adding biquad example from Rebecca

2 files changed, 50 insertions, 66 deletions

diff --git a/maximilian_examples/13.Advanced-Filters.cpp b/maximilian_examples/13.Advanced-Filters.cpp
new file mode 100644
index 0000000..b04d3d8
--- /dev/null
+++ b/maximilian_examples/13.Advanced-Filters.cpp
@@ -0,0 +1,50 @@
+//Using BPF equation from http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt
+//Example contributed by Rebecca Fiebrink
+
+#include "maximilian.h"
+
+float xs[3], ys[3];
+float a0, a1, a2, b0, b1, b2;
+float f0 = 400; //THE FREQUENCY
+float Q = 1.0;
+
+maxiOsc mySwitchableOsc;
+
+void setup() {//some inits
+    double w0 = 2*PI*f0/44100;
+    double alpha = sin(w0)/(2*Q);
+    //Band-pass reson:
+    //    b0 =   alpha;
+    //     b1 =   0;
+    //     b2 =  -1 * alpha;
+    //     a0 =   1 + alpha;
+    //     a1 =  -2*cos(w0);
+    //     a2 =   1 - alpha;
+    
+    //Notch:
+    b0 =   1;
+    b1 =  -2*cos(w0);
+    b2 =   1;
+    a0 =   1 + alpha;
+    a1 =  -2*cos(w0);
+    a2 =   1 - alpha;
+    
+    //LPF:
+    //    b0 =  (1 - cos(w0))/2;
+    //    b1 =   1 - cos(w0);
+    //    b2 =  (1 - cos(w0))/2;
+    //    a0 =   1 + alpha;
+    //    a1 =  -2*cos(w0);
+    //    a2 =   1 - alpha;
+}
+
+void play(double *output) {
+    xs[0] = mySwitchableOsc.sawn(400);
+    ys[0] = (b0/a0)*xs[0] + (b1/a0)*xs[1] + (b2/a0)*xs[2]
+    - (a1/a0)*ys[1] - (a2/a0)*ys[2];
+    
+    *output = ys[0];
+    
+    ys[2] = ys[1]; ys[1] = ys[0];
+    xs[2] = xs[1]; xs[1] = xs[0];
+}
diff --git a/maximilian_examples/13.Sequencing.cpp b/maximilian_examples/13.Sequencing.cpp
deleted file mode 100644
index de7172b..0000000
--- a/maximilian_examples/13.Sequencing.cpp
+++ /dev/null
@@ -1,66 +0,0 @@
-#include "maximilian.h"
-
-double outputs[2],moreoutputs[2]; //some track outputs
-double filtered,patch1,patch2,tune,delayed,
-mixed,ramp,filtered2,noise,pan,more;//a bunch of patch cables
-int beat,lastbeat,morebeats,lastmorebeats;//some rhythmic elemts
-double env[4]={200,0,0,50};//the kick drum pitch envelope data
-double env2[6]={10000,0,9000,5,0,5};//the hi hat pitch envelope dat
-double melody[14]={600,0,0,650,0,0,400,0,0,425,0,300,0,315};//the melody data
-int rhythm1[16]={1,0,0,1,0,0,1,0,0,1,0,0,1,0,1,0};//another way of doing a rhythm
-maxiOsc a,c,d,e,g,h,i,j,squarewave;//some oscillators
-maxiEnvelope b,f;//two envelopers
-maxiDelayline delay;//a delay line
-maxiFilter myfilter,antia;// a FAT filter
-maxiMix mymix,bobbins;//some panning busses
-maxiSample beats;
-
-void setup() {//some inits
-	b.amplitude=env[0];//starting value for envelope b
-	f.amplitude=env2[0];//same for f
-	beats.load("/Users/chris/src/Maximilian/beat2.wav");//put a path to a soundfile here. Wav format only.
-	printf("Summary:\n%s", beats.getSummary());//get info on samples if you like
-	
-}
-
-void play(double *output) {//this is where the magic happens. Very slow magic.
-	beat=((int) c.phasor(8));//this oscillator is now a counter
-	morebeats=((int) e.phasor(0.5,0,16));//so is this one
-	patch1=b.line(4,env);//here's envelope b
-	patch2=f.line(6,env2);//here's envelop f
-	tune=g.saw(melody[morebeats]*0.25);//here's the melody, which occurs at certain times
-	
-	if (lastbeat!=beat) {//this is a nice sample and hold routine for the kick drum 
-		f.trigger(0, env2[0]);//it runs off the hi hat.
-		
-		
-		if (rhythm1[morebeats]==1) {
-			b.trigger(0, env[0]);//and gets played when it's time.
-		}
-	}
-	lastbeat=beat;//let's start again. It's a loop
-	ramp=i.phasor(0.5,1,2048);//create a basic ramp
-	pan=j.phasor(0.25);//some panning from a phasor (object is equal power)
-	delayed=delay.dl(tune, ramp, 0.9)*0.125;//the delay line
-	//then it all gets mixed.
-	mixed=((a.sinewave(patch1)*0.5)+((d.saw(patch2))*0.125)+(delayed*0.3)*0.5);
-	//add some noise
-	noise=i.noise()*0.25;
-	filtered2=beats.play(1*(1./16.),0,beats.length);
-	//	filtered2=beats.play(-1);
-	
-	more=squarewave.pulse(melody[morebeats],pan)*0.05;
-	//filter the noise! this lores takes values between 1 and 100 for res, and freq for cutoff.
-	filtered=myfilter.lores(filtered2, 1+(pan*10000), 10)*0.4;
-	
-	//now we send the sounds to some stereo busses.
-	mymix.stereo(more+mixed+delayed, outputs, 1-pan);
-	bobbins.stereo(filtered, moreoutputs, pan);//invert the pan
-	
-	//mixing
-	
-	output[0]=outputs[0]+moreoutputs[0];//stick it in the out!!
-	output[1]=outputs[1]+moreoutputs[1];
-	
-}
-