Box2DX.Common.Mat22.Multiply C# (CSharp) Метод

Multiply() публичный Метод

public Multiply ( System.Vector2 vector ) : System.Vector2
vector System.Vector2
Результат System.Vector2
        public Vector2 Multiply(Vector2 vector)
        {
            return new Vector2(Col1.x * vector.x + Col2.x * vector.y, Col1.y * vector.x + Col2.y * vector.y);
        }

Usage Example

Пример #1
0
        internal override bool SolvePositionConstraints(float baumgarte)
        {
            Body b1 = _body1;
            Body b2 = _body2;

            Vector2 c1 = b1._sweep.C;
            float a1 = b1._sweep.A;

            Vector2 c2 = b2._sweep.C;
            float a2 = b2._sweep.A;

            // Solve linear limit constraint.
            float linearError = 0.0f, angularError = 0.0f;
            bool active = false;
            float C2 = 0.0f;

            Mat22 R1 = new Mat22(a1), R2 = new Mat22(a2);

            Vector2 r1 = R1.Multiply(_localAnchor1 - _localCenter1);
            Vector2 r2 = R2.Multiply(_localAnchor2 - _localCenter2);
            Vector2 d = c2 + r2 - c1 - r1;

            if (_enableLimit)
            {
                _axis = R1.Multiply(_localXAxis1);

                _a1 = (d + r1).Cross(_axis);
                _a2 = r2.Cross(_axis);

                float translation = Vector2.Dot(_axis, d);
                if (Mathf.Abs(_upperTranslation - _lowerTranslation) < 2.0f * Settings.LinearSlop)
                {
                    // Prevent large angular corrections
                    C2 = Mathf.Clamp(translation, -Settings.MaxLinearCorrection, Settings.MaxLinearCorrection);
                    linearError = Box2DX.Common.Math.Abs(translation);
                    active = true;
                }
                else if (translation <= _lowerTranslation)
                {
                    // Prevent large linear corrections and allow some slop.
                    C2 = Mathf.Clamp(translation - _lowerTranslation + Settings.LinearSlop, -Settings.MaxLinearCorrection, 0.0f);
                    linearError = _lowerTranslation - translation;
                    active = true;
                }
                else if (translation >= _upperTranslation)
                {
                    // Prevent large linear corrections and allow some slop.
                    C2 = Mathf.Clamp(translation - _upperTranslation - Settings.LinearSlop, 0.0f, Settings.MaxLinearCorrection);
                    linearError = translation - _upperTranslation;
                    active = true;
                }
            }

            _perp = R1.Multiply(_localYAxis1);

            _s1 = (d + r1).Cross(_perp);
            _s2 = r2.Cross(_perp);

            Vector2 impulse;
            float C1;
            C1 = Vector2.Dot(_perp, d);

            linearError = Box2DX.Common.Math.Max(linearError, Box2DX.Common.Math.Abs(C1));
            angularError = 0.0f;

            if (active)
            {
                float m1 = _invMass1, m2 = _invMass2;
                float i1 = _invI1, i2 = _invI2;

                float k11 = m1 + m2 + i1 * _s1 * _s1 + i2 * _s2 * _s2;
                float k12 = i1 * _s1 * _a1 + i2 * _s2 * _a2;
                float k22 = m1 + m2 + i1 * _a1 * _a1 + i2 * _a2 * _a2;

                _K.Col1 = new Vector2(k11, k12);
                _K.Col2 = new Vector2(k12, k22);

                Vector2 C = new Vector2();
                C.x = C1;
                C.y = C2;

                impulse = _K.Solve(-C);
            }
            else
            {
                float m1 = _invMass1, m2 = _invMass2;
                float i1 = _invI1, i2 = _invI2;

                float k11 = m1 + m2 + i1 * _s1 * _s1 + i2 * _s2 * _s2;

                float impulse1 = (-C1) / k11;
                impulse.x = impulse1;
                impulse.y = 0.0f;
            }

            Vector2 P = impulse.x * _perp + impulse.y * _axis;
            float L1 = impulse.x * _s1 + impulse.y * _a1;
            float L2 = impulse.x * _s2 + impulse.y * _a2;

            c1 -= _invMass1 * P;
            a1 -= _invI1 * L1;
            c2 += _invMass2 * P;
            a2 += _invI2 * L2;

            // TODO_ERIN remove need for this.
            b1._sweep.C = c1;
            b1._sweep.A = a1;
            b2._sweep.C = c2;
            b2._sweep.A = a2;
            b1.SynchronizeTransform();
            b2.SynchronizeTransform();

            return linearError <= Settings.LinearSlop && angularError <= Settings.AngularSlop;
        }