Merge remote branch 'leaf/master'

1 files changed, 97 insertions, 5 deletions

diff --git a/wirish/wirish_math.h b/wirish/wirish_math.h
index ae73d61..14614ba 100644
--- a/wirish/wirish_math.h
+++ b/wirish/wirish_math.h
@@ -22,6 +22,11 @@
  * THE SOFTWARE.
  *****************************************************************************/
 
+/**
+ * @file wirish_math.h
+ * @brief Includes cmath; provides Arduino-compatible math routines.
+ */
+
 #ifndef _WIRING_MATH_H_
 #define _WIRING_MATH_H_
 
@@ -29,12 +34,55 @@
 
 #ifdef __cplusplus
 
-void randomSeed(unsigned int);
-long random(long);
-long random(long, long);
+/**
+ * @brief Initialize the pseudo-random number generator.
+ * @param seed the number used to initialize the seed; cannot be zero.
+ */
+void randomSeed(unsigned int seed);
+
+/**
+ * @brief Generate a pseudo-random number with upper bound.
+ * @param max An upper bound on the returned value, exclusive.
+ * @return A pseudo-random number in the range [0,max).
+ * @see randomSeed()
+ */
+long random(long max);
+
+/**
+ * @brief Generate a pseudo-random number with lower and upper bounds.
+ * @param min Lower bound on the returned value, inclusive.
+ * @param max Upper bound on the returned value, exclusive.
+ * @return A pseudo-random number in the range [min, max).
+ * @see randomSeed()
+ */
+long random(long min, long max);
+
+/**
+ * @brief Remap a number from one range to another.
+ *
+ * That is, a value equal to fromStart gets mapped to toStart, a value
+ * of fromEnd to toEnd, and other values are mapped proportionately.
+ *
+ * Does not constrain value to lie within [fromStart, fromEnd].
+ *
+ * If a "start" value is larger than its corresponding "end", the
+ * ranges are reversed, so map(n, 1, 10, 10, 1) would reverse the
+ * range [1,10].
+ *
+ * Negative numbers may appear as any argument.
+ *
+ * @param value the value to map.
+ * @param fromStart the beginning of the value's current range.
+ * @param fromEnd the end of the value's current range.
+ * @param toStart the beginning of the value's mapped range.
+ * @param toEnd the end of the value's mapped range.
+ * @return the mapped value.
+ */
 /* TODO: profile code bloat due to inlining this */
-inline long map(long x, long in_min, long in_max, long out_min, long out_max) {
-    return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
+inline long map(long value, long fromStart, long fromEnd,
+                long toStart, long toEnd) {
+    return (value - fromStart) * (toEnd - toStart) / (fromEnd - fromStart) +
+        toStart;
 }
 
 #define PI          3.1415926535897932384626433832795
@@ -59,4 +107,48 @@ inline long map(long x, long in_min, long in_max, long out_min, long out_max) {
 
 #endif
 
+/* Following are duplicate declarations (with Doxygen comments) for
+ * some of the math.h functions; this is for the convenience of the
+ * Sphinx docs.
+ */
+
+/**
+ * Compute the cosine of an angle, in radians.
+ * @param x The radian measure of the angle.
+ * @return The cosine of x.  This value will be between -1 and 1.
+ */
+double cos(double x);
+
+/**
+ * Compute the sine of an angle, in radians.
+ * @param x The radian measure of the angle.
+ * @return The sine of x.  This value will be between -1 and 1.
+ */
+double sin(double x);
+
+/**
+ * Compute the tangent of an angle, in radians.
+ * @param x The radian measure of the angle.
+ * @return The tangent of x.  There are no limits on the return value
+ * of this function.
+ */
+double tan(double x);
+
+/**
+ * Compute the square root of a number.
+ * @param x The number whose square root to find.  This value cannot
+ * be negative.
+ * @return The square root of x.  The return value is never negative.
+ */
+double sqrt(double x);
+
+/**
+ * Compute an exponentiation.
+ * @param x the base. This value cannot be zero if y <= 0.  This value
+ * cannot be negative if y is not an integral value.
+ * @param y the exponent.
+ * @return x raised to the power y.
+ */
+double pow(double x, double y);
+
 #endif