Move the filter implementation to a separate directory

4 files changed, 4 insertions, 202 deletions

diff --git a/OpenAL32/Include/alFilter.h b/OpenAL32/Include/alFilter.h
index 4e506722..2634d5e8 100644
--- a/OpenAL32/Include/alFilter.h
+++ b/OpenAL32/Include/alFilter.h
@@ -1,9 +1,8 @@
 #ifndef _AL_FILTER_H_
 #define _AL_FILTER_H_
 
-#include "alMain.h"
-
-#include "math_defs.h"
+#include "AL/alc.h"
+#include "AL/al.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -13,118 +12,6 @@ extern "C" {
 #define HIGHPASSFREQREF  (250.0f)
 
 
-/* Filters implementation is based on the "Cookbook formulae for audio
- * EQ biquad filter coefficients" by Robert Bristow-Johnson
- * http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt
- */
-/* Implementation note: For the shelf filters, the specified gain is for the
- * reference frequency, which is the centerpoint of the transition band. This
- * better matches EFX filter design. To set the gain for the shelf itself, use
- * the square root of the desired linear gain (or halve the dB gain).
- */
-
-typedef enum ALfilterType {
-    /** EFX-style low-pass filter, specifying a gain and reference frequency. */
-    ALfilterType_HighShelf,
-    /** EFX-style high-pass filter, specifying a gain and reference frequency. */
-    ALfilterType_LowShelf,
-    /** Peaking filter, specifying a gain and reference frequency. */
-    ALfilterType_Peaking,
-
-    /** Low-pass cut-off filter, specifying a cut-off frequency. */
-    ALfilterType_LowPass,
-    /** High-pass cut-off filter, specifying a cut-off frequency. */
-    ALfilterType_HighPass,
-    /** Band-pass filter, specifying a center frequency. */
-    ALfilterType_BandPass,
-} ALfilterType;
-
-typedef struct ALfilterState {
-    ALfloat x[2]; /* History of two last input samples  */
-    ALfloat y[2]; /* History of two last output samples */
-    ALfloat b0, b1, b2; /* Transfer function coefficients "b" */
-    ALfloat a1, a2; /* Transfer function coefficients "a" (a0 is pre-applied) */
-} ALfilterState;
-/* Currently only a C-based filter process method is implemented. */
-#define ALfilterState_process ALfilterState_processC
-
-/**
- * Calculates the rcpQ (i.e. 1/Q) coefficient for shelving filters, using the
- * reference gain and shelf slope parameter.
- * \param gain 0 < gain
- * \param slope 0 < slope <= 1
- */
-inline ALfloat calc_rcpQ_from_slope(ALfloat gain, ALfloat slope)
-{
-    return sqrtf((gain + 1.0f/gain)*(1.0f/slope - 1.0f) + 2.0f);
-}
-/**
- * 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(ALfloat f0norm, ALfloat bandwidth)
-{
-    ALfloat w0 = F_TAU * f0norm;
-    return 2.0f*sinhf(logf(2.0f)/2.0f*bandwidth*w0/sinf(w0));
-}
-
-inline void ALfilterState_clear(ALfilterState *filter)
-{
-    filter->x[0] = 0.0f;
-    filter->x[1] = 0.0f;
-    filter->y[0] = 0.0f;
-    filter->y[1] = 0.0f;
-}
-
-/**
- * Sets up the filter state for the specified filter type and its parameters.
- *
- * \param filter The filter object to prepare.
- * \param type The type of filter for the object to apply.
- * \param gain The gain for the reference frequency response. Only used by the
- *             Shelf and Peaking filter types.
- * \param f0norm The normalized reference frequency (ref_freq / sample_rate).
- *               This is the center point for the Shelf, Peaking, and BandPass
- *               filter types, or the cutoff frequency for the LowPass and
- *               HighPass filter types.
- * \param rcpQ The reciprocal of the Q coefficient for the filter's transition
- *             band. Can be generated from calc_rcpQ_from_slope or
- *             calc_rcpQ_from_bandwidth depending on the available data.
- */
-void ALfilterState_setParams(ALfilterState *filter, ALfilterType type, ALfloat gain, ALfloat f0norm, ALfloat rcpQ);
-
-inline void ALfilterState_copyParams(ALfilterState *restrict dst, const ALfilterState *restrict src)
-{
-    dst->b0 = src->b0;
-    dst->b1 = src->b1;
-    dst->b2 = src->b2;
-    dst->a1 = src->a1;
-    dst->a2 = src->a2;
-}
-
-void ALfilterState_processC(ALfilterState *filter, ALfloat *restrict dst, const ALfloat *restrict src, ALsizei numsamples);
-
-inline void ALfilterState_processPassthru(ALfilterState *filter, const ALfloat *restrict src, ALsizei numsamples)
-{
-    if(numsamples >= 2)
-    {
-        filter->x[1] = src[numsamples-2];
-        filter->x[0] = src[numsamples-1];
-        filter->y[1] = src[numsamples-2];
-        filter->y[0] = src[numsamples-1];
-    }
-    else if(numsamples == 1)
-    {
-        filter->x[1] = filter->x[0];
-        filter->x[0] = src[0];
-        filter->y[1] = filter->y[0];
-        filter->y[0] = src[0];
-    }
-}
-
-
 struct ALfilter;
 
 typedef struct ALfilterVtable {
diff --git a/OpenAL32/Include/alu.h b/OpenAL32/Include/alu.h
index 14262d9b..341b3760 100644
--- a/OpenAL32/Include/alu.h
+++ b/OpenAL32/Include/alu.h
@@ -12,13 +12,12 @@
 
 #include "alMain.h"
 #include "alBuffer.h"
-#include "alFilter.h"
-#include "alAuxEffectSlot.h"
 
 #include "hrtf.h"
 #include "align.h"
 #include "nfcfilter.h"
 #include "math_defs.h"
+#include "filters/defs.h"
 
 
 #define MAX_PITCH  (255)
diff --git a/OpenAL32/alFilter.c b/OpenAL32/alFilter.c
index 08f66d26..7d8a886c 100644
--- a/OpenAL32/alFilter.c
+++ b/OpenAL32/alFilter.c
@@ -30,11 +30,6 @@
 
 extern inline void LockFilterList(ALCdevice *device);
 extern inline void UnlockFilterList(ALCdevice *device);
-extern inline void ALfilterState_clear(ALfilterState *filter);
-extern inline void ALfilterState_copyParams(ALfilterState *restrict dst, const ALfilterState *restrict src);
-extern inline void ALfilterState_processPassthru(ALfilterState *filter, const ALfloat *restrict src, ALsizei numsamples);
-extern inline ALfloat calc_rcpQ_from_slope(ALfloat gain, ALfloat slope);
-extern inline ALfloat calc_rcpQ_from_bandwidth(ALfloat f0norm, ALfloat bandwidth);
 
 static ALfilter *AllocFilter(ALCcontext *context);
 static void FreeFilter(ALCdevice *device, ALfilter *filter);
@@ -343,86 +338,6 @@ AL_API ALvoid AL_APIENTRY alGetFilterfv(ALuint filter, ALenum param, ALfloat *va
 }
 
 
-void ALfilterState_setParams(ALfilterState *filter, ALfilterType type, ALfloat gain, ALfloat f0norm, ALfloat rcpQ)
-{
-    ALfloat alpha, sqrtgain_alpha_2;
-    ALfloat w0, sin_w0, cos_w0;
-    ALfloat a[3] = { 1.0f, 0.0f, 0.0f };
-    ALfloat b[3] = { 1.0f, 0.0f, 0.0f };
-
-    // Limit gain to -100dB
-    assert(gain > 0.00001f);
-
-    w0 = F_TAU * f0norm;
-    sin_w0 = sinf(w0);
-    cos_w0 = cosf(w0);
-    alpha = sin_w0/2.0f * rcpQ;
-
-    /* Calculate filter coefficients depending on filter type */
-    switch(type)
-    {
-        case ALfilterType_HighShelf:
-            sqrtgain_alpha_2 = 2.0f * sqrtf(gain) * alpha;
-            b[0] =       gain*((gain+1.0f) + (gain-1.0f)*cos_w0 + sqrtgain_alpha_2);
-            b[1] = -2.0f*gain*((gain-1.0f) + (gain+1.0f)*cos_w0                   );
-            b[2] =       gain*((gain+1.0f) + (gain-1.0f)*cos_w0 - sqrtgain_alpha_2);
-            a[0] =             (gain+1.0f) - (gain-1.0f)*cos_w0 + sqrtgain_alpha_2;
-            a[1] =  2.0f*     ((gain-1.0f) - (gain+1.0f)*cos_w0                   );
-            a[2] =             (gain+1.0f) - (gain-1.0f)*cos_w0 - sqrtgain_alpha_2;
-            break;
-        case ALfilterType_LowShelf:
-            sqrtgain_alpha_2 = 2.0f * sqrtf(gain) * alpha;
-            b[0] =       gain*((gain+1.0f) - (gain-1.0f)*cos_w0 + sqrtgain_alpha_2);
-            b[1] =  2.0f*gain*((gain-1.0f) - (gain+1.0f)*cos_w0                   );
-            b[2] =       gain*((gain+1.0f) - (gain-1.0f)*cos_w0 - sqrtgain_alpha_2);
-            a[0] =             (gain+1.0f) + (gain-1.0f)*cos_w0 + sqrtgain_alpha_2;
-            a[1] = -2.0f*     ((gain-1.0f) + (gain+1.0f)*cos_w0                   );
-            a[2] =             (gain+1.0f) + (gain-1.0f)*cos_w0 - sqrtgain_alpha_2;
-            break;
-        case ALfilterType_Peaking:
-            gain = sqrtf(gain);
-            b[0] =  1.0f + alpha * gain;
-            b[1] = -2.0f * cos_w0;
-            b[2] =  1.0f - alpha * gain;
-            a[0] =  1.0f + alpha / gain;
-            a[1] = -2.0f * cos_w0;
-            a[2] =  1.0f - alpha / gain;
-            break;
-
-        case ALfilterType_LowPass:
-            b[0] = (1.0f - cos_w0) / 2.0f;
-            b[1] =  1.0f - cos_w0;
-            b[2] = (1.0f - cos_w0) / 2.0f;
-            a[0] =  1.0f + alpha;
-            a[1] = -2.0f * cos_w0;
-            a[2] =  1.0f - alpha;
-            break;
-        case ALfilterType_HighPass:
-            b[0] =  (1.0f + cos_w0) / 2.0f;
-            b[1] = -(1.0f + cos_w0);
-            b[2] =  (1.0f + cos_w0) / 2.0f;
-            a[0] =   1.0f + alpha;
-            a[1] =  -2.0f * cos_w0;
-            a[2] =   1.0f - alpha;
-            break;
-        case ALfilterType_BandPass:
-            b[0] =  alpha;
-            b[1] =  0;
-            b[2] = -alpha;
-            a[0] =  1.0f + alpha;
-            a[1] = -2.0f * cos_w0;
-            a[2] =  1.0f - alpha;
-            break;
-    }
-
-    filter->a1 = a[1] / a[0];
-    filter->a2 = a[2] / a[0];
-    filter->b0 = b[0] / a[0];
-    filter->b1 = b[1] / a[0];
-    filter->b2 = b[2] / a[0];
-}
-
-
 static void ALlowpass_setParami(ALfilter *UNUSED(filter), ALCcontext *context, ALenum param, ALint UNUSED(val))
 { alSetError(context, AL_INVALID_ENUM, "Invalid low-pass integer property 0x%04x", param); }
 static void ALlowpass_setParamiv(ALfilter *UNUSED(filter), ALCcontext *context, ALenum param, const ALint *UNUSED(vals))
diff --git a/OpenAL32/alSource.c b/OpenAL32/alSource.c
index 40b2c494..e3e40166 100644
--- a/OpenAL32/alSource.c
+++ b/OpenAL32/alSource.c
@@ -31,6 +31,7 @@
 #include "alError.h"
 #include "alSource.h"
 #include "alBuffer.h"
+#include "alFilter.h"
 #include "alAuxEffectSlot.h"
 #include "ringbuffer.h"