[csharp] Fixed precision problems when inherit rotation is disabled and parent rotated by disabling sin/cos/atan2 look up table based implementation. Define can manually be enabled in code in case anyone really receives any measuarable performance impact (which I did not). Closes #1606.

spine-csharp/src/MathUtils.cs

@@ -27,6 +27,8 @@
  * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *****************************************************************************/
 
+//#define USE_FAST_SIN_COS_ATAN2_APPROXIMATIONS
+
 using System;
 
 namespace Spine {
@@ -47,6 +49,7 @@ namespace Spine {
 
 		static Random random = new Random();
 
+	#if USE_FAST_SIN_COS_ATAN2_APPROXIMATIONS
 		static MathUtils () {
 			for (int i = 0; i < SIN_COUNT; i++)
 				sin[i] = (float)Math.Sin((i + 0.5f) / SIN_COUNT * RadFull);
@@ -54,22 +57,22 @@ namespace Spine {
 				sin[(int)(i * DegToIndex) & SIN_MASK] = (float)Math.Sin(i * DegRad);
 		}
 
-		/// <summary>Returns the sine in radians from a lookup table.</summary>
+		/// <summary>Returns the sine of a given angle in radians from a lookup table.</summary>
 		static public float Sin (float radians) {
 			return sin[(int)(radians * RadToIndex) & SIN_MASK];
 		}
 
-		/// <summary>Returns the cosine in radians from a lookup table.</summary>
+		/// <summary>Returns the cosine of a given angle in radians from a lookup table.</summary>
 		static public float Cos (float radians) {
 			return sin[(int)((radians + PI / 2) * RadToIndex) & SIN_MASK];
 		}
 
-		/// <summary>Returns the sine in radians from a lookup table.</summary>
+		/// <summary>Returns the sine of a given angle in degrees from a lookup table.</summary>
 		static public float SinDeg (float degrees) {
 			return sin[(int)(degrees * DegToIndex) & SIN_MASK];
 		}
 
-		/// <summary>Returns the cosine in radians from a lookup table.</summary>
+		/// <summary>Returns the cosine of a given angle in degrees from a lookup table.</summary>
 		static public float CosDeg (float degrees) {
 			return sin[(int)((degrees + 90) * DegToIndex) & SIN_MASK];
 		}
@@ -91,7 +94,32 @@ namespace Spine {
 			atan = PI / 2 - z / (z * z + 0.28f);
 			return y < 0f ? atan - PI : atan;
 		}
+	#else
+		/// <summary>Returns the sine of a given angle in radians.</summary>
+		static public float Sin (float radians) {
+			return (float)Math.Sin(radians);
+		}
+
+		/// <summary>Returns the cosine of a given angle in radians.</summary>
+		static public float Cos (float radians) {
+			return (float)Math.Cos(radians);
+		}
+
+		/// <summary>Returns the sine of a given angle in degrees.</summary>
+		static public float SinDeg (float degrees) {
+			return (float)Math.Sin(degrees * DegRad);
+		}
 
+		/// <summary>Returns the cosine of a given angle in degrees.</summary>
+		static public float CosDeg (float degrees) {
+			return (float)Math.Cos(degrees * DegRad);
+		}
+
+		/// <summary>Returns the atan2 using Math.Atan2.</summary>
+		static public float Atan2 (float y, float x) {
+			return (float)Math.Atan2(y, x);
+		}
+	#endif
 		static public float Clamp (float value, float min, float max) {
 			if (value < min) return min;
 			if (value > max) return max;