Initial import.

1 files changed, 140 insertions, 0 deletions

diff --git a/src/libdraw/icossin.c b/src/libdraw/icossin.c
new file mode 100644
index 00000000..b66417d4
--- /dev/null
+++ b/src/libdraw/icossin.c
@@ -0,0 +1,140 @@
+#include	<u.h>
+#include	<libc.h>
+#include	<draw.h>
+
+/*
+ * Integer sine and cosine for integral degree argument.
+ * Tables computed by (sin,cos)(PI*d/180).
+ */
+static short sinus[91] = {
+	0,	/* 0 */
+	18,	/* 1 */
+	36,	/* 2 */
+	54,	/* 3 */
+	71,	/* 4 */
+	89,	/* 5 */
+	107,	/* 6 */
+	125,	/* 7 */
+	143,	/* 8 */
+	160,	/* 9 */
+	178,	/* 10 */
+	195,	/* 11 */
+	213,	/* 12 */
+	230,	/* 13 */
+	248,	/* 14 */
+	265,	/* 15 */
+	282,	/* 16 */
+	299,	/* 17 */
+	316,	/* 18 */
+	333,	/* 19 */
+	350,	/* 20 */
+	367,	/* 21 */
+	384,	/* 22 */
+	400,	/* 23 */
+	416,	/* 24 */
+	433,	/* 25 */
+	449,	/* 26 */
+	465,	/* 27 */
+	481,	/* 28 */
+	496,	/* 29 */
+	512,	/* 30 */
+	527,	/* 31 */
+	543,	/* 32 */
+	558,	/* 33 */
+	573,	/* 34 */
+	587,	/* 35 */
+	602,	/* 36 */
+	616,	/* 37 */
+	630,	/* 38 */
+	644,	/* 39 */
+	658,	/* 40 */
+	672,	/* 41 */
+	685,	/* 42 */
+	698,	/* 43 */
+	711,	/* 44 */
+	724,	/* 45 */
+	737,	/* 46 */
+	749,	/* 47 */
+	761,	/* 48 */
+	773,	/* 49 */
+	784,	/* 50 */
+	796,	/* 51 */
+	807,	/* 52 */
+	818,	/* 53 */
+	828,	/* 54 */
+	839,	/* 55 */
+	849,	/* 56 */
+	859,	/* 57 */
+	868,	/* 58 */
+	878,	/* 59 */
+	887,	/* 60 */
+	896,	/* 61 */
+	904,	/* 62 */
+	912,	/* 63 */
+	920,	/* 64 */
+	928,	/* 65 */
+	935,	/* 66 */
+	943,	/* 67 */
+	949,	/* 68 */
+	956,	/* 69 */
+	962,	/* 70 */
+	968,	/* 71 */
+	974,	/* 72 */
+	979,	/* 73 */
+	984,	/* 74 */
+	989,	/* 75 */
+	994,	/* 76 */
+	998,	/* 77 */
+	1002,	/* 78 */
+	1005,	/* 79 */
+	1008,	/* 80 */
+	1011,	/* 81 */
+	1014,	/* 82 */
+	1016,	/* 83 */
+	1018,	/* 84 */
+	1020,	/* 85 */
+	1022,	/* 86 */
+	1023,	/* 87 */
+	1023,	/* 88 */
+	1024,	/* 89 */
+	1024,	/* 90 */
+};
+
+void
+icossin(int deg, int *cosp, int *sinp)
+{
+	int sinsign, cossign;
+	short *stp, *ctp;
+
+	deg %= 360;
+	if(deg < 0)
+		deg += 360;
+	sinsign = 1;
+	cossign = 1;
+	stp = 0;
+	ctp = 0;
+	switch(deg/90){
+	case 2:
+		sinsign = -1;
+		cossign = -1;
+		deg -= 180;
+		/* fall through */
+	case 0:
+		stp = &sinus[deg];
+		ctp = &sinus[90-deg];
+		break;
+	case 3:
+		sinsign = -1;
+		cossign = -1;
+		deg -= 180;
+		/* fall through */
+	case 1:
+		deg = 180-deg;
+		cossign = -cossign;
+		stp = &sinus[deg];
+		ctp = &sinus[90-deg];
+		break;
+	}
+	*sinp = sinsign*stp[0];
+	*cosp = cossign*ctp[0];
+}