distortion effect

This commit is contained in:
Juan Linietsky 2017-01-21 20:57:48 -03:00
parent 0aa7242624
commit 63fa5486a4
3 changed files with 241 additions and 0 deletions

View File

@ -0,0 +1,170 @@
#include "audio_effect_distortion.h"
#include "servers/audio_server.h"
void AudioEffectDistortionInstance::process(const AudioFrame *p_src_frames,AudioFrame *p_dst_frames,int p_frame_count) {
const float *src = (const float*)p_src_frames;
float *dst = (float*)p_dst_frames;
//float lpf_c=expf(-2.0*M_PI*keep_hf_hz.get()/(mix_rate*(float)OVERSAMPLE));
float lpf_c=expf(-2.0*M_PI*base->keep_hf_hz/(AudioServer::get_singleton()->get_mix_rate()));
float lpf_ic=1.0-lpf_c;
float drive_f=base->drive;
float pregain_f=Math::db2linear(base->pre_gain);
float postgain_f=Math::db2linear(base->post_gain);
float atan_mult=pow(10,drive_f*drive_f*3.0)-1.0+0.001;
float atan_div=1.0/(atanf(atan_mult)*(1.0+drive_f*8));
float lofi_mult=powf(2.0,2.0+(1.0-drive_f)*14); //goes from 16 to 2 bits
for (int i=0;i<p_frame_count*2;i++) {
float out=undenormalise(src[i]*lpf_ic+lpf_c*h[i&1]);
h[i&1]=out;
float a=out;
float ha=src[i]-out; //high freqs
a*=pregain_f;
switch (base->mode) {
case AudioEffectDistortion::MODE_CLIP: {
a=powf(a,1.0001-drive_f);
if (a>1.0)
a=1.0;
else if (a<(-1.0))
a=-1.0;
} break;
case AudioEffectDistortion::MODE_ATAN: {
a=atanf(a*atan_mult)*atan_div;
} break;
case AudioEffectDistortion::MODE_LOFI: {
a = floorf(a*lofi_mult+0.5)/lofi_mult;
} break;
case AudioEffectDistortion::MODE_OVERDRIVE: {
const double x = a * 0.686306;
const double z = 1 + exp (sqrt (fabs (x)) * -0.75);
a = (expf(x) - expf(-x * z)) / (expf(x) + expf(-x));
} break;
case AudioEffectDistortion::MODE_WAVESHAPE: {
float x = a;
float k= 2*drive_f/(1.00001-drive_f);
a = (1.0+k)*x/(1.0+k*fabsf(x));
} break;
}
dst[i]=a*postgain_f+ha;
}
}
Ref<AudioEffectInstance> AudioEffectDistortion::instance() {
Ref<AudioEffectDistortionInstance> ins;
ins.instance();
ins->base=Ref<AudioEffectDistortion>(this);
ins->h[0]=0;
ins->h[1]=0;
return ins;
}
void AudioEffectDistortion::set_mode(Mode p_mode) {
mode=p_mode;
}
AudioEffectDistortion::Mode AudioEffectDistortion::get_mode() const{
return mode;
}
void AudioEffectDistortion::set_pre_gain(float p_pre_gain){
pre_gain=p_pre_gain;
}
float AudioEffectDistortion::get_pre_gain() const{
return pre_gain;
}
void AudioEffectDistortion::set_keep_hf_hz(float p_keep_hf_hz){
keep_hf_hz=p_keep_hf_hz;
}
float AudioEffectDistortion::get_keep_hf_hz() const{
return keep_hf_hz;
}
void AudioEffectDistortion::set_drive(float p_drive){
drive=p_drive;
}
float AudioEffectDistortion::get_drive() const{
return drive;
}
void AudioEffectDistortion::set_post_gain(float p_post_gain){
post_gain=p_post_gain;
}
float AudioEffectDistortion::get_post_gain() const{
return post_gain;
}
void AudioEffectDistortion::_bind_methods() {
ClassDB::bind_method(_MD("set_mode","mode"),&AudioEffectDistortion::set_mode);
ClassDB::bind_method(_MD("get_mode"),&AudioEffectDistortion::get_mode);
ClassDB::bind_method(_MD("set_pre_gain","pre_gain"),&AudioEffectDistortion::set_pre_gain);
ClassDB::bind_method(_MD("get_pre_gain"),&AudioEffectDistortion::get_pre_gain);
ClassDB::bind_method(_MD("set_keep_hf_hz","keep_hf_hz"),&AudioEffectDistortion::set_keep_hf_hz);
ClassDB::bind_method(_MD("get_keep_hf_hz"),&AudioEffectDistortion::get_keep_hf_hz);
ClassDB::bind_method(_MD("set_drive","drive"),&AudioEffectDistortion::set_drive);
ClassDB::bind_method(_MD("get_drive"),&AudioEffectDistortion::get_drive);
ClassDB::bind_method(_MD("set_post_gain","post_gain"),&AudioEffectDistortion::set_post_gain);
ClassDB::bind_method(_MD("get_post_gain"),&AudioEffectDistortion::get_post_gain);
ADD_PROPERTY(PropertyInfo(Variant::INT,"mode",PROPERTY_HINT_ENUM,"Clip,ATan,LoFi,Overdrive,WaveShape"),_SCS("set_mode"),_SCS("get_mode"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"pre_gain",PROPERTY_HINT_RANGE,"-60,60,0.01"),_SCS("set_pre_gain"),_SCS("get_pre_gain"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"keep_hf_hz",PROPERTY_HINT_RANGE,"1,20000,1"),_SCS("set_keep_hf_hz"),_SCS("get_keep_hf_hz"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"drive",PROPERTY_HINT_RANGE,"0,1,0.01"),_SCS("set_drive"),_SCS("get_drive"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"post_gain",PROPERTY_HINT_RANGE,"-80,24,0.01"),_SCS("set_post_gain"),_SCS("get_post_gain"));
}
AudioEffectDistortion::AudioEffectDistortion()
{
mode=MODE_CLIP;
pre_gain=0;
post_gain=0;
keep_hf_hz=16000;
drive=0;
}

View File

@ -0,0 +1,69 @@
#ifndef AUDIOEFFECTDISTORTION_H
#define AUDIOEFFECTDISTORTION_H
#include "servers/audio/audio_effect.h"
class AudioEffectDistortion;
class AudioEffectDistortionInstance : public AudioEffectInstance {
GDCLASS(AudioEffectDistortionInstance,AudioEffectInstance)
friend class AudioEffectDistortion;
Ref<AudioEffectDistortion> base;
float h[2];
public:
virtual void process(const AudioFrame *p_src_frames,AudioFrame *p_dst_frames,int p_frame_count);
};
class AudioEffectDistortion : public AudioEffect {
GDCLASS(AudioEffectDistortion,AudioEffect)
public:
enum Mode {
MODE_CLIP,
MODE_ATAN,
MODE_LOFI,
MODE_OVERDRIVE,
MODE_WAVESHAPE,
};
friend class AudioEffectDistortionInstance;
Mode mode;
float pre_gain;
float post_gain;
float keep_hf_hz;
float drive;
protected:
static void _bind_methods();
public:
Ref<AudioEffectInstance> instance();
void set_mode(Mode p_mode);
Mode get_mode() const;
void set_pre_gain(float pre_gain);
float get_pre_gain() const;
void set_keep_hf_hz(float keep_hf_hz);
float get_keep_hf_hz() const;
void set_drive(float drive);
float get_drive() const;
void set_post_gain(float post_gain);
float get_post_gain() const;
AudioEffectDistortion();
};
VARIANT_ENUM_CAST( AudioEffectDistortion::Mode )
#endif // AUDIOEFFECTDISTORTION_H

View File

@ -41,6 +41,7 @@
#include "audio/effects/audio_effect_reverb.h"
#include "audio/effects/audio_effect_filter.h"
#include "audio/effects/audio_effect_eq.h"
#include "audio/effects/audio_effect_distortion.h"
static void _debugger_get_resource_usage(List<ScriptDebuggerRemote::ResourceUsage>* r_usage) {
@ -93,6 +94,7 @@ void register_server_types() {
ClassDB::register_class<AudioEffectEQ10>();
ClassDB::register_class<AudioEffectEQ21>();
ClassDB::register_class<AudioEffectDistortion>();
ClassDB::register_virtual_class<Physics2DDirectBodyState>();
ClassDB::register_virtual_class<Physics2DDirectSpaceState>();