Trigonometric movement?

[zuperxtreme]

:/

Not really sure how to apply the math to get my desired effect.

There are 3:

Sinusoidal wave to a target and invert when it reaches it's destination.

Sinusoidal wave towards a target.

Parabola? Line, half a circle turn, line.

Anywho, I don't want to draw the lines, I want an object to move in those paths. Ideas?

For visual aid:

[Archon68]

You can use the Math class to take advantage of basic trig functions.

AS3: http://livedocs.adobe.com/flash/9.0/Acti onScriptLangRefV3/Math.html
AS2: http://livedocs.adobe.com/flash/9.0/main /wwhelp/wwhimpl/common/html/wwhelp.htm?c ontext=LiveDocs_Parts&file=00001842.html

[polym]

At 11/8/09 05:53 PM, Archon68 wrote:

Hate to emphasize your stupidity once again but he's asking how to apply the math.

[Montycarlo]

Didn't you ever do functions in Maths class?

f(x) = cos(2x)/sin(x)
Create a rule like that and substitute the time elapsed into x (Or whatever variable you wish to use)

[henke37]

That doesn't turn at a specific point.

[zeefoes]

The two lines below will get your object to move in the direction it's facing.
bullet.x += Math.sin(bulletAngle*Math.PI/180) * bulletSpeed;
bullet.y += Math.cos(bulletAngle*Math.PI/180) * -bulletSpeed;

Now you have to either make checkpoints, or tween a single checkpoint along the path. After you do that you need to make your moving object face the checkpoint. To do this you calculate the angle of a vector between your two objects and plug it into the following formula.

angle = tan inverse ( X / Y)
X is (bullet.x - checkpoint.x);
Y is (bullet.y - checkpoint.y);

if(bullet.rotation <= -5) bullet.rotation++;
if(bullet.rotation >= 5) bullet.rotation--;
These two if statements should keep your object facing the checkpoint by comparing your objects rotation to the angle of the vector, and if it's facing the checkpoint it will go towards it.

You may have to convert to or from radians... or maybe change the angles in the if statements for this to work, the concept works but the code is untested. Hope this helps.

[zeefoes]

Or you could always use tweenmax, it's probably easier than what I posted above.
www.tweenmax.com/

[henke37]

y=baseline+sin(phase+=phasespeed)*amplit ude for basic waving. Then just add a normal reversal on the x axis.
For the path with a halfcircle turn, you need different movement modes so that you can know what you should be doing right now.

[zuperxtreme]

Thanks everyone! I'll check over this carefully when I'm at home with Flash.