flash 4 has very few built-in math functions, so you have to calculate most of them by hand. below you can download a code library to add trigonometric functions to your flash files so you can retrieve the sine, cosine, tangent, secant, cosecant, and cotangent of an angle (in degrees, not radians).
>>download the .fla (zipped)
>>view the demo
here's how to use the trig library in your movies:
- copy the "trig library" movie clip to your .fla file.
- place an instance of it on the main movie stage, and name it "trig".
- set the angle on which to perform your trig function as follows:
set variable: "/trig:arg" = yourangle
- call the function you wish to execute as follows:
call ("/trig:getSin")
- the calculated value will be returned in the variable "output", which is inside the "/trig" movie clip. to retrieve it, use something like this:
set variable: "var1" = /trig:output
usage note
if you know your angle is between 0 and 360, you can quickly retrieve the sin,cos, or tan, by using this construction:
eval ("/trig:sin" & yourangle)
- february 17, 2000: posted.
- may 29, 2000: fixed a little bug in cotangent. i was getting cotan 90 by doing 1/tan, but since tan 90 is actually infinity 1/infinity was causing an error, whereas cotan 90 is actually 0. thanks to ben chun over at mit for catching this one...
