void modWave(float _amp, float _sampleRate){

 glLineWidth(10.0);

 glColor3f( 0,1,0 );//sets color can add a alpha on end 255,255,255,255

 glBegin(GL_LINE_STRIP);

 _amp = 25;

 _sampleRate= 200;

for (int i =0; i< 1080; i++){ //i< number gives length how many cycles will reapeat

float x = i; // this is the x thats used 

float y = _amp * d_sin(((x/_sampleRate)*360) ); // this doesn't return x this gives a ratio of how often it gets sampled

float f = y*2;

 //

f += f * d_sin((x/200)*360);

y += f * d_sin((x/100)*360);

y += f * d_sin((x/50)*360);

y += f * d_sin((x/40)*360);

glVertex2f((x),(y+200)); // offset

}

glEnd();

 }