[SCM] calf/master: Added adjustable knee support.

[js at users.alioth.debian.org]

The following commit has been merged in the master branch:
commit 2e2261ff154975d3bafc731158e14e6747915219
Author: Thor Harald Johansen <thj at thj.no>
Date:   Fri Oct 31 21:35:30 2008 +0100

    Added adjustable knee support.

diff --git a/src/calf/modules_dev.h b/src/calf/modules_dev.h
index b785886..ecb026b 100644
--- a/src/calf/modules_dev.h
+++ b/src/calf/modules_dev.h
@@ -38,17 +38,17 @@ public:
     uint32_t srate;
     static parameter_properties param_props[];
     void activate() {
-        target = 1;
-        aim = 1;
+        target = 1.f;
+        aim = 1.f;
     }
     uint32_t process(uint32_t offset, uint32_t numsamples, uint32_t inputs_mask, uint32_t outputs_mask) {
         numsamples += offset;
         float threshold = *params[param_threshold];
         float ratio = *params[param_ratio];
-        float attack_coeff = 1 / (*params[param_attack] * srate / 4000);
-        float release_coeff = 1 / (*params[param_release] * srate / 4000);
+        float attack_coeff = 1.f / (*params[param_attack] * srate / 4000.f);
+        float release_coeff = 1.f / (*params[param_release] * srate / 4000.f);
         float makeup = *params[param_makeup];
-        bool knee = *params[param_knee] > 0.5;
+        float knee = *params[param_knee];
 
         if(params[param_compression] != NULL) {
             *params[param_compression] = aim;
@@ -57,21 +57,17 @@ public:
         while(offset < numsamples) {
             float asample = std::max(fabs(ins[0][offset]), fabs(ins[1][offset]));
             for(int channel = 0; channel < in_count; channel++) {
-                if(asample > threshold) {
+                if(asample > 0 && (asample > threshold || knee < 1)) {
                     target = asample - threshold;
                     target /= ratio;
                     target += threshold;
-                    target /= asample;
-                } else if(asample > 0 && knee) {
-                    target = asample - threshold;
-                    target /= ratio;
-                    target += threshold;
-                    float knee1 = pow(asample / threshold, 3);
-                    float knee2 = 1 - knee1;
-                    target = target * knee1 + asample * knee2;
+                    if(knee < 1) {
+                        float t = std::min(1.f, std::max(0.f, asample - knee) / (1.f - knee) / threshold);
+                        target = (target - asample) * t + asample;
+                    }
                     target /= asample;
                 } else {
-                    target = 1;
+                    target = 1.f;
                 }
                 
                 outs[channel][offset] = ins[channel][offset] * aim * makeup;
diff --git a/src/modules.cpp b/src/modules.cpp
index c80441c..a91b158 100644
--- a/src/modules.cpp
+++ b/src/modules.cpp
@@ -179,7 +179,7 @@ parameter_properties compressor_audio_module::param_props[] = {
     { 10,     1, 2000, 0, PF_FLOAT | PF_SCALE_LOG | PF_CTL_KNOB | PF_UNIT_MSEC, NULL, "attack", "Attack" },
     { 100,    1, 2000, 0, PF_FLOAT | PF_SCALE_LOG | PF_CTL_KNOB | PF_UNIT_MSEC, NULL, "release", "Release" },
     { 1,      1, 12,   0, PF_FLOAT | PF_SCALE_GAIN | PF_CTL_KNOB | PF_UNIT_DB, NULL, "makeup", "Makeup Gain" },
-    { 0,      0,  1,   0, PF_BOOL | PF_CTL_TOGGLE, NULL, "knee", "Knee" },
+    { 1,      0,  1,   0, PF_FLOAT | PF_SCALE_GAIN | PF_CTL_KNOB | PF_UNIT_DB, NULL, "knee", "Knee" },
     { 0, 0.03125, 1,    0, PF_FLOAT | PF_SCALE_GAIN | PF_CTL_METER | PF_CTLO_LABEL | PF_CTLO_REVERSE | PF_UNIT_DB | PF_PROP_OUTPUT | PF_PROP_OPTIONAL, NULL, "compression", "Compression" }
 };
 

-- 
calf audio plugins packaging