Comments on: Pythagorean Distance Between Two Points http://gamedev.michaeljameswilliams.com/2009/05/08/pythagorean-distance-between-two-points/ I help people make Flash games Sat, 20 Mar 2010 16:28:21 -0700 http://wordpress.org/?v=2.9.2 hourly 1 By: Michael Williams http://gamedev.michaeljameswilliams.com/2009/05/08/pythagorean-distance-between-two-points/comment-page-1/#comment-2080 Michael Williams Tue, 28 Jul 2009 10:44:22 +0000 http://gamedev.michaeljameswilliams.com/?p=613#comment-2080 <p>Hullo Daniel. Homework? :P</p> <p>Sounds like you're looking for a more general explanation of the the theorem than this game-related one, in which case I'd recommend <a href="http://betterexplained.com/articles/measure-any-distance-with-the-pythagorean-theorem/" rel="nofollow">this post</a> over at BetterExplained.</p> <p>But basically, you just:</p> <ul> <li>Subtract one x-coordinate from the other, and square the result</li> <li>Subtract one y-coordinate from the other, and square the result</li> <li>Add those two squares together</li> <li>Square root the result</li> </ul> <p>So: sqrt( [( -4 ) - 1]squared + [ ( -3 ) - 1 ]squared )</p> <p>Hope that helps ;)</p> Hullo Daniel. Homework? :P

Sounds like you’re looking for a more general explanation of the the theorem than this game-related one, in which case I’d recommend this post over at BetterExplained.

But basically, you just:

  • Subtract one x-coordinate from the other, and square the result
  • Subtract one y-coordinate from the other, and square the result
  • Add those two squares together
  • Square root the result

So: sqrt( [( -4 ) - 1]squared + [ ( -3 ) - 1 ]squared )

Hope that helps ;)

]]> By: Daniel http://gamedev.michaeljameswilliams.com/2009/05/08/pythagorean-distance-between-two-points/comment-page-1/#comment-2078 Daniel Tue, 28 Jul 2009 06:37:15 +0000 http://gamedev.michaeljameswilliams.com/?p=613#comment-2078 <p>I am on 7th grade, i dont get this proplem at all, Math is my worts subject, can you help please? Explain how you could use the Pythagorean Theorem to find the distance between the (-4,-3) points and (1,1). Find the distance. You can type to indicate "squared" and "sqrt"</p> I am on 7th grade, i dont get this proplem at all, Math is my worts subject, can you help please? Explain how you could use the Pythagorean Theorem to find the distance between the (-4,-3) points and (1,1). Find the distance. You can type to indicate “squared” and “sqrt”

]]> By: Avoider game tutorial – Moving with mouse and using speed http://gamedev.michaeljameswilliams.com/2009/05/08/pythagorean-distance-between-two-points/comment-page-1/#comment-2058 Avoider game tutorial – Moving with mouse and using speed Mon, 27 Jul 2009 00:37:17 +0000 http://gamedev.michaeljameswilliams.com/?p=613#comment-2058 <p>[...] you remember this post from MJW? We will use it now to calculate the distance between our mouse and our avatar. If the [...]</p> [...] you remember this post from MJW? We will use it now to calculate the distance between our mouse and our avatar. If the [...]

]]> By: tomdeaap http://gamedev.michaeljameswilliams.com/2009/05/08/pythagorean-distance-between-two-points/comment-page-1/#comment-1800 tomdeaap Wed, 10 Jun 2009 15:40:28 +0000 http://gamedev.michaeljameswilliams.com/?p=613#comment-1800 <p>Oh ... Pretty late answer to your question ... but here is the explination: s - schuine zijde o- overstaande rechthoekszijde s- sin c- cos t - tan a- aanligende rechthoekszijde</p> <p>Not that it explains anything ... since it's dutch .. :)</p> Oh … Pretty late answer to your question … but here is the explination: s – schuine zijde o- overstaande rechthoekszijde s- sin c- cos t – tan a- aanligende rechthoekszijde

Not that it explains anything … since it’s dutch .. :)

]]> By: 8 way Character Movement @ Rasmus Wriedt Larsen - Flash Game Development http://gamedev.michaeljameswilliams.com/2009/05/08/pythagorean-distance-between-two-points/comment-page-1/#comment-1789 8 way Character Movement @ Rasmus Wriedt Larsen - Flash Game Development Tue, 09 Jun 2009 22:06:19 +0000 http://gamedev.michaeljameswilliams.com/?p=613#comment-1789 <p>[...] Now we made a simple movement, just as almost every other game out there, this may be fine for some games (fx platformers), but for a top-down game we need to do a little more of work. Can you find the error yourself? What if I told you to take one sped forward, and afterwards take a step where you moved both forward and just as much to the left, would you have taken a 40 % lager step? I think not, but our little guy is doing just exactly this right now. Many times walking diagonally like this could change the gameplay a lot! I’ve made a green circle to show where the player actually should be going.(click to it to activate, use arrow keys or WASD to move - you have to hold them for 0.5 second) (Either JavaScript is not active or you are using an old version of Adobe Flash Player. Please install the newest Flash Player.) How to fix this you ask? Phythagoras. If you don’t know what this is, then I would surges you checked out Michael James Williams post on this [...]</p> [...] Now we made a simple movement, just as almost every other game out there, this may be fine for some games (fx platformers), but for a top-down game we need to do a little more of work. Can you find the error yourself? What if I told you to take one sped forward, and afterwards take a step where you moved both forward and just as much to the left, would you have taken a 40 % lager step? I think not, but our little guy is doing just exactly this right now. Many times walking diagonally like this could change the gameplay a lot! I’ve made a green circle to show where the player actually should be going.(click to it to activate, use arrow keys or WASD to move – you have to hold them for 0.5 second) (Either JavaScript is not active or you are using an old version of Adobe Flash Player. Please install the newest Flash Player.) How to fix this you ask? Phythagoras. If you don’t know what this is, then I would surges you checked out Michael James Williams post on this [...]

]]> By: Character Movement @ Rasmus Wriedt Larsen - Flash Game Development http://gamedev.michaeljameswilliams.com/2009/05/08/pythagorean-distance-between-two-points/comment-page-1/#comment-1725 Character Movement @ Rasmus Wriedt Larsen - Flash Game Development Thu, 04 Jun 2009 14:57:09 +0000 http://gamedev.michaeljameswilliams.com/?p=613#comment-1725 <p>[...] Now we made a simple movement, just as almost every other game out there, this may be fine for some games (fx platformers), but for a top-down game we need to do a little more of work. Can you find the error yourself? What if I told you to take one sped forward, and afterwards take a step where you moved both forward and just as much to the left, would you have taken a 40 % lager step? I think not, but our little guy is doing just exactly this right now. Many times walking diagonally like this could change the gameplay a lot! I’ve made a green circle to show where the player actually should be going. (Either JavaScript is not active or you are using an old version of Adobe Flash Player. Please install the newest Flash Player.) How to fix this you ask? Phythagoras. If you don’t know what this is, then I would surges you checked out Michael James Williams post on this [...]</p> [...] Now we made a simple movement, just as almost every other game out there, this may be fine for some games (fx platformers), but for a top-down game we need to do a little more of work. Can you find the error yourself? What if I told you to take one sped forward, and afterwards take a step where you moved both forward and just as much to the left, would you have taken a 40 % lager step? I think not, but our little guy is doing just exactly this right now. Many times walking diagonally like this could change the gameplay a lot! I’ve made a green circle to show where the player actually should be going. (Either JavaScript is not active or you are using an old version of Adobe Flash Player. Please install the newest Flash Player.) How to fix this you ask? Phythagoras. If you don’t know what this is, then I would surges you checked out Michael James Williams post on this [...]

]]> By: Michael Williams http://gamedev.michaeljameswilliams.com/2009/05/08/pythagorean-distance-between-two-points/comment-page-1/#comment-1675 Michael Williams Tue, 02 Jun 2009 12:33:18 +0000 http://gamedev.michaeljameswilliams.com/?p=613#comment-1675 <p>Wow, interesting question.</p> <p>First, I just want to make it clear that "non-Euclidean space" doesn't necessarily refer to any particular type of space (like a balloon-shaped or spherical space), but just any type of space that isn't Euclidean.</p> <p>So yeah, you probably could find a non-Euclidean space where walking left made you move upward or downward as well -- but then, you could argue that "left" doesn't really mean anything in such a space!</p> <p>On a space that is the surface of a sphere, you can think of things in terms of the Earth's surface -- if you walk far enough west, you'll eventually return to your starting point. This doesn't happen in a flat, Euclidean space.</p> Wow, interesting question.

First, I just want to make it clear that “non-Euclidean space” doesn’t necessarily refer to any particular type of space (like a balloon-shaped or spherical space), but just any type of space that isn’t Euclidean.

So yeah, you probably could find a non-Euclidean space where walking left made you move upward or downward as well — but then, you could argue that “left” doesn’t really mean anything in such a space!

On a space that is the surface of a sphere, you can think of things in terms of the Earth’s surface — if you walk far enough west, you’ll eventually return to your starting point. This doesn’t happen in a flat, Euclidean space.

]]> By: Gianfun http://gamedev.michaeljameswilliams.com/2009/05/08/pythagorean-distance-between-two-points/comment-page-1/#comment-1655 Gianfun Mon, 01 Jun 2009 22:18:08 +0000 http://gamedev.michaeljameswilliams.com/?p=613#comment-1655 <p>Hey michael! One question. If a game were to be on a non-euclidian space, if one would walk to a direction (i.e. left), he would gradually curve upwards/downwards, like the lines on a (burst) balloon?</p> Hey michael! One question. If a game were to be on a non-euclidian space, if one would walk to a direction (i.e. left), he would gradually curve upwards/downwards, like the lines on a (burst) balloon?

]]> By: Michael Williams http://gamedev.michaeljameswilliams.com/2009/05/08/pythagorean-distance-between-two-points/comment-page-1/#comment-1576 Michael Williams Thu, 28 May 2009 21:46:46 +0000 http://gamedev.michaeljameswilliams.com/?p=613#comment-1576 <p>Cheers Gianfun!</p> <p>Oops, thanks for pointing out those typos. Corrected :)</p> Cheers Gianfun!

Oops, thanks for pointing out those typos. Corrected :)

]]> By: Gianfun http://gamedev.michaeljameswilliams.com/2009/05/08/pythagorean-distance-between-two-points/comment-page-1/#comment-1572 Gianfun Thu, 28 May 2009 21:15:38 +0000 http://gamedev.michaeljameswilliams.com/?p=613#comment-1572 <p>Hey! nice article :) Now I wont have to think as much when I have to find the distance between 2 things (I bet I would spend some time looking for the answer), and also thanks for the 'not sqare rooting' tip !</p> <p>Yeah, I learn all of this at school too :P</p> <p>Btw Michael, you did a little typo here, which may confuse people that didn't learn pythagoras " i.e. ( 10 * 10 ) + ( 15 + 15 ), so 100 + 225, which equals 325." should be "( 10 * 10 ) + ( 15 * 15 )" (*, not +) And also you wrote Pythagorus once :D</p> Hey! nice article :) Now I wont have to think as much when I have to find the distance between 2 things (I bet I would spend some time looking for the answer), and also thanks for the ‘not sqare rooting’ tip !

Yeah, I learn all of this at school too :P

Btw Michael, you did a little typo here, which may confuse people that didn’t learn pythagoras ” i.e. ( 10 * 10 ) + ( 15 + 15 ), so 100 + 225, which equals 325.” should be “( 10 * 10 ) + ( 15 * 15 )” (*, not +) And also you wrote Pythagorus once :D

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