zynaddsubfx

commit e5b543aa4d684d01f452268b90475073aa9ce8a2
parent 46341e5bd909710d0c2f3921d95c3f53227d1378
Author: Johannes Lorenz <johannes89@ist-einmalig.de>
Date:   Thu, 21 Jul 2016 16:36:08 +0200

Implement complete version fix.

Diffstat:
M
src/Params/EnvelopeParams.cpp
 | 
48
+++++++++++++++++++++++++++++++-----------------

1 file changed, 31 insertions(+), 17 deletions(-)
diff --git a/src/Params/EnvelopeParams.cpp b/src/Params/EnvelopeParams.cpp
@@ -359,30 +359,42 @@ void EnvelopeParams::add2XML(XMLwrapper& xml)
         }
 }
 
-static float EnvelopeParams::env_dB2rap(float db) {
+float EnvelopeParams::env_dB2rap(float db) {
     return (powf(10.0f, db / 20.0f) - 0.01)/.99f;
 }
 
-static float EnvelopeParams::env_rap2dB(float rap) {
+float EnvelopeParams::env_rap2dB(float rap) {
     return 20.0f * log10f(rap * 0.99f + 0.01);
 }
 
-int value(int input, bool mismatch)
+/**
+    since commit 5334d94283a513ae42e472aa020db571a3589fb9, i.e. between
+    versions 2.4.3 and 2.4.4, the amplitude envelope has been converted
+    differently from dB to rap for AmplitudeEnvelope (mode 2)
+    this converts the values read from an XML file once
+*/
+struct version_fixer_t
 {
-    int res = input;
-    if(mismatch)
+    const bool mismatch;
+public:
+    int operator()(int input)
     {
-        // the errors occured when calling env_dB2rap,
-        // thus, we use this formula:
-
+        return (mismatch)
+            // The errors occured when calling env_dB2rap. Let f be the
+            // conversion function for mode 2 (see Envelope.cpp), then we
+            // load values with (let "o" be the function composition symbol):
+            //   f^{-1} o (env_dB2rap^{-1}) o dB2rap o f
+            // from the xml file. This results in the following formula:
+            ? 127.0f * (0.5f * log10f( 0.01f + 0.99f * powf(100, input/127.0f - 1)) + 1)
+            : input;
     }
-    return res;
-}
+    version_fixer_t(const version_type& fileversion, int env_mode) :
+        mismatch(fileversion < version_type(2,4,4) &&
+                 (env_mode == 2)) {}
+};
 
 void EnvelopeParams::getfromXML(XMLwrapper& xml)
 {
-    bool mismatch = xml.fileversion() < version_type(2,4,4);
-
     Pfreemode       = xml.getparbool("free_mode", Pfreemode);
     Penvpoints      = xml.getpar127("env_points", Penvpoints);
     Penvsustain     = xml.getpar127("env_sustain", Penvsustain);
@@ -390,20 +402,22 @@ void EnvelopeParams::getfromXML(XMLwrapper& xml)
     Pforcedrelease  = xml.getparbool("forced_release", Pforcedrelease);
     Plinearenvelope = xml.getparbool("linear_envelope", Plinearenvelope);
 
+    version_fixer_t version_fix(xml.fileversion(), Envmode);
+
     PA_dt  = xml.getpar127("A_dt", PA_dt);
     PD_dt  = xml.getpar127("D_dt", PD_dt);
     PR_dt  = xml.getpar127("R_dt", PR_dt);
-    PA_val = value(xml.getpar127("A_val", PA_val), mismatch);
-    PD_val = value(xml.getpar127("D_val", PD_val), mismatch);
-    PS_val = value(xml.getpar127("S_val", PS_val), mismatch);
-    PR_val = value(xml.getpar127("R_val", PR_val), mismatch);
+    PA_val = version_fix(xml.getpar127("A_val", PA_val));
+    PD_val = version_fix(xml.getpar127("D_val", PD_val));
+    PS_val = version_fix(xml.getpar127("S_val", PS_val));
+    PR_val = version_fix(xml.getpar127("R_val", PR_val));
 
     for(int i = 0; i < Penvpoints; ++i) {
         if(xml.enterbranch("POINT", i) == 0)
             continue;
         if(i != 0)
             Penvdt[i] = xml.getpar127("dt", Penvdt[i]);
-        Penvval[i] = value(xml.getpar127("val", Penvval[i]), mismatch);
+        Penvval[i] = version_fix(xml.getpar127("val", Penvval[i]));
         xml.exitbranch();
     }