Skip to main content

Moving an image towards its direction? [closed]

Image
By User



I'm a relatively young java developer. I don't know much geometry yet. I need to know what the algorithm is (in code form) to move an object towards the direction it is rotated in. Thanks!




Labels:

Comments

  1. Tips For AllFebruary 24, 2012 at 7:30 AM

    (Learning basic geometry/basic vector math would help a lot i.e. http://www.helixsoft.nl/articles/circle/sincos.htm)

    If your direction is some sort of vector - just offset current position by corresponding x and y components (potentially scaled).

    If you direction is by angle - use sin/cos to compute offsets and scale:

    x = speed * cos (angleRadians);
    y = speed * sin (angleRadians);


    To transform degrees to radians - divide by PI.

    ReplyDelete

Post a Comment

Popular posts from this blog

Why is this Javascript much *slower* than its jQuery equivalent?

By User
I have a HTML list of about 500 items and a "filter" box above it. I started by using jQuery to filter the list when I typed a letter (timing code added later): $('#filter').keyup( function() { var jqStart = (new Date).getTime(); var search = $(this).val().toLowerCase(); var $list = $('ul.ablist > li'); $list.each( function() { if ( $(this).text().toLowerCase().indexOf(search) === -1 ) $(this).hide(); else $(this).show(); } ); console.log('Time: ' + ((new Date).getTime() - jqStart)); } ); However, there was a couple of seconds delay after typing each letter (particularly the first letter). So I thought it may be slightly quicker if I used plain Javascript (I read recently that jQuery's each function is particularly slow). Here's my JS equivalent: document.getElementById('filter').addEventListener( 'keyup', function () { var jsStart = (new Date).getTime()...
3 comments
Read more

Is it possible to have IF statement in an Echo statement in PHP

By User
Thanks in advance. I did look at the other questions/answers that were similar and didn't find exactly what I was looking for. I'm trying to do this, am I on the right path? echo " <div id='tabs-".$match."'> <textarea id='".$match."' name='".$match."'>". if ($COLUMN_NAME === $match) { echo $FIELD_WITH_COLUMN_NAME; } else { } ."</textarea> <script type='text/javascript'> CKEDITOR.replace( '".$match."' ); </script> </div>"; I am getting the following error message in the browser: Parse error: syntax error, unexpected T_IF Please let me know if this is the right way to go about nesting an IF statement inside an echo. Thank you.
5 comments
Read more