uniform sampler2D NotesData;

uniform float     OverallSoundPosition;
uniform float     ThisSoundLength;

#define NOTES 36
#define BASEFREQ 40.

#define FREQ 50.

float saw(float time)
{
	//works in the same time domain as GLSL sine
	float x = mod(time, 6.28318531) / 3.14159265;
	return x - 1.;
}

float triangle(float time)
{
	//works in the same time domain as GLSL sine
	float x = mod(time, 6.28318531) / 3.14159265;
	float f = floor(x);
	x = (x*(1.-f)) + ((2.-x)*f);
	return (x*2.)-1.;
}

void main()
{
	int i;
	float fvol = 0.;

	float TimeSample = gl_TexCoord[0].y * ThisSoundLength + OverallSoundPosition;
	float channel = gl_TexCoord[0].x;

	//simple test tone

	float carrier1 = saw( 6.28318531 * FREQ * TimeSample);
	float carrier2 = saw( 6.28318531 * FREQ * 1.5 * TimeSample);

	float m1 = triangle( 6.28318531 * 3. * TimeSample );
	float m2 = triangle( FREQ * 2.718281828459045 );

	fvol = sin(carrier1+carrier2+(.3*m1)+(.7*m2));

	gl_FragColor = vec4( fvol );
}