*Less* reliable? At least/dev/null willl never lose your zeros.
On a serious note, I've seen XFS fail in a machine that was rebooted normally only once; that is, installed the system on a XFS partition, booted it up, shutdown -r now after 2 months... file system error. No bad blocks on the disk, just fs corruption during normal operation.
I do like how Konqueror will let you just type "ssh://SOMEADDRESS" and act as nice file browser with all the drag and drop joy you get locally, and maybe Nautilus will let you do that
It works, athough "ssh" will be automatically replaced by "sftp".
"Preserving momentum" is just a matter of rotating the velocity to the new orientation. Some complications may arise when a complex system of interconnected bodies goes partially through the portal (e.g. you can't move just one body to the new location, or you'll violate the joints' constraints). Other than that, ODE can trivially support "portalling" bodies. Make sure to create contact joints in the proper places (they must be relative to the body).
I believe the worst standards are the ones that limit the languages to make them work as another language. Typically it's C++, or even Java, transformed into C. "No operator overloading, no virtual methods, no multiple inheritance, no function/method overloading, no const, no 'non-standard for' constructs, no return statements (other than at a function's end), no function call inside parenthesis (as an operator, or as an if/while test), no class constructors/destructors, no STL/Boost/whatever, no long (+15 chars) identifier names".
Amazingly, even Google (which you would expect to only hire high-level developers) has some of these guidelines for C++.
The best guideline is no guideline at all. Take your potential guideline, and present the rationale to the developers, with colorful examples to show what problems the guidelines are trying to avoid. Show them what "bad code" looks like and as soon as they realize they will naturally avoid it. If they argue against a specific rule it means that it's either a silly one (and should be discarded) or the guy is too dense to understand the problem (which means he needs more training, like maintaining a really awful code base).
Ray tracing is firing rays from each screen pixel, test for collision against the geometry, and figure out the proper color. RTM is firing rays from each polygon's "pixel", test for collision against the "texture geometry", and figure out the proper color. It's just ray tracing in a subset of the screen pixels, in a geometry (heigthmap) represented by a texture (or multiple textures) from a polygonal face. Why do you think this is not related to ray tracing?
A good way to mix both techniques is Relief Texture Mapping. It's a good way to get smooth surfaces thanks to the texture interpolation hardware, with no extra polygons.
That's pretty much unfeasible. Every game needs a different physics simulation. Rigid bodies, ropes, soft bodies, particles, cloth, and so on; each requires a very different strategy. And there are many special cases where you can customize the algorithms for your specific simulation; using a more general algorithm when a specialized one is possible is less efficient.
And this doesn't even get into the details about strategy; continuous vs fixed time steps, different orders of integration, collision detection and so on. Each has its own quirks; and Nintendo is proving us all the time that you can create superb games using almost no physics.
A constructor may throw an exception; partially-constructed objects may not be destructed. Not only you have destruct the objects in the reverse order, but have to figure out which objects to destruct. It's much more complex than plain return or goto.
Not only that, exceptions aren't supposed to slow down your program when you don't throw any; so to compile efficiently, you have to maintain some specialized data structures to avoid "checking for exceptions" for every function call.
Then there's the catch block: if you throw a Child object you can catch it as a Mother class; and C++ allows multiple-inheritance (thanks God^H^H^HStroustrup), so at every catch block you have to test (efficiently) if the types match.
So I don't think a compiler supporting just goto and return can acceptably implement exceptions.
It only approaches O(n log n) behavior when the data are completely randomized.
No. Quicksort is O(n log n) on average. There are pathological scenarios, but all other instances absorb the O(n^2) worst case. Sedgewick's PhD (under Knuth's) was about Quicksort, try reading it if you are nuts enough. Or even read Knuth's volume on sorting, to see hem distilating and comparing even the constants from the algorithms.
But let's not forget that when an iterator "go outside their container" you already have a serious logic error. The same logic error can be even more catastrophic in other languages that do run-time checking to avoid crashing, and allow you to do something like "on error resume next". BTW, you are allowed to derivate from standard containers and create checked operations (like operator[] that maps to at()).
Other languages have novel approaches to solve C++ problems, but nothing can stop logic errors, wrong algorithms, bad programmers, etc.
I'm accessing youtube from Brazil right now. The judge's decision was not clear as to wheter only the video be censored for Brazil, or the whole site be blocked. Cicarelli's lawyer seems to think that the whole site should be blocked from all the 8 backbones that serve internet connectivity to Brazil. Nobody else seems to interpret the judge's decision that way. This issue will be clarified monday.
Renato Malzoni Filho is from a very rich and influent family (go figure). They are in fact fighting against any common sense, everybody in the media is saying how absurd is to try to block a whole site in the whole country. It could backfire. In fact, it already did; everyone in Brazil is downloading said video from other sources just because it was on the news.
The video is pretty boring, there are much more hardcore stuffs on brazilian dramas.
In short, Novell can "protect" SCO from being crushed by IBM; [GNU]/Linux will lose the opportunity to be shown to be "legitim" (contrary to some of SCO's claims), thus closing the possibility for a precedent (that would free it from the risk of future attacks).
I don't like coments like yours. You are assuming that I could afford a machine powerful enough to run anything more than Win9x.
Here on Brazil, computers are expensive because people earn less money than on 1st world countries. For you, a new computer (or a significant upgrade) may cost only a few bucks; but here it is expensive. The machine in question only recently had an upgrade from 128 MB to 256 MB (and only then it was able to run a free desktop at a not-so-annoying speed); it's a P3 650 MHz, acquired in 1999 as a P2 400 MHz with 32 MB. You know what, a lot of people in the world don't have money to buy computers, let alone upgrade it every 2 years to run the latest MS crap.
Win9x runs pefectly on old machines - and are a lot faster on newer ones. On the downside, any GNU/Linux desktop is able to perform even slower than WinXP on any machine, unless it's completely stripped down. The main reason is for the memory consumption (Linux's memory manager sucks beyond imagination; it doesn't crash, but any user program can easily halt the reponsivity).
Interestingly, a few years ago I was always telling my parents how great GNU/Linux was, and because of this they "should buy me a new HD" to install it. Unfortunately I didn't get the HD, but they were "educated" by my insistence. A few months ago (a few months after me installing Mandriva 2005 on their computers) I found out that they were having GNU/Linux classes. Now they are happily using Firefox, GAIM, Frozen Bubble, Lilypond, etc. Guess what, my mother was even able to configure the WiFi network on her Mandriva 2006 (using nothing but a few "numbers" I had written down on paper).
So yes, it's about the approach. Learn what they want to do with their computers, then show how this "new" operating system will be much more fun and useful to use. You should see my mother's face when she learned how to use Firefox' tabs, or my father's when he learned that he could transcribe his partitures collection to the computer. In a few months I'll remove the Win98SE from that machine, and I bet they'll never miss it again.
Your text gives the idea that Celestia is an amateur software. Let's just make it clear for those who know nothing about it. Celestia is an excelent software, just isn't designed for this purpose.
Last time I heard, Celestia had stagnated. The main developer is taking "prolonged vacations", and nobody else understands the complex engine enough to make further improvements.
If you consider the "freedom" involved in Free Software, you'll notice that they use their modified software for their own purposes. They are free to use the software in any way, they are free to modify it. And they aren't distributing it, so they aren't distributing the source code of their changes. I don't see any problem with it.
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*Less* reliable? At least /dev/null willl never lose your zeros.
On a serious note, I've seen XFS fail in a machine that was rebooted normally only once; that is, installed the system on a XFS partition, booted it up, shutdown -r now after 2 months... file system error. No bad blocks on the disk, just fs corruption during normal operation.
I do like how Konqueror will let you just type "ssh://SOMEADDRESS" and act as nice file browser with all the drag and drop joy you get locally, and maybe Nautilus will let you do that
It works, athough "ssh" will be automatically replaced by "sftp".
"Preserving momentum" is just a matter of rotating the velocity to the new orientation. Some complications may arise when a complex system of interconnected bodies goes partially through the portal (e.g. you can't move just one body to the new location, or you'll violate the joints' constraints). Other than that, ODE can trivially support "portalling" bodies. Make sure to create contact joints in the proper places (they must be relative to the body).
I believe the worst standards are the ones that limit the languages to make them work as another language. Typically it's C++, or even Java, transformed into C. "No operator overloading, no virtual methods, no multiple inheritance, no function/method overloading, no const, no 'non-standard for' constructs, no return statements (other than at a function's end), no function call inside parenthesis (as an operator, or as an if/while test), no class constructors/destructors, no STL/Boost/whatever, no long (+15 chars) identifier names".
Amazingly, even Google (which you would expect to only hire high-level developers) has some of these guidelines for C++.
The best guideline is no guideline at all. Take your potential guideline, and present the rationale to the developers, with colorful examples to show what problems the guidelines are trying to avoid. Show them what "bad code" looks like and as soon as they realize they will naturally avoid it. If they argue against a specific rule it means that it's either a silly one (and should be discarded) or the guy is too dense to understand the problem (which means he needs more training, like maintaining a really awful code base).
Ray tracing is firing rays from each screen pixel, test for collision against the geometry, and figure out the proper color. RTM is firing rays from each polygon's "pixel", test for collision against the "texture geometry", and figure out the proper color. It's just ray tracing in a subset of the screen pixels, in a geometry (heigthmap) represented by a texture (or multiple textures) from a polygonal face. Why do you think this is not related to ray tracing?
Yes, it can. See the "Relief Maps with Silhouttes" demo. Notice the shadows too. Try the demos, they even work on wine, with a cheap FX 5200.
A good way to mix both techniques is Relief Texture Mapping. It's a good way to get smooth surfaces thanks to the texture interpolation hardware, with no extra polygons.
Which amounts to 58 bits. With 64 bit integers, so we can have a granularity of 1/64 of a second.
That's pretty much unfeasible. Every game needs a different physics simulation. Rigid bodies, ropes, soft bodies, particles, cloth, and so on; each requires a very different strategy. And there are many special cases where you can customize the algorithms for your specific simulation; using a more general algorithm when a specialized one is possible is less efficient.
And this doesn't even get into the details about strategy; continuous vs fixed time steps, different orders of integration, collision detection and so on. Each has its own quirks; and Nintendo is proving us all the time that you can create superb games using almost no physics.
2 words: constructors and destructors.
A constructor may throw an exception; partially-constructed objects may not be destructed. Not only you have destruct the objects in the reverse order, but have to figure out which objects to destruct. It's much more complex than plain return or goto.
Not only that, exceptions aren't supposed to slow down your program when you don't throw any; so to compile efficiently, you have to maintain some specialized data structures to avoid "checking for exceptions" for every function call.
Then there's the catch block: if you throw a Child object you can catch it as a Mother class; and C++ allows multiple-inheritance (thanks God^H^H^HStroustrup), so at every catch block you have to test (efficiently) if the types match.
So I don't think a compiler supporting just goto and return can acceptably implement exceptions.
Actually, LoGH has no sound in space, only inside exploding ships.
No. Quicksort is O(n log n) on average. There are pathological scenarios, but all other instances absorb the O(n^2) worst case. Sedgewick's PhD (under Knuth's) was about Quicksort, try reading it if you are nuts enough. Or even read Knuth's volume on sorting, to see hem distilating and comparing even the constants from the algorithms.
But let's not forget that when an iterator "go outside their container" you already have a serious logic error. The same logic error can be even more catastrophic in other languages that do run-time checking to avoid crashing, and allow you to do something like "on error resume next". BTW, you are allowed to derivate from standard containers and create checked operations (like operator[] that maps to at()).
Other languages have novel approaches to solve C++ problems, but nothing can stop logic errors, wrong algorithms, bad programmers, etc.
Some interesting points:
I'm accessing youtube from Brazil right now. The judge's decision was not clear as to wheter only the video be censored for Brazil, or the whole site be blocked. Cicarelli's lawyer seems to think that the whole site should be blocked from all the 8 backbones that serve internet connectivity to Brazil. Nobody else seems to interpret the judge's decision that way. This issue will be clarified monday.
Renato Malzoni Filho is from a very rich and influent family (go figure). They are in fact fighting against any common sense, everybody in the media is saying how absurd is to try to block a whole site in the whole country. It could backfire. In fact, it already did; everyone in Brazil is downloading said video from other sources just because it was on the news.
The video is pretty boring, there are much more hardcore stuffs on brazilian dramas.
In short, Novell can "protect" SCO from being crushed by IBM; [GNU]/Linux will lose the opportunity to be shown to be "legitim" (contrary to some of SCO's claims), thus closing the possibility for a precedent (that would free it from the risk of future attacks).
I don't like coments like yours. You are assuming that I could afford a machine powerful enough to run anything more than Win9x.
Here on Brazil, computers are expensive because people earn less money than on 1st world countries. For you, a new computer (or a significant upgrade) may cost only a few bucks; but here it is expensive. The machine in question only recently had an upgrade from 128 MB to 256 MB (and only then it was able to run a free desktop at a not-so-annoying speed); it's a P3 650 MHz, acquired in 1999 as a P2 400 MHz with 32 MB. You know what, a lot of people in the world don't have money to buy computers, let alone upgrade it every 2 years to run the latest MS crap.
Win9x runs pefectly on old machines - and are a lot faster on newer ones. On the downside, any GNU/Linux desktop is able to perform even slower than WinXP on any machine, unless it's completely stripped down. The main reason is for the memory consumption (Linux's memory manager sucks beyond imagination; it doesn't crash, but any user program can easily halt the reponsivity).
Your sandwiches never had to use old hardware. :P
Interestingly, a few years ago I was always telling my parents how great GNU/Linux was, and because of this they "should buy me a new HD" to install it. Unfortunately I didn't get the HD, but they were "educated" by my insistence. A few months ago (a few months after me installing Mandriva 2005 on their computers) I found out that they were having GNU/Linux classes. Now they are happily using Firefox, GAIM, Frozen Bubble, Lilypond, etc. Guess what, my mother was even able to configure the WiFi network on her Mandriva 2006 (using nothing but a few "numbers" I had written down on paper).
So yes, it's about the approach. Learn what they want to do with their computers, then show how this "new" operating system will be much more fun and useful to use. You should see my mother's face when she learned how to use Firefox' tabs, or my father's when he learned that he could transcribe his partitures collection to the computer. In a few months I'll remove the Win98SE from that machine, and I bet they'll never miss it again.
Your text gives the idea that Celestia is an amateur software. Let's just make it clear for those who know nothing about it. Celestia is an excelent software, just isn't designed for this purpose.
Last time I heard, Celestia had stagnated. The main developer is taking "prolonged vacations", and nobody else understands the complex engine enough to make further improvements.
Google knows this one:
Answer
Actually, even Win98 has auto-defragmentation, using a 3rd-party app. Microsoft did a good deal when they bought Diskeeper and shipped it with WinXP.
If you consider the "freedom" involved in Free Software, you'll notice that they use their modified software for their own purposes. They are free to use the software in any way, they are free to modify it. And they aren't distributing it, so they aren't distributing the source code of their changes. I don't see any problem with it.
The Frozen Bubble's author don't want people porting his app to non-free operating systems.
Please post a link to the original when you copy it to your post.
http://www.neystadt.org/john/humor/The-C-Bible.htm
I'll stick with my @abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvw xyzabcdefghijk.com mail account, thank you.