hyades.physics.Body.RotateShape C# (CSharp) Méthode

        private void RotateShape(double elapsed)
        {
            // find the average angle of all of the masses.
            float angle = 0;
            int originalSign = 1;
            float originalAngle = 0;
            for (int i = 0; i < count; i++)
            {
                Vector2 baseNorm = new Vector2();
                baseNorm.X = base_shape.points[i].X;
                baseNorm.Y = base_shape.points[i].Y;
                Vector2.Normalize(ref baseNorm, out baseNorm);

                Vector2 curNorm = new Vector2();
                curNorm.X = pointmass_list[i].position.X - position.X;
                curNorm.Y = pointmass_list[i].position.Y - position.Y;
                Vector2.Normalize(ref curNorm, out curNorm);

                float dot;
                Vector2.Dot(ref baseNorm, ref curNorm, out dot);
                if (dot > 1.0f) { dot = 1.0f; }
                if (dot < -1.0f) { dot = -1.0f; }

                float thisAngle = (float)Math.Acos(dot);
                if (!VectorHelper.IsCCW(ref baseNorm, ref curNorm)) { thisAngle = -thisAngle; }

                if (i == 0)
                {
                    originalSign = (thisAngle >= 0.0f) ? 1 : -1;
                    originalAngle = thisAngle;
                }
                else
                {
                    float diff = (thisAngle - originalAngle);
                    int thisSign = (thisAngle >= 0.0f) ? 1 : -1;

                    if ((Math.Abs(diff) > Math.PI) && (thisSign != originalSign))
                    {
                        thisAngle = (thisSign == -1) ? ((float)Math.PI + ((float)Math.PI + thisAngle)) : (((float)Math.PI - thisAngle) - (float)Math.PI);
                    }
                }

                angle += thisAngle;
            }

            angle = angle / count;

            // now calculate the derived Omega, based on change in angle over time.
            float angleChange = (angle - prev_angle);
            if (Math.Abs(angleChange) >= Math.PI)
            {
                if (angleChange < 0f)
                    angleChange = angleChange + (float)(Math.PI * 2);
                else
                    angleChange = angleChange - (float)(Math.PI * 2);
            }

            omega = angleChange / (float)elapsed;
            prev_angle = angle;

            for (int i = 0; i < count; i++)
            {
                float x = base_shape.points[i].X * scale.X;
                float y = base_shape.points[i].Y * scale.Y;
                float c = (float)Math.Cos(angle);
                float s = (float)Math.Sin(angle);
                curr_shape.points[i].X = (c * x) - (s * y) + position.X;
                curr_shape.points[i].Y = (c * y) + (s * x) + position.Y;
            }
        }