// License: LGPL - http://www.gnu.org/licenses/lgpl.html

desc: Simple FM Tone Generator
//tags: frequency modulation synthesis
//author: Drake Andersen

slider1:440<0.1,10000,0.1>Carrier Frequency (Hz)
slider2:2<0.1,100,0.1>Harmonicity Ratio
slider3:1<0,50,0.01> Modulation Index
slider4:-20<-120,0,1>Output (dB)

@slider
vol1=2^(slider4/6);
freqCarrier=slider1;
freqMod=slider1*slider2;
modIndex=slider3;

@sample
adj1 = (2.0*$pi*(freqCarrier+(toneMod*modIndex*freqMod)))/srate;
adj2 = 2.0*$pi*freqMod/srate;

toneCarrier = cos(pos1);
toneMod = cos(pos2);

spl0 = vol1*toneCarrier;
spl1 = vol1*toneCarrier;

pos1 += adj1;
(pos1 >= 2.0*$pi) ? pos1 -= 2.0*$pi;

pos2 += adj2;
(pos2 >= 2.0*$pi) ? pos2 -= 2.0*$pi;