[SOLVED] I need an ease function

[tibberous]

Here is the header.

 

function ease (startingX, startingY, endingX, endingY, frame, framesTotal, ease){

 

return Array(currentX, currentY);

}

 

Basically it takes 2 sets of points, the starting location of an object and the ending location. It returns the location the object would be at at frame, provided there are framesTotal total frames. Ease simulates easing in or out, causing the object to move slower at the beginning or the end of the function.

 

Anyone know how to write this? I used to know but I forget.

[tibberous]

Here, I'll help:

 

function ease (startingX, startingY, endingX, endingY, frame, framesTotal, ease){

currentX = startingX - ( (startingX - endingX) * (frame/framesTotal) );

currentY = startingY - ( (startingY - endingY) * (frame/framesTotal) );

 

return Array(currentX, currentY);

}

 

That works so long as ease is 0. Can someone tell me how to add easing?

[tibberous]

function easeTo (startingX, startingY, endingX, endingY, frame, framesTotal, ease){

if(ease > 0) ease = 1 + (ease / 100);

else if(ease < 0) ease = 1 + (ease / 200);

else ease = 1;

currentX = startingX - ( (startingX - endingX) * Math.pow( (frame/framesTotal) , ease) );

currentY = startingY - ( (startingY - endingY) * Math.pow( (frame/framesTotal) , ease) );

 

return Array(currentX, currentY);

}