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-rw-r--r--Alc/filters/biquad.cpp44
-rw-r--r--Alc/filters/biquad.h43
2 files changed, 51 insertions, 36 deletions
diff --git a/Alc/filters/biquad.cpp b/Alc/filters/biquad.cpp
index 16a1b3fb..b010ebed 100644
--- a/Alc/filters/biquad.cpp
+++ b/Alc/filters/biquad.cpp
@@ -10,19 +10,20 @@
#include "biquad.h"
-void BiquadFilter::setParams(BiquadType type, float gain, float f0norm, float rcpQ)
+template<typename Real>
+void BiquadFilterR<Real>::setParams(BiquadType type, Real gain, Real f0norm, Real rcpQ)
{
// Limit gain to -100dB
assert(gain > 0.00001f);
- const float w0{F_TAU * f0norm};
- const float sin_w0{std::sin(w0)};
- const float cos_w0{std::cos(w0)};
- const float alpha{sin_w0/2.0f * rcpQ};
+ const Real w0{F_TAU * f0norm};
+ const Real sin_w0{std::sin(w0)};
+ const Real cos_w0{std::cos(w0)};
+ const Real alpha{sin_w0/2.0f * rcpQ};
- float sqrtgain_alpha_2;
- float a[3]{ 1.0f, 0.0f, 0.0f };
- float b[3]{ 1.0f, 0.0f, 0.0f };
+ Real sqrtgain_alpha_2;
+ Real a[3]{ 1.0f, 0.0f, 0.0f };
+ Real b[3]{ 1.0f, 0.0f, 0.0f };
/* Calculate filter coefficients depending on filter type */
switch(type)
@@ -73,7 +74,7 @@ void BiquadFilter::setParams(BiquadType type, float gain, float f0norm, float rc
break;
case BiquadType::BandPass:
b[0] = alpha;
- b[1] = 0;
+ b[1] = 0.0f;
b[2] = -alpha;
a[0] = 1.0f + alpha;
a[1] = -2.0f * cos_w0;
@@ -88,18 +89,18 @@ void BiquadFilter::setParams(BiquadType type, float gain, float f0norm, float rc
b2 = b[2] / a[0];
}
-
-void BiquadFilter::process(float *dst, const float *src, int numsamples)
+template<typename Real>
+void BiquadFilterR<Real>::process(Real *dst, const Real *src, int numsamples)
{
ASSUME(numsamples > 0);
- const float b0{this->b0};
- const float b1{this->b1};
- const float b2{this->b2};
- const float a1{this->a1};
- const float a2{this->a2};
- float z1{this->z1};
- float z2{this->z2};
+ const Real b0{this->b0};
+ const Real b1{this->b1};
+ const Real b2{this->b2};
+ const Real a1{this->a1};
+ const Real a2{this->a2};
+ Real z1{this->z1};
+ Real z2{this->z2};
/* Processing loop is Transposed Direct Form II. This requires less storage
* compared to Direct Form I (only two delay components, instead of a four-
@@ -109,9 +110,9 @@ void BiquadFilter::process(float *dst, const float *src, int numsamples)
*
* See: http://www.earlevel.com/main/2003/02/28/biquads/
*/
- auto proc_sample = [b0,b1,b2,a1,a2,&z1,&z2](float input) noexcept -> float
+ auto proc_sample = [b0,b1,b2,a1,a2,&z1,&z2](Real input) noexcept -> Real
{
- float output = input*b0 + z1;
+ Real output = input*b0 + z1;
z1 = input*b1 - output*a1 + z2;
z2 = input*b2 - output*a2;
return output;
@@ -121,3 +122,6 @@ void BiquadFilter::process(float *dst, const float *src, int numsamples)
this->z1 = z1;
this->z2 = z2;
}
+
+template class BiquadFilterR<float>;
+template class BiquadFilterR<double>;
diff --git a/Alc/filters/biquad.h b/Alc/filters/biquad.h
index eccaed35..a7d830a2 100644
--- a/Alc/filters/biquad.h
+++ b/Alc/filters/biquad.h
@@ -34,13 +34,14 @@ enum class BiquadType {
BandPass,
};
-class BiquadFilter {
+template<typename Real>
+class BiquadFilterR {
/* Last two delayed components for direct form II. */
- float z1{0.0f}, z2{0.0f};
+ Real z1{0.0f}, z2{0.0f};
/* Transfer function coefficients "b" (numerator) */
- float b0{1.0f}, b1{0.0f}, b2{0.0f};
+ Real b0{1.0f}, b1{0.0f}, b2{0.0f};
/* Transfer function coefficients "a" (denominator; a0 is pre-applied). */
- float a1{0.0f}, a2{0.0f};
+ Real a1{0.0f}, a2{0.0f};
public:
void clear() noexcept { z1 = z2 = 0.0f; }
@@ -59,9 +60,9 @@ public:
* transition band. Can be generated from calc_rcpQ_from_slope
* or calc_rcpQ_from_bandwidth as needed.
*/
- void setParams(BiquadType type, float gain, float f0norm, float rcpQ);
+ void setParams(BiquadType type, Real gain, Real f0norm, Real rcpQ);
- void copyParamsFrom(const BiquadFilter &other)
+ void copyParamsFrom(const BiquadFilterR &other)
{
b0 = other.b0;
b1 = other.b1;
@@ -71,7 +72,7 @@ public:
}
- void process(float *dst, const float *src, int numsamples);
+ void process(Real *dst, const Real *src, int numsamples);
void passthru(int numsamples) noexcept
{
@@ -88,19 +89,21 @@ public:
}
/* Rather hacky. It's just here to support "manual" processing. */
- std::pair<float,float> getComponents() const noexcept
+ std::pair<Real,Real> getComponents() const noexcept
{ return {z1, z2}; }
- void setComponents(float z1_, float z2_) noexcept
+ void setComponents(Real z1_, Real z2_) noexcept
{ z1 = z1_; z2 = z2_; }
- float processOne(const float in, float &z1_, float &z2_) const noexcept
+ Real processOne(const Real in, Real &z1_, Real &z2_) const noexcept
{
- float out{in*b0 + z1_};
+ Real out{in*b0 + z1_};
z1_ = in*b1 - out*a1 + z2_;
z2_ = in*b2 - out*a2;
return out;
}
};
+using BiquadFilter = BiquadFilterR<float>;
+
/**
* Calculates the rcpQ (i.e. 1/Q) coefficient for shelving filters, using the
* reference gain and shelf slope parameter.
@@ -108,19 +111,27 @@ public:
* \param slope 0 < slope <= 1
*/
inline float calc_rcpQ_from_slope(float gain, float slope)
-{
- return std::sqrt((gain + 1.0f/gain)*(1.0f/slope - 1.0f) + 2.0f);
-}
+{ return std::sqrt((gain + 1.0f/gain)*(1.0f/slope - 1.0f) + 2.0f); }
+
+inline double calc_rcpQ_from_slope(double gain, double slope)
+{ return std::sqrt((gain + 1.0/gain)*(1.0/slope - 1.0) + 2.0); }
+
/**
* Calculates the rcpQ (i.e. 1/Q) coefficient for filters, using the normalized
* reference frequency and bandwidth.
* \param f0norm 0 < f0norm < 0.5.
* \param bandwidth 0 < bandwidth
*/
-inline ALfloat calc_rcpQ_from_bandwidth(float f0norm, float bandwidth)
+inline float calc_rcpQ_from_bandwidth(float f0norm, float bandwidth)
{
- float w0 = F_TAU * f0norm;
+ const float w0{F_TAU * f0norm};
return 2.0f*std::sinh(std::log(2.0f)/2.0f*bandwidth*w0/std::sin(w0));
}
+inline double calc_rcpQ_from_bandwidth(double f0norm, double bandwidth)
+{
+ const double w0{F_TAU * f0norm};
+ return 2.0*std::sinh(std::log(2.0)/2.0*bandwidth*w0/std::sin(w0));
+}
+
#endif /* FILTERS_BIQUAD_H */