# IPlug2 controls not affecting Faust DSP params **URL:** \ **Category:** Faust\ **Created:** [10 April 2022 11:49 UTC](https://iplug2.discourse.group/t/iplug2-controls-not-affecting-faust-dsp-params/619 "2022-04-10T11:49:06Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![ftw](https://yyz2.discourse-cdn.com/free1/user_avatar/iplug2.discourse.group/ftw/32/278_2.png) [@ftw](https://iplug2.discourse.group/u/ftw)\ **Post date:** [10 April 2022 11:49 UTC](https://iplug2.discourse.group/t/iplug2-controls-not-affecting-faust-dsp-params/619/1 "2022-04-10T11:49:06Z")
I am now able to run my Faust instrument inside of an IPlug2 app, and I was able to get far enough to link IPlug params to Faust params and create controls that at least start out matching the DSP defaults. However, changing the controls in the UI does nothing: > Relevant code snippets: ```cpp // near the top of the constructor mFaustProcessor.CreateIPlugParameters(this, 0, mFaustProcessor.NParams()); pushBandParams(0); pushBandParams(1); pushBandParams(2); pushBandParams(4); pushBandParams(6); pushBandParams(8); pushBandParams(10); pushBandParams(12); pushBandParams(14); pushBandParams(16); // inside mLayoutFunc for (auto band = 0; band < mBandParams.size(); band++) { auto &bandParamIds = mBandParams.at(band); IRECT bandStrip = b.GetGridCell(0, band, 1, mBandParams.size()); IRECT slider = bandStrip.ReduceFromTop(150); pGraphics->AttachControl(new IVSliderControl(slider, bandParamIds.gain, "Gain")); IRECT envKnobs = bandStrip.ReduceFromTop(250); pGraphics->AttachControl(new IVKnobControl(envKnobs.GetGridCell(0, 0, 4, 1), bandParamIds.attack, "Attack")); pGraphics->AttachControl(new IVKnobControl(envKnobs.GetGridCell(1, 0, 4, 1), bandParamIds.decay, "Decay")); pGraphics->AttachControl(new IVKnobControl(envKnobs.GetGridCell(2, 0, 4, 1), bandParamIds.sustain, "Sustain")); pGraphics->AttachControl(new IVKnobControl(envKnobs.GetGridCell(3, 0, 4, 1), bandParamIds.release, "Release")); } // the helper pushBandParams function. this iterates over all plugin params - initialised by // mFaustProcessor.CreateIPlugParameters - and builds a map of partial number to param ids // based on what I called the parameters in the Faust code. void WeirdOrgan::pushBandParams(int bandId) { std::string gainName = "partial gain " + std::to_string(bandId); std::string attackName = "attack " + std::to_string(bandId); std::string decayName = "decay " + std::to_string(bandId); std::string sustainName = "sustain " + std::to_string(bandId); std::string releaseName = "release " + std::to_string(bandId); int gainId = -1; int attackId = -1; int decayId = -1; int sustainId = -1; int releaseId = -1; for (int i = 0; i < NParams(); i++) { auto name = GetParam(i)->GetName(); if (gainName.compare(name) == 0) { gainId = i; continue; } if (attackName.compare(name) == 0) { attackId = i; continue; } if (decayName.compare(name) == 0) { decayId = i; continue; } if (sustainName.compare(name) == 0) { sustainId = i; continue; } if (releaseName.compare(name) == 0) { releaseId = i; continue; } } mBandParams.emplace_back(gainId, attackId, decayId, sustainId, releaseId); } ``` ---
**Author:** ![olilarkin](https://yyz2.discourse-cdn.com/free1/user_avatar/iplug2.discourse.group/olilarkin/32/2_2.png) [@olilarkin](https://iplug2.discourse.group/u/olilarkin)\ **Post date:** [10 April 2022 12:25 UTC](https://iplug2.discourse.group/t/iplug2-controls-not-affecting-faust-dsp-params/619/2 "2022-04-10T12:25:02Z")
bit hard to see whats wrong. is your source code online? ---
**Author:** ![ftw](https://yyz2.discourse-cdn.com/free1/user_avatar/iplug2.discourse.group/ftw/32/278_2.png) [@ftw](https://iplug2.discourse.group/u/ftw)\ **Post date:** [10 April 2022 12:30 UTC](https://iplug2.discourse.group/t/iplug2-controls-not-affecting-faust-dsp-params/619/3 "2022-04-10T12:30:59Z")
C++: [FTWAudioPlugins/WeirdOrgan.cpp at main · FLamparski/FTWAudioPlugins · GitHub](https://github.com/FLamparski/FTWAudioPlugins/blob/main/WeirdOrgan/WeirdOrgan.cpp) Faust: [FTWAudioPlugins/WeirdOrgan.dsp at main · FLamparski/FTWAudioPlugins · GitHub](https://github.com/FLamparski/FTWAudioPlugins/blob/main/WeirdOrgan/WeirdOrgan.dsp) Since I’m building on Windows I’m always using FAUST\_COMPILED, otherwise the plugin always crashes. I’m also not getting any output from it in a DAW (I’m using Ardour) ---
**Author:** ![olilarkin](https://yyz2.discourse-cdn.com/free1/user_avatar/iplug2.discourse.group/olilarkin/32/2_2.png) [@olilarkin](https://iplug2.discourse.group/u/olilarkin)\ **Post date:** [10 April 2022 14:01 UTC](https://iplug2.discourse.group/t/iplug2-controls-not-affecting-faust-dsp-params/619/4 "2022-04-10T14:01:51Z")
It seems your faust dsp has more parameters than the iPlug plug-in. If you comment this check, i think it might work > ---
**Author:** ![ftw](https://yyz2.discourse-cdn.com/free1/user_avatar/iplug2.discourse.group/ftw/32/278_2.png) [@ftw](https://iplug2.discourse.group/u/ftw)\ **Post date:** [10 April 2022 15:03 UTC](https://iplug2.discourse.group/t/iplug2-controls-not-affecting-faust-dsp-params/619/5 "2022-04-10T15:03:55Z")
I think the zone/parameter confusion theory is right - I added an extra debug message and I’m seeing disagreement between the parameters that IPlug is picking up and the number of zones: ```nohighlight 0 Panic 1 attack 0 2 decay 0 3 freq 4 gate 5 partial gain 0 6 q 7 release 0 8 sustain 0 9 attack 1 10 decay 1 11 partial gain 1 12 release 1 13 sustain 1 14 attack 2 15 decay 2 16 partial gain 2 17 release 2 18 sustain 2 19 attack 4 20 decay 4 21 partial gain 4 22 release 4 23 sustain 4 24 attack 6 25 decay 6 26 partial gain 6 27 release 6 28 sustain 6 29 attack 8 30 decay 8 31 partial gain 8 32 release 8 33 sustain 8 34 attack 10 35 decay 10 36 partial gain 10 37 release 10 38 sustain 10 39 attack 12 40 decay 12 41 partial gain 12 42 release 12 43 sustain 12 44 attack 14 45 decay 14 46 partial gain 14 47 release 14 48 sustain 14 49 attack 16 50 decay 16 51 partial gain 16 52 release 16 53 sustain 16 54 gain 55 volume number of Faust zones = 83 ``` ---
**Author:** ![ftw](https://yyz2.discourse-cdn.com/free1/user_avatar/iplug2.discourse.group/ftw/32/278_2.png) [@ftw](https://iplug2.discourse.group/u/ftw)\ **Post date:** [13 April 2022 08:39 UTC](https://iplug2.discourse.group/t/iplug2-controls-not-affecting-faust-dsp-params/619/6 "2022-04-13T08:39:10Z")
Seems like a bug in Faust actually: [Surprising effects of vgroup/hgroup on how controls and parameters work · Issue #725 · grame-cncm/faust · GitHub](https://github.com/grame-cncm/faust/issues/725)