Rename Alc to alc

1 files changed, 188 insertions, 0 deletions

diff --git a/alc/bs2b.cpp b/alc/bs2b.cpp
new file mode 100644
index 00000000..2d1b96aa
--- /dev/null
+++ b/alc/bs2b.cpp
@@ -0,0 +1,188 @@
+/*-
+ * Copyright (c) 2005 Boris Mikhaylov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "config.h"
+
+#include <cmath>
+#include <cstring>
+#include <algorithm>
+
+#include "bs2b.h"
+#include "math_defs.h"
+
+
+/* Set up all data. */
+static void init(struct bs2b *bs2b)
+{
+    float Fc_lo, Fc_hi;
+    float G_lo,  G_hi;
+    float x, g;
+
+    switch(bs2b->level)
+    {
+    case BS2B_LOW_CLEVEL: /* Low crossfeed level */
+        Fc_lo = 360.0f;
+        Fc_hi = 501.0f;
+        G_lo  = 0.398107170553497f;
+        G_hi  = 0.205671765275719f;
+        break;
+
+    case BS2B_MIDDLE_CLEVEL: /* Middle crossfeed level */
+        Fc_lo = 500.0f;
+        Fc_hi = 711.0f;
+        G_lo  = 0.459726988530872f;
+        G_hi  = 0.228208484414988f;
+        break;
+
+    case BS2B_HIGH_CLEVEL: /* High crossfeed level (virtual speakers are closer to itself) */
+        Fc_lo = 700.0f;
+        Fc_hi = 1021.0f;
+        G_lo  = 0.530884444230988f;
+        G_hi  = 0.250105790667544f;
+        break;
+
+    case BS2B_LOW_ECLEVEL: /* Low easy crossfeed level */
+        Fc_lo = 360.0f;
+        Fc_hi = 494.0f;
+        G_lo  = 0.316227766016838f;
+        G_hi  = 0.168236228897329f;
+        break;
+
+    case BS2B_MIDDLE_ECLEVEL: /* Middle easy crossfeed level */
+        Fc_lo = 500.0f;
+        Fc_hi = 689.0f;
+        G_lo  = 0.354813389233575f;
+        G_hi  = 0.187169483835901f;
+        break;
+
+    default: /* High easy crossfeed level */
+        bs2b->level = BS2B_HIGH_ECLEVEL;
+
+        Fc_lo = 700.0f;
+        Fc_hi = 975.0f;
+        G_lo  = 0.398107170553497f;
+        G_hi  = 0.205671765275719f;
+        break;
+    } /* switch */
+
+    g = 1.0f / (1.0f - G_hi + G_lo);
+
+    /* $fc = $Fc / $s;
+     * $d  = 1 / 2 / pi / $fc;
+     * $x  = exp(-1 / $d);
+     */
+    x           = std::exp(-al::MathDefs<float>::Tau() * Fc_lo / bs2b->srate);
+    bs2b->b1_lo = x;
+    bs2b->a0_lo = G_lo * (1.0f - x) * g;
+
+    x           = std::exp(-al::MathDefs<float>::Tau() * Fc_hi / bs2b->srate);
+    bs2b->b1_hi = x;
+    bs2b->a0_hi = (1.0f - G_hi * (1.0f - x)) * g;
+    bs2b->a1_hi = -x * g;
+} /* init */
+
+
+/* Exported functions.
+ * See descriptions in "bs2b.h"
+ */
+
+void bs2b_set_params(struct bs2b *bs2b, int level, int srate)
+{
+    if(srate <= 0) srate = 1;
+
+    bs2b->level = level;
+    bs2b->srate = srate;
+    init(bs2b);
+} /* bs2b_set_params */
+
+int bs2b_get_level(struct bs2b *bs2b)
+{
+    return bs2b->level;
+} /* bs2b_get_level */
+
+int bs2b_get_srate(struct bs2b *bs2b)
+{
+    return bs2b->srate;
+} /* bs2b_get_srate */
+
+void bs2b_clear(struct bs2b *bs2b)
+{
+    std::fill(std::begin(bs2b->last_sample), std::end(bs2b->last_sample), bs2b::t_last_sample{});
+} /* bs2b_clear */
+
+void bs2b_cross_feed(struct bs2b *bs2b, float *RESTRICT Left, float *RESTRICT Right, int SamplesToDo)
+{
+    float lsamples[128][2];
+    float rsamples[128][2];
+    int base;
+
+    for(base = 0;base < SamplesToDo;)
+    {
+        int todo = std::min(128, SamplesToDo-base);
+        int i;
+
+        /* Process left input */
+        lsamples[0][0] = bs2b->a0_lo*Left[0] +
+                         bs2b->b1_lo*bs2b->last_sample[0].lo;
+        lsamples[0][1] = bs2b->a0_hi*Left[0] +
+                         bs2b->a1_hi*bs2b->last_sample[0].asis +
+                         bs2b->b1_hi*bs2b->last_sample[0].hi;
+        for(i = 1;i < todo;i++)
+        {
+            lsamples[i][0] = bs2b->a0_lo*Left[i] +
+                             bs2b->b1_lo*lsamples[i-1][0];
+            lsamples[i][1] = bs2b->a0_hi*Left[i] +
+                             bs2b->a1_hi*Left[i-1] +
+                             bs2b->b1_hi*lsamples[i-1][1];
+        }
+        bs2b->last_sample[0].asis = Left[i-1];
+        bs2b->last_sample[0].lo = lsamples[i-1][0];
+        bs2b->last_sample[0].hi = lsamples[i-1][1];
+
+        /* Process right input */
+        rsamples[0][0] = bs2b->a0_lo*Right[0] +
+                         bs2b->b1_lo*bs2b->last_sample[1].lo;
+        rsamples[0][1] = bs2b->a0_hi*Right[0] +
+                         bs2b->a1_hi*bs2b->last_sample[1].asis +
+                         bs2b->b1_hi*bs2b->last_sample[1].hi;
+        for(i = 1;i < todo;i++)
+        {
+            rsamples[i][0] = bs2b->a0_lo*Right[i] +
+                             bs2b->b1_lo*rsamples[i-1][0];
+            rsamples[i][1] = bs2b->a0_hi*Right[i] +
+                             bs2b->a1_hi*Right[i-1] +
+                             bs2b->b1_hi*rsamples[i-1][1];
+        }
+        bs2b->last_sample[1].asis = Right[i-1];
+        bs2b->last_sample[1].lo = rsamples[i-1][0];
+        bs2b->last_sample[1].hi = rsamples[i-1][1];
+
+        /* Crossfeed */
+        for(i = 0;i < todo;i++)
+            *(Left++) = lsamples[i][1] + rsamples[i][0];
+        for(i = 0;i < todo;i++)
+            *(Right++) = rsamples[i][1] + lsamples[i][0];
+
+        base += todo;
+    }
+} /* bs2b_cross_feed */