Re: gd project question

I believe you will need to use sin and cos to do this... I experimented with drawing circles in javascript (sorry, it's not PHP but you can see the concept) and ended up with this: for (j = 0; j <= 360; j += (360 / 10)) { // x1 & y1 are offset values var s = x1 + radius * Math.cos (j); var t = y1 + radius * Math.sin (j); setLayer (layer_count, s, t); layer_count++; } You would be able to work out the angle by making it a percentage of 180 degrees - although for horizontal gauges, you would need to offset it by -90. Hope this helps... Mikey "Michael Geier" <mgeier@cdmsports.com> wrote in message news:CDEMKNODHLIIOKOJNIHGCEPECMAA.mgeier@cdmsports.com... > I have the following issue: > > I am making a "gas guage" based on a percentage. > ie. > - a 180 degree arc is created > - the range will be 0 to n (undetermined ammount) > - there will be x number of entries > - the needle will pount to a a percentage > for (int)floor((x / n) * 100) > > The issue is, I have the starting pt for the needle (imagefilledarc > needs the center of the 'circle' as the starting pt, which is where > the needle will start too), but how would I get the x|y coordinates > for the end of the needle based on a perentage of a half-circle > (180 degree arc)? > > Appreciate any clues or ideas. > > --- > Michael Geier >