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-rw-r--r--src/emu/sound/filter.cpp234
1 files changed, 0 insertions, 234 deletions
diff --git a/src/emu/sound/filter.cpp b/src/emu/sound/filter.cpp
deleted file mode 100644
index b01ec7efc4b..00000000000
--- a/src/emu/sound/filter.cpp
+++ /dev/null
@@ -1,234 +0,0 @@
-// license:BSD-3-Clause
-// copyright-holders:Derrick Renaud, Couriersud
-#include "emu.h"
-#include "filter.h"
-
-static filter* filter_alloc(void) {
- auto f = global_alloc(filter);
- return f;
-}
-
-void filter_free(filter* f) {
- global_free(f);
-}
-
-void filter_state_reset(filter* f, filter_state* s) {
- int i;
- s->prev_mac = 0;
- for(i=0;i<f->order;++i) {
- s->xprev[i] = 0;
- }
-}
-
-filter_state* filter_state_alloc(void) {
- int i;
- auto s = global_alloc(filter_state);
- s->prev_mac = 0;
- for(i=0;i<FILTER_ORDER_MAX;++i)
- s->xprev[i] = 0;
- return s;
-}
-
-void filter_state_free(filter_state* s) {
- global_free(s);
-}
-
-/****************************************************************************/
-/* FIR */
-
-filter_real filter_compute(filter* f, filter_state* s) {
- unsigned order = f->order;
- unsigned midorder = f->order / 2;
- filter_real y = 0;
- unsigned i,j,k;
-
- /* i == [0] */
- /* j == [-2*midorder] */
- i = s->prev_mac;
- j = i + 1;
- if (j == order)
- j = 0;
-
- /* x */
- for(k=0;k<midorder;++k) {
- y += f->xcoeffs[midorder-k] * (s->xprev[i] + s->xprev[j]);
- ++j;
- if (j == order)
- j = 0;
- if (i == 0)
- i = order - 1;
- else
- --i;
- }
- y += f->xcoeffs[0] * s->xprev[i];
-
-#ifdef FILTER_USE_INT
- return y >> FILTER_INT_FRACT;
-#else
- return y;
-#endif
-}
-
-filter* filter_lp_fir_alloc(double freq, int order) {
- filter* f = filter_alloc();
- unsigned midorder = (order - 1) / 2;
- unsigned i;
- double gain;
-
- assert( order <= FILTER_ORDER_MAX );
- assert( order % 2 == 1 );
- assert( 0 < freq && freq <= 0.5 );
-
- /* Compute the antitrasform of the perfect low pass filter */
- gain = 2*freq;
-#ifdef FILTER_USE_INT
- f->xcoeffs[0] = gain * (1 << FILTER_INT_FRACT);
-#else
- f->xcoeffs[0] = gain;
-#endif
- for(i=1;i<=midorder;++i) {
- /* number of the sample starting from 0 to (order-1) included */
- unsigned n = i + midorder;
-
- /* sample value */
- double c = sin(2*M_PI*freq*i) / (M_PI*i);
-
- /* apply only one window or none */
- /* double w = 2 - 2*n/(order-1); */ /* Bartlett (triangular) */
- /* double w = 0.5 * (1 - cos(2*M_PI*n/(order-1))); */ /* Hanning */
- double w = 0.54 - 0.46 * cos(2*M_PI*n/(order-1)); /* Hamming */
- /* double w = 0.42 - 0.5 * cos(2*M_PI*n/(order-1)) + 0.08 * cos(4*M_PI*n/(order-1)); */ /* Blackman */
-
- /* apply the window */
- c *= w;
-
- /* update the gain */
- gain += 2*c;
-
- /* insert the coeff */
-#ifdef FILTER_USE_INT
- f->xcoeffs[i] = c * (1 << FILTER_INT_FRACT);
-#else
- f->xcoeffs[i] = c;
-#endif
- }
-
- /* adjust the gain to be exact 1.0 */
- for(i=0;i<=midorder;++i) {
-#ifdef FILTER_USE_INT
- f->xcoeffs[i] /= gain;
-#else
- f->xcoeffs[i] = f->xcoeffs[i] * (double)(1 << FILTER_INT_FRAC) / gain;
-#endif
- }
-
- /* decrease the order if the last coeffs are 0 */
- i = midorder;
- while (i > 0 && f->xcoeffs[i] == 0.0)
- --i;
-
- f->order = i * 2 + 1;
-
- return f;
-}
-
-
-void filter2_setup(device_t *device, int type, double fc, double d, double gain,
- filter2_context *filter2)
-{
- int sample_rate = device->machine().sample_rate();
- double w; /* cutoff freq, in radians/sec */
- double w_squared;
- double den; /* temp variable */
- double two_over_T = 2*sample_rate;
- double two_over_T_squared = two_over_T * two_over_T;
-
- /* calculate digital filter coefficents */
- /*w = 2.0*M_PI*fc; no pre-warping */
- w = sample_rate*2.0*tan(M_PI*fc/sample_rate); /* pre-warping */
- w_squared = w*w;
-
- den = two_over_T_squared + d*w*two_over_T + w_squared;
-
- filter2->a1 = 2.0*(-two_over_T_squared + w_squared)/den;
- filter2->a2 = (two_over_T_squared - d*w*two_over_T + w_squared)/den;
-
- switch (type)
- {
- case FILTER_LOWPASS:
- filter2->b0 = filter2->b2 = w_squared/den;
- filter2->b1 = 2.0*(filter2->b0);
- break;
- case FILTER_BANDPASS:
- filter2->b0 = d*w*two_over_T/den;
- filter2->b1 = 0.0;
- filter2->b2 = -(filter2->b0);
- break;
- case FILTER_HIGHPASS:
- filter2->b0 = filter2->b2 = two_over_T_squared/den;
- filter2->b1 = -2.0*(filter2->b0);
- break;
- default:
- device->logerror("filter2_setup() - Invalid filter type for 2nd order filter.");
- break;
- }
-
- filter2->b0 *= gain;
- filter2->b1 *= gain;
- filter2->b2 *= gain;
-}
-
-
-/* Reset the input/output voltages to 0. */
-void filter2_reset(filter2_context *filter2)
-{
- filter2->x0 = 0;
- filter2->x1 = 0;
- filter2->x2 = 0;
- filter2->y0 = 0;
- filter2->y1 = 0;
- filter2->y2 = 0;
-}
-
-
-/* Step the filter. */
-void filter2_step(filter2_context *filter2)
-{
- filter2->y0 = -filter2->a1 * filter2->y1 - filter2->a2 * filter2->y2 +
- filter2->b0 * filter2->x0 + filter2->b1 * filter2->x1 + filter2->b2 * filter2->x2;
- filter2->x2 = filter2->x1;
- filter2->x1 = filter2->x0;
- filter2->y2 = filter2->y1;
- filter2->y1 = filter2->y0;
-}
-
-
-/* Setup a filter2 structure based on an op-amp multipole bandpass circuit. */
-void filter_opamp_m_bandpass_setup(device_t *device, double r1, double r2, double r3, double c1, double c2,
- filter2_context *filter2)
-{
- double r_in, fc, d, gain;
-
- if (r1 == 0)
- {
- device->logerror("filter_opamp_m_bandpass_setup() - r1 can not be 0");
- return; /* Filter can not be setup. Undefined results. */
- }
-
- if (r2 == 0)
- {
- gain = 1;
- r_in = r1;
- }
- else
- {
- gain = r2 / (r1 + r2);
- r_in = 1.0 / (1.0/r1 + 1.0/r2);
- }
-
- fc = 1.0 / (2 * M_PI * sqrt(r_in * r3 * c1 * c2));
- d = (c1 + c2) / sqrt(r3 / r_in * c1 * c2);
- gain *= -r3 / r_in * c2 / (c1 + c2);
-
- filter2_setup(device, FILTER_BANDPASS, fc, d, gain, filter2);
-}