packages have unmet dependencies: linux-image-server: Depends: linux-image-2.6.32-36-server but it is not going to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution). But I can't fix the dependency (presumably due to low disk space): phrogz@planar:/boot$ sudo apt-get -f install Reading package lists... Done Building dependency tree Reading state information... Done Correcting dependencies... Done The following packages were automatically installed and are no longer required: liblcms1 linux-headers-2.6.32-32-server libnspr4-0d linux-headers-2.6.32-33-server linux-headers-2.6.32-32 linux-headers-2.6.32-33 linux-headers-2.6.32-34 libcups2 tzdata-java libjpeg62 linux-headers-2.6.32-34-server libavahi-client3 ca-certificates-java libnss3-1d Use 'apt-get autoremove' to remove them. The following extra packages will be installed: linux-image-2.6.32-36-server Suggested packages: fdutils linux-doc-2.6.32 linux-source-2.6.32 linux-tools The following NEW packages will be installed: linux-image-2.6.32-36-server 0 upgraded, 1 newly installed, 0 to remove and 8 not upgraded. 3 not fully installed or removed. Need to get 0B/31.8MB of archives. After this operation, 128MB of additional disk space will be used. Do you want to continue [Y/n]? (Reading database ... 145200 files and directories currently installed.) Unpacking linux-image-2.6.32-36-server (from .../linux-image-2.6.32-36-server_2.6.32-36.79_amd64.deb) ... Done. dpkg: error processing /var/cache/apt/archives/linux-image-2.6.32-36-server_2.6.32-36.79_amd64.deb (--unpack): failed in buffer_write(fd) (10, ret=-1): backend dpkg-deb during `./boot/vmlinuz-2.6.32-36-server': No space left on device dpkg-deb: subprocess paste killed by signal (Broken pipe) Running postrm hook script /usr/sbin/update-grub. Generating grub.cfg ... Found linux image: /boot/vmlinuz-2.6.32-35-server Found linux image: /boot/vmlinuz-2.6.32-34-server Found initrd image: /boot/initrd.img-2.6.32-34-server Found linux image: /boot/vmlinuz-2.6.32-33-server Found initrd image: /boot/initrd.img-2.6.32-33-server Found linux image: /boot/vmlinuz-2.6.32-32-server Found initrd image: /boot/initrd.img-2.6.32-32-server Found linux image: /boot/vmlinuz-2.6.32-31-server Found initrd image: /boot/initrd.img-2.6.32-31-server Found linux image: /boot/vmlinuz-2.6.32-30-server Found initrd image: /boot/initrd.img-2.6.32-30-server Found memtest86+ image: /memtest86+.bin done Errors were encountered while processing: /var/cache/apt/archives/linux-image-2.6.32-36-server_2.6.32-36.79_amd64.deb E: Sub-process /usr/bin/dpkg returned an error code (1) How do I free up space on /boot so that I can fix my dependencies? Should I just delete the files manually? And then, should I resize my /boot to be larger, so this doesn't happen again? If so, how? If not, what maintenance should I be running regularly to prevent the accumulation of this cruft?

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• Where to draw the line between development-led security and administration-led security?

  - by haylem

  There are cases where you have the opportunity, as a developer, to enforce stricter security features and protections on a software, though they could very well be managed at an environmental level (ie, the operating system would take care of it). Where would you say you draw the line, and what elements do you factor in your decision? Concrete Examples User Management is the OS's responsibility Not exactly meant as a security feature, but in a similar case Google Chrome used to not allow separate profiles. The invoked reason (though it now supports multiple profiles for a same OS user) used to be that user management was the operating system's responsibility. Disabling Web-Form Fields A recurrent request I see addressed online is to have auto-completion be disabled on form fields. Auto-completion didn't exist in old browsers, and was a welcome feature at the time it was introduced for people who needed to fill in forms often. But it also brought in some security concerns, and so some browsers started to implement, on top of the (obviously needed) setting in their own preference/customization panel, an autocomplete attribute for form or input fields. And this has now been introduced into the upcoming HTML5 standard. For browsers who do not listen to this attribute, strange hacks *\ are offered, like generating unique IDs and names for fields to avoid them from being suggested in future forms (which comes with another herd of issues, like polluting your local auto-fill cache and not preventing a password from being stored in it, but instead probably duplicating its occurences). In this particular case, and others, I'd argue that this is a user setting and that it's the user's desire and the user's responsibility to enable or disable auto-fill (by disabling the feature altogether). And if it is based on an internal policy and security requirement in a corporate environment, then substitute the user for the administrator in the above. I assume it could be counter-argued that the user may want to access non-critical applications (or sites) with this handy feature enabled, and critical applications with this feature disabled. But then I'd think that's what security zones are for (in some browsers), or the sign that you need a more secure (and dedicated) environment / account to use these applications. * I obviously don't deny the ingenuity of the people who were forced to find workarounds, just the necessity of said workarounds. Questions That was a tad long-winded, so I guess my questions are: Would you in general consider it to be the application's (hence, the developer's) responsiblity? Where do you draw the line, if not in the "general" case?

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• Prevent your Silverlight XAP file from caching in your browser.

  - by mbcrump

  If you work with Silverlight daily then you have run into this problem. Your XAP file has been cached in your browser and you have to empty your browser cache to resolve it. If your using Google Chrome then you typically do the following: Go to Options –> Clear Browsing History –> Empty the Cache and finally click Clear Browsing data. As you can see, this is a lot of unnecessary steps. It is even worse when you have a customer that says, “I can’t see the new features you just implemented!” and you realize it’s a cached xap problem.  I have been struggling with a way to prevent my XAP file from caching inside of a browser for a while now and decided to implement the following solution. If the Visual Studio Debugger is attached then add a unique query string to the source param to force the XAP file to be refreshed. If the Visual Studio Debugger is not attached then add the source param as Visual Studio generates it. This is also in case I forget to remove the above code in my production environment. I want the ASP.NET code to be inline with my .ASPX page. (I do not want a separate code behind .cs page or .vb page attached to the .aspx page.) Below is an example of the hosting code generated when you create a new Silverlight project. As a quick refresher, the hard coded param name = “source” specifies the location of your XAP file.  <form id="form1" runat="server" style="height:100%"> <div id="silverlightControlHost"> <object data="data:application/x-silverlight-2," type="application/x-silverlight-2" width="100%" height="100%"> <param name="source" value="ClientBin/SilverlightApplication2.xap"/> <param name="onError" value="onSilverlightError" /> <param name="background" value="white" /> <param name="minRuntimeVersion" value="4.0.50826.0" /> <param name="autoUpgrade" value="true" /> <a href="http://go.microsoft.com/fwlink/?LinkID=149156&v=4.0.50826.0" style="text-decoration:none"> <img src="http://go.microsoft.com/fwlink/?LinkId=161376" alt="Get Microsoft Silverlight" style="border-style:none"/> </a> </object><iframe id="_sl_historyFrame" style="visibility:hidden;height:0px;width:0px;border:0px"></iframe></div> </form> We are going to use a little bit of inline ASP.NET to generate the param name = source dynamically to prevent the XAP file from caching. Lets look at the completed solution: <form id="form1" runat="server" style="height:100%"> <div id="silverlightControlHost"> <object data="data:application/x-silverlight-2," type="application/x-silverlight-2" width="100%" height="100%"> <% string strSourceFile = @"ClientBin/SilverlightApplication2.xap"; string param; if (System.Diagnostics.Debugger.IsAttached) //Debugger Attached - Refresh the XAP file. param = "<param name=\"source\" value=\"" + strSourceFile + "?" + DateTime.Now.Ticks + "\" />"; else { //Production Mode param = "<param name=\"source\" value=\"" + strSourceFile + "\" />"; } Response.Write(param); %> <param name="onError" value="onSilverlightError" /> <param name="background" value="white" /> <param name="minRuntimeVersion" value="4.0.50826.0" /> <param name="autoUpgrade" value="true" /> <a href="http://go.microsoft.com/fwlink/?LinkID=149156&v=4.0.50826.0" style="text-decoration:none"> <img src="http://go.microsoft.com/fwlink/?LinkId=161376" alt="Get Microsoft Silverlight" style="border-style:none"/> </a> </object><iframe id="_sl_historyFrame" style="visibility:hidden;height:0px;width:0px;border:0px"></iframe></div> </form> We add the location to our XAP file to strSourceFile and if the debugger is attached then it will append DateTime.Now.Ticks to the XAP file source and force the browser to download the .XAP. If you view the page source of your Silverlight Application then you can verify it worked properly by looking at the param name = “source” tag as shown below. <param name="source" value="ClientBin/SilverlightApplication2.xap?634299001187160148" /> If the debugger is not attached then it will use the standard source tag as shown below. <param name="source" value="ClientBin/SilverlightApplication2.xap"/> At this point you may be asking, How do I prevent my XAP file from being cached on my production app? Well, you have two easy options: 1) I really don’t recommend this approach but you can force the XAP to be refreshed everytime with the following code snippet.  <param name="source" value="ClientBin/SilverlightApplication2.xap?<%=Guid.NewGuid().ToString() %>"/> NOTE: You could also substitute the “Guid.NewGuid().ToString() for anything that create a random field. (I used DateTime.Now.Ticks earlier). 2) Another solution that I like even better involves checking the XAP Creation Date and appending it to the param name = source. This method was described by Lars Holm Jenson. <% string strSourceFile = @"ClientBin/SilverlightApplication2.xap"; string param; if (System.Diagnostics.Debugger.IsAttached) param = "<param name=\"source\" value=\"" + strSourceFile + "\" />"; else { string xappath = HttpContext.Current.Server.MapPath(@"") + @"\" + strSourceFile; DateTime xapCreationDate = System.IO.File.GetLastWriteTime(xappath); param = "<param name=\"source\" value=\"" + strSourceFile + "?ignore=" + xapCreationDate.ToString() + "\" />"; } Response.Write(param); %> As you can see, this problem has been solved. It will work with all web browsers and stubborn proxy servers that are caching your .XAP. If you enjoyed this article then check out my blog for others like this. You may also want to subscribe to my blog or follow me on Twitter.   Subscribe to my feed

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• Why All The Hype Around Live Help?

  - by ruth.donohue

  I am pleased to introduce guest blogger, Damien Acheson today. Based in Cambridge, MA, Damien is the Product Marketing Manager for ATG’s Live Help products. Welcome, Damien!! BY DAMIEN ACHESON Why all the hype around live help? An eCommerce professional recently asked me: “Why all the hype around live chat and click to call?” I already have a customer service phone number that’s available to my online visitors. Why would I want to add live help? If anything, I want my website to reduce the number of calls to my contact center, not increase it!” The effect of adding live help to a website is counter-intuitive. Done right, live help doesn’t increase your call volume; it optimizes it by replacing traditional telephone calls with smarter, more productive, live voice and live chat interactions. This generates instant cost savings, and a measurable lift in sales and customer retention. A live help interaction differs from a traditional telephone call in six radical ways: Targeting. With live help you can target specific visitors at just the exact right time with a live call or live chat invitation based on hundreds of different parameters. For example, visitors who appear to hesitate before making a large purchase may receive a live help invitation, while others may not. Productivity. By reserving live voice to visitors with complex questions, and offering self-service and live chat for more simple interactions, agents with the right domain expertise can handle simultaneous queries and achieve substantial productivity gains. Routing. Live help interactions take into account visitors’ web context to intelligently route queries to the best available agent, thereby lifting first contact resolution. Context. Traditional telephone numbers force online customers to “change channels” and “start over” with a phone agent. With Live help, agents get the context of the web session and can instantly access the customer’s transaction details and account information, substantially reducing handle times. Interaction. Agents can solve a customer’s problem more effectively co-browsing and collaborating with the visitor in real-time to complete online forms and transactions. Analytics. Unlike traditional telephone numbers, live help allows you to tie Web analytics to customer satisfaction and agent performance indicators. To better understand these differences and advantages over traditional customer service, watch this demo on optimizing customer interactions with Live Help. Technorati Tags: ATG,Live Help,Commerce

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• SQL SERVER – Weekly Series – Memory Lane – #034

  - by Pinal Dave

  Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 UDF – User Defined Function to Strip HTML – Parse HTML – No Regular Expression The UDF used in the blog does fantastic task – it scans entire HTML text and removes all the HTML tags. It keeps only valid text data without HTML task. This is one of the quite commonly requested tasks many developers have to face everyday. De-fragmentation of Database at Operating System to Improve Performance Operating system skips MDF file while defragging the entire filesystem of the operating system. It is absolutely fine and there is no impact of the same on performance. Read the entire blog post for my conversation with our network engineers. Delay Function – WAITFOR clause – Delay Execution of Commands How do you delay execution of the commands in SQL Server – ofcourse by using WAITFOR keyword. In this blog post, I explain the same with the help of T-SQL script. Find Length of Text Field To measure the length of TEXT fields the function is DATALENGTH(textfield). Len will not work for text field. As of SQL Server 2005, developers should migrate all the text fields to VARCHAR(MAX) as that is the way forward. Retrieve Current Date Time in SQL Server CURRENT_TIMESTAMP, GETDATE(), {fn NOW()} There are three ways to retrieve the current datetime in SQL SERVER. CURRENT_TIMESTAMP, GETDATE(), {fn NOW()} Explanation and Comparison of NULLIF and ISNULL An interesting observation is NULLIF returns null if it comparison is successful, whereas ISNULL returns not null if its comparison is successful. In one way they are opposite to each other. Here is my question to you - How to create infinite loop using NULLIF and ISNULL? If this is even possible? 2008 Introduction to SERVERPROPERTY and example SERVERPROPERTY is a very interesting system function. It returns many of the system values. I use it very frequently to get different server values like Server Collation, Server Name etc. SQL Server Start Time We can use DMV to find out what is the start time of SQL Server in 2008 and later version. In this blog you can see how you can do the same. Find Current Identity of Table Many times we need to know what is the current identity of the column. I have found one of my developers using aggregated function MAX () to find the current identity. However, I prefer following DBCC command to figure out current identity. Create Check Constraint on Column Some time we just need to create a simple constraint over the table but I have noticed that developers do many different things to make table column follow rules than just creating constraint. I suggest constraint is a very useful concept and every SQL Developer should pay good attention to this subject. 2009 List Schema Name and Table Name for Database This is one of the blog post where I straight forward display script. One of the kind of blog posts, which I still love to read and write. Clustered Index on Separate Drive From Table Location A table devoid of primary key index is called heap, and here data is not arranged in a particular order, which gives rise to issues that adversely affect performance. Data must be stored in some kind of order. If we put clustered index on it then the order will be forced by that index and the data will be stored in that particular order. Understanding Table Hints with Examples Hints are options and strong suggestions specified for enforcement by the SQL Server query processor on DML statements. The hints override any execution plan the query optimizer might select for a query. 2010 Data Pages in Buffer Pool – Data Stored in Memory Cache One of my earlier year article, which I still read it many times and point developers to read it again. It is clear from the Resultset that when more than one index is used, datapages related to both or all of the indexes are stored in Memory Cache separately. TRANSACTION, DML and Schema Locks Can you create a situation where you can see Schema Lock? Well, this is a very simple question, however during the interview I notice over 50 candidates failed to come up with the scenario. In this blog post, I have demonstrated the situation where we can see the schema lock in database. 2011 Solution – Puzzle – Statistics are not updated but are Created Once In this example I have created following situation: Create Table Insert 1000 Records Check the Statistics Now insert 10 times more 10,000 indexes Check the Statistics – it will be NOT updated Auto Update Statistics and Auto Create Statistics for database is TRUE Now I have requested two things in the example 1) Why this is happening? 2) How to fix this issue? Selecting Domain from Email Address This is a straight to script blog post where I explain how to select only domain name from entire email address. Solution – Generating Zero Without using Any Numbers in T-SQL How to get zero digit without using any digit? This is indeed a very interesting question and the answer is even interesting. Try to come up with answer in next 10 minutes and if you can’t come up with the answer the blog post read this post for solution. 2012 Simple Explanation and Puzzle with SOUNDEX Function and DIFFERENCE Function In simple words - SOUNDEX converts an alphanumeric string to a four-character code to find similar-sounding words or names. DIFFERENCE function returns an integer value. The  integer returned is the number of characters in the SOUNDEX values that are the same. Read Only Files and SQL Server Management Studio (SSMS) I have come across a very interesting feature in SSMS related to “Read Only” files. I believe it is a little unknown feature as well so decided to write a blog about the same. Identifying Column Data Type of uniqueidentifier without Querying System Tables How do I know if any table has a uniqueidentifier column and what is its value without using any DMV or System Catalogues? Only information you know is the table name and you are allowed to return any kind of error if the table does not have uniqueidentifier column. Read the blog post to find the answer. Solution – User Not Able to See Any User Created Object in Tables – Security and Permissions Issue Interesting question – “When I try to connect to SQL Server, it lets me connect just fine as well let me open and explore the database. I noticed that I do not see any user created instances but when my colleague attempts to connect to the server, he is able to explore the database as well see all the user created tables and other objects. Can you help me fix it?” Importing CSV File Into Database – SQL in Sixty Seconds #018 – Video Here is interesting small 60 second video on how to import CSV file into Database. ColumnStore Index – Batch Mode vs Row Mode Here is the logic behind when Columnstore Index uses Batch Mode and when it uses Row Mode. A batch typically represents about 1000 rows of data. Batch mode processing also uses algorithms that are optimized for the multicore CPUs and increased memory throughput. Follow up – Usage of $rowguid and $IDENTITY This is an excellent follow up blog post of my earlier blog post where I explain where to use $rowguid and $identity.  If you do not know the difference between them, this is a blog with a script example. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• ASP.NET WebAPI Security 5: JavaScript Clients

  - by Your DisplayName here!

  All samples I showed in my last post were in C#. Christian contributed another client sample in some strange language that is supposed to work well in browsers ;) JavaScript client scenarios There are two fundamental scenarios when it comes to JavaScript clients. The most common is probably that the JS code is originating from the same web application that also contains the web APIs. Think a web page that does some AJAX style callbacks to an API that belongs to that web app – Validation, data access etc. come to mind. Single page apps often fall in that category. The good news here is that this scenario just works. The typical course of events is that the user first logs on to the web application – which will result in an authentication cookie of some sort. That cookie will get round-tripped with your AJAX calls and ASP.NET does its magic to establish a client identity context. Since WebAPI inherits the security context from its (web) host, the client identity is also available here. The other fundamental scenario is JavaScript code *not* running in the context of the WebAPI hosting application. This is more or less just like a normal desktop client – either running in the browser, or if you think of Windows 8 Metro style apps as “real” desktop apps. In that scenario we do exactly the same as the samples did in my last post – obtain a token, then use it to call the service. Obtaining a token from IdentityServer’s resource owner credential OAuth2 endpoint could look like this: thinktectureIdentityModel.BrokeredAuthentication = function (stsEndpointAddress, scope) {     this.stsEndpointAddress = stsEndpointAddress;     this.scope = scope; }; thinktectureIdentityModel.BrokeredAuthentication.prototype = function () {     getIdpToken = function (un, pw, callback) {         $.ajax({             type: 'POST',             cache: false,             url: this.stsEndpointAddress,             data: { grant_type: "password", username: un, password: pw, scope: this.scope },             success: function (result) {                 callback(result.access_token);             },             error: function (error) {                 if (error.status == 401) {                     alert('Unauthorized');                 }                 else {                     alert('Error calling STS: ' + error.responseText);                 }             }         });     };     createAuthenticationHeader = function (token) {         var tok = 'IdSrv ' + token;         return tok;     };     return {         getIdpToken: getIdpToken,         createAuthenticationHeader: createAuthenticationHeader     }; } (); Calling the service with the requested token could look like this: function getIdentityClaimsFromService() {     authHeader = authN.createAuthenticationHeader(token);     $.ajax({         type: 'GET',         cache: false,         url: serviceEndpoint,         beforeSend: function (req) {             req.setRequestHeader('Authorization', authHeader);         },         success: function (result) {              $.each(result.Claims, function (key, val) {                 $('#claims').append($('<li>' + val.Value + '</li>'))             });         },         error: function (error) {             alert('Error: ' + error.responseText);         }     }); I updated the github repository, you can can play around with the code yourself.

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• Guide to MySQL & NoSQL, Webinar Q&A

  - by Mat Keep

  0 0 1 959 5469 Homework 45 12 6416 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-ansi-language:EN-US;} Yesterday we ran a webinar discussing the demands of next generation web services and how blending the best of relational and NoSQL technologies enables developers and architects to deliver the agility, performance and availability needed to be successful. Attendees posted a number of great questions to the MySQL developers, serving to provide additional insights into areas like auto-sharding and cross-shard JOINs, replication, performance, client libraries, etc. So I thought it would be useful to post those below, for the benefit of those unable to attend the webinar. Before getting to the Q&A, there are a couple of other resources that maybe useful to those looking at NoSQL capabilities within MySQL: - On-Demand webinar (coming soon!) - Slides used during the webinar - Guide to MySQL and NoSQL whitepaper  - MySQL Cluster demo, including NoSQL interfaces, auto-sharing, high availability, etc.  So here is the Q&A from the event  Q. Where does MySQL Cluster fit in to the CAP theorem? A. MySQL Cluster is flexible. A single Cluster will prefer consistency over availability in the presence of network partitions. A pair of Clusters can be configured to prefer availability over consistency. A full explanation can be found on the MySQL Cluster & CAP Theorem blog post.  Q. Can you configure the number of replicas? (the slide used a replication factor of 1) Yes. A cluster is configured by an .ini file. The option NoOfReplicas sets the number of originals and replicas: 1 = no data redundancy, 2 = one copy etc. Usually there's no benefit in setting it >2. Q. Interestingly most (if not all) of the NoSQL databases recommend having 3 copies of data (the replication factor).    Yes, with configurable quorum based Reads and writes. MySQL Cluster does not need a quorum of replicas online to provide service. Systems that require a quorum need > 2 replicas to be able to tolerate a single failure. Additionally, many NoSQL systems take liberal inspiration from the original GFS paper which described a 3 replica configuration. MySQL Cluster avoids the need for a quorum by using a lightweight arbitrator. You can configure more than 2 replicas, but this is a tradeoff between incrementally improved availability, and linearly increased cost. Q. Can you have cross node group JOINS? Wouldn't that run into the risk of flooding the network? MySQL Cluster 7.2 supports cross nodegroup joins. A full cross-join can require a large amount of data transfer, which may bottleneck on network bandwidth. However, for more selective joins, typically seen with OLTP and light analytic applications, cross node-group joins give a great performance boost and network bandwidth saving over having the MySQL Server perform the join. Q. Are the details of the benchmark available anywhere? According to my calculations it results in approx. 350k ops/sec per processor which is the largest number I've seen lately The details are linked from Mikael Ronstrom's blog The benchmark uses a benchmarking tool we call flexAsynch which runs parallel asynchronous transactions. It involved 100 byte reads, of 25 columns each. Regarding the per-processor ops/s, MySQL Cluster is particularly efficient in terms of throughput/node. It uses lock-free minimal copy message passing internally, and maximizes ID cache reuse. Note also that these are in-memory tables, there is no need to read anything from disk. Q. Is access control (like table) planned to be supported for NoSQL access mode? Currently we have not seen much need for full SQL-like access control (which has always been overkill for web apps and telco apps). So we have no plans, though especially with memcached it is certainly possible to turn-on connection-level access control. But specifically table level controls are not planned. Q. How is the performance of memcached APi with MySQL against memcached+MySQL or any other Object Cache like Ecache with MySQL DB? With the memcache API we generally see a memcached response in less than 1 ms. and a small cluster with one memcached server can handle tens of thousands of operations per second. Q. Can .NET can access MemcachedAPI? Yes, just use a .Net memcache client such as the enyim or BeIT memcache libraries. Q. Is the row level locking applicable when you update a column through memcached API? An update that comes through memcached uses a row lock and then releases it immediately. Memcached operations like "INCREMENT" are actually pushed down to the data nodes. In most cases the locks are not even held long enough for a network round trip. Q. Has anyone published an example using something like PHP? I am assuming that you just use the PHP memcached extension to hook into the memcached API. Is that correct? Not that I'm aware of but absolutely you can use it with php or any of the other drivers Q. For beginner we need more examples. Take a look here for a fully worked example Q. Can I access MySQL using Cobol (Open Cobol) or C and if so where can I find the coding libraries etc? A. There is a cobol implementation that works well with MySQL, but I do not think it is Open Cobol. Also there is a MySQL C client library that is a standard part of every mysql distribution Q. Is there a place to go to find help when testing and/implementing the NoSQL access? If using Cluster then you can use the [email protected] alias or post on the MySQL Cluster forum Q. Are there any white papers on this?  Yes - there is more detail in the MySQL Guide to NoSQL whitepaper If you have further questions, please don’t hesitate to use the comments below!

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• Impulsioned jumping

  - by Mutoh

  There's one thing that has been puzzling me, and that is how to implement a 'faux-impulsed' jump in a platformer. If you don't know what I'm talking about, then think of the jumps of Mario, Kirby, and Quote from Cave Story. What do they have in common? Well, the height of your jump is determined by how long you keep the jump button pressed. Knowing that these character's 'impulses' are built not before their jump, as in actual physics, but rather while in mid-air - that is, you can very well lift your finger midway of the max height and it will stop, even if with desacceleration between it and the full stop; which is why you can simply tap for a hop and hold it for a long jump -, I am mesmerized by how they keep their trajetories as arcs. My current implementation works as following: While the jump button is pressed, gravity is turned off and the avatar's Y coordenate is decremented by the constant value of the gravity. For example, if things fall at Z units per tick, it will rise Z units per tick. Once the button is released or the limit is reached, the avatar desaccelerates in an amount that would make it cover X units until its speed reaches 0; once it does, it accelerates up until its speed matches gravity - sticking to the example, I could say it accelerates from 0 to Z units/tick while still covering X units. This implementation, however, makes jumps too diagonal, and unless the avatar's speed is faster than the gravity, which would make it way too fast in my current project (it moves at about 4 pixels per tick and gravity is 10 pixels per tick, at a framerate of 40FPS), it also makes it more vertical than horizontal. Those familiar with platformers would notice that the character's arc'd jump almost always allows them to jump further even if they aren't as fast as the game's gravity, and when it doesn't, if not played right, would prove itself to be very counter-intuitive. I know this because I could attest that my implementation is very annoying. Has anyone ever attempted at similar mechanics, and maybe even succeeded? I'd like to know what's behind this kind of platformer jumping. If you haven't ever had any experience with this beforehand and want to give it a go, then please, don't try to correct or enhance my explained implementation, unless I was on the right way - try to make up your solution from scratch. I don't care if you use gravity, physics or whatnot, as long as it shows how these pseudo-impulses work, it does the job. Also, I'd like its presentation to avoid a language-specific coding; like, sharing us a C++ example, or Delphi... As much as I'm using the XNA framework for my project and wouldn't mind C# stuff, I don't have much patience to read other's code, and I'm certain game developers of other languages would be interested in what we achieve here, so don't mind sticking to pseudo-code. Thank you beforehand.

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• Wifi hotspot disconnected after some time

  - by Rohit Bansal

  I am trying to use my Ubuntu system as Wifi Hotspot, but for some reason Hotspot get disconnected on its own. Searching for the solution, I found this help : Why is my ethernet connection connecting and disconnecting repeatedly? Reading through the above article I used the following command sudo killall dnsmasq as a result I manage to establish hotspot for around 5-10 sec before getting disconnected as against immediately.... Here's the system log (in case needed) tail -f /var/log/syslog : Apr 1 23:31:42 NetworkManager[901]: <info> Starting dnsmasq... Apr 1 23:31:42 NetworkManager[901]: <info> (wlan0): device state change: ip-config -> activated (reason 'none') [70 100 0] Apr 1 23:31:42 dnsmasq[4159]: started, version 2.57 cachesize 150 Apr 1 23:31:42 dnsmasq[4159]: compile time options: IPv6 GNU-getopt DBus I18N DHCP TFTP IDN Apr 1 23:31:42 dnsmasq-dhcp[4159]: DHCP, IP range 10.42.43.10 -- 10.42.43.100, lease time 1h Apr 1 23:31:42 dnsmasq[4159]: reading /etc/resolv.conf Apr 1 23:31:42 dnsmasq[4159]: using nameserver 220.226.6.104#53 Apr 1 23:31:42 dnsmasq[4159]: using nameserver 220.226.100.40#53 Apr 1 23:31:42 dnsmasq[4159]: cleared cache Apr 1 23:31:42 NetworkManager[901]: <info> Activation (wlan0) successful, device activated. Apr 1 23:31:42 NetworkManager[901]: <info> Activation (wlan0) Stage 5 of 5 (IP Configure Commit) complete. Apr 1 23:31:42 NetworkManager[901]: <info> Activation (wlan0) Stage 4 of 5 (IP4 Configure Get) complete. Apr 1 23:31:42 dbus[885]: [system] Activating service name='org.freedesktop.nm_dispatcher' (using servicehelper) Apr 1 23:31:42 dbus[885]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher' Connection established at this point....now disconnecting after 10 sec... Apr 1 23:31:52 ntpdate[4194]: adjust time server 91.189.94.4 offset -0.011589 sec Apr 1 23:32:01 NetworkManager[901]: <info> (wlan0): IP6 addrconf timed out or failed. Apr 1 23:32:01 NetworkManager[901]: <info> Activation (wlan0) Stage 4 of 5 (IP6 Configure Timeout) scheduled... Apr 1 23:32:01 NetworkManager[901]: <info> Activation (wlan0) Stage 4 of 5 (IP6 Configure Timeout) started... Apr 1 23:32:01 NetworkManager[901]: <info> Activation (wlan0) Stage 5 of 5 (IP Configure Commit) started... Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert INPUT --in-interface wlan0 --protocol tcp --destination-port 53 --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert INPUT --in-interface wlan0 --protocol udp --destination-port 53 --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert INPUT --in-interface wlan0 --protocol tcp --destination-port 67 --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert INPUT --in-interface wlan0 --protocol udp --destination-port 67 --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert FORWARD --in-interface wlan0 --jump REJECT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert FORWARD --out-interface wlan0 --jump REJECT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert FORWARD --in-interface wlan0 --out-interface wlan0 --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert FORWARD --source 10.42.43.0/255.255.255.0 --in-interface wlan0 --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert FORWARD --destination 10.42.43.0/255.255.255.0 --out-interface wlan0 --match state --state ESTABLISHED,RELATED --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table nat --insert POSTROUTING --source 10.42.43.0/255.255.255.0 ! --destination 10.42.43.0/255.255.255.0 --jump MASQUERADE Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert INPUT --in-interface wlan0 --protocol tcp --destination-port 53 --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert INPUT --in-interface wlan0 --protocol udp --destination-port 53 --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert INPUT --in-interface wlan0 --protocol tcp --destination-port 67 --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert INPUT --in-interface wlan0 --protocol udp --destination-port 67 --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert FORWARD --in-interface wlan0 --jump REJECT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert FORWARD --out-interface wlan0 --jump REJECT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert FORWARD --in-interface wlan0 --out-interface wlan0 --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert FORWARD --source 10.42.43.0/255.255.255.0 --in-interface wlan0 --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table filter --insert FORWARD --destination 10.42.43.0/255.255.255.0 --out-interface wlan0 --match state --state ESTABLISHED,RELATED --jump ACCEPT Apr 1 23:32:01 NetworkManager[901]: <info> Executing: /sbin/iptables --table nat --insert POSTROUTING --source 10.42.43.0/255.255.255.0 ! --destination 10.42.43.0/255.255.255.0 --jump MASQUERADE Apr 1 23:32:01 NetworkManager[901]: <info> Starting dnsmasq... Apr 1 23:32:01 NetworkManager[901]: <info> Activation (wlan0) Stage 5 of 5 (IP Configure Commit) complete. Apr 1 23:32:01 NetworkManager[901]: <info> Activation (wlan0) Stage 4 of 5 (IP6 Configure Timeout) complete. Apr 1 23:32:01 NetworkManager[901]: <warn> dnsmasq died with signal 9 Apr 1 23:32:01 NetworkManager[901]: <info> (wlan0): device state change: activated -> failed (reason 'sharing-start-failed') [100 120 18] Apr 1 23:32:01 dnsmasq[4235]: started, version 2.57 cachesize 150 Apr 1 23:32:01 dnsmasq[4235]: compile time options: IPv6 GNU-getopt DBus I18N DHCP TFTP IDN Apr 1 23:32:01 dnsmasq-dhcp[4235]: DHCP, IP range 10.42.43.10 -- 10.42.43.100, lease time 1h Apr 1 23:32:01 NetworkManager[901]: <warn> Activation (wlan0) failed for access point (Reppify Ubuntu) Apr 1 23:32:01 dnsmasq[4235]: reading /etc/resolv.conf Apr 1 23:32:01 dnsmasq[4235]: using nameserver 220.226.6.104#53 Apr 1 23:32:01 dnsmasq[4235]: using nameserver 220.226.100.40#53 Apr 1 23:32:01 dnsmasq[4235]: cleared cache Apr 1 23:32:01 NetworkManager[901]: <warn> Activation (wlan0) failed. Apr 1 23:32:01 NetworkManager[901]: <info> (wlan0): device state change: failed -> disconnected (reason 'none') [120 30 0] Apr 1 23:32:01 NetworkManager[901]: <info> (wlan0): deactivating device (reason 'none') [0] Apr 1 23:32:01 dbus[885]: [system] Activating service name='org.freedesktop.nm_dispatcher' (using servicehelper) Apr 1 23:32:01 dbus[885]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher' Apr 1 23:32:01 NetworkManager[901]: <error> [1333303321.565351] [nm-device-wifi.c:1815] nm_device_wifi_set_mode(): (wlan0): error setting mode 2

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• How much freedom should a programmer have in choosing a language and framework?

  - by Spencer

  I started working at a company that is primarily a C# oriented. We have a few people who like Java and JRuby, but a majority of programmers here like C#. I was hired because I have a lot of experience building web applications and because I lean towards newer technologies like JRuby on Rails or nodejs. I have recently started on a project building a web application with a focus on getting a lot of stuff done in a short amount of time. The software lead has dictated that I use mvc4 instead of rails. That might be OK, except I don't know mvc4, I don't know C# and I am the only one responsible for creating the web application server and front-end UI. Wouldn't it make sense to use a framework that I already know extremely well (Rails) instead of using mvc4? The two reasons behind the decision was that the tech lead doesn't know Jruby/rails and there would be no way to reuse the code. Counter arguments: He won't be contributing to the code and is frankly, not needed on this project. So, it doesn't really matter if he knows JRuby/rails or not. We actually can reuse the code since we have a lot of java apps that JRuby can pull code from and vice-versa. In fact, he has dedicated some resources to convert a Java library to C#, instead of just running the Java library on the JRuby on Rails app. All because he doesn't like Java or JRuby I have built many web applications, but using something unfamiliar is causing some spin-up and I am unable to build an awesome application in as short of a time that I'm used to. This would be fine, learning new technologies is important in this field. The problem is, for this project, we need to get a lot done in a short period of time. At what point should a developer be allowed to choose his tools? Is this dependent on the company? Does my company suck or is this considered normal? Do greener pastures exist? Am I looking at this the wrong way? Bonus: Should I just keep my head down and move along at a snails pace, or defy orders and go with what I know in order to make this project more successful? Edit: I had actually created a fully function rails application (on my own time) and showed it to the team and it did not seem to matter. I am currently porting it to mvc4 (slowly).

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• Development-led security vs administration-led security in a software product?

  - by haylem

  There are cases where you have the opportunity, as a developer, to enforce stricter security features and protections on a software, though they could very well be managed at an environmental level (ie, the operating system would take care of it). Where would you say you draw the line, and what elements do you factor in your decision? Concrete Examples User Management is the OS's responsibility Not exactly meant as a security feature, but in a similar case Google Chrome used to not allow separate profiles. The invoked reason (though it now supports multiple profiles for a same OS user) used to be that user management was the operating system's responsibility. Disabling Web-Form Fields A recurrent request I see addressed online is to have auto-completion be disabled on form fields. Auto-completion didn't exist in old browsers, and was a welcome feature at the time it was introduced for people who needed to fill in forms often. But it also brought in some security concerns, and so some browsers started to implement, on top of the (obviously needed) setting in their own preference/customization panel, an autocomplete attribute for form or input fields. And this has now been introduced into the upcoming HTML5 standard. For browsers that do not listen to this attribute, strange hacks* are offered, like generating unique IDs and names for fields to avoid them from being suggested in future forms (which comes with another herd of issues, like polluting your local auto-fill cache and not preventing a password from being stored in it, but instead probably duplicating its occurences). In this particular case, and others, I'd argue that this is a user setting and that it's the user's desire and the user's responsibility to enable or disable auto-fill (by disabling the feature altogether). And if it is based on an internal policy and security requirement in a corporate environment, then substitute the user for the administrator in the above. I assume it could be counter-argued that the user may want to access non-critical applications (or sites) with this handy feature enabled, and critical applications with this feature disabled. But then I'd think that's what security zones are for (in some browsers), or the sign that you need a more secure (and dedicated) environment / account to use these applications. * I obviously don't deny the ingeniosity of the people who were forced to find workarounds, just the necessity of said workarounds. Questions That was a tad long-winded, so I guess my questions are: Would you in general consider it to be the application's (hence, the developer's) responsiblity? Where do you draw the line, if not in the "general" case?

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• Does Your Customer Engagement Create an Ah Feeling?

  - by Richard Lefebvre

  An (Oracle CX Blog) article by Christina McKeon Companies that successfully engage customers all have one thing in common. They make it seem easy for the customer to get what they need. No one would argue that brands don’t want to leave customers with this “ah” feeling. Since 94% of customers who have a low-effort service experience will buy from that company again, it makes financial sense for brands.1 Some brands are thinking differently about how they engage their customers to create ah feelings. How do they do it? Toyota is a great example of using smart assistance technology to understand customer intent and answer questions before customers hit the submit button online. What is unique in this situation is that Toyota captures intent while customers are filling out email forms. Toyota analyzes the data in the form and suggests responses before the customer sends the email. The customer gets the right answer, and the email never makes it to your contact center — which makes you and the customer happy. Most brands are fully aware of chat as a service channel, but some brands take chat to a whole new level. Beauty.com, part of the drugstore.com and Walgreens family of brands, uses live chat to replicate the personal experience that one would find at high-end department store cosmetic counters. Trained beauty advisors, all with esthetician or beauty counter experience, engage in live chat sessions with online shoppers to share immediate advice on the best products for their personal needs. Agents can watch customer activity online and determine the right time to reach out and offer help, just as help would be offered in a brick-and-mortar store. And, agents can co-browse along with the customer helping customers with online check-out. These personal chat discussions also give Beauty.com the opportunity to present products, advertise promotions, and resolve customer issues when they arise. Beauty.com converts approximately 25% of chat sessions into product orders. Photobox, the European market leader in online photo services, wanted to deliver personal and responsive service to its 24 million members. It ensures customer inquiries on personalized photo products are routed based on agent knowledge so customers get what they need from the company experts. By using a queuing system to ensure that the agent with the most appropriate knowledge handles the query, agent productivity increased while response times to 1,500 customer queries per day decreased. A real-time dashboard prevents agents from being overloaded with queries. This approach has produced financial results with a 15% increase in sales to existing customers and a 45% increase in orders from newly referred customers.

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• Windows Azure Diagnostics: Next to Useless?

  - by Your DisplayName here!

  To quote my good friend Christian: “Tracing is probably one of the most discussed topics in the Windows Azure world. Not because it is freaking cool – but because it can be very tedious and partly massively counter-intuitive.” <rant> The .NET Framework has this wonderful facility called TraceSource. You define a named trace and route that to a configurable listener. This gives you a lot of flexibility – you can create a single trace file – or multiple ones. There is even nice tooling around that. SvcTraceViewer from the SDK let’s you open the XML trace files – you can filter and sort by trace source and event type, aggreate multiple files…blablabla. Just what you would expect from a decent tracing infrastructure. Now comes Windows Azure. I was already were grateful that starting with the SDK 1.2 we finally had a way to do tracing and diagnostics in the cloud (kudos!). But the way the Azure DiagnosticMonitor is currently implemented – could be called flawed. The Azure SDK provides a DiagnosticsMonitorTraceListener – which is the right way to go. The only problem is, that way this works is, that all traces (from all sources) get written to an ETW trace. Then the DiagMon listens to these traces and copies them periodically to your storage account. So far so good. But guess what happens to your nice trace files: the trace source names get “lost”. They appear in your message text at the end. So much for filtering and sorting and aggregating (regex #fail or #win??). Every trace line becomes an entry in a Azure Storage Table – the svclog format is gone. So much for the existing tooling. To solve that problem, one workaround was to write your own trace listener (!) that creates svclog files inside of local storage and use the DiagMon to copy those. Christian has a blog post about that. OK done that. Now it turns out that this mechanism does not work anymore in 1.3 with FullIIS (see here). Quoting: “Some IIS 7.0 logs not collected due to permissions issues...The root cause to both of these issues is the permissions on the log files.” And the workaround: “To read the files yourself, log on to the instance with a remote desktop connection.” Now then have fun with your multi-instance deployments…. </rant>

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• add collision detection to sprite?

  - by xBroak

  bassically im trying to add collision detection to the sprite below, using the following: self.rect = bounds_rect collide = pygame.sprite.spritecollide(self, wall_list, False) if collide: # yes print("collide") However it seems that when the collide is triggered it continuously prints 'collide' over and over when instead i want them to simply not be able to walk through the object, any help? def update(self, time_passed): """ Update the creep. time_passed: The time passed (in ms) since the previous update. """ if self.state == Creep.ALIVE: # Maybe it's time to change the direction ? # self._change_direction(time_passed) # Make the creep point in the correct direction. # Since our direction vector is in screen coordinates # (i.e. right bottom is 1, 1), and rotate() rotates # counter-clockwise, the angle must be inverted to # work correctly. # self.image = pygame.transform.rotate( self.base_image, -self.direction.angle) # Compute and apply the displacement to the position # vector. The displacement is a vector, having the angle # of self.direction (which is normalized to not affect # the magnitude of the displacement) # displacement = vec2d( self.direction.x * self.speed * time_passed, self.direction.y * self.speed * time_passed) self.pos += displacement # When the image is rotated, its size is changed. # We must take the size into account for detecting # collisions with the walls. # self.image_w, self.image_h = self.image.get_size() global bounds_rect bounds_rect = self.field.inflate( -self.image_w, -self.image_h) if self.pos.x < bounds_rect.left: self.pos.x = bounds_rect.left self.direction.x *= -1 elif self.pos.x > bounds_rect.right: self.pos.x = bounds_rect.right self.direction.x *= -1 elif self.pos.y < bounds_rect.top: self.pos.y = bounds_rect.top self.direction.y *= -1 elif self.pos.y > bounds_rect.bottom: self.pos.y = bounds_rect.bottom self.direction.y *= -1 self.rect = bounds_rect collide = pygame.sprite.spritecollide(self, wall_list, False) if collide: # yes print("collide") elif self.state == Creep.EXPLODING: if self.explode_animation.active: self.explode_animation.update(time_passed) else: self.state = Creep.DEAD self.kill() elif self.state == Creep.DEAD: pass #------------------ PRIVATE PARTS ------------------# # States the creep can be in. # # ALIVE: The creep is roaming around the screen # EXPLODING: # The creep is now exploding, just a moment before dying. # DEAD: The creep is dead and inactive # (ALIVE, EXPLODING, DEAD) = range(3) _counter = 0 def _change_direction(self, time_passed): """ Turn by 45 degrees in a random direction once per 0.4 to 0.5 seconds. """ self._counter += time_passed if self._counter > randint(400, 500): self.direction.rotate(45 * randint(-1, 1)) self._counter = 0 def _point_is_inside(self, point): """ Is the point (given as a vec2d) inside our creep's body? """ img_point = point - vec2d( int(self.pos.x - self.image_w / 2), int(self.pos.y - self.image_h / 2)) try: pix = self.image.get_at(img_point) return pix[3] > 0 except IndexError: return False def _decrease_health(self, n): """ Decrease my health by n (or to 0, if it's currently less than n) """ self.health = max(0, self.health - n) if self.health == 0: self._explode() def _explode(self): """ Starts the explosion animation that ends the Creep's life. """ self.state = Creep.EXPLODING pos = ( self.pos.x - self.explosion_images[0].get_width() / 2, self.pos.y - self.explosion_images[0].get_height() / 2) self.explode_animation = SimpleAnimation( self.screen, pos, self.explosion_images, 100, 300) global remainingCreeps remainingCreeps-=1 if remainingCreeps == 0: print("all dead")

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• My Graduate Experience at Oracle by Mayuri Khinvasara

  - by david.talamelli

  My experience at Oracle. I still vividly remember the day, when my name was announced in the campus hiring list of Oracle at my college. I was proud of myself but at the same time, I was getting goose bumps!!! A new world had arrived before me and the anxiousness of whether I could survive it or not had gripped me. Nervous about moving into an unknown city, I came to visit Hyderabad with my father. One look at the Oracle Campus and I felt some kind of magnetism pulling me towards it. And then, I joined Oracle in June 2009, with a lot of apprehensions in my mind. The HR Rep made us really comfortable in the first week itself. I met so many new people, managers, HR folks and most importantly 20 other Campus Hires like me. Then we had our team bonding sessions, team parties etc. I didn’t realize when the transition from campus to corporate happened. And I had started loving it. The confidence the HR Reps gave us and the bonding our managers imbibed in us, made us all ready for the new life ahead. Then started the rigorous training sessions, the excitement about our new work, new cubicles, new desktops, our first business cards, our first conference call and so on. I made new friends which were now my extended family, the freedom and courage of living alone. I was enjoying all that. As I was getting totally immersed into my regular work schedule I started getting to know the innumerable Oracle products, their functionalities, implementations and realizing the brand that Oracle is. Work pressure started increasing and so did the challenges to understand and deliver. I Didn’t realize how days and soon months passed by. Then came a golden chance to visit the Oracle Headquarters in US for 45 days training in November 2009. Once again, the excitement was enormous about the counter team-mates in HQ, the trainings ahead, the US work culture and my stay there. I felt so privileged for the company I was working. Boarding an international flight for the first time and visiting famous US cities which I had just seen in movies, was now a reality. It was a totally amazing experience. Work pressure kept me really busy, with learning new things every day, the immense satisfaction of delivering something, the nightmares of debugging a mistake, only to realize how silly it was.  I was enjoying the process. Soon a year passed by. I had transformed into this corporate software professional, I couldn’t believe I could be. Today, I complete 1 year and 8 months at Oracle and continue to look forward to the enriching experience I will have here. Truly one of the Top Companies in the World. Mayuri Khinvasara

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• Misadventures at Radio Shack

  - by Chris Williams

  While I'm waiting for my Arduino kits to show up, I started reading the Getting Started With Arduino book from O'Reilly (review coming later) and I'm about 40 pages in when I get to a parts list for one of the first projects. Looks pretty straightforward, and even has Radio Shack part numbers next to almost everything. So on my lunch today, I decided to run out to "The Shack" (seriously, that's their rebranding?) to pick up some basics, like a couple resistors, a breadboard, a momentary switch and a pack of pre-cut jumper wires. I found the resistors without any difficulty, and while they didn't have the exact switch I wanted, it was easy enough to find one that would do. That's where my good luck abruptly ended. I was surprised that I couldn't find a breadboard or any jumper wires, so while I was looking around, a guy came up and asked me if I needed some help. I told him I did, explained what I needed and even gave him the Radio Shack part number for the pack of jumper wires. After a couple minutes he says he can't find anything in the system, which was unfortunate but not the end of the world.  So then I asked him about the breadboard, and he pointed me to some blank circuitboards (which are not the same thing) and I said (nicely) that those weren't breadboards and attempted to explain (again) what I needed, at which point he says to me "I don't even know what the hell you're looking for!" I stood there for a moment and tried to process his words. About that time, another salesperson came up and asked what I was trying to find. I told her I needed a breadboard, and she pointed to the blank circuit boards and said "they're right in front of you..." After seeing the look on my face, she thought for a minute and said... "OH! you mean those white things. We don't have those anymore." I thanked her, set everything down on the counter and left. (I wasn't going to buy only half the stuff I needed.. and I was pretty sure I was never going to be buying ANYTHING at that particular location ever again.) Guess I'll be ordering more stuff online at this point. It's a shame really, because I used to LOVE going to Radio Shack as a kid, and looking through all the cool electronics components and stuff, even if I didnt understand what most of them were at the time. Seems like the only thing they carry in any quantity/variety now is cell phones and random stereo connectors.

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• Configurable tables in sql database

  - by dot

  I have the following tables in my database: Config Table: ====================================== Start_Range | End Range | Config_id 10 | 15 | 1 ====================================== Available_UserIDs ========================== ID | UserID | Used_YN | 1 | 10 | t | 1 | 11 | f | 1 | 12 | f | 1 | 13 | f | 1 | 14 | f | 1 | 15 | f | ========================== Users ========================== UserId | FName | LName | 10 |John | Doe | ========================== This is used in a reservation system of sorts... which lets an administrator specify a range of numbers that will be assigned to users in the config table. Once the range has been defined, the system then populates the Available_userIDs table with all the numbers in between the range, and sets the Used_YN flag to false As users sign up, they grab the next user_id number that's not in use... and reserve it. Then the system adds a record to the Users table. Once the admin has specified a range, it is possible that they can change it. For example, they can start with 10-15... and then when the range is used up, they should be able to specify another range like 16 - 99. I've put a unique constraint on the Available_UserIDs table, as well as on the Users table - to ensure that UserIds can't be duplicated. My questions are as follows: What's the best way to prevent the admins from using a range that's already in use? I thought of the following options: -- check either the Users table to see if the start range or ending range numbers are being used. If they are, assume that all the numbers in between are in use too, and reject the range. -- let them specify whatever they want, try to populate the Available_UserIDs table. If there are duplicates, just ignore that specific error message from the database and continue on. How do I find gaps in the number ranges? For example, if they specify 10-15, and then 20-25, it'd be nice to be able to somehow suggest on my web page that 16-19 is currently available. I found this article: http://stackoverflow.com/questions/1312101/how-to-find-a-gap-in-running-counter-with-sql But it only seems to return the first available number... so in my example above, it would only return the number 16. I'm sure there's a simpler way to do things that I'm overlooking!

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• How to refactor my design, if it seems to require multiple inheritance?

  - by Omega

  Recently I made a question about Java classes implementing methods from two sources (kinda like multiple inheritance). However, it was pointed out that this sort of need may be a sign of a design flaw. Hence, it is probably better to address my current design rather than trying to simulate multiple inheritance. Before tackling the actual problem, some background info about a particular mechanic in this framework: It is a simple game development framework. Several components allocate some memory (like pixel data), and it is necessary to get rid of it as soon as you don't need it. Sprites are an example of this. Anyway, I decided to implement something ala Manual-Reference-Counting from Objective-C. Certain classes, like Sprites, contain an internal counter, which is increased when you call retain(), and decreased on release(). Thus the Resource abstract class was created. Any subclass of this will obtain the retain() and release() implementations for free. When its count hits 0 (nobody is using this class), it will call the destroy() method. The subclass needs only to implement destroy(). This is because I don't want to rely on the Garbage Collector to get rid of unused pixel data. Game objects are all subclasses of the Node class - which is the main construction block, as it provides info such as position, size, rotation, etc. See, two classes are used often in my game. Sprites and Labels. Ah... but wait. Sprites contain pixel data, remember? And as such, they need to extend Resource. But this, of course, can't be done. Sprites ARE nodes, hence they must subclass Node. But heck, they are resources too. Why not making Resource an interface? Because I'd have to re-implement retain() and release(). I am avoiding this in virtue of not writing the same code over and over (remember that there are multiple classes that need this memory-management system). Why not composition? Because I'd still have to implement methods in Sprite (and similar classes) that essentially call the methods of Resource. I'd still be writing the same code over and over! What is your advice in this situation, then?

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• Collision in PyGame for spinning rectangular object.touching circles

  - by OverAchiever

  I'm creating a variation of Pong. One of the differences is that I use a rectangular structure as the object which is being bounced around, and I use circles as paddles. So far, all the collision handling I've worked with was using simple math (I wasn't using the collision "feature" in PyGame). The game is contained within a 2-dimensional continuous space. The idea is that the rectangular structure will spin at different speed depending on how far from the center you touch it with the circle. Also, any extremity of the rectangular structure should be able to touch any extremity of the circle. So I need to keep track of where it has been touched on both the circle and the rectangle to figure out the direction it will be bounced to. I intend to have basically 8 possible directions (Up, down, left, right and the half points between each one of those). I can work out the calculation of how the objected will be dislocated once I get the direction it will be dislocated to based on where it has been touch. I also need to keep track of where it has been touched to decide if the rectangular structure will spin clockwise or counter-clockwise after it collided. Before I started coding, I read the resources available at the PyGame website on the collision class they have (And its respective functions). I tried to work out the logic of what I was trying to achieve based on those resources and how the game will function. The only thing I could figure out that I could do was to make each one of these objects as a group of rectangular objects, and depending on which rectangle was touched the other would behave accordingly and give the illusion it is a single object. However, not only I don't know if this will work, but I also don't know if it is gonna look convincing based on how PyGame redraws the objects. Is there a way I can use PyGame to handle these collision detections by still having a single object? Can I figure out the point of collision on both objects using functions within PyGame precisely enough to achieve what I'm looking for? P.s: I hope the question was specific and clear enough. I apologize if there were any grammar mistakes, English is not my native language.

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• RTS Game Style Application [closed]

  - by Daniel Wynand van Wyk

  My question may seem somewhat odd, but I hope that my specifications will clarify EXACTLY what it is that I am after. I need some help choosing the right tooling for a particular endeavour. My background is in desktop application development and large back-end systems. I have worked primarily on the Microsoft stack using C# and the .Net framework. My goal is to develop a 2D, RTS style, interactive office simulation. The simulation will model various office spaces, office equipment, employees and their interactions with one another. The idea is to abstract the concept of an office completely. Under the hood the application will do many things that are nothing like a game. This includes P2P networking, VPN tunnelling, streaming video, instant messaging, document collaboration, remote screen sharing, file-sharing, virus scanning, VOIP, document scanning, faxing, emailing, distributed computing, content management and much more! A somewhat similar thing has been attempted by IBM, where they created a virtual office in second life. If their attempt was a game, the game-play would be notably horrible, to say the least! The users/players will drive and control my application through the various objects modelled in the simulation. A single application capable of performing all of these various tasks would be a nightmare to navigate for even the most expert user. Using the concept of a game, I can easily separate functionality by assigning them to objects that relate 1-1 with their real world counter-parts. This can greatly simplify computing for novice users, with many added benefits in terms of visibility, transparency of process and centralized configuration. My hope is to make complex computing tasks accessible to all kinds of users and to greatly reduce the cognitive load associated with using the many different utilities and applications inside office settings. The complexity is therefore limited to the complexity of the space in which you find yourself. I want the application to target as many platforms as possible and run on computers that have no accelerated graphics capabilities. The simulation won't contain any of the fancy eye-candy you find in modern games, to the contrary, my "game" will purposefully be clean and simple. The closest thing I could imagine would be an old game like "Theme Hospital" or the first instalment of "The Sims". All the content will be pre-created and not user-generated like Second Life. New functionality will be added via a plugin system. Given my background and nature of my "game", I would like to spend most of my time writing code that does not have to do with the simulated office, as the "game" is really just a glorified application menu. I have done much reading about existing engines, frameworks and tools. I need the help of an experienced game developer who has tried and tested various products over the years who can guide me in the right direction given my very particular needs. I would appreciate any help I can get!

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