Quaternion: Euler angles math fix and documentation

HelpSource/Classes/Quaternion.schelp

@@ -73,6 +73,28 @@ METHOD:: distance
 Return the distance between two quaternions.
 
 
+METHOD:: yaw
+Return the yaw (rotation about the z-axis) Euler angle in radians. Returns values between -pi and pi (-180 and 180 degrees).
+
+
+METHOD:: roll
+Return the roll (rotation about the x-axis) Euler angle in radians. Returns values between -pi and pi (-180 and 180 degrees).
+
+
+METHOD:: pitch
+Return the pitch (rotation about the y-axis) Euler angle in radians. Returns values between -0.5pi and 0.5pi (-90 and 90 degrees).
+
+
+METHOD:: rotate
+Return the rotate (rotation about the z-axis) Euler angle in radians. Returns values between -pi and pi (-180 and 180 degrees). Equivalent to link::#-yaw::.
+
+
+METHOD:: tilt
+Return the tilt (rotation about the x-axis) Euler angle in radians. Returns values between -pi and pi (-180 and 180 degrees). Equivalent to link::#-roll::.
+
+
+METHOD:: tumble
+Return the tumble (rotation about the y-axis) Euler angle in radians. Returns values between -0.5pi and 0.5pi (-90 and 90 degrees). Equivalent to link::#-pitch::.
 
 
 EXAMPLES::

classes/various/Quaternion.sc

@@ -111,19 +111,30 @@ Quaternion {
 	// conversion to euler angles
 	// Math taken from https://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles#Quaternion_to_Euler_Angles_Conversion
 
-	// roll
+
+	roll {
+		^atan2((2 * (a * b + (c * d))), (1 - (2 * (b.squared + c.squared))))
+	}
+
+	pitch {
+		^asin((2 * (a * c - (b * d))).clip(-1.0, 1.0));
+	}
+
+	yaw {
+		^atan2((2 * (a * d + (c * b))), (1 - (2 * (d.squared + c.squared))))
+	}
+
+	// for convenience with the naming convention
 	tilt {
-		^atan2((2 * (a * b - (c * d))), (1 - (2*(b.squared + c.squared))))
+		^this.roll
 	}
 
-	// pitch
 	tumble {
-		^asin((2 * (a * c + (b * d))).clip(-1.0, 1.0));
+		^this.pitch
 	}
 
-	// yaw
 	rotate {
-		^atan2((2 * (a * d - (c * b))), (1 - (2*(d.squared + c.squared))))
+		^this.yaw
 	}
 }