From 6b906192de7d8498e188ef90c4a17619b2be9c33 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Thu, 11 Jun 2020 20:39:04 +0200
Subject: [PATCH 01/19] Stretch tuning demo

---
 src/sfizz/Tuning.cpp        |  73 +++++++++++++++++
 src/sfizz/Tuning.h          |  12 +++
 src/sfizz/railsback/2-1.h   | 135 +++++++++++++++++++++++++++++++
 src/sfizz/railsback/4-1.h   | 135 +++++++++++++++++++++++++++++++
 src/sfizz/railsback/4-2.h   | 135 +++++++++++++++++++++++++++++++
 tests/CMakeLists.txt        |   4 +
 tests/DemoStretchTuning.cpp | 154 ++++++++++++++++++++++++++++++++++++
 tests/DemoStretchTuning.ui  |  68 ++++++++++++++++
 8 files changed, 716 insertions(+)
 create mode 100644 src/sfizz/railsback/2-1.h
 create mode 100644 src/sfizz/railsback/4-1.h
 create mode 100644 src/sfizz/railsback/4-2.h
 create mode 100644 tests/DemoStretchTuning.cpp
 create mode 100644 tests/DemoStretchTuning.ui

diff --git a/src/sfizz/Tuning.cpp b/src/sfizz/Tuning.cpp
index 4f14acb8e..2d4b3d99a 100644
--- a/src/sfizz/Tuning.cpp
+++ b/src/sfizz/Tuning.cpp
@@ -8,6 +8,7 @@
 #include "Debug.h"
 #include "absl/types/optional.h"
 #include "Tunings.h" // Surge tuning library
+#include <algorithm>
 #include <fstream>
 #include <sstream>
 #include <array>
@@ -248,5 +249,77 @@ bool Tuning::shouldReloadScala()
     return impl_->shouldReloadScala();
 }
 
+///
+float StretchTuning::getRatioForIntegralKey(int key) const noexcept
+{
+    return keyDetuneRatio_[std::max(0, std::min(127, key))];
+}
+
+float StretchTuning::getRatioForFractionalKey(float key) const noexcept
+{
+    int index1 = static_cast<int>(key);
+    float mu = key - index1;
+
+    index1 = std::max(0, std::min(127, index1));
+    int index2 = std::min(127, index1 + 1);
+
+    return keyDetuneRatio_[index1] * (1 - mu) + keyDetuneRatio_[index2] * mu;
+}
+
+StretchTuning StretchTuning::createFromDetuneRatios(const float detune[128])
+{
+    StretchTuning t;
+    std::copy(detune, detune + 128, t.keyDetuneRatio_);
+    return t;
+}
+
+StretchTuning StretchTuning::createRailsbackFromRatio(float stretch)
+{
+    float data[128];
+
+    static constexpr float railsback21[128] = {
+        #include "sfizz/railsback/2-1.h"
+    };
+    static constexpr float railsback41[128] = {
+        #include "sfizz/railsback/4-1.h"
+    };
+    static constexpr float railsback42[128] = {
+        #include "sfizz/railsback/4-2.h"
+    };
+
+    // known curves and their matching knob positions
+    const int num_curves = 3;
+    const float* curves[] = {railsback21, railsback41, railsback42};
+    const float points[] = {0.25f, 0.5f, 1.0f};
+
+    //
+    int index = -1;
+    while (index + 1 < num_curves && stretch >= points[index + 1])
+        ++index;
+
+    //
+    if (index < 0) {
+        float mu = std::max(0.0f, stretch / points[0]);
+        const float* c = curves[0];
+        for (int i = 0; i < 128; ++i)
+            data[i] = mu * c[i] + (1 - mu);
+    }
+    else if (index + 1 < num_curves) {
+        float mu = (stretch - points[index]) / (points[index + 1] - points[index]);
+        const float* c1 = curves[index];
+        const float* c2 = curves[index + 1];
+        for (int i = 0; i < 128; ++i)
+            data[i] = mu * c2[i] + (1 - mu) * c1[i];
+    }
+    else {
+        const float* c = curves[num_curves - 1];
+        for (int i = 0; i < 128; ++i)
+            data[i] = c[i];
+    }
+
+    //
+    return createFromDetuneRatios(data);
+
+}
 
 } // namespace sfz
diff --git a/src/sfizz/Tuning.h b/src/sfizz/Tuning.h
index 507bf44f9..35793f0b9 100644
--- a/src/sfizz/Tuning.h
+++ b/src/sfizz/Tuning.h
@@ -71,4 +71,16 @@ class Tuning {
     std::unique_ptr<Impl> impl_;
 };
 
+class StretchTuning {
+public:
+    float getRatioForIntegralKey(int key) const noexcept;
+    float getRatioForFractionalKey(float key) const noexcept;
+
+    static StretchTuning createFromDetuneRatios(const float detune[128]);
+    static StretchTuning createRailsbackFromRatio(float stretch);
+
+private:
+    float keyDetuneRatio_[128] {};
+};
+
 } // namespace sfz
diff --git a/src/sfizz/railsback/2-1.h b/src/sfizz/railsback/2-1.h
new file mode 100644
index 000000000..cc4a3e54c
--- /dev/null
+++ b/src/sfizz/railsback/2-1.h
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: BSD-2-Clause
+
+// This code is part of the sfizz library and is licensed under a BSD 2-clause
+// license. You should have receive a LICENSE.md file along with the code.
+// If not, contact the sfizz maintainers at https://github.com/sfztools/sfizz
+
+/* Railsback curve 2-1 */
+  0.995011, /* key   0:  -8.658702 cents (extrapolated) */
+  0.995085, /* key   1:  -8.529617 cents (extrapolated) */
+  0.995162, /* key   2:  -8.395871 cents (extrapolated) */
+  0.995242, /* key   3:  -8.257465 cents (extrapolated) */
+  0.995324, /* key   4:  -8.114399 cents (extrapolated) */
+  0.995409, /* key   5:  -7.966672 cents (extrapolated) */
+  0.995496, /* key   6:  -7.814285 cents (extrapolated) */
+  0.995587, /* key   7:  -7.657238 cents (extrapolated) */
+  0.995680, /* key   8:  -7.495530 cents (extrapolated) */
+  0.995775, /* key   9:  -7.329161 cents (extrapolated) */
+  0.995874, /* key  10:  -7.158133 cents (extrapolated) */
+  0.995975, /* key  11:  -6.982444 cents (extrapolated) */
+  0.996079, /* key  12:  -6.802095 cents (extrapolated) */
+  0.996185, /* key  13:  -6.617085 cents (extrapolated) */
+  0.996294, /* key  14:  -6.427415 cents (extrapolated) */
+  0.996406, /* key  15:  -6.233084 cents (extrapolated) */
+  0.996521, /* key  16:  -6.034094 cents (extrapolated) */
+  0.996638, /* key  17:  -5.830443 cents (extrapolated) */
+  0.996758, /* key  18:  -5.622131 cents (extrapolated) */
+  0.996880, /* key  19:  -5.409159 cents (extrapolated) */
+  0.997006, /* key  20:  -5.191527 cents (extrapolated) */
+  0.997134, /* key  21:  -4.969234 cents (extrapolated) */
+  0.997264, /* key  22:  -4.742281 cents (extrapolated) */
+  0.997398, /* key  23:  -4.510668 cents (extrapolated) */
+  0.997534, /* key  24:  -4.274394 cents (extrapolated) */
+  0.997673, /* key  25:  -4.033460 cents (extrapolated) */
+  0.997814, /* key  26:  -3.787866 cents (extrapolated) */
+  0.997959, /* key  27:  -3.537611 cents */
+  0.998106, /* key  28:  -3.282696 cents */
+  0.998255, /* key  29:  -3.023120 cents */
+  0.998408, /* key  30:  -2.758884 cents */
+  0.998562, /* key  31:  -2.491368 cents */
+  0.998706, /* key  32:  -2.241976 cents */
+  0.998835, /* key  33:  -2.018026 cents */
+  0.998951, /* key  34:  -1.817862 cents */
+  0.999066, /* key  35:  -1.617934 cents */
+  0.999186, /* key  36:  -1.410588 cents */
+  0.999308, /* key  37:  -1.197763 cents */
+  0.999421, /* key  38:  -1.002872 cents */
+  0.999519, /* key  39:  -0.832780 cents */
+  0.999604, /* key  40:  -0.686387 cents */
+  0.999683, /* key  41:  -0.549253 cents */
+  0.999759, /* key  42:  -0.416912 cents */
+  0.999833, /* key  43:  -0.289964 cents */
+  0.999899, /* key  44:  -0.175639 cents */
+  0.999956, /* key  45:  -0.076060 cents */
+  1.000005, /* key  46:   0.008822 cents */
+  1.000046, /* key  47:   0.079500 cents */
+  1.000079, /* key  48:   0.136106 cents */
+  1.000103, /* key  49:   0.178641 cents */
+  1.000120, /* key  50:   0.207103 cents */
+  1.000128, /* key  51:   0.221494 cents */
+  1.000129, /* key  52:   0.222942 cents */
+  1.000129, /* key  53:   0.223104 cents */
+  1.000130, /* key  54:   0.225054 cents */
+  1.000132, /* key  55:   0.228792 cents */
+  1.000135, /* key  56:   0.234318 cents */
+  1.000140, /* key  57:   0.241632 cents */
+  1.000145, /* key  58:   0.250734 cents */
+  1.000151, /* key  59:   0.261624 cents */
+  1.000158, /* key  60:   0.274302 cents */
+  1.000167, /* key  61:   0.288924 cents */
+  1.000177, /* key  62:   0.306785 cents */
+  1.000190, /* key  63:   0.328176 cents */
+  1.000204, /* key  64:   0.353095 cents */
+  1.000220, /* key  65:   0.381543 cents */
+  1.000239, /* key  66:   0.413520 cents */
+  1.000261, /* key  67:   0.452181 cents */
+  1.000301, /* key  68:   0.520401 cents */
+  1.000360, /* key  69:   0.622735 cents */
+  1.000437, /* key  70:   0.756456 cents */
+  1.000522, /* key  71:   0.904153 cents */
+  1.000614, /* key  72:   1.062739 cents */
+  1.000711, /* key  73:   1.231072 cents */
+  1.000810, /* key  74:   1.401365 cents */
+  1.000909, /* key  75:   1.572155 cents */
+  1.001009, /* key  76:   1.745072 cents */
+  1.001119, /* key  77:   1.935654 cents */
+  1.001241, /* key  78:   2.147768 cents */
+  1.001376, /* key  79:   2.381211 cents */
+  1.001523, /* key  80:   2.634168 cents */
+  1.001680, /* key  81:   2.906211 cents */
+  1.001847, /* key  82:   3.193974 cents */
+  1.002007, /* key  83:   3.471247 cents */
+  1.002158, /* key  84:   3.732482 cents */
+  1.002305, /* key  85:   3.985981 cents */
+  1.002487, /* key  86:   4.301067 cents */
+  1.002715, /* key  87:   4.693299 cents */
+  1.002982, /* key  88:   5.154494 cents */
+  1.003252, /* key  89:   5.620512 cents */
+  1.003517, /* key  90:   6.077690 cents */
+  1.003779, /* key  91:   6.530662 cents */
+  1.004058, /* key  92:   7.011498 cents */
+  1.004357, /* key  93:   7.526323 cents */
+  1.004673, /* key  94:   8.071295 cents */
+  1.004991, /* key  95:   8.619646 cents */
+  1.005309, /* key  96:   9.166235 cents */
+  1.005630, /* key  97:   9.720017 cents */
+  1.005990, /* key  98:  10.339965 cents */
+  1.006395, /* key  99:  11.036832 cents */
+  1.006839, /* key 100:  11.800397 cents */
+  1.007285, /* key 101:  12.566840 cents */
+  1.007727, /* key 102:  13.325103 cents */
+  1.008163, /* key 103:  14.075186 cents */
+  1.008595, /* key 104:  14.817087 cents */
+  1.009023, /* key 105:  15.550807 cents (extrapolated) */
+  1.009446, /* key 106:  16.276347 cents (extrapolated) */
+  1.009864, /* key 107:  16.993705 cents (extrapolated) */
+  1.010278, /* key 108:  17.702883 cents (extrapolated) */
+  1.010687, /* key 109:  18.403880 cents (extrapolated) */
+  1.011092, /* key 110:  19.096696 cents (extrapolated) */
+  1.011492, /* key 111:  19.781331 cents (extrapolated) */
+  1.011887, /* key 112:  20.457786 cents (extrapolated) */
+  1.012278, /* key 113:  21.126059 cents (extrapolated) */
+  1.012664, /* key 114:  21.786151 cents (extrapolated) */
+  1.013045, /* key 115:  22.438063 cents (extrapolated) */
+  1.013422, /* key 116:  23.081794 cents (extrapolated) */
+  1.013794, /* key 117:  23.717344 cents (extrapolated) */
+  1.014161, /* key 118:  24.344713 cents (extrapolated) */
+  1.014524, /* key 119:  24.963901 cents (extrapolated) */
+  1.014882, /* key 120:  25.574908 cents (extrapolated) */
+  1.015236, /* key 121:  26.177735 cents (extrapolated) */
+  1.015585, /* key 122:  26.772380 cents (extrapolated) */
+  1.015929, /* key 123:  27.358845 cents (extrapolated) */
+  1.016268, /* key 124:  27.937129 cents (extrapolated) */
+  1.016603, /* key 125:  28.507232 cents (extrapolated) */
+  1.016933, /* key 126:  29.069154 cents (extrapolated) */
+  1.017258, /* key 127:  29.622895 cents (extrapolated) */
diff --git a/src/sfizz/railsback/4-1.h b/src/sfizz/railsback/4-1.h
new file mode 100644
index 000000000..34d93725b
--- /dev/null
+++ b/src/sfizz/railsback/4-1.h
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: BSD-2-Clause
+
+// This code is part of the sfizz library and is licensed under a BSD 2-clause
+// license. You should have receive a LICENSE.md file along with the code.
+// If not, contact the sfizz maintainers at https://github.com/sfztools/sfizz
+
+/* Railsback curve 4-1 */
+  0.939286, /* key   0: -108.436476 cents (extrapolated) */
+  0.942401, /* key   1: -102.705252 cents (extrapolated) */
+  0.945435, /* key   2: -97.139571 cents (extrapolated) */
+  0.948389, /* key   3: -91.739433 cents (extrapolated) */
+  0.951261, /* key   4: -86.504836 cents (extrapolated) */
+  0.954050, /* key   5: -81.435782 cents (extrapolated) */
+  0.956756, /* key   6: -76.532270 cents (extrapolated) */
+  0.959378, /* key   7: -71.794300 cents (extrapolated) */
+  0.961915, /* key   8: -67.221873 cents (extrapolated) */
+  0.964367, /* key   9: -62.814988 cents (extrapolated) */
+  0.966732, /* key  10: -58.573645 cents (extrapolated) */
+  0.969011, /* key  11: -54.497845 cents (extrapolated) */
+  0.971202, /* key  12: -50.587587 cents (extrapolated) */
+  0.973305, /* key  13: -46.842871 cents (extrapolated) */
+  0.975320, /* key  14: -43.263697 cents (extrapolated) */
+  0.977245, /* key  15: -39.850066 cents (extrapolated) */
+  0.979080, /* key  16: -36.601977 cents (extrapolated) */
+  0.980825, /* key  17: -33.519430 cents (extrapolated) */
+  0.982479, /* key  18: -30.602425 cents (extrapolated) */
+  0.984041, /* key  19: -27.850963 cents (extrapolated) */
+  0.985512, /* key  20: -25.265043 cents (extrapolated) */
+  0.986891, /* key  21: -22.844666 cents (extrapolated) */
+  0.988177, /* key  22: -20.589830 cents (extrapolated) */
+  0.989371, /* key  23: -18.500537 cents (extrapolated) */
+  0.990471, /* key  24: -16.576786 cents (extrapolated) */
+  0.991477, /* key  25: -14.818578 cents (extrapolated) */
+  0.992390, /* key  26: -13.225912 cents (extrapolated) */
+  0.993208, /* key  27: -11.798788 cents */
+  0.993932, /* key  28: -10.537206 cents */
+  0.994561, /* key  29:  -9.441167 cents */
+  0.995096, /* key  30:  -8.510670 cents */
+  0.995559, /* key  31:  -7.706263 cents */
+  0.995995, /* key  32:  -6.947307 cents */
+  0.996407, /* key  33:  -6.231943 cents */
+  0.996789, /* key  34:  -5.567941 cents */
+  0.997140, /* key  35:  -4.957876 cents */
+  0.997460, /* key  36:  -4.403642 cents */
+  0.997745, /* key  37:  -3.908466 cents */
+  0.997997, /* key  38:  -3.470683 cents */
+  0.998229, /* key  39:  -3.068428 cents */
+  0.998444, /* key  40:  -2.695061 cents */
+  0.998640, /* key  41:  -2.355536 cents */
+  0.998811, /* key  42:  -2.059656 cents */
+  0.998957, /* key  43:  -1.805795 cents */
+  0.999095, /* key  44:  -1.567663 cents */
+  0.999228, /* key  45:  -1.336825 cents */
+  0.999357, /* key  46:  -1.113643 cents */
+  0.999479, /* key  47:  -0.902246 cents */
+  0.999594, /* key  48:  -0.703804 cents */
+  0.999701, /* key  49:  -0.518051 cents */
+  0.999803, /* key  50:  -0.341900 cents */
+  0.999899, /* key  51:  -0.174467 cents */
+  0.999990, /* key  52:  -0.016924 cents */
+  1.000069, /* key  53:   0.119979 cents */
+  1.000135, /* key  54:   0.233645 cents */
+  1.000196, /* key  55:   0.338454 cents */
+  1.000261, /* key  56:   0.452623 cents */
+  1.000330, /* key  57:   0.571568 cents */
+  1.000398, /* key  58:   0.688154 cents */
+  1.000463, /* key  59:   0.801883 cents */
+  1.000525, /* key  60:   0.908646 cents */
+  1.000582, /* key  61:   1.007402 cents */
+  1.000635, /* key  62:   1.099408 cents */
+  1.000690, /* key  63:   1.194622 cents */
+  1.000748, /* key  64:   1.295185 cents */
+  1.000809, /* key  65:   1.400548 cents */
+  1.000871, /* key  66:   1.506439 cents */
+  1.000932, /* key  67:   1.611953 cents */
+  1.000998, /* key  68:   1.727714 cents */
+  1.001079, /* key  69:   1.867793 cents */
+  1.001173, /* key  70:   2.029542 cents */
+  1.001269, /* key  71:   2.195080 cents */
+  1.001365, /* key  72:   2.361143 cents */
+  1.001463, /* key  73:   2.530246 cents */
+  1.001572, /* key  74:   2.719392 cents */
+  1.001695, /* key  75:   2.931762 cents */
+  1.001831, /* key  76:   3.166801 cents */
+  1.001977, /* key  77:   3.418944 cents */
+  1.002132, /* key  78:   3.686750 cents */
+  1.002296, /* key  79:   3.970898 cents */
+  1.002474, /* key  80:   4.277766 cents */
+  1.002666, /* key  81:   4.608921 cents */
+  1.002873, /* key  82:   4.965874 cents */
+  1.003102, /* key  83:   5.361161 cents */
+  1.003354, /* key  84:   5.797580 cents */
+  1.003633, /* key  85:   6.277406 cents */
+  1.003948, /* key  86:   6.821544 cents */
+  1.004304, /* key  87:   7.435055 cents */
+  1.004696, /* key  88:   8.110190 cents */
+  1.005088, /* key  89:   8.786767 cents */
+  1.005475, /* key  90:   9.452064 cents */
+  1.005861, /* key  91:  10.116356 cents */
+  1.006287, /* key  92:  10.849495 cents */
+  1.006760, /* key  93:  11.664603 cents */
+  1.007286, /* key  94:  12.567428 cents */
+  1.007886, /* key  95:  13.598919 cents */
+  1.008566, /* key  96:  14.767105 cents */
+  1.009328, /* key  97:  16.073381 cents */
+  1.010176, /* key  98:  17.527215 cents */
+  1.011111, /* key  99:  19.130383 cents */
+  1.012135, /* key 100:  20.882887 cents */
+  1.013248, /* key 101:  22.784726 cents (extrapolated) */
+  1.014449, /* key 102:  24.835900 cents (extrapolated) */
+  1.015739, /* key 103:  27.036410 cents (extrapolated) */
+  1.017119, /* key 104:  29.386254 cents (extrapolated) */
+  1.018588, /* key 105:  31.885434 cents (extrapolated) */
+  1.020148, /* key 106:  34.533949 cents (extrapolated) */
+  1.021798, /* key 107:  37.331799 cents (extrapolated) */
+  1.023539, /* key 108:  40.278984 cents (extrapolated) */
+  1.025371, /* key 109:  43.375505 cents (extrapolated) */
+  1.027295, /* key 110:  46.621360 cents (extrapolated) */
+  1.029312, /* key 111:  50.016551 cents (extrapolated) */
+  1.031422, /* key 112:  53.561077 cents (extrapolated) */
+  1.033625, /* key 113:  57.254938 cents (extrapolated) */
+  1.035922, /* key 114:  61.098134 cents (extrapolated) */
+  1.038314, /* key 115:  65.090666 cents (extrapolated) */
+  1.040801, /* key 116:  69.232533 cents (extrapolated) */
+  1.043384, /* key 117:  73.523734 cents (extrapolated) */
+  1.046063, /* key 118:  77.964271 cents (extrapolated) */
+  1.048840, /* key 119:  82.554143 cents (extrapolated) */
+  1.051715, /* key 120:  87.293351 cents (extrapolated) */
+  1.054689, /* key 121:  92.181893 cents (extrapolated) */
+  1.057763, /* key 122:  97.219771 cents (extrapolated) */
+  1.060937, /* key 123: 102.406984 cents (extrapolated) */
+  1.064213, /* key 124: 107.743532 cents (extrapolated) */
+  1.067590, /* key 125: 113.229415 cents (extrapolated) */
+  1.071071, /* key 126: 118.864633 cents (extrapolated) */
+  1.074656, /* key 127: 124.649187 cents (extrapolated) */
diff --git a/src/sfizz/railsback/4-2.h b/src/sfizz/railsback/4-2.h
new file mode 100644
index 000000000..52825f2cd
--- /dev/null
+++ b/src/sfizz/railsback/4-2.h
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: BSD-2-Clause
+
+// This code is part of the sfizz library and is licensed under a BSD 2-clause
+// license. You should have receive a LICENSE.md file along with the code.
+// If not, contact the sfizz maintainers at https://github.com/sfztools/sfizz
+
+/* Railsback curve 4-2 */
+  0.968133, /* key   0: -56.068174 cents (extrapolated) */
+  0.969216, /* key   1: -54.130975 cents (extrapolated) */
+  0.970284, /* key   2: -52.225304 cents (extrapolated) */
+  0.971335, /* key   3: -50.351161 cents (extrapolated) */
+  0.972369, /* key   4: -48.508548 cents (extrapolated) */
+  0.973387, /* key   5: -46.697464 cents (extrapolated) */
+  0.974388, /* key   6: -44.917908 cents (extrapolated) */
+  0.975372, /* key   7: -43.169881 cents (extrapolated) */
+  0.976340, /* key   8: -41.453383 cents (extrapolated) */
+  0.977291, /* key   9: -39.768414 cents (extrapolated) */
+  0.978225, /* key  10: -38.114974 cents (extrapolated) */
+  0.979141, /* key  11: -36.493062 cents (extrapolated) */
+  0.980041, /* key  12: -34.902679 cents (extrapolated) */
+  0.980924, /* key  13: -33.343826 cents (extrapolated) */
+  0.981790, /* key  14: -31.816500 cents (extrapolated) */
+  0.982639, /* key  15: -30.320704 cents (extrapolated) */
+  0.983470, /* key  16: -28.856437 cents (extrapolated) */
+  0.984284, /* key  17: -27.423698 cents (extrapolated) */
+  0.985081, /* key  18: -26.022489 cents (extrapolated) */
+  0.985861, /* key  19: -24.652808 cents (extrapolated) */
+  0.986623, /* key  20: -23.314656 cents (extrapolated) */
+  0.987368, /* key  21: -22.008032 cents (extrapolated) */
+  0.988096, /* key  22: -20.732938 cents (extrapolated) */
+  0.988806, /* key  23: -19.489372 cents (extrapolated) */
+  0.989498, /* key  24: -18.277335 cents (extrapolated) */
+  0.990173, /* key  25: -17.096827 cents (extrapolated) */
+  0.990830, /* key  26: -15.947848 cents (extrapolated) */
+  0.991470, /* key  27: -14.830398 cents (extrapolated) */
+  0.992092, /* key  28: -13.744476 cents */
+  0.992697, /* key  29: -12.690084 cents */
+  0.993283, /* key  30: -11.667220 cents */
+  0.993852, /* key  31: -10.675885 cents */
+  0.994403, /* key  32:  -9.716079 cents */
+  0.994935, /* key  33:  -8.791019 cents */
+  0.995443, /* key  34:  -7.906923 cents */
+  0.995928, /* key  35:  -7.063949 cents */
+  0.996389, /* key  36:  -6.263628 cents */
+  0.996814, /* key  37:  -5.524320 cents */
+  0.997202, /* key  38:  -4.851382 cents */
+  0.997551, /* key  39:  -4.244205 cents */
+  0.997868, /* key  40:  -3.695396 cents */
+  0.998152, /* key  41:  -3.202781 cents */
+  0.998405, /* key  42:  -2.763831 cents */
+  0.998641, /* key  43:  -2.354022 cents */
+  0.998864, /* key  44:  -1.967171 cents */
+  0.999074, /* key  45:  -1.603278 cents */
+  0.999267, /* key  46:  -1.268779 cents */
+  0.999438, /* key  47:  -0.973349 cents */
+  0.999586, /* key  48:  -0.717082 cents */
+  0.999713, /* key  49:  -0.497215 cents */
+  0.999837, /* key  50:  -0.283052 cents */
+  0.999962, /* key  51:  -0.066075 cents */
+  1.000087, /* key  52:   0.150991 cents */
+  1.000196, /* key  53:   0.340017 cents */
+  1.000285, /* key  54:   0.493590 cents */
+  1.000364, /* key  55:   0.630714 cents */
+  1.000450, /* key  56:   0.778589 cents */
+  1.000542, /* key  57:   0.937723 cents */
+  1.000641, /* key  58:   1.108577 cents */
+  1.000746, /* key  59:   1.291156 cents */
+  1.000860, /* key  60:   1.487486 cents */
+  1.000983, /* key  61:   1.700692 cents */
+  1.001116, /* key  62:   1.930806 cents */
+  1.001259, /* key  63:   2.177830 cents */
+  1.001419, /* key  64:   2.454501 cents */
+  1.001605, /* key  65:   2.777218 cents */
+  1.001819, /* key  66:   3.146046 cents */
+  1.002058, /* key  67:   3.558460 cents */
+  1.002311, /* key  68:   3.995879 cents */
+  1.002576, /* key  69:   4.454554 cents */
+  1.002854, /* key  70:   4.934013 cents */
+  1.003142, /* key  71:   5.431357 cents */
+  1.003441, /* key  72:   5.946093 cents */
+  1.003750, /* key  73:   6.480558 cents */
+  1.004081, /* key  74:   7.050077 cents */
+  1.004433, /* key  75:   7.657436 cents */
+  1.004808, /* key  76:   8.304413 cents */
+  1.005217, /* key  77:   9.008633 cents */
+  1.005662, /* key  78:   9.774607 cents */
+  1.006141, /* key  79:  10.598988 cents */
+  1.006636, /* key  80:  11.450574 cents */
+  1.007143, /* key  81:  12.321738 cents */
+  1.007662, /* key  82:  13.213585 cents */
+  1.008198, /* key  83:  14.135184 cents */
+  1.008754, /* key  84:  15.088542 cents */
+  1.009329, /* key  85:  16.076215 cents */
+  1.009939, /* key  86:  17.121007 cents */
+  1.010585, /* key  87:  18.228310 cents */
+  1.011265, /* key  88:  19.392518 cents */
+  1.011950, /* key  89:  20.566206 cents */
+  1.012636, /* key  90:  21.738618 cents */
+  1.013327, /* key  91:  22.919118 cents */
+  1.014061, /* key  92:  24.173747 cents */
+  1.014847, /* key  93:  25.515341 cents */
+  1.015679, /* key  94:  26.934203 cents */
+  1.016517, /* key  95:  28.360657 cents */
+  1.017351, /* key  96:  29.780936 cents */
+  1.018188, /* key  97:  31.204307 cents */
+  1.019062, /* key  98:  32.690667 cents */
+  1.019981, /* key  99:  34.250749 cents */
+  1.020944, /* key 100:  35.884552 cents (extrapolated) */
+  1.021952, /* key 101:  37.592078 cents (extrapolated) */
+  1.023004, /* key 102:  39.373326 cents (extrapolated) */
+  1.024100, /* key 103:  41.228296 cents (extrapolated) */
+  1.025242, /* key 104:  43.156987 cents (extrapolated) */
+  1.026428, /* key 105:  45.159401 cents (extrapolated) */
+  1.027660, /* key 106:  47.235537 cents (extrapolated) */
+  1.028937, /* key 107:  49.385395 cents (extrapolated) */
+  1.030259, /* key 108:  51.608975 cents (extrapolated) */
+  1.031627, /* key 109:  53.906277 cents (extrapolated) */
+  1.033041, /* key 110:  56.277301 cents (extrapolated) */
+  1.034501, /* key 111:  58.722047 cents (extrapolated) */
+  1.036007, /* key 112:  61.240515 cents (extrapolated) */
+  1.037559, /* key 113:  63.832705 cents (extrapolated) */
+  1.039158, /* key 114:  66.498617 cents (extrapolated) */
+  1.040804, /* key 115:  69.238251 cents (extrapolated) */
+  1.042497, /* key 116:  72.051607 cents (extrapolated) */
+  1.044237, /* key 117:  74.938686 cents (extrapolated) */
+  1.046024, /* key 118:  77.899486 cents (extrapolated) */
+  1.047859, /* key 119:  80.934008 cents (extrapolated) */
+  1.049742, /* key 120:  84.042253 cents (extrapolated) */
+  1.051673, /* key 121:  87.224219 cents (extrapolated) */
+  1.053653, /* key 122:  90.479907 cents (extrapolated) */
+  1.055681, /* key 123:  93.809318 cents (extrapolated) */
+  1.057759, /* key 124:  97.212450 cents (extrapolated) */
+  1.059885, /* key 125: 100.689305 cents (extrapolated) */
+  1.062061, /* key 126: 104.239881 cents (extrapolated) */
+  1.064287, /* key 127: 107.864180 cents (extrapolated) */
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index af4981dc2..c71cee5b5 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -64,6 +64,10 @@ if(JACK_FOUND AND TARGET Qt5::Widgets)
     add_executable(sfizz_demo_parser DemoParser.cpp)
     target_link_libraries(sfizz_demo_parser PRIVATE sfizz_parser Qt5::Widgets)
     set_target_properties(sfizz_demo_parser PROPERTIES AUTOUIC ON)
+
+    add_executable(sfizz_demo_stretch_tuning DemoStretchTuning.cpp)
+    target_link_libraries(sfizz_demo_stretch_tuning PRIVATE sfizz::sfizz Qt5::Widgets)
+    set_target_properties(sfizz_demo_stretch_tuning PROPERTIES AUTOUIC ON)
 endif()
 
 add_executable(eq_apply EQ.cpp)
diff --git a/tests/DemoStretchTuning.cpp b/tests/DemoStretchTuning.cpp
new file mode 100644
index 000000000..6604f1510
--- /dev/null
+++ b/tests/DemoStretchTuning.cpp
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: BSD-2-Clause
+
+// This code is part of the sfizz library and is licensed under a BSD 2-clause
+// license. You should have receive a LICENSE.md file along with the code.
+// If not, contact the sfizz maintainers at https://github.com/sfztools/sfizz
+
+#include "sfizz/Tuning.h"
+#include "ui_DemoStretchTuning.h"
+#include <QApplication>
+#include <QMainWindow>
+#include <QPainter>
+#include <QPainterPath>
+#include <QDebug>
+#include <functional>
+#include <cmath>
+
+class DataPlotWidget;
+
+///
+class DemoApp : public QApplication {
+public:
+    DemoApp(int& argc, char** argv);
+    void initWindow();
+
+private:
+    void updateStretch();
+
+private:
+    QMainWindow* fWindow = nullptr;
+    DataPlotWidget* fDataPlot = nullptr;
+    Ui::DemoStretchTuningWindow fUi;
+
+    sfz::StretchTuning fTuning;
+};
+
+///
+class DataPlotWidget : public QWidget {
+public:
+    explicit DataPlotWidget(QWidget* parent = nullptr);
+    void setYRange(float y1, float y2);
+    void setYFunction(std::function<qreal(qreal)> fun);
+
+protected:
+    void paintEvent(QPaintEvent* event) override;
+
+    float yRange1_ = 0.0f;
+    float yRange2_ = 0.0f;
+    std::function<qreal(qreal)> yFunction_;
+};
+
+DataPlotWidget::DataPlotWidget(QWidget* parent)
+    : QWidget(parent)
+{
+}
+
+void DataPlotWidget::setYRange(float y1, float y2)
+{
+    yRange1_ = y1;
+    yRange2_ = y2;
+}
+
+void DataPlotWidget::setYFunction(std::function<qreal(qreal)> fun)
+{
+    yFunction_ = fun;
+    repaint();
+}
+
+void DataPlotWidget::paintEvent(QPaintEvent* event)
+{
+    Q_UNUSED(event);
+
+    QPainter painter(this);
+
+    painter.fillRect(rect(), Qt::white);
+
+    const qreal yRange1 = yRange1_;
+    const qreal yRange2 = yRange2_;
+    std::function<qreal(qreal)> yFunction = yFunction_;
+
+    if (yRange1 == yRange2 || !yFunction)
+        return;
+
+    int w = width();
+    int h = height();
+
+    auto yPointToCoord = [h, yRange1, yRange2](qreal y) {
+        qreal r = (y - yRange1) / (yRange2 - yRange1);
+        return (1 - r) * (h - 1);
+    };
+
+    QPainterPath path;
+    path.moveTo(0.0, yPointToCoord(yFunction(0.0)));
+    for (int x = 1; x < w; ++x) {
+        qreal wRatio = x * (qreal(1.0) / (w - 1));
+        path.lineTo(x, yPointToCoord(yFunction(wRatio * 127)));
+    }
+
+    painter.strokePath(path, QPen(Qt::red, 1.0));
+}
+
+///
+DemoApp::DemoApp(int& argc, char** argv)
+    : QApplication(argc, argv)
+{
+    setApplicationName(tr("Sfizz Stretch Tuning"));
+}
+
+void DemoApp::initWindow()
+{
+    QMainWindow* window = new QMainWindow;
+    fWindow = window;
+    fUi.setupUi(window);
+
+    QVBoxLayout* lPlot = new QVBoxLayout;
+    lPlot->setContentsMargins(QMargins());
+    DataPlotWidget* dataPlot = new DataPlotWidget;
+    fDataPlot = dataPlot;
+    lPlot->addWidget(dataPlot);
+    fUi.frmPlot->setLayout(lPlot);
+
+    dataPlot->setYRange(-50.0, +50.0);
+
+    connect(
+        fUi.valStretch, &QSlider::valueChanged,
+        this, [this]() { updateStretch(); });
+
+    fUi.valStretch->setValue(fUi.valStretch->maximum() / 2);
+
+    window->setWindowTitle(applicationDisplayName());
+    window->show();
+}
+
+void DemoApp::updateStretch()
+{
+    qreal stretch = qreal(fUi.valStretch->value()) / fUi.valStretch->maximum();
+
+    sfz::StretchTuning& tuning = fTuning;
+    tuning = sfz::StretchTuning::createRailsbackFromRatio(stretch);
+
+    fDataPlot->setYFunction([this](qreal x) -> qreal {
+        float ratio = fTuning.getRatioForFractionalKey(x);
+        float cents = 1200.0f * std::log2(ratio);
+        return cents;
+    });
+}
+
+int main(int argc, char *argv[])
+{
+    DemoApp app(argc, argv);
+
+    app.initWindow();
+
+    return app.exec();
+}
diff --git a/tests/DemoStretchTuning.ui b/tests/DemoStretchTuning.ui
new file mode 100644
index 000000000..126ac256e
--- /dev/null
+++ b/tests/DemoStretchTuning.ui
@@ -0,0 +1,68 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>DemoStretchTuningWindow</class>
+ <widget class="QMainWindow" name="DemoStretchTuningWindow">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>800</width>
+    <height>600</height>
+   </rect>
+  </property>
+  <widget class="QWidget" name="centralwidget">
+   <layout class="QVBoxLayout" name="verticalLayout">
+    <item>
+     <widget class="QFrame" name="frmPlot">
+      <property name="frameShape">
+       <enum>QFrame::StyledPanel</enum>
+      </property>
+      <property name="frameShadow">
+       <enum>QFrame::Raised</enum>
+      </property>
+     </widget>
+    </item>
+    <item>
+     <widget class="QFrame" name="frame">
+      <property name="sizePolicy">
+       <sizepolicy hsizetype="Preferred" vsizetype="Maximum">
+        <horstretch>0</horstretch>
+        <verstretch>0</verstretch>
+       </sizepolicy>
+      </property>
+      <property name="frameShape">
+       <enum>QFrame::StyledPanel</enum>
+      </property>
+      <property name="frameShadow">
+       <enum>QFrame::Raised</enum>
+      </property>
+      <layout class="QVBoxLayout" name="verticalLayout_3">
+       <item>
+        <widget class="QLabel" name="label">
+         <property name="text">
+          <string>Stretch</string>
+         </property>
+         <property name="alignment">
+          <set>Qt::AlignCenter</set>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QSlider" name="valStretch">
+         <property name="maximum">
+          <number>100</number>
+         </property>
+         <property name="orientation">
+          <enum>Qt::Horizontal</enum>
+         </property>
+        </widget>
+       </item>
+      </layout>
+     </widget>
+    </item>
+   </layout>
+  </widget>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>

From 1ba7e6deb23c229b7a4510e87bf28e86de5e5ef6 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Thu, 11 Jun 2020 22:22:47 +0200
Subject: [PATCH 02/19] Add stretch tuning API and implement

---
 src/sfizz.h                 |  9 +++++++++
 src/sfizz.hpp               |  8 ++++++++
 src/sfizz/Resources.h       |  2 ++
 src/sfizz/Synth.cpp         | 11 +++++++++++
 src/sfizz/Synth.h           |  6 ++++++
 src/sfizz/Voice.cpp         |  5 +++++
 src/sfizz/sfizz.cpp         |  5 +++++
 src/sfizz/sfizz_wrapper.cpp |  6 ++++++
 8 files changed, 52 insertions(+)

diff --git a/src/sfizz.h b/src/sfizz.h
index e0a0c0a2f..69bff64b6 100644
--- a/src/sfizz.h
+++ b/src/sfizz.h
@@ -137,6 +137,15 @@ SFIZZ_EXPORTED_API void sfizz_set_tuning_frequency(sfizz_synth_t* synth, float f
  */
 SFIZZ_EXPORTED_API float sfizz_get_tuning_frequency(sfizz_synth_t* synth);
 
+/**
+ * @brief      Configure stretch tuning using a predefined parametric Railsback curve.
+ *             A ratio 1/2 is supposed to match the average piano; 0 disables (the default).
+ *
+ * @param      synth          The sfizz synth.
+ * @param      ratio          The parameter in domain 0-1.
+ */
+SFIZZ_EXPORTED_API void sfizz_load_stretch_tuning_by_ratio(sfizz_synth_t* synth, float ratio);
+
 /**
  * @brief      Return the number of regions in the currently loaded SFZ file.
  *
diff --git a/src/sfizz.hpp b/src/sfizz.hpp
index a57a5a4dc..8dbffc365 100644
--- a/src/sfizz.hpp
+++ b/src/sfizz.hpp
@@ -119,6 +119,14 @@ class SFIZZ_EXPORTED_API Sfizz
      */
     float getTuningFrequency() const;
 
+    /**
+     * @brief Configure stretch tuning using a predefined parametric Railsback curve.
+     * A ratio 1/2 is supposed to match the average piano; 0 disables (the default).
+     *
+     * @param ratio The parameter in domain 0-1.
+     */
+    void loadStretchTuningByRatio(float ratio);
+
     /**
      * @brief Return the current number of regions loaded.
      */
diff --git a/src/sfizz/Resources.h b/src/sfizz/Resources.h
index c998eb3cb..933dde27e 100644
--- a/src/sfizz/Resources.h
+++ b/src/sfizz/Resources.h
@@ -13,6 +13,7 @@
 #include "Wavetables.h"
 #include "Curve.h"
 #include "Tuning.h"
+#include "absl/types/optional.h"
 
 namespace sfz
 {
@@ -29,6 +30,7 @@ struct Resources
     EQPool eqPool { midiState };
     WavetablePool wavePool;
     Tuning tuning;
+    absl::optional<StretchTuning> stretch;
 
     void setSampleRate(float samplerate)
     {
diff --git a/src/sfizz/Synth.cpp b/src/sfizz/Synth.cpp
index 2718a1e10..50e9a569f 100644
--- a/src/sfizz/Synth.cpp
+++ b/src/sfizz/Synth.cpp
@@ -516,6 +516,17 @@ float sfz::Synth::getTuningFrequency() const
     return resources.tuning.getTuningFrequency();
 }
 
+void sfz::Synth::loadStretchTuningByRatio(float ratio)
+{
+    CHECK(ratio >= 0.0f && ratio <= 1.0f);
+    ratio = clamp(ratio, 0.0f, 1.0f);
+
+    if (ratio > 0.0f)
+        resources.stretch = StretchTuning::createRailsbackFromRatio(ratio);
+    else
+        resources.stretch.reset();
+}
+
 sfz::Voice* sfz::Synth::findFreeVoice() noexcept
 {
     auto freeVoice = absl::c_find_if(voices, [](const std::unique_ptr<Voice>& voice) {
diff --git a/src/sfizz/Synth.h b/src/sfizz/Synth.h
index 0819880e3..843307341 100644
--- a/src/sfizz/Synth.h
+++ b/src/sfizz/Synth.h
@@ -150,6 +150,12 @@ class Synth final : public Parser::Listener {
      * @return The frequency which indicates where standard tuning A4 is (default 440 Hz).
      */
     float getTuningFrequency() const;
+    /**
+     * @brief Configure stretch tuning using a predefined parametric Railsback curve.
+     *
+     * @param ratio The parameter in domain 0-1.
+     */
+    void loadStretchTuningByRatio(float ratio);
     /**
      * @brief Get the current number of regions loaded
      *
diff --git a/src/sfizz/Voice.cpp b/src/sfizz/Voice.cpp
index 6ae90db2e..9f6df3a31 100644
--- a/src/sfizz/Voice.cpp
+++ b/src/sfizz/Voice.cpp
@@ -87,6 +87,11 @@ void sfz::Voice::startVoice(Region* region, int delay, int number, float value,
     const float numberRetuned = resources.tuning.getKeyFractional12TET(number);
 
     pitchRatio = region->getBasePitchVariation(numberRetuned, value);
+
+    // apply stretch tuning if set
+    if (resources.stretch)
+        pitchRatio *= resources.stretch->getRatioForFractionalKey(numberRetuned);
+
     baseVolumedB = region->getBaseVolumedB(number);
     baseGain = region->getBaseGain();
     if (triggerType != TriggerType::CC)
diff --git a/src/sfizz/sfizz.cpp b/src/sfizz/sfizz.cpp
index 31047c775..b110b4e1a 100644
--- a/src/sfizz/sfizz.cpp
+++ b/src/sfizz/sfizz.cpp
@@ -58,6 +58,11 @@ float sfz::Sfizz::getTuningFrequency() const
     return synth->getTuningFrequency();
 }
 
+void sfz::Sfizz::loadStretchTuningByRatio(float ratio)
+{
+    return synth->loadStretchTuningByRatio(ratio);
+}
+
 int sfz::Sfizz::getNumRegions() const noexcept
 {
     return synth->getNumRegions();
diff --git a/src/sfizz/sfizz_wrapper.cpp b/src/sfizz/sfizz_wrapper.cpp
index 86ef1b67e..15310942a 100644
--- a/src/sfizz/sfizz_wrapper.cpp
+++ b/src/sfizz/sfizz_wrapper.cpp
@@ -67,6 +67,12 @@ float sfizz_get_tuning_frequency(sfizz_synth_t* synth)
     return self->getTuningFrequency();
 }
 
+void sfizz_load_stretch_tuning_by_ratio(sfizz_synth_t* synth, float ratio)
+{
+    auto self = reinterpret_cast<sfz::Synth*>(synth);
+    self->loadStretchTuningByRatio(ratio);
+}
+
 void sfizz_free(sfizz_synth_t* synth)
 {
     delete reinterpret_cast<sfz::Synth*>(synth);

From 2895a2bfee782ebb5d9c7a6879ffaff2f181fa0f Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Thu, 11 Jun 2020 22:37:08 +0200
Subject: [PATCH 03/19] Implement stretch tuning in LV2

---
 lv2/sfizz.c      | 19 +++++++++++++++++++
 lv2/sfizz.ttl.in | 11 +++++++++++
 2 files changed, 30 insertions(+)

diff --git a/lv2/sfizz.c b/lv2/sfizz.c
index 69784a854..52815295c 100644
--- a/lv2/sfizz.c
+++ b/lv2/sfizz.c
@@ -108,6 +108,7 @@ typedef struct
     const float *freewheel_port;
     const float *scala_root_key_port;
     const float *tuning_frequency_port;
+    const float *stretch_tuning_port;
 
     // Atom forge
     LV2_Atom_Forge forge;              ///< Forge for writing atoms in run thread
@@ -150,6 +151,7 @@ typedef struct
     int num_voices;
     unsigned int preload_size;
     sfizz_oversampling_factor_t oversampling;
+    float stretch_tuning;
     volatile bool check_modification;
     int max_block_size;
     int sample_counter;
@@ -170,6 +172,7 @@ enum
     SFIZZ_FREEWHEELING = 8,
     SFIZZ_SCALA_ROOT_KEY = 9,
     SFIZZ_TUNING_FREQUENCY = 10,
+    SFIZZ_STRETCH_TUNING = 11,
 };
 
 static void
@@ -242,6 +245,9 @@ connect_port(LV2_Handle instance,
     case SFIZZ_TUNING_FREQUENCY:
         self->tuning_frequency_port = (const float *)data;
         break;
+    case SFIZZ_STRETCH_TUNING:
+        self->stretch_tuning_port = (const float *)data;
+        break;
     default:
         break;
     }
@@ -302,6 +308,7 @@ instantiate(const LV2_Descriptor *descriptor,
     self->num_voices = DEFAULT_VOICES;
     self->oversampling = DEFAULT_OVERSAMPLING;
     self->preload_size = DEFAULT_PRELOAD;
+    self->stretch_tuning = 0.0f;
     self->check_modification = true;
     self->sample_counter = 0;
 
@@ -654,6 +661,17 @@ sfizz_lv2_check_freewheeling(sfizz_plugin_t* self)
     }
 }
 
+static void
+sfizz_lv2_check_stretch_tuning(sfizz_plugin_t* self)
+{
+    float stretch_tuning = (float)*self->stretch_tuning_port;
+    if (stretch_tuning != self->stretch_tuning)
+    {
+        sfizz_load_stretch_tuning_by_ratio(self->synth, stretch_tuning);
+        self->stretch_tuning = stretch_tuning;
+    }
+}
+
 static void
 run(LV2_Handle instance, uint32_t sample_count)
 {
@@ -719,6 +737,7 @@ run(LV2_Handle instance, uint32_t sample_count)
     sfizz_set_volume(self->synth, *(self->volume_port));
     sfizz_set_scala_root_key(self->synth, *(self->scala_root_key_port));
     sfizz_set_tuning_frequency(self->synth, *(self->tuning_frequency_port));
+    sfizz_lv2_check_stretch_tuning(self);
     sfizz_lv2_check_preload_size(self);
     sfizz_lv2_check_oversampling(self);
     sfizz_lv2_check_num_voices(self);
diff --git a/lv2/sfizz.ttl.in b/lv2/sfizz.ttl.in
index 4e52bcfe9..189849baf 100644
--- a/lv2/sfizz.ttl.in
+++ b/lv2/sfizz.ttl.in
@@ -280,4 +280,15 @@ midnam:update a lv2:Feature .
     lv2:minimum 300.0 ;
     lv2:maximum 500.0 ;
     units:unit units:hz
+  ] , [
+    a lv2:InputPort, lv2:ControlPort ;
+    lv2:index 11 ;
+    lv2:symbol "stretched_tuning" ;
+    lv2:name "Stretched tuning",
+      "Accordage étiré"@fr ;
+    pg:group <@LV2PLUGIN_URI@#tuning> ;
+    lv2:default 0.0 ;
+    lv2:minimum 0.0 ;
+    lv2:maximum 1.0 ;
+    units:unit units:coef
   ] .

From f0f4c34ad8e52f2624b7db608d87c158d38aaee2 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Sun, 17 May 2020 21:42:57 +0200
Subject: [PATCH 04/19] Numbering of regions and voices

---
 src/sfizz/Region.h                 | 14 ++++++++++--
 src/sfizz/Synth.cpp                |  5 +++--
 src/sfizz/Voice.cpp                |  4 ++--
 src/sfizz/Voice.h                  | 12 +++++++++-
 tests/RegionActivationT.cpp        |  2 +-
 tests/RegionT.cpp                  |  4 ++--
 tests/RegionTriggersT.cpp          |  4 ++--
 tests/RegionValueComputationsT.cpp | 36 +++++++++++++++---------------
 8 files changed, 51 insertions(+), 30 deletions(-)

diff --git a/src/sfizz/Region.h b/src/sfizz/Region.h
index 5ce49ff84..9b6e01b27 100644
--- a/src/sfizz/Region.h
+++ b/src/sfizz/Region.h
@@ -35,8 +35,8 @@ namespace sfz {
  *
  */
 struct Region {
-    Region(const MidiState& midiState, absl::string_view defaultPath = "")
-    : midiState(midiState), defaultPath(std::move(defaultPath))
+    Region(int regionNumber, const MidiState& midiState, absl::string_view defaultPath = "")
+    : regionNumber(regionNumber), midiState(midiState), defaultPath(std::move(defaultPath))
     {
         ccSwitched.set();
 
@@ -46,6 +46,14 @@ struct Region {
     Region(const Region&) = default;
     ~Region() = default;
 
+    /**
+     * @brief Get the number which identifies this region, also its index
+     */
+    int getIdNumber() const noexcept
+    {
+        return regionNumber;
+    }
+
     /**
      * @brief Triggers on release?
      *
@@ -238,6 +246,8 @@ struct Region {
      */
     float getGainToEffectBus(unsigned number) const noexcept;
 
+    const int regionNumber {};
+
     // Sound source: sample playback
     FileId sampleId {}; // Sample
     int sampleQuality { Default::sampleQuality };
diff --git a/src/sfizz/Synth.cpp b/src/sfizz/Synth.cpp
index 2718a1e10..b46a18b6f 100644
--- a/src/sfizz/Synth.cpp
+++ b/src/sfizz/Synth.cpp
@@ -95,7 +95,8 @@ void sfz::Synth::onParseWarning(const SourceRange& range, const std::string& mes
 
 void sfz::Synth::buildRegion(const std::vector<Opcode>& regionOpcodes)
 {
-    auto lastRegion = absl::make_unique<Region>(resources.midiState, defaultPath);
+    int regionNumber = static_cast<int>(regions.size());
+    auto lastRegion = absl::make_unique<Region>(regionNumber, resources.midiState, defaultPath);
 
     auto parseOpcodes = [&](const std::vector<Opcode>& opcodes) {
         for (auto& opcode : opcodes) {
@@ -1094,7 +1095,7 @@ void sfz::Synth::resetVoices(int numVoices)
     voices.reserve(numVoices);
 
     for (int i = 0; i < numVoices; ++i)
-        voices.push_back(absl::make_unique<Voice>(resources));
+        voices.push_back(absl::make_unique<Voice>(i, resources));
 
     voiceViewArray.clear();
     voiceViewArray.reserve(numVoices);
diff --git a/src/sfizz/Voice.cpp b/src/sfizz/Voice.cpp
index 6ae90db2e..2f3ebe05f 100644
--- a/src/sfizz/Voice.cpp
+++ b/src/sfizz/Voice.cpp
@@ -14,8 +14,8 @@
 #include "Interpolators.h"
 #include "absl/algorithm/container.h"
 
-sfz::Voice::Voice(sfz::Resources& resources)
-: resources(resources)
+sfz::Voice::Voice(int voiceNumber, sfz::Resources& resources)
+: voiceNumber(voiceNumber), resources(resources)
 {
     filters.reserve(config::filtersPerVoice);
     equalizers.reserve(config::eqsPerVoice);
diff --git a/src/sfizz/Voice.h b/src/sfizz/Voice.h
index a709eb58d..0c7937c78 100644
--- a/src/sfizz/Voice.h
+++ b/src/sfizz/Voice.h
@@ -32,14 +32,22 @@ class Voice {
     /**
      * @brief Construct a new voice with the midistate singleton
      *
+     * @param voiceNumber
      * @param midiState
      */
-    Voice(Resources& resources);
+    Voice(int voiceNumber, Resources& resources);
     enum class TriggerType {
         NoteOn,
         NoteOff,
         CC
     };
+    /**
+     * @brief Get the number which identifies this voice, its index
+     */
+    int getIdNumber() const noexcept
+    {
+        return voiceNumber;
+    }
     /**
      * @brief Change the sample rate of the voice. This is used to compute all
      * pitch related transformations so it needs to be propagated from the synth
@@ -270,6 +278,8 @@ class Voice {
     void setupOscillatorUnison();
     void updateChannelPowers(AudioSpan<float> buffer);
 
+    const int voiceNumber {};
+
     Region* region { nullptr };
 
     enum class State {
diff --git a/tests/RegionActivationT.cpp b/tests/RegionActivationT.cpp
index e65934b7c..41990934c 100644
--- a/tests/RegionActivationT.cpp
+++ b/tests/RegionActivationT.cpp
@@ -13,7 +13,7 @@ using namespace sfz::literals;
 TEST_CASE("Region activation", "Region tests")
 {
     sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
 
     region.parseOpcode({ "sample", "*sine" });
     SECTION("Basic state")
diff --git a/tests/RegionT.cpp b/tests/RegionT.cpp
index db2c9511a..c683cd96c 100644
--- a/tests/RegionT.cpp
+++ b/tests/RegionT.cpp
@@ -14,7 +14,7 @@ using namespace sfz::literals;
 TEST_CASE("[Region] Parsing opcodes")
 {
     sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
 
     SECTION("sample")
     {
@@ -1672,7 +1672,7 @@ TEST_CASE("[Region] Parsing opcodes")
 TEST_CASE("[Region] Non-conforming floating point values in integer opcodes")
 {
     sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "offset", "2014.5" });
     REQUIRE(region.offset == 2014);
     region.parseOpcode({ "pitch_keytrack", "-2.1" });
diff --git a/tests/RegionTriggersT.cpp b/tests/RegionTriggersT.cpp
index 75f5d9b5d..4ee56cde9 100644
--- a/tests/RegionTriggersT.cpp
+++ b/tests/RegionTriggersT.cpp
@@ -13,7 +13,7 @@ using namespace sfz::literals;
 TEST_CASE("Basic triggers", "Region triggers")
 {
     sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
 
     region.parseOpcode({ "sample", "*sine" });
     SECTION("key")
@@ -130,7 +130,7 @@ TEST_CASE("Basic triggers", "Region triggers")
 TEST_CASE("Legato triggers", "Region triggers")
 {
     sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     SECTION("First note playing")
     {
diff --git a/tests/RegionValueComputationsT.cpp b/tests/RegionValueComputationsT.cpp
index e6547b01a..50deb2317 100644
--- a/tests/RegionValueComputationsT.cpp
+++ b/tests/RegionValueComputationsT.cpp
@@ -17,7 +17,7 @@ constexpr int numRandomTests { 64 };
 TEST_CASE("[Region] Crossfade in on key")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfin_lokey", "1" });
     region.parseOpcode({ "xfin_hikey", "3" });
@@ -29,7 +29,7 @@ TEST_CASE("[Region] Crossfade in on key")
 TEST_CASE("[Region] Crossfade in on key - 2")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfin_lokey", "1" });
     region.parseOpcode({ "xfin_hikey", "5" });
@@ -44,7 +44,7 @@ TEST_CASE("[Region] Crossfade in on key - 2")
 TEST_CASE("[Region] Crossfade in on key - gain")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfin_lokey", "1" });
     region.parseOpcode({ "xfin_hikey", "5" });
@@ -59,7 +59,7 @@ TEST_CASE("[Region] Crossfade in on key - gain")
 TEST_CASE("[Region] Crossfade out on key")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfout_lokey", "51" });
     region.parseOpcode({ "xfout_hikey", "55" });
@@ -75,7 +75,7 @@ TEST_CASE("[Region] Crossfade out on key")
 TEST_CASE("[Region] Crossfade out on key - gain")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfout_lokey", "51" });
     region.parseOpcode({ "xfout_hikey", "55" });
@@ -92,7 +92,7 @@ TEST_CASE("[Region] Crossfade out on key - gain")
 TEST_CASE("[Region] Crossfade in on velocity")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfin_lovel", "20" });
     region.parseOpcode({ "xfin_hivel", "24" });
@@ -109,7 +109,7 @@ TEST_CASE("[Region] Crossfade in on velocity")
 TEST_CASE("[Region] Crossfade in on vel - gain")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfin_lovel", "20" });
     region.parseOpcode({ "xfin_hivel", "24" });
@@ -127,7 +127,7 @@ TEST_CASE("[Region] Crossfade in on vel - gain")
 TEST_CASE("[Region] Crossfade out on vel")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfout_lovel", "51" });
     region.parseOpcode({ "xfout_hivel", "55" });
@@ -144,7 +144,7 @@ TEST_CASE("[Region] Crossfade out on vel")
 TEST_CASE("[Region] Crossfade out on vel - gain")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfout_lovel", "51" });
     region.parseOpcode({ "xfout_hivel", "55" });
@@ -162,7 +162,7 @@ TEST_CASE("[Region] Crossfade out on vel - gain")
 TEST_CASE("[Region] Crossfade in on CC")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfin_locc24", "20" });
     region.parseOpcode({ "xfin_hicc24", "24" });
@@ -186,7 +186,7 @@ TEST_CASE("[Region] Crossfade in on CC")
 TEST_CASE("[Region] Crossfade in on CC - gain")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfin_locc24", "20" });
     region.parseOpcode({ "xfin_hicc24", "24" });
@@ -210,7 +210,7 @@ TEST_CASE("[Region] Crossfade in on CC - gain")
 TEST_CASE("[Region] Crossfade out on CC")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfout_locc24", "20" });
     region.parseOpcode({ "xfout_hicc24", "24" });
@@ -234,7 +234,7 @@ TEST_CASE("[Region] Crossfade out on CC")
 TEST_CASE("[Region] Crossfade out on CC - gain")
 {
 	sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "xfout_locc24", "20" });
     region.parseOpcode({ "xfout_hicc24", "24" });
@@ -259,7 +259,7 @@ TEST_CASE("[Region] Crossfade out on CC - gain")
 TEST_CASE("[Region] Velocity bug for extreme values - veltrack at 0")
 {
     sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "amp_veltrack", "0" });
     REQUIRE(region.getNoteGain(64, 127_norm) == 1.0_a);
@@ -270,7 +270,7 @@ TEST_CASE("[Region] Velocity bug for extreme values - veltrack at 0")
 TEST_CASE("[Region] Velocity bug for extreme values - positive veltrack")
 {
     sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "amp_veltrack", "100" });
     REQUIRE(region.getNoteGain(64, 127_norm) == 1.0_a);
@@ -280,7 +280,7 @@ TEST_CASE("[Region] Velocity bug for extreme values - positive veltrack")
 TEST_CASE("[Region] Velocity bug for extreme values - negative veltrack")
 {
     sfz::MidiState midiState;
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "amp_veltrack", "-100" });
     REQUIRE(region.getNoteGain(64, 127_norm) == Approx(0.0).margin(0.0001));
@@ -291,7 +291,7 @@ TEST_CASE("[Region] rt_decay")
 {
     sfz::MidiState midiState;
     midiState.setSampleRate(1000);
-    sfz::Region region { midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "trigger", "release" });
     region.parseOpcode({ "rt_decay", "10" });
@@ -311,7 +311,7 @@ TEST_CASE("[Region] rt_decay")
 TEST_CASE("[Region] Base delay")
 {
     sfz::MidiState midiState;
-    sfz::Region region{ midiState };
+    sfz::Region region { 0, midiState };
     region.parseOpcode({ "sample", "*sine" });
     region.parseOpcode({ "delay", "10" });
     REQUIRE( region.getDelay() == 10.0f );

From 2c3314d0adbc0e5acb0fad65fb0c5d5f5a569898 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Mon, 18 May 2020 11:59:31 +0200
Subject: [PATCH 05/19] Add a listener of voice state changes

---
 src/sfizz/Synth.cpp | 14 ++++++++++++--
 src/sfizz/Synth.h   |  8 +++++++-
 src/sfizz/Voice.cpp | 16 +++++++++++++---
 src/sfizz/Voice.h   | 26 ++++++++++++++++++++++----
 4 files changed, 54 insertions(+), 10 deletions(-)

diff --git a/src/sfizz/Synth.cpp b/src/sfizz/Synth.cpp
index b46a18b6f..2c889bf0c 100644
--- a/src/sfizz/Synth.cpp
+++ b/src/sfizz/Synth.cpp
@@ -44,6 +44,13 @@ sfz::Synth::~Synth()
     resources.filePool.emptyFileLoadingQueues();
 }
 
+void sfz::Synth::onVoiceStateChanged(int idNumber, Voice::State state)
+{
+    (void)idNumber;
+    (void)state;
+    DBG("Voice " << idNumber << ": state " << static_cast<int>(state));
+}
+
 void sfz::Synth::onParseFullBlock(const std::string& header, const std::vector<Opcode>& members)
 {
     switch (hash(header)) {
@@ -1094,8 +1101,11 @@ void sfz::Synth::resetVoices(int numVoices)
     voices.clear();
     voices.reserve(numVoices);
 
-    for (int i = 0; i < numVoices; ++i)
-        voices.push_back(absl::make_unique<Voice>(i, resources));
+    for (int i = 0; i < numVoices; ++i) {
+        auto voice = absl::make_unique<Voice>(i, resources);
+        voice->setStateListener(this);
+        voices.emplace_back(std::move(voice));
+    }
 
     voiceViewArray.clear();
     voiceViewArray.reserve(numVoices);
diff --git a/src/sfizz/Synth.h b/src/sfizz/Synth.h
index 0819880e3..883fedf46 100644
--- a/src/sfizz/Synth.h
+++ b/src/sfizz/Synth.h
@@ -60,7 +60,7 @@ namespace sfz {
  * The jack_client.cpp file contains examples of the most classical usage of the
  * synth and can be used as a reference.
  */
-class Synth final : public Parser::Listener {
+class Synth final : public Voice::StateListener, public Parser::Listener {
 public:
     /**
      * @brief Construct a new Synth object with no voices. If you want sound
@@ -493,6 +493,12 @@ class Synth final : public Parser::Listener {
      */
     const std::vector<CCNamePair>& getCCLabels() const noexcept { return ccLabels; }
 
+protected:
+    /**
+     * @brief The voice callback which is called during a change of state.
+     */
+    void onVoiceStateChanged(int idNumber, Voice::State state) override;
+
 protected:
     /**
      * @brief The parser callback; this is called by the parent object each time
diff --git a/src/sfizz/Voice.cpp b/src/sfizz/Voice.cpp
index 2f3ebe05f..fc65892c7 100644
--- a/src/sfizz/Voice.cpp
+++ b/src/sfizz/Voice.cpp
@@ -15,7 +15,7 @@
 #include "absl/algorithm/container.h"
 
 sfz::Voice::Voice(int voiceNumber, sfz::Resources& resources)
-: voiceNumber(voiceNumber), resources(resources)
+: voiceNumber(voiceNumber), stateListener(nullptr), resources(resources)
 {
     filters.reserve(config::filtersPerVoice);
     equalizers.reserve(config::eqsPerVoice);
@@ -36,7 +36,7 @@ void sfz::Voice::startVoice(Region* region, int delay, int number, float value,
     triggerValue = value;
 
     this->region = region;
-    state = State::playing;
+    switchState(State::playing);
 
     ASSERT(delay >= 0);
     if (delay < 0)
@@ -647,7 +647,7 @@ bool sfz::Voice::checkOffGroup(int delay, uint32_t group) noexcept
 
 void sfz::Voice::reset() noexcept
 {
-    state = State::idle;
+    switchState(State::idle);
     region = nullptr;
     currentPromise.reset();
     sourcePosition = 0;
@@ -766,3 +766,13 @@ void sfz::Voice::updateChannelPowers(AudioSpan<float> buffer)
                 channelEnvelopeFilters[i].tickLowpass(std::abs(input[s]));
     }
 }
+
+
+void sfz::Voice::switchState(State s)
+{
+    if (s != state) {
+        state = s;
+        if (stateListener)
+            stateListener->onVoiceStateChanged(voiceNumber, s);
+    }
+}
diff --git a/src/sfizz/Voice.h b/src/sfizz/Voice.h
index 0c7937c78..a9b347d27 100644
--- a/src/sfizz/Voice.h
+++ b/src/sfizz/Voice.h
@@ -48,6 +48,22 @@ class Voice {
     {
         return voiceNumber;
     }
+
+    enum class State {
+        idle,
+        playing
+    };
+
+    class StateListener {
+    public:
+        virtual void onVoiceStateChanged(int /*idNumber*/, State /*state*/) {}
+    };
+
+    /**
+     * @brief Sets the listener which is called when the voice state changes.
+     */
+    void setStateListener(StateListener *l) noexcept { stateListener = l; }
+
     /**
      * @brief Change the sample rate of the voice. This is used to compute all
      * pitch related transformations so it needs to be propagated from the synth
@@ -278,14 +294,16 @@ class Voice {
     void setupOscillatorUnison();
     void updateChannelPowers(AudioSpan<float> buffer);
 
+    /**
+     * @brief Modify the voice state and notify any listeners.
+     */
+    void switchState(State s);
+
     const int voiceNumber {};
+    StateListener* stateListener = nullptr;
 
     Region* region { nullptr };
 
-    enum class State {
-        idle,
-        playing
-    };
     State state { State::idle };
     bool noteIsOff { false };
 

From c239629be1079a2d74b9c6ac83ac3783ad581df7 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Sat, 30 May 2020 17:54:21 +0200
Subject: [PATCH 06/19] Initialize id number to -1, do not consider it as index

---
 src/sfizz/Region.h | 4 ++--
 src/sfizz/Voice.h  | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/sfizz/Region.h b/src/sfizz/Region.h
index 9b6e01b27..b18b7bd57 100644
--- a/src/sfizz/Region.h
+++ b/src/sfizz/Region.h
@@ -47,7 +47,7 @@ struct Region {
     ~Region() = default;
 
     /**
-     * @brief Get the number which identifies this region, also its index
+     * @brief Get the number which identifies this region
      */
     int getIdNumber() const noexcept
     {
@@ -246,7 +246,7 @@ struct Region {
      */
     float getGainToEffectBus(unsigned number) const noexcept;
 
-    const int regionNumber {};
+    const int regionNumber { -1 };
 
     // Sound source: sample playback
     FileId sampleId {}; // Sample
diff --git a/src/sfizz/Voice.h b/src/sfizz/Voice.h
index a9b347d27..59058c593 100644
--- a/src/sfizz/Voice.h
+++ b/src/sfizz/Voice.h
@@ -42,7 +42,7 @@ class Voice {
         CC
     };
     /**
-     * @brief Get the number which identifies this voice, its index
+     * @brief Get the number which identifies this voice
      */
     int getIdNumber() const noexcept
     {
@@ -299,7 +299,7 @@ class Voice {
      */
     void switchState(State s);
 
-    const int voiceNumber {};
+    const int voiceNumber { -1 };
     StateListener* stateListener = nullptr;
 
     Region* region { nullptr };

From e07912f7ce5b01aa6c1df525a11994599e61b790 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Thu, 11 Jun 2020 23:50:41 +0200
Subject: [PATCH 07/19] Implement the identifier in a better and more safe way

---
 src/sfizz/NumericId.h | 31 +++++++++++++++++++++++++++++++
 src/sfizz/Region.h    |  9 +++++----
 src/sfizz/Synth.cpp   |  6 +++---
 src/sfizz/Synth.h     |  2 +-
 src/sfizz/Voice.cpp   |  4 ++--
 src/sfizz/Voice.h     | 12 +++++++-----
 6 files changed, 49 insertions(+), 15 deletions(-)
 create mode 100644 src/sfizz/NumericId.h

diff --git a/src/sfizz/NumericId.h b/src/sfizz/NumericId.h
new file mode 100644
index 000000000..1d975ec03
--- /dev/null
+++ b/src/sfizz/NumericId.h
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: BSD-2-Clause
+
+// This code is part of the sfizz library and is licensed under a BSD 2-clause
+// license. You should have receive a LICENSE.md file along with the code.
+// If not, contact the sfizz maintainers at https://github.com/sfztools/sfizz
+
+#pragma once
+
+/**
+ * @brief Numeric identifier
+ *
+ * It is a generic numeric identifier. The template wrapper serves to enforce a
+ * stronger compile-time check, such that one kind of identifier can't be
+ * mistaken for another kind, or for an unrelated integer such as an index.
+ */
+template <class T>
+struct NumericId {
+    constexpr NumericId() = default;
+
+    explicit constexpr NumericId(int number)
+        : number(number)
+    {
+    }
+
+    constexpr bool valid() const noexcept
+    {
+        return number != -1;
+    }
+
+    const int number = -1;
+};
diff --git a/src/sfizz/Region.h b/src/sfizz/Region.h
index b18b7bd57..ad81f97e3 100644
--- a/src/sfizz/Region.h
+++ b/src/sfizz/Region.h
@@ -16,6 +16,7 @@
 #include "AudioBuffer.h"
 #include "MidiState.h"
 #include "FileId.h"
+#include "NumericId.h"
 #include "absl/types/optional.h"
 #include <bitset>
 #include <string>
@@ -36,7 +37,7 @@ namespace sfz {
  */
 struct Region {
     Region(int regionNumber, const MidiState& midiState, absl::string_view defaultPath = "")
-    : regionNumber(regionNumber), midiState(midiState), defaultPath(std::move(defaultPath))
+    : id{regionNumber}, midiState(midiState), defaultPath(std::move(defaultPath))
     {
         ccSwitched.set();
 
@@ -49,9 +50,9 @@ struct Region {
     /**
      * @brief Get the number which identifies this region
      */
-    int getIdNumber() const noexcept
+    NumericId<Region> getId() const noexcept
     {
-        return regionNumber;
+        return id;
     }
 
     /**
@@ -246,7 +247,7 @@ struct Region {
      */
     float getGainToEffectBus(unsigned number) const noexcept;
 
-    const int regionNumber { -1 };
+    const NumericId<Region> id;
 
     // Sound source: sample playback
     FileId sampleId {}; // Sample
diff --git a/src/sfizz/Synth.cpp b/src/sfizz/Synth.cpp
index 2c889bf0c..c609d3c50 100644
--- a/src/sfizz/Synth.cpp
+++ b/src/sfizz/Synth.cpp
@@ -44,11 +44,11 @@ sfz::Synth::~Synth()
     resources.filePool.emptyFileLoadingQueues();
 }
 
-void sfz::Synth::onVoiceStateChanged(int idNumber, Voice::State state)
+void sfz::Synth::onVoiceStateChanged(NumericId<Voice> id, Voice::State state)
 {
-    (void)idNumber;
+    (void)id;
     (void)state;
-    DBG("Voice " << idNumber << ": state " << static_cast<int>(state));
+    DBG("Voice " << id.number << ": state " << static_cast<int>(state));
 }
 
 void sfz::Synth::onParseFullBlock(const std::string& header, const std::vector<Opcode>& members)
diff --git a/src/sfizz/Synth.h b/src/sfizz/Synth.h
index 883fedf46..d04a5c963 100644
--- a/src/sfizz/Synth.h
+++ b/src/sfizz/Synth.h
@@ -497,7 +497,7 @@ class Synth final : public Voice::StateListener, public Parser::Listener {
     /**
      * @brief The voice callback which is called during a change of state.
      */
-    void onVoiceStateChanged(int idNumber, Voice::State state) override;
+    void onVoiceStateChanged(NumericId<Voice> idNumber, Voice::State state) override;
 
 protected:
     /**
diff --git a/src/sfizz/Voice.cpp b/src/sfizz/Voice.cpp
index fc65892c7..37dafdde6 100644
--- a/src/sfizz/Voice.cpp
+++ b/src/sfizz/Voice.cpp
@@ -15,7 +15,7 @@
 #include "absl/algorithm/container.h"
 
 sfz::Voice::Voice(int voiceNumber, sfz::Resources& resources)
-: voiceNumber(voiceNumber), stateListener(nullptr), resources(resources)
+: id{voiceNumber}, stateListener(nullptr), resources(resources)
 {
     filters.reserve(config::filtersPerVoice);
     equalizers.reserve(config::eqsPerVoice);
@@ -773,6 +773,6 @@ void sfz::Voice::switchState(State s)
     if (s != state) {
         state = s;
         if (stateListener)
-            stateListener->onVoiceStateChanged(voiceNumber, s);
+            stateListener->onVoiceStateChanged(id, s);
     }
 }
diff --git a/src/sfizz/Voice.h b/src/sfizz/Voice.h
index 59058c593..515feb128 100644
--- a/src/sfizz/Voice.h
+++ b/src/sfizz/Voice.h
@@ -14,6 +14,7 @@
 #include "AudioSpan.h"
 #include "LeakDetector.h"
 #include "OnePoleFilter.h"
+#include "NumericId.h"
 #include "absl/types/span.h"
 #include <memory>
 #include <random>
@@ -41,12 +42,13 @@ class Voice {
         NoteOff,
         CC
     };
+
     /**
-     * @brief Get the number which identifies this voice
+     * @brief Get the unique identifier of this voice in a synth
      */
-    int getIdNumber() const noexcept
+    NumericId<Voice> getId() const noexcept
     {
-        return voiceNumber;
+        return id;
     }
 
     enum class State {
@@ -56,7 +58,7 @@ class Voice {
 
     class StateListener {
     public:
-        virtual void onVoiceStateChanged(int /*idNumber*/, State /*state*/) {}
+        virtual void onVoiceStateChanged(NumericId<Voice> /*id*/, State /*state*/) {}
     };
 
     /**
@@ -299,7 +301,7 @@ class Voice {
      */
     void switchState(State s);
 
-    const int voiceNumber { -1 };
+    const NumericId<Voice> id;
     StateListener* stateListener = nullptr;
 
     Region* region { nullptr };

From 37ef2b99429d6721d9e7f5872346066df1512d1d Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Thu, 11 Jun 2020 23:52:17 +0200
Subject: [PATCH 08/19] Update benchmarks

---
 benchmarks/BM_ADSR.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/benchmarks/BM_ADSR.cpp b/benchmarks/BM_ADSR.cpp
index e2d077c05..c17a1a313 100644
--- a/benchmarks/BM_ADSR.cpp
+++ b/benchmarks/BM_ADSR.cpp
@@ -35,7 +35,7 @@ class EnvelopeFixture : public benchmark::Fixture
     }
 
     sfz::MidiState midiState;
-    sfz::Region region{midiState};
+    sfz::Region region{0, midiState};
     sfz::ADSREnvelope<float> envelope;
     std::vector<float> output;
 };

From 2c10173356c42707612ebfa93fefd0a0fc8658fb Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Fri, 12 Jun 2020 00:26:02 +0200
Subject: [PATCH 09/19] Add the lookup functions by identifier

---
 src/sfizz/NumericId.h | 10 ++++++++++
 src/sfizz/Synth.cpp   | 34 ++++++++++++++++++++++++++++++++++
 src/sfizz/Synth.h     | 14 ++++++++++++++
 3 files changed, 58 insertions(+)

diff --git a/src/sfizz/NumericId.h b/src/sfizz/NumericId.h
index 1d975ec03..b2fed5017 100644
--- a/src/sfizz/NumericId.h
+++ b/src/sfizz/NumericId.h
@@ -27,5 +27,15 @@ struct NumericId {
         return number != -1;
     }
 
+    constexpr bool operator==(NumericId other) const noexcept
+    {
+        return number == other.number;
+    }
+
+    constexpr bool operator!=(NumericId other) const noexcept
+    {
+        return number != other.number;
+    }
+
     const int number = -1;
 };
diff --git a/src/sfizz/Synth.cpp b/src/sfizz/Synth.cpp
index c609d3c50..001dae481 100644
--- a/src/sfizz/Synth.cpp
+++ b/src/sfizz/Synth.cpp
@@ -1056,6 +1056,40 @@ const sfz::EffectBus* sfz::Synth::getEffectBusView(int idx) const noexcept
     return (size_t)idx < effectBuses.size() ? effectBuses[idx].get() : nullptr;
 }
 
+const sfz::Region* sfz::Synth::getRegionById(NumericId<Region> id) const noexcept
+{
+    const size_t size = regions.size();
+
+    if (size == 0 || !id.valid())
+        return nullptr;
+
+    // search a sequence of ordered identifiers with potential gaps
+    size_t index = static_cast<size_t>(id.number);
+    index = std::min(index, size - 1);
+
+    while (index > 0 && regions[index]->getId().number > id.number)
+        --index;
+
+    return (regions[index]->getId() == id) ? regions[index].get() : nullptr;
+}
+
+const sfz::Voice* sfz::Synth::getVoiceById(NumericId<Voice> id) const noexcept
+{
+    const size_t size = voices.size();
+
+    if (size == 0 || !id.valid())
+        return nullptr;
+
+    // search a sequence of ordered identifiers with potential gaps
+    size_t index = static_cast<size_t>(id.number);
+    index = std::min(index, size - 1);
+
+    while (index > 0 && voices[index]->getId().number > id.number)
+        --index;
+
+    return (voices[index]->getId() == id) ? voices[index].get() : nullptr;
+}
+
 const sfz::Voice* sfz::Synth::getVoiceView(int idx) const noexcept
 {
     return (size_t)idx < voices.size() ? voices[idx].get() : nullptr;
diff --git a/src/sfizz/Synth.h b/src/sfizz/Synth.h
index d04a5c963..9c5420e90 100644
--- a/src/sfizz/Synth.h
+++ b/src/sfizz/Synth.h
@@ -178,6 +178,20 @@ class Synth final : public Voice::StateListener, public Parser::Listener {
      * @brief Export a MIDI Name document describing the loaded instrument
      */
     std::string exportMidnam(absl::string_view model = {}) const;
+    /**
+     * @brief Find the region which is associated with the given identifier.
+     *
+     * @param id
+     * @return const Region*
+     */
+    const Region* getRegionById(NumericId<Region> id) const noexcept;
+    /**
+     * @brief Find the voice which is associated with the given identifier.
+     *
+     * @param id
+     * @return const Voice*
+     */
+    const Voice* getVoiceById(NumericId<Voice> id) const noexcept;
     /**
      * @brief Get a raw view into a specific region. This is mostly used
      * for testing.

From 215077deaace5171b4723aa875631556759eaad1 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Fri, 12 Jun 2020 00:53:22 +0200
Subject: [PATCH 10/19] Make region removal order-preserving

---
 src/sfizz/Synth.cpp | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/src/sfizz/Synth.cpp b/src/sfizz/Synth.cpp
index 001dae481..7c535aa6a 100644
--- a/src/sfizz/Synth.cpp
+++ b/src/sfizz/Synth.cpp
@@ -361,22 +361,20 @@ void sfz::Synth::finalizeSfzLoad()
 {
     resources.filePool.setRootDirectory(parser.originalDirectory());
 
-    auto currentRegion = regions.begin();
-    auto lastRegion = regions.rbegin();
-    auto removeCurrentRegion = [&currentRegion, &lastRegion]() {
-        if (currentRegion->get() == nullptr)
-            return;
-
-        DBG("Removing the region with sample " << currentRegion->get()->sampleId);
-        std::iter_swap(currentRegion, lastRegion);
-        ++lastRegion;
+    size_t currentRegionIndex = 0;
+    size_t currentRegionCount = regions.size();
+
+    auto removeCurrentRegion = [this, &currentRegionIndex, &currentRegionCount]() {
+        DBG("Removing the region with sample " << regions[currentRegionIndex]->sampleId);
+        regions.erase(regions.begin() + currentRegionIndex);
+        --currentRegionCount;
     };
 
     size_t maxFilters { 0 };
     size_t maxEQs { 0 };
 
-    while (currentRegion < lastRegion.base()) {
-        auto region = currentRegion->get();
+    while (currentRegionIndex < currentRegionCount) {
+        auto region = regions[currentRegionIndex].get();
 
         if (!region->oscillator && !region->isGenerator()) {
             if (!resources.filePool.checkSampleId(region->sampleId)) {
@@ -481,11 +479,10 @@ void sfz::Synth::finalizeSfzLoad()
         maxFilters = max(maxFilters, region->filters.size());
         maxEQs = max(maxEQs, region->equalizers.size());
 
-        ++currentRegion;
+        ++currentRegionIndex;
     }
-    const auto remainingRegions = std::distance(regions.begin(), lastRegion.base());
-    DBG("Removing " << (regions.size() - remainingRegions) << " out of " << regions.size() << " regions");
-    regions.resize(remainingRegions);
+    DBG("Removing " << (regions.size() - currentRegionCount) << " out of " << regions.size() << " regions");
+    regions.resize(currentRegionCount);
     modificationTime = checkModificationTime();
 
     for (auto& voice : voices) {

From 0bbb1e930f1d0c889b032f673242297fb636339e Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Fri, 12 Jun 2020 00:53:36 +0200
Subject: [PATCH 11/19] Add test

---
 tests/SynthT.cpp | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/tests/SynthT.cpp b/tests/SynthT.cpp
index e59df54f0..112acb0dd 100644
--- a/tests/SynthT.cpp
+++ b/tests/SynthT.cpp
@@ -6,6 +6,7 @@
 
 #include "sfizz/Synth.h"
 #include "sfizz/SfzHelpers.h"
+#include "sfizz/NumericId.h"
 #include "catch2/catch.hpp"
 using namespace Catch::literals;
 using namespace sfz::literals;
@@ -462,3 +463,26 @@ TEST_CASE("[Synth] velcurve")
     REQUIRE( synth.getRegionView(1)->velocityCurve(96_norm) == Approx(0.5f).margin(1e-2) );
     REQUIRE( synth.getRegionView(1)->velocityCurve(127_norm) == 0.0_a );
 }
+
+TEST_CASE("[Synth] Region by identifier")
+{
+    sfz::Synth synth;
+    synth.loadSfzString("regionByIdentifier.sfz", R"(
+<region>sample=*sine
+<region>sample=*sine
+<region>sample=doesNotExist.wav
+<region>sample=*sine
+<region>sample=doesNotExist.wav
+<region>sample=*sine
+)");
+
+    REQUIRE(synth.getNumRegions() == 4);
+    REQUIRE(synth.getRegionView(0) == synth.getRegionById(NumericId<sfz::Region>{0}));
+    REQUIRE(synth.getRegionView(1) == synth.getRegionById(NumericId<sfz::Region>{1}));
+    REQUIRE(nullptr == synth.getRegionById(NumericId<sfz::Region>{2}));
+    REQUIRE(synth.getRegionView(2) == synth.getRegionById(NumericId<sfz::Region>{3}));
+    REQUIRE(nullptr == synth.getRegionById(NumericId<sfz::Region>{4}));
+    REQUIRE(synth.getRegionView(3) == synth.getRegionById(NumericId<sfz::Region>{5}));
+    REQUIRE(nullptr == synth.getRegionById(NumericId<sfz::Region>{6}));
+    REQUIRE(nullptr == synth.getRegionById(NumericId<sfz::Region>{}));
+}

From bdaf8f7f11d5461886280922a49655c569ec0426 Mon Sep 17 00:00:00 2001
From: Paul Ferrand <paul@localhost.localdomain>
Date: Fri, 12 Jun 2020 19:45:41 +0200
Subject: [PATCH 12/19] Debug message called an unknown variable (previous PR
 leftover)

---
 src/sfizz/Tuning.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/sfizz/Tuning.cpp b/src/sfizz/Tuning.cpp
index 2d4b3d99a..fa83ebca4 100644
--- a/src/sfizz/Tuning.cpp
+++ b/src/sfizz/Tuning.cpp
@@ -201,7 +201,7 @@ bool Tuning::loadScalaString(const std::string& text)
     }
 
     if (scl.count <= 0) {
-        DBG("The scale file is empty: " << path);
+        DBG("Error loading scala string: " << text);
         return false;
     }
 

From 5fa43a0efb44390a29ed5933cd156ae003f05e46 Mon Sep 17 00:00:00 2001
From: Paul Ferrand <paul@localhost.localdomain>
Date: Fri, 12 Jun 2020 20:04:21 +0200
Subject: [PATCH 13/19] Check the number of curves at compile time

---
 src/sfizz/Tuning.cpp | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/sfizz/Tuning.cpp b/src/sfizz/Tuning.cpp
index fa83ebca4..36a8fbcd8 100644
--- a/src/sfizz/Tuning.cpp
+++ b/src/sfizz/Tuning.cpp
@@ -288,9 +288,9 @@ StretchTuning StretchTuning::createRailsbackFromRatio(float stretch)
     };
 
     // known curves and their matching knob positions
-    const int num_curves = 3;
-    const float* curves[] = {railsback21, railsback41, railsback42};
-    const float points[] = {0.25f, 0.5f, 1.0f};
+    const float* curves[] = { railsback21, railsback41, railsback42 };
+    const float points[] = { 0.25f, 0.5f, 1.0f };
+    constexpr int num_curves = sizeof(curves) / sizeof(decltype(curves[0]));
 
     //
     int index = -1;
@@ -319,7 +319,6 @@ StretchTuning StretchTuning::createRailsbackFromRatio(float stretch)
 
     //
     return createFromDetuneRatios(data);
-
 }
 
 } // namespace sfz

From 32d01ded03b896ee01caebb698dcee59805deb14 Mon Sep 17 00:00:00 2001
From: Paul Ferrand <paul@localhost.localdomain>
Date: Fri, 12 Jun 2020 20:20:01 +0200
Subject: [PATCH 14/19] Added some tests

---
 tests/TuningT.cpp | 106 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)

diff --git a/tests/TuningT.cpp b/tests/TuningT.cpp
index 76c94d675..430c031c2 100644
--- a/tests/TuningT.cpp
+++ b/tests/TuningT.cpp
@@ -15,3 +15,109 @@ TEST_CASE("[Tuning] Default tuning")
     for (int key = 0; key < 128; ++key)
         REQUIRE(defaultTuning.getFrequencyOfKey(key) == Approx(midiNoteFrequency(key)));
 }
+
+TEST_CASE("[Tuning] Railsback disabled")
+{
+    auto tuning = sfz::StretchTuning::createRailsbackFromRatio(0.0f);
+    for (int key = 0; key < 128; ++key)
+        REQUIRE(tuning.getRatioForIntegralKey(key) == 1.0f);
+}
+
+TEST_CASE("[Tuning] Stretch integral == float")
+{
+    auto tuning = sfz::StretchTuning::createRailsbackFromRatio(0.25f);
+    for (int key = 0; key < 128; ++key)
+        REQUIRE(tuning.getRatioForIntegralKey(key) == tuning.getRatioForFractionalKey(static_cast<float>(key)));
+}
+
+TEST_CASE("[Tuning] Stretch definition points")
+{
+    SECTION("For 0.5f")
+    {
+        static constexpr float railsback[128] = {
+            #include "sfizz/railsback/4-1.h"
+        };
+        auto tuning = sfz::StretchTuning::createRailsbackFromRatio(0.5f);
+        for (int key = 0; key < 128; ++key)
+            REQUIRE(tuning.getRatioForIntegralKey(key) == railsback[key]);
+    }
+    SECTION("For 1.0f")
+    {
+        static constexpr float railsback[128] = {
+            #include "sfizz/railsback/4-2.h"
+        };
+        auto tuning = sfz::StretchTuning::createRailsbackFromRatio(1.0f);
+        for (int key = 0; key < 128; ++key)
+            REQUIRE(tuning.getRatioForIntegralKey(key) == railsback[key]);
+    }
+
+    SECTION("For 0.25f")
+    {
+        static constexpr float railsback[128] = {
+            #include "sfizz/railsback/2-1.h"
+        };
+        auto tuning = sfz::StretchTuning::createRailsbackFromRatio(0.25f);
+        for (int key = 0; key < 128; ++key)
+            REQUIRE(tuning.getRatioForIntegralKey(key) == railsback[key]);
+    }
+}
+
+TEST_CASE("[Tuning] Stretch interpolation bounds")
+{
+    SECTION("Between 0 and 0.25f")
+    {
+        static constexpr float bound1[128] = {
+            #include "sfizz/railsback/2-1.h"
+        };
+        auto tuning = sfz::StretchTuning::createRailsbackFromRatio(0.1f);
+        for (int key = 0; key < 128; ++key) {
+            if (bound1[key] < 1.0f) {
+                REQUIRE(tuning.getRatioForIntegralKey(key) >= bound1[key]);
+                REQUIRE(tuning.getRatioForIntegralKey(key) <= 1.0f);
+            } else {
+                REQUIRE(tuning.getRatioForIntegralKey(key) <= bound1[key]);
+                REQUIRE(tuning.getRatioForIntegralKey(key) >= 1.0f);
+            }
+        }
+    }
+    SECTION("Between 0.25f and 0.5f")
+    {
+        static constexpr float bound1[128] = {
+            #include "sfizz/railsback/2-1.h"
+        };
+        static constexpr float bound2[128] = {
+            #include "sfizz/railsback/4-1.h"
+        };
+        auto tuning = sfz::StretchTuning::createRailsbackFromRatio(0.3f);
+        for (int key = 0; key < 128; ++key) {
+            if (bound1[key] < bound2[key]) {
+                REQUIRE(tuning.getRatioForIntegralKey(key) >= bound1[key]);
+                REQUIRE(tuning.getRatioForIntegralKey(key) <= bound2[key]);
+            } else {
+                REQUIRE(tuning.getRatioForIntegralKey(key) <= bound1[key]);
+                REQUIRE(tuning.getRatioForIntegralKey(key) >= bound2[key]);
+            }
+        }
+    }
+    SECTION("Between 0.5f and 1.0f")
+    {
+        static constexpr float bound1[128] = {
+            #include "sfizz/railsback/4-1.h"
+        };
+        static constexpr float bound2[128] = {
+            #include "sfizz/railsback/4-2.h"
+        };
+        auto tuning = sfz::StretchTuning::createRailsbackFromRatio(0.7f);
+        for (int key = 0; key < 128; ++key) {
+            if (bound1[key] < bound2[key]) {
+                REQUIRE(tuning.getRatioForIntegralKey(key) >= bound1[key]);
+                REQUIRE(tuning.getRatioForIntegralKey(key) <= bound2[key]);
+            } else {
+                REQUIRE(tuning.getRatioForIntegralKey(key) <= bound1[key]);
+                REQUIRE(tuning.getRatioForIntegralKey(key) >= bound2[key]);
+            }
+        }
+    }
+}
+
+

From ff34bb5ccb03df54032ae65a07d4c3bee64da75d Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Fri, 12 Jun 2020 17:53:15 +0200
Subject: [PATCH 15/19] Fix LV2 problems with the atom sequence - pop the frame
 when finished writing - add safety checks in case write space is short

---
 lv2/sfizz.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/lv2/sfizz.c b/lv2/sfizz.c
index 52815295c..3aa123bd0 100644
--- a/lv2/sfizz.c
+++ b/lv2/sfizz.c
@@ -445,13 +445,17 @@ static void
 sfizz_lv2_send_file_path(sfizz_plugin_t *self, LV2_URID urid, const char *path)
 {
     LV2_Atom_Forge_Frame frame;
-    lv2_atom_forge_frame_time(&self->forge, 0);
-    lv2_atom_forge_object(&self->forge, &frame, 0, self->patch_set_uri);
-    lv2_atom_forge_key(&self->forge, self->patch_property_uri);
-    lv2_atom_forge_urid(&self->forge, urid);
-    lv2_atom_forge_key(&self->forge, self->patch_value_uri);
-    lv2_atom_forge_path(&self->forge, path, (uint32_t)strlen(path));
-    lv2_atom_forge_pop(&self->forge, &frame);
+
+    bool write_ok =
+        lv2_atom_forge_frame_time(&self->forge, 0) &&
+        lv2_atom_forge_object(&self->forge, &frame, 0, self->patch_set_uri) &&
+        lv2_atom_forge_key(&self->forge, self->patch_property_uri) &&
+        lv2_atom_forge_urid(&self->forge, urid) &&
+        lv2_atom_forge_key(&self->forge, self->patch_value_uri) &&
+        lv2_atom_forge_path(&self->forge, path, (uint32_t)strlen(path));
+
+    if (write_ok)
+        lv2_atom_forge_pop(&self->forge, &frame);
 }
 
 
@@ -775,6 +779,8 @@ run(LV2_Handle instance, uint32_t sample_count)
     {
         self->midnam->update(self->midnam->handle);
     }
+
+    lv2_atom_forge_pop(&self->forge, &self->notify_frame);
 }
 
 static uint32_t

From f15ed45035bf2e1b719da7b2bb3f2ddfeb7f9ca1 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Fri, 12 Jun 2020 21:40:57 +0200
Subject: [PATCH 16/19] Construct work atoms using a forge

---
 lv2/sfizz.c | 36 ++++++++++++++++++++----------------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/lv2/sfizz.c b/lv2/sfizz.c
index 3aa123bd0..e26dbd21d 100644
--- a/lv2/sfizz.c
+++ b/lv2/sfizz.c
@@ -114,6 +114,9 @@ typedef struct
     LV2_Atom_Forge forge;              ///< Forge for writing atoms in run thread
     LV2_Atom_Forge_Frame notify_frame; ///< Cached for worker replies
 
+    // Atom forge
+    LV2_Atom_Forge forge_secondary;    ///< Forge for writing into other buffers
+
     // Logger
     LV2_Log_Logger logger;
 
@@ -366,6 +369,7 @@ instantiate(const LV2_Descriptor *descriptor,
 
     // Initialize the forge
     lv2_atom_forge_init(&self->forge, self->map);
+    lv2_atom_forge_init(&self->forge_secondary, self->map);
 
     // Check the options for the block size and sample rate parameters
     if (options)
@@ -491,28 +495,28 @@ sfizz_lv2_handle_atom_object(sfizz_plugin_t *self, const LV2_Atom_Object *obj)
         return;
     }
 
+    typedef struct
+    {
+        LV2_Atom atom;
+        char body[MAX_PATH_SIZE];
+    } sfizz_path_atom_buffer_t;
+
     if (key == self->sfizz_sfz_file_uri)
     {
-        const uint32_t original_atom_size = lv2_atom_total_size((const LV2_Atom *)atom);
-        const uint32_t null_terminated_atom_size = original_atom_size + 1;
-        char atom_buffer[MAX_PATH_SIZE];
-        memcpy(&atom_buffer, atom, original_atom_size);
-        atom_buffer[original_atom_size] = 0; // Null terminate the string for safety
-        LV2_Atom *sfz_file_path = (LV2_Atom *)&atom_buffer;
-        sfz_file_path->type = self->sfizz_sfz_file_uri;
-        self->worker->schedule_work(self->worker->handle, null_terminated_atom_size, sfz_file_path);
+        LV2_Atom_Forge *forge = &self->forge_secondary;
+        sfizz_path_atom_buffer_t buffer;
+        lv2_atom_forge_set_buffer(forge, (uint8_t *)&buffer, sizeof(buffer));
+        if (lv2_atom_forge_typed_string(forge, self->sfizz_sfz_file_uri, LV2_ATOM_BODY_CONST(atom), strnlen(LV2_ATOM_BODY_CONST(atom), atom->size)))
+            self->worker->schedule_work(self->worker->handle, lv2_atom_total_size(&buffer.atom), &buffer.atom);
         self->check_modification = false;
     }
     else if (key == self->sfizz_scala_file_uri)
     {
-        const uint32_t original_atom_size = lv2_atom_total_size((const LV2_Atom *)atom);
-        const uint32_t null_terminated_atom_size = original_atom_size + 1;
-        char atom_buffer[MAX_PATH_SIZE];
-        memcpy(&atom_buffer, atom, original_atom_size);
-        atom_buffer[original_atom_size] = 0; // Null terminate the string for safety
-        LV2_Atom *scala_file_path = (LV2_Atom *)&atom_buffer;
-        scala_file_path->type = self->sfizz_scala_file_uri;
-        self->worker->schedule_work(self->worker->handle, null_terminated_atom_size, scala_file_path);
+        LV2_Atom_Forge *forge = &self->forge_secondary;
+        sfizz_path_atom_buffer_t buffer;
+        lv2_atom_forge_set_buffer(forge, (uint8_t *)&buffer, sizeof(buffer));
+        if (lv2_atom_forge_typed_string(forge, self->sfizz_scala_file_uri, LV2_ATOM_BODY_CONST(atom), strnlen(LV2_ATOM_BODY_CONST(atom), atom->size)))
+            self->worker->schedule_work(self->worker->handle, lv2_atom_total_size(&buffer.atom), &buffer.atom);
         self->check_modification = false;
     }
     else

From ba0716e7e190db4a6b1877a08a1fc3618e756e3b Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Fri, 12 Jun 2020 21:52:45 +0200
Subject: [PATCH 17/19] Make notify_frame local to run()

---
 lv2/sfizz.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/lv2/sfizz.c b/lv2/sfizz.c
index e26dbd21d..54b3f99b7 100644
--- a/lv2/sfizz.c
+++ b/lv2/sfizz.c
@@ -112,9 +112,6 @@ typedef struct
 
     // Atom forge
     LV2_Atom_Forge forge;              ///< Forge for writing atoms in run thread
-    LV2_Atom_Forge_Frame notify_frame; ///< Cached for worker replies
-
-    // Atom forge
     LV2_Atom_Forge forge_secondary;    ///< Forge for writing into other buffers
 
     // Logger
@@ -692,7 +689,9 @@ run(LV2_Handle instance, uint32_t sample_count)
     lv2_atom_forge_set_buffer(&self->forge, (uint8_t *)self->notify_port, notify_capacity);
 
     // Start a sequence in the notify output port.
-    lv2_atom_forge_sequence_head(&self->forge, &self->notify_frame, 0);
+    LV2_Atom_Forge_Frame notify_frame;
+    if (!lv2_atom_forge_sequence_head(&self->forge, &notify_frame, 0))
+        assert(false);
 
     LV2_ATOM_SEQUENCE_FOREACH(self->control_port, ev)
     {
@@ -784,7 +783,7 @@ run(LV2_Handle instance, uint32_t sample_count)
         self->midnam->update(self->midnam->handle);
     }
 
-    lv2_atom_forge_pop(&self->forge, &self->notify_frame);
+    lv2_atom_forge_pop(&self->forge, &notify_frame);
 }
 
 static uint32_t

From 578dad574d8a7e175dc81bf7acd59354c8275e1d Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Sat, 13 Jun 2020 22:09:58 +0200
Subject: [PATCH 18/19] Build macOS in C++14, can fix runtime link issues

---
 .travis/script_osx.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.travis/script_osx.sh b/.travis/script_osx.sh
index 0b271c84e..0385f8c3c 100755
--- a/.travis/script_osx.sh
+++ b/.travis/script_osx.sh
@@ -6,7 +6,7 @@ cmake -DCMAKE_BUILD_TYPE=Release \
       -DSFIZZ_VST=ON \
       -DSFIZZ_AU=ON \
       -DSFIZZ_TESTS=OFF \
-      -DCMAKE_CXX_STANDARD=17 \
+      -DCMAKE_CXX_STANDARD=14 \
       -DLV2PLUGIN_INSTALL_DIR=/Library/Audio/Plug-Ins/LV2 \
       -DVSTPLUGIN_INSTALL_DIR=/Library/Audio/Plug-Ins/VST3 \
       -DAUPLUGIN_INSTALL_DIR=/Library/Audio/Plug-Ins/Components \

From 399408923334cc1ef8deae22af8c2240ef2963d2 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Sat, 13 Jun 2020 16:55:25 -0700
Subject: [PATCH 19/19] Fix the bad macOS suffix in LV2 manifest template

---
 lv2/manifest.ttl.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lv2/manifest.ttl.in b/lv2/manifest.ttl.in
index 1f954f015..3ea4e8838 100644
--- a/lv2/manifest.ttl.in
+++ b/lv2/manifest.ttl.in
@@ -3,5 +3,5 @@
 
 <@LV2PLUGIN_URI@>
   a lv2:Plugin ;
-  lv2:binary <@PROJECT_NAME@@CMAKE_SHARED_LIBRARY_SUFFIX@> ;
+  lv2:binary <@PROJECT_NAME@@CMAKE_SHARED_MODULE_SUFFIX@> ;
   rdfs:seeAlso <@PROJECT_NAME@.ttl> .