Merge pull request #6 from fleximeter/class_refactor_2

Class refactor 2

Author: fleximeter

README.md

@@ -28,6 +28,9 @@ A phase vocoder pitch shifter and time stretcher using the [RubberBand library](
 ### RubberBandStretcherBuf
 A phase vocoder pitch shifter and time stretcher using the [RubberBand library](https://breakfastquay.com/rubberband/). This version writes the stretched audio to a buffer rather than outputting it directly.
 
+### FIR
+A flexible FIR filter that allows you to provide an arbitrary number of coefficients directly (as opposed to loading them in a buffer with Convolution3).
+
 ### ImpulseDropout
 A modified version of Impulse that randomly drops a percentage of impulses, producing a stuttering effect.
 

src/filters/FIR.schelp

@@ -4,18 +4,26 @@ related:: Classes/Convolution3, Classes/FOS, Classes/SOS, Classes/OneZero
 categories::  Libraries>FlexUGens, UGens>Filters>Linear
 
 Description::
-A no-nonsense FIR filter where you provide your own coefficients. FIR duplicates the functionality 
+A flexible time-domain FIR filter where you provide your own coefficients. FIR duplicates the functionality 
 of link::Classes/Convolution3::. The difference is that FIR does not require you to load your 
 filter coefficients into a link::Classes/Buffer::. Instead, you can provide them directly as a 
 link::Classes/Ref:: in the same way as is done in link::Classes/DynKlank::.
 
+FIR internally limits the number of coefficients to 32. This is because time-domain convolution only makes sense for 
+very short impulse responses--Frank Wefers writes that "the
+theoretical break-even point where FFT-based convolution becomes
+faster is between 16-32 samples."footnote::Frank Wefers, "Partitioned convolution algorithms
+for real-time auralization," Logos Verlag Berlin (2015), 224.:: One potential use of this UGen is 
+to perform Savitsky-Golay filtering for control signal smoothing 
+(see link::https://en.wikipedia.org/wiki/Savitzky%E2%80%93Golay_filter:: for coefficient tables).
+
 classmethods::
 
-method::ar
+method::ar, kr
 
 argument::coefs
 A link::Classes/Ref:: to a list of FIR filter coefficients. The number of coefficients can change 
-over time, but can never exceed the server block size (if it does, extra coefficients will be truncated).
+over time, but can never exceed 32 (if it does, extra coefficients will be truncated).
 
 argument::in
 The input signal to filter

src/filters/filters.sc

@@ -20,6 +20,7 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+// A flexible FIR filter
 FIR : UGen {
     *ar {
         arg coefs, in, mul=1, add=0;

src/filters/fir.cpp

@@ -3,7 +3,7 @@ File: fir.cpp
 Author: Jeff Martin
 
 Description:
-A raw FIR filter
+A flexible FIR filter
 
 Copyright © 2026 by Jeffrey Martin. All rights reserved.
 Website: https://www.jeffreymartincomposer.com
@@ -26,8 +26,8 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 extern InterfaceTable *ft;
 
 FlexPlugins::FIR::FIR() {
-    m_z = static_cast<float*>(RTAlloc(mWorld, fullBufferSize() * sizeof(float)));
-    for (size_t i = 0; i < fullBufferSize(); i++) {
+    m_z = static_cast<float*>(RTAlloc(mWorld, MAX_COEFS * sizeof(float)));
+    for (size_t i = 0; i < MAX_COEFS; i++) {
         m_z[i] = 0.f;
     }
     set_calc_function<FIR, &FIR::next>();
@@ -40,13 +40,13 @@ FlexPlugins::FIR::~FIR() {
 
 void FlexPlugins::FIR::next(int inNumSamples) {
     size_t numCoefs = static_cast<size_t>(mNumInputs - 1);
-    numCoefs = sc_clip(numCoefs, 0, static_cast<size_t>(fullBufferSize()));
+    numCoefs = sc_clip(numCoefs, 0, static_cast<size_t>(MAX_COEFS));
     const float *inBuf = in(0);
     float *outBuf = out(0);
     for (size_t i = 0; i < inNumSamples; i++) {
         float convResult = 0.f;
         // unit delay
-        for (size_t j = fullBufferSize() - 1; j > 0; j--) {
+        for (size_t j = MAX_COEFS - 1; j > 0; j--) {
             m_z[j] = m_z[j-1];
         }
         m_z[0] = inBuf[i];

src/filters/fir.hpp

@@ -3,7 +3,7 @@ File: fir.hpp
 Author: Jeff Martin
 
 Description:
-A raw FIR filter
+A flexible FIR filter
 
 Copyright © 2026 by Jeffrey Martin. All rights reserved.
 Website: https://www.jeffreymartincomposer.com
@@ -26,6 +26,8 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 #include "SC_PlugIn.hpp"
 
+#define MAX_COEFS 32
+
 namespace FlexPlugins {
     class FIR : public SCUnit {
     public:

src/generators/ImpulseJitter.schelp

@@ -32,17 +32,19 @@ This value will be added to the output.
 
 Examples::
 
+Generating audio:
 code::
-(
-SynthDef(\jitter, {
-	arg freq, jitterFrac, amp;
-    var sig;
-	sig = ImpulseJitter.ar(freq, 0.0, jitterFrac, amp);
-    sig = LPF.ar(sig, freq);
-    sig = LeakDC.ar(sig);
-	Out.ar(0, sig);
-}).add;
-
-Synth(\jitter, [\freq, 440.0, \jitterFrac, 0.1, \amp, -12.dbamp]);
-)
+{
+	var sig;
+	sig = ImpulseJitter.ar(440, 0, XLine.kr(1, 2, 5)-1);
+	Pan2.ar(sig);
+}.play;
+::
+
+An increasingly noisy impulse train as a control signal:
+code::
+{
+	var sig;
+	sig = ImpulseJitter.kr(10, 0, XLine.kr(1, 2, 2) - 1);
+}.plot(2);
 ::

src/generators/arrayheap.cpp

@@ -25,7 +25,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #include "arrayheap.hpp"
 
 // Inserts into the heap
-int heapInsert(IntMinHeap* heap, int data) {
+int FlexPlugins::heapInsert(IntMinHeap* heap, int data) {
     if (heap->size == heap->maxSize) {
         return 0;
     } else {
@@ -54,7 +54,7 @@ int heapInsert(IntMinHeap* heap, int data) {
 }
 
 // Removes from the heap and returns the value popped. Returns 0 if the heap is empty.
-int heapPop(IntMinHeap* heap) {
+int FlexPlugins::heapPop(IntMinHeap* heap) {
     if (heap->size > 1) {
         int val = heap->heap[1];
         heap->heap[1] = heap->heap[heap->size-1];
@@ -97,7 +97,7 @@ int heapPop(IntMinHeap* heap) {
 }
 
 // Safe peek at the top of the heap
-int heapPeek(IntMinHeap* heap) {
+int FlexPlugins::heapPeek(IntMinHeap* heap) {
     if (heap->size > 1) {
         return heap->heap[1];
     } else {

src/generators/arrayheap.hpp

@@ -25,18 +25,20 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #pragma once
 #include <cstddef>
 
-/// A min heap for ints.
-typedef struct {
-    int* heap;
-    size_t size;
-    size_t maxSize;
-} IntMinHeap;
-
-/// Inserts into the heap
-int heapInsert(IntMinHeap* heap, int data);
-
-/// Removes from the heap and returns the value popped. Returns 0 if the heap is empty.
-int heapPop(IntMinHeap* heap);
-
-/// Safe peek at the top of the heap
-int heapPeek(IntMinHeap* heap);
+namespace FlexPlugins {
+    /// A min heap for ints.
+    typedef struct {
+        int* heap;
+        size_t size;
+        size_t maxSize;
+    } IntMinHeap;
+
+    /// Inserts into the heap
+    int heapInsert(IntMinHeap* heap, int data);
+
+    /// Removes from the heap and returns the value popped. Returns 0 if the heap is empty.
+    int heapPop(IntMinHeap* heap);
+
+    /// Safe peek at the top of the heap
+    int heapPeek(IntMinHeap* heap);
+}

src/pv/pvCFreeze.cpp

@@ -63,22 +63,22 @@ void FlexPlugins::PV_CFreeze::next(int inNumSamples) {
         // Pull random DC and nyquist magnitudes
         p->dc = mDc[rgen.irand(mNumFrames)];
         p->nyq = mNyq[rgen.irand(mNumFrames)];
-        for (int xxn = 0; xxn < mNumBins; xxn++) {
+        for (int k = 0; k < mNumBins; k++) {
             // For each bin, grab a random magnitude and phase diff pair
             int idx = rgen.irand(mNumFrames);
-            idx = idx * mNumBins + xxn;
-            p->bin[xxn].mag = mMags[idx];
-            mPhase[xxn] = sc_wrap(mPhase[xxn] + mPhaseDiffs[idx], 0.f, static_cast<float>(twopi));
-            p->bin[xxn].phase = mPhase[xxn];
+            idx = idx * mNumBins + k;
+            p->bin[k].mag = mMags[idx];
+            mPhase[k] = sc_wrap(mPhase[k] + mPhaseDiffs[idx], 0.f, static_cast<float>(twopi));
+            p->bin[k].phase = mPhase[k];
         }
     } else {
         // We're writing to a circular buffer, so pull the current magnitude and phase diff arrays
         float *currentMagArr = mMags + (mWritePtr * mNumBins);
         float *currentPhaseDiffArr = mPhaseDiffs + (mWritePtr * mNumBins);
-        for (int xxn = 0; xxn < numbins; xxn++) {
-            currentMagArr[xxn] = p->bin[xxn].mag;
-            currentPhaseDiffArr[xxn] = sc_wrap(p->bin[xxn].phase - mPhase[xxn], 0.f, static_cast<float>(twopi));
-            mPhase[xxn] = p->bin[xxn].phase;
+        for (int k = 0; k < numbins; k++) {
+            currentMagArr[k] = p->bin[k].mag;
+            currentPhaseDiffArr[k] = sc_wrap(p->bin[k].phase - mPhase[k], 0.f, static_cast<float>(twopi));
+            mPhase[k] = p->bin[k].phase;
         }
         mDc[mWritePtr] = p->dc;
         mNyq[mWritePtr] = p->nyq;