Revert "Consolidate all fixed point math routines in one library (FS#10400) by Jeffrey Goode"

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21635 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 118 insertions, 1 deletions

diff --git a/apps/codecs/adx.c b/apps/codecs/adx.c
index e23b3d4f80..cc36f6a908 100644
--- a/apps/codecs/adx.c
+++ b/apps/codecs/adx.c
@@ -21,7 +21,6 @@
 #include "codeclib.h"
 #include "inttypes.h"
 #include "math.h"
-#include "fixedpoint.h"
 
 CODEC_HEADER
 
@@ -42,6 +41,124 @@ const long cutoff = 500;
 
 static int16_t samples[WAV_CHUNK_SIZE] IBSS_ATTR;
 
+/* fixed point stuff from apps/plugins/lib/fixedpoint.c */
+
+/* Inverse gain of circular cordic rotation in s0.31 format. */
+static const long cordic_circular_gain = 0xb2458939; /* 0.607252929 */
+
+/* Table of values of atan(2^-i) in 0.32 format fractions of pi where pi = 0xffffffff / 2 */
+static const unsigned long atan_table[] = {
+    0x1fffffff, /* +0.785398163 (or pi/4) */
+    0x12e4051d, /* +0.463647609 */
+    0x09fb385b, /* +0.244978663 */
+    0x051111d4, /* +0.124354995 */
+    0x028b0d43, /* +0.062418810 */
+    0x0145d7e1, /* +0.031239833 */
+    0x00a2f61e, /* +0.015623729 */
+    0x00517c55, /* +0.007812341 */
+    0x0028be53, /* +0.003906230 */
+    0x00145f2e, /* +0.001953123 */
+    0x000a2f98, /* +0.000976562 */
+    0x000517cc, /* +0.000488281 */
+    0x00028be6, /* +0.000244141 */
+    0x000145f3, /* +0.000122070 */
+    0x0000a2f9, /* +0.000061035 */
+    0x0000517c, /* +0.000030518 */
+    0x000028be, /* +0.000015259 */
+    0x0000145f, /* +0.000007629 */
+    0x00000a2f, /* +0.000003815 */
+    0x00000517, /* +0.000001907 */
+    0x0000028b, /* +0.000000954 */
+    0x00000145, /* +0.000000477 */
+    0x000000a2, /* +0.000000238 */
+    0x00000051, /* +0.000000119 */
+    0x00000028, /* +0.000000060 */
+    0x00000014, /* +0.000000030 */
+    0x0000000a, /* +0.000000015 */
+    0x00000005, /* +0.000000007 */
+    0x00000002, /* +0.000000004 */
+    0x00000001, /* +0.000000002 */
+    0x00000000, /* +0.000000001 */
+    0x00000000, /* +0.000000000 */
+};
+
+/**
+ * Implements sin and cos using CORDIC rotation.
+ *
+ * @param phase has range from 0 to 0xffffffff, representing 0 and
+ *        2*pi respectively.
+ * @param cos return address for cos
+ * @return sin of phase, value is a signed value from LONG_MIN to LONG_MAX,
+ *         representing -1 and 1 respectively. 
+ */
+static long fsincos(unsigned long phase, long *cos)
+{
+    int32_t x, x1, y, y1;
+    unsigned long z, z1;
+    int i;
+
+    /* Setup initial vector */
+    x = cordic_circular_gain;
+    y = 0;
+    z = phase;
+
+    /* The phase has to be somewhere between 0..pi for this to work right */
+    if (z < 0xffffffff / 4) {
+        /* z in first quadrant, z += pi/2 to correct */
+        x = -x;
+        z += 0xffffffff / 4;
+    } else if (z < 3 * (0xffffffff / 4)) {
+        /* z in third quadrant, z -= pi/2 to correct */
+        z -= 0xffffffff / 4;
+    } else {
+        /* z in fourth quadrant, z -= 3pi/2 to correct */
+        x = -x;
+        z -= 3 * (0xffffffff / 4);
+    }
+
+    /* Each iteration adds roughly 1-bit of extra precision */
+    for (i = 0; i < 31; i++) {
+        x1 = x >> i;
+        y1 = y >> i;
+        z1 = atan_table[i];
+
+        /* Decided which direction to rotate vector. Pivot point is pi/2 */
+        if (z >= 0xffffffff / 4) {
+            x -= y1;
+            y += x1;
+            z -= z1;
+        } else {
+            x += y1;
+            y -= x1;
+            z += z1;
+        }
+    }
+
+    if (cos)
+        *cos = x;
+
+    return y;
+}
+
+/**
+ * Fixed point square root via Newton-Raphson.
+ * @param a square root argument.
+ * @param fracbits specifies number of fractional bits in argument.
+ * @return Square root of argument in same fixed point format as input. 
+ */
+static long fsqrt(long a, unsigned int fracbits)
+{
+    long b = a/2 + (1 << fracbits); /* initial approximation */
+    unsigned n;
+    const unsigned iterations = 8;  /* bumped up from 4 as it wasn't
+                                       nearly enough for 28 fractional bits */
+
+    for (n = 0; n < iterations; ++n)
+        b = (b + (long)(((long long)(a) << fracbits)/b))/2;
+
+    return b;
+}
+
 /* this is the codec entry point */
 enum codec_status codec_main(void)
 {