godot/servers/audio/effects/audio_effect_distortion.cpp
Hein-Pieter van Braam 0f687f0ccb Remove use of _SCS from ADD_METHOD
This saves typing and is a step towards fixing #56
2017-02-13 10:37:47 +01:00

172 lines
4.3 KiB
C++

#include "audio_effect_distortion.h"
#include "servers/audio_server.h"
#include "math_funcs.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*Math_PI*keep_hf_hz.get()/(mix_rate*(float)OVERSAMPLE));
float lpf_c=expf(-2.0*Math_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"),"set_mode","get_mode");
ADD_PROPERTY(PropertyInfo(Variant::REAL,"pre_gain",PROPERTY_HINT_RANGE,"-60,60,0.01"),"set_pre_gain","get_pre_gain");
ADD_PROPERTY(PropertyInfo(Variant::REAL,"keep_hf_hz",PROPERTY_HINT_RANGE,"1,20000,1"),"set_keep_hf_hz","get_keep_hf_hz");
ADD_PROPERTY(PropertyInfo(Variant::REAL,"drive",PROPERTY_HINT_RANGE,"0,1,0.01"),"set_drive","get_drive");
ADD_PROPERTY(PropertyInfo(Variant::REAL,"post_gain",PROPERTY_HINT_RANGE,"-80,24,0.01"),"set_post_gain","get_post_gain");
}
AudioEffectDistortion::AudioEffectDistortion()
{
mode=MODE_CLIP;
pre_gain=0;
post_gain=0;
keep_hf_hz=16000;
drive=0;
}