REVIEWED: QuaternionFromEuler() #1651

src/raymath.h

@@ -1439,21 +1439,22 @@ RMDEF void QuaternionToAxisAngle(Quaternion q, Vector3 *outAxis, float *outAngle
 }
 
 // Returns he quaternion equivalent to Euler angles
-RMDEF Quaternion QuaternionFromEuler(float roll, float pitch, float yaw)
+// NOTE: Rotation order is ZYX
+RMDEF Quaternion QuaternionFromEuler(float yaw, float pitch, float roll)
 {
     Quaternion q = { 0 };
 
-    float x0 = cosf(roll*0.5f);
-    float x1 = sinf(roll*0.5f);
-    float y0 = cosf(pitch*0.5f);
-    float y1 = sinf(pitch*0.5f);
-    float z0 = cosf(yaw*0.5f);
-    float z1 = sinf(yaw*0.5f);
-
-    q.x = x1*y0*z0 - x0*y1*z1;
-    q.y = x0*y1*z0 + x1*y0*z1;
-    q.z = x0*y0*z1 - x1*y1*z0;
-    q.w = x0*y0*z0 + x1*y1*z1;
+    float cy = cosf(yaw*0.5f);
+    float sy = sinf(yaw*0.5f);
+    float cp = cosf(pitch*0.5f);
+    float sp = sinf(pitch*0.5f);
+    float cr = cosf(roll*0.5f);
+    float sr = sinf(roll*0.5f);
+
+    q.x = sr*cp*cy - cr*sp*sy;
+    q.y = cr*sp*cy + sr*cp*sy;
+    q.z = cr*cp*sy - sr*sp*cy;
+    q.w = cr*cp*cy + sr*sp*sy;
 
     return q;
 }