FEAT: faster trigonometric functions (without conversions and bounds checks)

While the original functions SINE, COSINE, TANGENT and ARCTANGENT works also with degrees and do better output formating, these new functions: SIN, COS, TAN and ATAN expects only value in radians and are directly mapped to libc trigonometric functions. They will be faster, but one must expect different output in some cases!

Difference example:

>> tangent/radians (pi / 2)
== 1.#INF

>> tan (pi / 2)
== 1.633123935319537e16

NOTE: these functions are available only with INFINITY support (needs 1.#NaN value)

Author: Oldes

src/core/n-math.c

@@ -184,6 +184,97 @@ enum {SINE, COSINE, TANGENT};
 }
 
 
+// Follows faster trigonometric functions (without conversions and bounds checks)
+#ifndef USE_NO_INFINITY //use these functions only with INFINITY support (cos/sin may return 1.#NaN value)!
+
+/***********************************************************************
+**
+*/	REBNATIVE(cos)
+/*
+//	cos: native [
+//		{Returns the trigonometric cosine.}
+//		value [decimal!] "In radians"
+//	]
+***********************************************************************/
+{
+	SET_DECIMAL(D_RET, cos(VAL_DECIMAL(D_ARG(1))));
+	return R_RET;
+}
+
+/***********************************************************************
+**
+*/	REBNATIVE(sin)
+/*
+//	sin: native [
+//		{Returns the trigonometric sine.}
+//		value [decimal!] "In radians"
+//	]
+***********************************************************************/
+{
+	SET_DECIMAL(D_RET, sin(VAL_DECIMAL(D_ARG(1))));
+	return R_RET;
+}
+
+/***********************************************************************
+**
+*/	REBNATIVE(tan)
+/*
+//	tan: native [
+//		{Returns the trigonometric tangent.}
+//		value [decimal!] "In radians"
+//	]
+***********************************************************************/
+{
+	SET_DECIMAL(D_RET, tan(VAL_DECIMAL(D_ARG(1))));
+	return R_RET;
+}
+
+/***********************************************************************
+**
+*/	REBNATIVE(arctan)
+/*
+//	arctan: native [
+//		{Returns the trigonometric arctangent.}
+//		value [decimal!] "In radians"
+//	]
+***********************************************************************/
+{
+	SET_DECIMAL(D_RET, atan(VAL_DECIMAL(D_ARG(1))));
+	return R_RET;
+}
+
+/***********************************************************************
+**
+*/	REBNATIVE(asin)
+/*
+//	asin: native [
+//		{Returns the trigonometric arcsine.}
+//		value [decimal!] "In radians"
+//	]
+***********************************************************************/
+{
+	SET_DECIMAL(D_RET, asin(VAL_DECIMAL(D_ARG(1))));
+	return R_RET;
+}
+
+/***********************************************************************
+**
+*/	REBNATIVE(acos)
+/*
+//	acos: native [
+//		{Returns the trigonometric arccosine.}
+//		value [decimal!] "In radians"
+//	]
+***********************************************************************/
+{
+	SET_DECIMAL(D_RET, acos(VAL_DECIMAL(D_ARG(1))));
+	return R_RET;
+}
+
+#endif //!USE_NO_INFINITY
+
+
+
 /***********************************************************************
 **
 */	REBNATIVE(exp)