[csharp] Allow negative scale and shear mix in transform constraint. See #1227.

spine-csharp/src/TransformConstraint.cs

@@ -58,7 +58,7 @@ namespace Spine {
 			bones = new ExposedList<Bone>();
 			foreach (BoneData boneData in data.bones)
 				bones.Add (skeleton.FindBone (boneData.name));
-			
+
 			target = skeleton.FindBone(data.target.name);
 		}
 
@@ -230,13 +230,13 @@ namespace Spine {
 				}
 
 				float scaleX = bone.ascaleX, scaleY = bone.ascaleY;
-				if (scaleMix > 0) {
+				if (scaleMix != 0) {
 					if (scaleX > 0.00001f) scaleX = (scaleX + (target.ascaleX - scaleX + data.offsetScaleX) * scaleMix) / scaleX;
 					if (scaleY > 0.00001f) scaleY = (scaleY + (target.ascaleY - scaleY + data.offsetScaleY) * scaleMix) / scaleY;
 				}
 
 				float shearY = bone.ashearY;
-				if (shearMix > 0) {
+				if (shearMix != 0) {
 					float r = target.ashearY - shearY + data.offsetShearY;
 					r -= (16384 - (int)(16384.499999999996 - r / 360)) * 360;
 					bone.shearY += r * shearMix;
@@ -265,13 +265,13 @@ namespace Spine {
 				}
 
 				float scaleX = bone.ascaleX, scaleY = bone.ascaleY;
-				if (scaleMix > 0) {
+				if (scaleMix != 0) {
 					if (scaleX > 0.00001f) scaleX *= ((target.ascaleX - 1 + data.offsetScaleX) * scaleMix) + 1;
 					if (scaleY > 0.00001f) scaleY *= ((target.ascaleY - 1 + data.offsetScaleY) * scaleMix) + 1;
 				}
 
 				float shearY = bone.ashearY;
-				if (shearMix > 0) shearY += (target.ashearY + data.offsetShearY) * shearMix;
+				if (shearMix != 0) shearY += (target.ashearY + data.offsetShearY) * shearMix;
 
 				bone.UpdateWorldTransform(x, y, rotation, scaleX, scaleY, bone.ashearX, shearY);
 			}