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Tharky



Registered
  05/10/2009
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10th February, 2011 at 20:39:36 -

Hello guys, I just encountered a problem about "drawing the way from Point A to Point B".

I tried many ways to do that, changing the angle of a 1 pixel thick bar, looping and drawing 1 pixel until it reaches Point B...

But it doesn't give me the best look / graphics.

 
Newbie in Lua +
5 year experience with MMF =

Still nothing...

GamesterXIII



Registered
  04/12/2008
Points
  1110

I am an April Fool
10th February, 2011 at 22:58:25 -

Try turning anti-aliasing on with that 1-pixel thick bar and make sure the rotation quality is 1.

I've achieved this by scaling a bar that was a few pixels thick between two points, but I don't remember if I tried it with only 1 pixel.

 
n/a

Tharky



Registered
  05/10/2009
Points
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10th February, 2011 at 23:12:13 -

Actually, I haven't managed to do the precise line...

 
Newbie in Lua +
5 year experience with MMF =

Still nothing...

~Matt Esch~

Stone Goose

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  30/12/2006
Points
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10th February, 2011 at 23:19:21 -

I made this example a while ago

http://mattesch.info/click/linedraw.zip

 
http://create-games.com/project.asp?id=1875 Image


Tharky



Registered
  05/10/2009
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10th February, 2011 at 23:24:02 -


Originally Posted by ~Matt Esch~
I made this example a while ago

http://mattesch.info/click/linedraw.zip

Oh, Thanks a lot for the example Matt! This was exactly the thing I've asked. Thanks a lot.

Sorry, I don't have any point to give you a trophy

 
Newbie in Lua +
5 year experience with MMF =

Still nothing...

GamesterXIII



Registered
  04/12/2008
Points
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I am an April Fool
11th February, 2011 at 16:37:50 -


Originally Posted by ~Matt Esch~
I made this example a while ago

http://mattesch.info/click/linedraw.zip

Woah thats a little overly-complicated, but it works I guess . Why does the line jump around the line is drawn anywhere to the left?

 
n/a

~Matt Esch~

Stone Goose

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11th February, 2011 at 19:00:21 -

How would you simplify it? I do have a 1 line event that does it as well by taking dot products and wedge products to compute the angle of rotation. I am not sure what you mean by jumping around. Perhaps you refer to the slight unavoidable inaccuracy in the calculation?

 
http://create-games.com/project.asp?id=1875 Image


GamesterXIII



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  04/12/2008
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I am an April Fool
11th February, 2011 at 21:45:59 -

I dunno. You're obviously more well versed in math than I am, but the line jumps around pretty bad when the line is drawn towards the left/upper left region of the screen. I just remember the one I made used a less conventional - possibly longer yet a bit simpler method and it worked flawlessly. I'll see if I can dig it up, but I really don't think I have it anymore .

 
n/a

~Matt Esch~

Stone Goose

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11th February, 2011 at 22:03:46 -

Perhaps this is more accurate.

http://www.mattesch.info/click/linedraw2.zip

 
http://create-games.com/project.asp?id=1875 Image


GamesterXIII



Registered
  04/12/2008
Points
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I am an April Fool
11th February, 2011 at 22:08:18 -

Thats much much much better .

I actually came up with a method, but MMF loops aren't working properly for some reason - ie: they continue to run even if told to stop or even if a condition is no longer met =/. This happens to me randomly. Oh well- not like Its needed anymore anyways .

Nice work.



 
n/a

~Matt Esch~

Stone Goose

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  30/12/2006
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11th February, 2011 at 22:15:57 -

Well you say it's not needed, but some people might appreciate a simpler approach. Some people might be intimidated by expressions like


(((LeftY( "Line" )-RightY( "Line" ))/Abs(LeftY( "Line" )-RightY( "Line" )))+0.5)/Abs(((LeftY( "Line" )-RightY( "Line" ))/Abs(LeftY( "Line" )-RightY( "Line" )))+0.5)*ACos((RightX( "Line" )-LeftX( "Line" ))/Sqr(((RightX( "Line" )-LeftX( "Line" ))*(RightX( "Line" )-LeftX( "Line" )))+((RightY( "Line" )-LeftY( "Line" ))*(RightY( "Line" )-LeftY( "Line" )))))

I wouldn't really condone a brute force rotate-until-it's-right approach though.


 
http://create-games.com/project.asp?id=1875 Image


GamesterXIII



Registered
  04/12/2008
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I am an April Fool
11th February, 2011 at 22:45:51 -

Yeah I don't know formulas like that so I take my own way out x_x. I'm really not a fan of workarounds, but when I can't comprehend whats going when coding something the proper way I sometimes have no choice.

I just recently learned how to halfway use basic trig properly thanks to the atan2 function. I'm awful with stuff like that.

Edited by GamesterXIII

 
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Jenswa

Possibly Insane

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  26/08/2002
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12th February, 2011 at 22:08:10 -

I would go with the Bresenham Line algorithm, since that's with what I am playing these days.

But basically you need the slope to hop from spot to spot, and the slope is dy/dx where
dx = the horizontal distance between the two points and dy = the vertical distance between the two points.

Or read the wiki at http://en.wikipedia.org/wiki/Slope

Maths is fun, but those expressions in mmf aren't.

 
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UrbanMonk

BRING BACK MITCH

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12th February, 2011 at 22:31:22 -

This will help with mmf math

http://create-games.com/download.asp?id=7421

I use this all the time.

 
n/a

GamesterXIII



Registered
  04/12/2008
Points
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I am an April Fool
13th February, 2011 at 00:44:43 -


Originally Posted by UrbanMonk
This will help with mmf math

http://create-games.com/download.asp?id=7421

I use this all the time.



Thanks, this is actually an amazing little app.

I am a retard when it comes to using "other peoples work." I know this stuff has been around for ages, code is somewhat supposed to be shared, not protected, and that the work can't necessarily be tied to any one individual, but I am really weird (ieumb!).

I guess I'll have to stop being dumb and just learn to deal with it and just give credit where its due .

 
n/a

Tharky



Registered
  05/10/2009
Points
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25th February, 2011 at 00:22:17 -


Originally Posted by UrbanMonk
This will help with mmf math

http://create-games.com/download.asp?id=7421

I use this all the time.



Snippet Manager is great. I use that too. But I couldn't manage to do a simple line drawing, so I ended up creating a topic to ask you guys Thanks for all your responses!

 
Newbie in Lua +
5 year experience with MMF =

Still nothing...

Klikmaster

Master of all things Klik

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  08/07/2002
Points
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27th February, 2011 at 15:06:55 -

Does anyone use the overlay object anymore? I always use the overlay object for drawing lines. Simples

 
n/a

eliris



Registered
  14/05/2010
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19th October, 2011 at 14:36:04 -

I look so noob in front of you math geniuses

 
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