public static void ComputeCorrectiveImpulse(ref BodyVelocities wsvA, ref BodyVelocities wsvB, ref TangentFriction.Projection data, ref Jacobians jacobians, ref Vector <float> maximumImpulse, ref Vector2Wide accumulatedImpulse, out Vector2Wide correctiveCSI) { Matrix2x3Wide.TransformByTransposeWithoutOverlap(wsvA.Linear, jacobians.LinearA, out var csvaLinear); Matrix2x3Wide.TransformByTransposeWithoutOverlap(wsvA.Angular, jacobians.AngularA, out var csvaAngular); Matrix2x3Wide.TransformByTransposeWithoutOverlap(wsvB.Linear, jacobians.LinearA, out var csvbLinear); Matrix2x3Wide.TransformByTransposeWithoutOverlap(wsvB.Angular, jacobians.AngularB, out var csvbAngular); //Note that the velocity in constraint space is (csvaLinear - csvbLinear + csvaAngular + csvbAngular). //The subtraction there is due to sharing the linear jacobian between both bodies3D. //In the following, we need to compute the constraint space *violating* velocity- which is the negation of the above velocity in constraint space. //So, (csvbLinear - csvaLinear - (csvaAngular + csvbAngular)). Vector2Wide.Subtract(csvbLinear, csvaLinear, out var csvLinear); Vector2Wide.Add(csvaAngular, csvbAngular, out var csvAngular); Vector2Wide.Subtract(csvLinear, csvAngular, out var csv); Symmetric2x2Wide.TransformWithoutOverlap(csv, data.EffectiveMass, out var csi); var previousAccumulated = accumulatedImpulse; Vector2Wide.Add(accumulatedImpulse, csi, out accumulatedImpulse); //The maximum force of friction depends upon the normal impulse. The maximum is supplied per iteration. Vector2Wide.Length(accumulatedImpulse, out var accumulatedMagnitude); //Note division by zero guard. var scale = Vector.Min(Vector <float> .One, maximumImpulse / Vector.Max(new Vector <float>(1e-16f), accumulatedMagnitude)); Vector2Wide.Scale(accumulatedImpulse, scale, out accumulatedImpulse); Vector2Wide.Subtract(accumulatedImpulse, previousAccumulated, out correctiveCSI); }
public static void ComputeCorrectiveImpulse(ref BodyVelocities wsvA, ref Projection data, ref Jacobians jacobians, ref Vector <float> maximumImpulse, ref Vector2Wide accumulatedImpulse, out Vector2Wide correctiveCSI) { Matrix2x3Wide.TransformByTransposeWithoutOverlap(wsvA.Linear, jacobians.LinearA, out var csvaLinear); Matrix2x3Wide.TransformByTransposeWithoutOverlap(wsvA.Angular, jacobians.AngularA, out var csvaAngular); Vector2Wide.Add(csvaLinear, csvaAngular, out var csv); //Required corrective velocity is the negation of the current constraint space velocity. Symmetric2x2Wide.TransformWithoutOverlap(csv, data.EffectiveMass, out var negativeCSI); var previousAccumulated = accumulatedImpulse; Vector2Wide.Subtract(accumulatedImpulse, negativeCSI, out accumulatedImpulse); //The maximum force of friction depends upon the normal impulse. The maximum is supplied per iteration. Vector2Wide.Length(accumulatedImpulse, out var accumulatedMagnitude); //Note division by zero guard. var scale = Vector.Min(Vector <float> .One, maximumImpulse / Vector.Max(new Vector <float>(1e-16f), accumulatedMagnitude)); Vector2Wide.Scale(accumulatedImpulse, scale, out accumulatedImpulse); Vector2Wide.Subtract(accumulatedImpulse, previousAccumulated, out correctiveCSI); }