598 lines
23 KiB
C++
598 lines
23 KiB
C++
// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
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// SPDX-FileCopyrightText: 2021 Jorrit Rouwe
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// SPDX-License-Identifier: MIT
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#pragma once
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#include <Jolt/Geometry/Ellipse.h>
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#include <Jolt/Physics/Constraints/ConstraintPart/RotationEulerConstraintPart.h>
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#include <Jolt/Physics/Constraints/ConstraintPart/AngleConstraintPart.h>
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JPH_NAMESPACE_BEGIN
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/// How the swing limit behaves
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enum class ESwingType : uint8
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{
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Cone, ///< Swing is limited by a cone shape, note that this cone starts to deform for larger swing angles. Cone limits only support limits that are symmetric around 0.
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Pyramid, ///< Swing is limited by a pyramid shape, note that this pyramid starts to deform for larger swing angles.
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};
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/// Quaternion based constraint that decomposes the rotation in constraint space in swing and twist: q = q_swing * q_twist
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/// where q_swing.x = 0 and where q_twist.y = q_twist.z = 0
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///
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/// - Rotation around the twist (x-axis) is within [inTwistMinAngle, inTwistMaxAngle].
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/// - Rotation around the swing axis (y and z axis) are limited to an ellipsoid in quaternion space formed by the equation:
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///
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/// (q_swing.y / sin(inSwingYHalfAngle / 2))^2 + (q_swing.z / sin(inSwingZHalfAngle / 2))^2 <= 1
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///
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/// Which roughly corresponds to an elliptic cone shape with major axis (inSwingYHalfAngle, inSwingZHalfAngle).
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///
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/// In case inSwingYHalfAngle = 0, the rotation around Y will be constrained to 0 and the rotation around Z
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/// will be constrained between [-inSwingZHalfAngle, inSwingZHalfAngle]. Vice versa if inSwingZHalfAngle = 0.
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class SwingTwistConstraintPart
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{
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public:
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/// Override the swing type
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void SetSwingType(ESwingType inSwingType)
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{
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mSwingType = inSwingType;
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}
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/// Get the swing type for this part
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ESwingType GetSwingType() const
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{
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return mSwingType;
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}
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/// Set limits for this constraint (see description above for parameters)
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void SetLimits(float inTwistMinAngle, float inTwistMaxAngle, float inSwingYMinAngle, float inSwingYMaxAngle, float inSwingZMinAngle, float inSwingZMaxAngle)
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{
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constexpr float cLockedAngle = DegreesToRadians(0.5f);
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constexpr float cFreeAngle = DegreesToRadians(179.5f);
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// Assume sane input
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JPH_ASSERT(inTwistMinAngle <= inTwistMaxAngle);
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JPH_ASSERT(inSwingYMinAngle <= inSwingYMaxAngle);
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JPH_ASSERT(inSwingZMinAngle <= inSwingZMaxAngle);
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JPH_ASSERT(inSwingYMinAngle >= -JPH_PI && inSwingYMaxAngle <= JPH_PI);
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JPH_ASSERT(inSwingZMinAngle >= -JPH_PI && inSwingZMaxAngle <= JPH_PI);
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// Calculate the sine and cosine of the half angles
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Vec4 half_twist = 0.5f * Vec4(inTwistMinAngle, inTwistMaxAngle, 0, 0);
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Vec4 twist_s, twist_c;
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half_twist.SinCos(twist_s, twist_c);
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Vec4 half_swing = 0.5f * Vec4(inSwingYMinAngle, inSwingYMaxAngle, inSwingZMinAngle, inSwingZMaxAngle);
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Vec4 swing_s, swing_c;
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half_swing.SinCos(swing_s, swing_c);
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// Store half angles for pyramid limit
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mSwingYHalfMinAngle = half_swing.GetX();
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mSwingYHalfMaxAngle = half_swing.GetY();
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mSwingZHalfMinAngle = half_swing.GetZ();
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mSwingZHalfMaxAngle = half_swing.GetW();
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// Store axis flags which are used at runtime to quickly decided which constraints to apply
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mRotationFlags = 0;
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if (inTwistMinAngle > -cLockedAngle && inTwistMaxAngle < cLockedAngle)
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{
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mRotationFlags |= TwistXLocked;
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mSinTwistHalfMinAngle = 0.0f;
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mSinTwistHalfMaxAngle = 0.0f;
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mCosTwistHalfMinAngle = 1.0f;
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mCosTwistHalfMaxAngle = 1.0f;
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}
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else if (inTwistMinAngle < -cFreeAngle && inTwistMaxAngle > cFreeAngle)
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{
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mRotationFlags |= TwistXFree;
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mSinTwistHalfMinAngle = -1.0f;
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mSinTwistHalfMaxAngle = 1.0f;
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mCosTwistHalfMinAngle = 0.0f;
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mCosTwistHalfMaxAngle = 0.0f;
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}
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else
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{
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mSinTwistHalfMinAngle = twist_s.GetX();
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mSinTwistHalfMaxAngle = twist_s.GetY();
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mCosTwistHalfMinAngle = twist_c.GetX();
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mCosTwistHalfMaxAngle = twist_c.GetY();
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}
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if (inSwingYMinAngle > -cLockedAngle && inSwingYMaxAngle < cLockedAngle)
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{
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mRotationFlags |= SwingYLocked;
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mSinSwingYHalfMinAngle = 0.0f;
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mSinSwingYHalfMaxAngle = 0.0f;
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mCosSwingYHalfMinAngle = 1.0f;
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mCosSwingYHalfMaxAngle = 1.0f;
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}
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else if (inSwingYMinAngle < -cFreeAngle && inSwingYMaxAngle > cFreeAngle)
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{
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mRotationFlags |= SwingYFree;
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mSinSwingYHalfMinAngle = -1.0f;
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mSinSwingYHalfMaxAngle = 1.0f;
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mCosSwingYHalfMinAngle = 0.0f;
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mCosSwingYHalfMaxAngle = 0.0f;
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}
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else
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{
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mSinSwingYHalfMinAngle = swing_s.GetX();
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mSinSwingYHalfMaxAngle = swing_s.GetY();
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mCosSwingYHalfMinAngle = swing_c.GetX();
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mCosSwingYHalfMaxAngle = swing_c.GetY();
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JPH_ASSERT(mSinSwingYHalfMinAngle <= mSinSwingYHalfMaxAngle);
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}
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if (inSwingZMinAngle > -cLockedAngle && inSwingZMaxAngle < cLockedAngle)
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{
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mRotationFlags |= SwingZLocked;
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mSinSwingZHalfMinAngle = 0.0f;
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mSinSwingZHalfMaxAngle = 0.0f;
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mCosSwingZHalfMinAngle = 1.0f;
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mCosSwingZHalfMaxAngle = 1.0f;
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}
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else if (inSwingZMinAngle < -cFreeAngle && inSwingZMaxAngle > cFreeAngle)
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{
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mRotationFlags |= SwingZFree;
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mSinSwingZHalfMinAngle = -1.0f;
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mSinSwingZHalfMaxAngle = 1.0f;
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mCosSwingZHalfMinAngle = 0.0f;
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mCosSwingZHalfMaxAngle = 0.0f;
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}
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else
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{
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mSinSwingZHalfMinAngle = swing_s.GetZ();
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mSinSwingZHalfMaxAngle = swing_s.GetW();
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mCosSwingZHalfMinAngle = swing_c.GetZ();
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mCosSwingZHalfMaxAngle = swing_c.GetW();
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JPH_ASSERT(mSinSwingZHalfMinAngle <= mSinSwingZHalfMaxAngle);
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}
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}
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/// Flags to indicate which axis got clamped by ClampSwingTwist
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static constexpr uint cClampedTwistMin = 1 << 0;
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static constexpr uint cClampedTwistMax = 1 << 1;
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static constexpr uint cClampedSwingYMin = 1 << 2;
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static constexpr uint cClampedSwingYMax = 1 << 3;
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static constexpr uint cClampedSwingZMin = 1 << 4;
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static constexpr uint cClampedSwingZMax = 1 << 5;
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/// Helper function to determine if we're clamped against the min or max limit
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static JPH_INLINE bool sDistanceToMinShorter(float inDeltaMin, float inDeltaMax)
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{
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// We're outside of the limits, get actual delta to min/max range
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// Note that a swing/twist of -1 and 1 represent the same angle, so if the difference is bigger than 1, the shortest angle is the other way around (2 - difference)
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// We should actually be working with angles rather than sin(angle / 2). When the difference is small the approximation is accurate, but
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// when working with extreme values the calculation is off and e.g. when the limit is between 0 and 180 a value of approx -60 will clamp
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// to 180 rather than 0 (you'd expect anything > -90 to go to 0).
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inDeltaMin = abs(inDeltaMin);
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if (inDeltaMin > 1.0f) inDeltaMin = 2.0f - inDeltaMin;
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inDeltaMax = abs(inDeltaMax);
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if (inDeltaMax > 1.0f) inDeltaMax = 2.0f - inDeltaMax;
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return inDeltaMin < inDeltaMax;
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}
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/// Clamp twist and swing against the constraint limits, returns which parts were clamped (everything assumed in constraint space)
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inline void ClampSwingTwist(Quat &ioSwing, Quat &ioTwist, uint &outClampedAxis) const
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{
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// Start with not clamped
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outClampedAxis = 0;
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// Check that swing and twist quaternions don't contain rotations around the wrong axis
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JPH_ASSERT(ioSwing.GetX() == 0.0f);
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JPH_ASSERT(ioTwist.GetY() == 0.0f);
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JPH_ASSERT(ioTwist.GetZ() == 0.0f);
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// Ensure quaternions have w > 0
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bool negate_swing = ioSwing.GetW() < 0.0f;
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if (negate_swing)
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ioSwing = -ioSwing;
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bool negate_twist = ioTwist.GetW() < 0.0f;
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if (negate_twist)
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ioTwist = -ioTwist;
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if (mRotationFlags & TwistXLocked)
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{
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// Twist axis is locked, clamp whenever twist is not identity
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outClampedAxis |= ioTwist.GetX() != 0.0f? (cClampedTwistMin | cClampedTwistMax) : 0;
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ioTwist = Quat::sIdentity();
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}
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else if ((mRotationFlags & TwistXFree) == 0)
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{
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// Twist axis has limit, clamp whenever out of range
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float delta_min = mSinTwistHalfMinAngle - ioTwist.GetX();
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float delta_max = ioTwist.GetX() - mSinTwistHalfMaxAngle;
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if (delta_min > 0.0f || delta_max > 0.0f)
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{
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// Pick the twist that corresponds to the smallest delta
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if (sDistanceToMinShorter(delta_min, delta_max))
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{
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ioTwist = Quat(mSinTwistHalfMinAngle, 0, 0, mCosTwistHalfMinAngle);
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outClampedAxis |= cClampedTwistMin;
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}
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else
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{
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ioTwist = Quat(mSinTwistHalfMaxAngle, 0, 0, mCosTwistHalfMaxAngle);
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outClampedAxis |= cClampedTwistMax;
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}
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}
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}
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// Clamp swing
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if (mRotationFlags & SwingYLocked)
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{
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if (mRotationFlags & SwingZLocked)
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{
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// Both swing Y and Z are disabled, no degrees of freedom in swing
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outClampedAxis |= ioSwing.GetY() != 0.0f? (cClampedSwingYMin | cClampedSwingYMax) : 0;
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outClampedAxis |= ioSwing.GetZ() != 0.0f? (cClampedSwingZMin | cClampedSwingZMax) : 0;
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ioSwing = Quat::sIdentity();
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}
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else
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{
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// Swing Y angle disabled, only 1 degree of freedom in swing
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outClampedAxis |= ioSwing.GetY() != 0.0f? (cClampedSwingYMin | cClampedSwingYMax) : 0;
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float delta_min = mSinSwingZHalfMinAngle - ioSwing.GetZ();
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float delta_max = ioSwing.GetZ() - mSinSwingZHalfMaxAngle;
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if (delta_min > 0.0f || delta_max > 0.0f)
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{
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// Pick the swing that corresponds to the smallest delta
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if (sDistanceToMinShorter(delta_min, delta_max))
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{
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ioSwing = Quat(0, 0, mSinSwingZHalfMinAngle, mCosSwingZHalfMinAngle);
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outClampedAxis |= cClampedSwingZMin;
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}
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else
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{
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ioSwing = Quat(0, 0, mSinSwingZHalfMaxAngle, mCosSwingZHalfMaxAngle);
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outClampedAxis |= cClampedSwingZMax;
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}
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}
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else if ((outClampedAxis & cClampedSwingYMin) != 0)
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{
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float z = ioSwing.GetZ();
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ioSwing = Quat(0, 0, z, sqrt(1.0f - Square(z)));
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}
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}
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}
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else if (mRotationFlags & SwingZLocked)
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{
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// Swing Z angle disabled, only 1 degree of freedom in swing
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outClampedAxis |= ioSwing.GetZ() != 0.0f? (cClampedSwingZMin | cClampedSwingZMax) : 0;
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float delta_min = mSinSwingYHalfMinAngle - ioSwing.GetY();
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float delta_max = ioSwing.GetY() - mSinSwingYHalfMaxAngle;
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if (delta_min > 0.0f || delta_max > 0.0f)
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{
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// Pick the swing that corresponds to the smallest delta
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if (sDistanceToMinShorter(delta_min, delta_max))
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{
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ioSwing = Quat(0, mSinSwingYHalfMinAngle, 0, mCosSwingYHalfMinAngle);
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outClampedAxis |= cClampedSwingYMin;
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}
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else
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{
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ioSwing = Quat(0, mSinSwingYHalfMaxAngle, 0, mCosSwingYHalfMaxAngle);
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outClampedAxis |= cClampedSwingYMax;
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}
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}
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else if ((outClampedAxis & cClampedSwingZMin) != 0)
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{
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float y = ioSwing.GetY();
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ioSwing = Quat(0, y, 0, sqrt(1.0f - Square(y)));
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}
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}
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else
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{
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// Two degrees of freedom
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if (mSwingType == ESwingType::Cone)
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{
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// Use ellipse to solve limits
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Ellipse ellipse(mSinSwingYHalfMaxAngle, mSinSwingZHalfMaxAngle);
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Float2 point(ioSwing.GetY(), ioSwing.GetZ());
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if (!ellipse.IsInside(point))
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{
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Float2 closest = ellipse.GetClosestPoint(point);
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ioSwing = Quat(0, closest.x, closest.y, sqrt(max(0.0f, 1.0f - Square(closest.x) - Square(closest.y))));
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outClampedAxis |= cClampedSwingYMin | cClampedSwingYMax | cClampedSwingZMin | cClampedSwingZMax; // We're not using the flags on which side we got clamped here
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}
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}
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else
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{
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// Use pyramid to solve limits
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// The quaternion rotating by angle y around the Y axis then rotating by angle z around the Z axis is:
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// q = Quat::sRotation(Vec3::sAxisZ(), z) * Quat::sRotation(Vec3::sAxisY(), y)
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// [q.x, q.y, q.z, q.w] = [-sin(y / 2) * sin(z / 2), sin(y / 2) * cos(z / 2), cos(y / 2) * sin(z / 2), cos(y / 2) * cos(z / 2)]
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// So we can calculate y / 2 = atan2(q.y, q.w) and z / 2 = atan2(q.z, q.w)
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Vec4 half_angle = Vec4::sATan2(ioSwing.GetXYZW().Swizzle<SWIZZLE_Y, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_Z>(), ioSwing.GetXYZW().SplatW());
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Vec4 min_half_angle(mSwingYHalfMinAngle, mSwingYHalfMinAngle, mSwingZHalfMinAngle, mSwingZHalfMinAngle);
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Vec4 max_half_angle(mSwingYHalfMaxAngle, mSwingYHalfMaxAngle, mSwingZHalfMaxAngle, mSwingZHalfMaxAngle);
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Vec4 clamped_half_angle = Vec4::sMin(Vec4::sMax(half_angle, min_half_angle), max_half_angle);
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UVec4 unclamped = Vec4::sEquals(half_angle, clamped_half_angle);
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if (!unclamped.TestAllTrue())
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{
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// We now calculate the quaternion again using the formula for q above,
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// but we leave out the x component in order to not introduce twist
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Vec4 s, c;
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clamped_half_angle.SinCos(s, c);
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ioSwing = Quat(0, s.GetY() * c.GetZ(), c.GetY() * s.GetZ(), c.GetY() * c.GetZ()).Normalized();
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outClampedAxis |= cClampedSwingYMin | cClampedSwingYMax | cClampedSwingZMin | cClampedSwingZMax; // We're not using the flags on which side we got clamped here
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}
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}
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}
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// Flip sign back
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if (negate_swing)
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ioSwing = -ioSwing;
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if (negate_twist)
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ioTwist = -ioTwist;
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JPH_ASSERT(ioSwing.IsNormalized());
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JPH_ASSERT(ioTwist.IsNormalized());
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}
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/// Calculate properties used during the functions below
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/// @param inBody1 The first body that this constraint is attached to
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/// @param inBody2 The second body that this constraint is attached to
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/// @param inConstraintRotation The current rotation of the constraint in constraint space
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/// @param inConstraintToWorld Rotates from constraint space into world space
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inline void CalculateConstraintProperties(const Body &inBody1, const Body &inBody2, QuatArg inConstraintRotation, QuatArg inConstraintToWorld)
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{
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// Decompose into swing and twist
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Quat q_swing, q_twist;
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inConstraintRotation.GetSwingTwist(q_swing, q_twist);
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// Clamp against joint limits
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Quat q_clamped_swing = q_swing, q_clamped_twist = q_twist;
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uint clamped_axis;
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ClampSwingTwist(q_clamped_swing, q_clamped_twist, clamped_axis);
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if (mRotationFlags & SwingYLocked)
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{
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Quat twist_to_world = inConstraintToWorld * q_swing;
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mWorldSpaceSwingLimitYRotationAxis = twist_to_world.RotateAxisY();
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mWorldSpaceSwingLimitZRotationAxis = twist_to_world.RotateAxisZ();
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if (mRotationFlags & SwingZLocked)
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{
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// Swing fully locked
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mSwingLimitYConstraintPart.CalculateConstraintProperties(inBody1, inBody2, mWorldSpaceSwingLimitYRotationAxis);
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mSwingLimitZConstraintPart.CalculateConstraintProperties(inBody1, inBody2, mWorldSpaceSwingLimitZRotationAxis);
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}
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else
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{
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// Swing only locked around Y
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mSwingLimitYConstraintPart.CalculateConstraintProperties(inBody1, inBody2, mWorldSpaceSwingLimitYRotationAxis);
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if ((clamped_axis & (cClampedSwingZMin | cClampedSwingZMax)) != 0)
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{
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if ((clamped_axis & cClampedSwingZMin) != 0)
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mWorldSpaceSwingLimitZRotationAxis = -mWorldSpaceSwingLimitZRotationAxis; // Flip axis if hitting min limit because the impulse limit is going to be between [-FLT_MAX, 0]
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mSwingLimitZConstraintPart.CalculateConstraintProperties(inBody1, inBody2, mWorldSpaceSwingLimitZRotationAxis);
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}
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else
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mSwingLimitZConstraintPart.Deactivate();
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}
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}
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else if (mRotationFlags & SwingZLocked)
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{
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// Swing only locked around Z
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Quat twist_to_world = inConstraintToWorld * q_swing;
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mWorldSpaceSwingLimitYRotationAxis = twist_to_world.RotateAxisY();
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mWorldSpaceSwingLimitZRotationAxis = twist_to_world.RotateAxisZ();
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if ((clamped_axis & (cClampedSwingYMin | cClampedSwingYMax)) != 0)
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{
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if ((clamped_axis & cClampedSwingYMin) != 0)
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mWorldSpaceSwingLimitYRotationAxis = -mWorldSpaceSwingLimitYRotationAxis; // Flip axis if hitting min limit because the impulse limit is going to be between [-FLT_MAX, 0]
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mSwingLimitYConstraintPart.CalculateConstraintProperties(inBody1, inBody2, mWorldSpaceSwingLimitYRotationAxis);
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}
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else
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mSwingLimitYConstraintPart.Deactivate();
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mSwingLimitZConstraintPart.CalculateConstraintProperties(inBody1, inBody2, mWorldSpaceSwingLimitZRotationAxis);
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}
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else if ((mRotationFlags & SwingYZFree) != SwingYZFree)
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{
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// Swing has limits around Y and Z
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if ((clamped_axis & (cClampedSwingYMin | cClampedSwingYMax | cClampedSwingZMin | cClampedSwingZMax)) != 0)
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{
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// Calculate axis of rotation from clamped swing to swing
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Vec3 current = (inConstraintToWorld * q_swing).RotateAxisX();
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Vec3 desired = (inConstraintToWorld * q_clamped_swing).RotateAxisX();
|
|
mWorldSpaceSwingLimitYRotationAxis = desired.Cross(current);
|
|
float len = mWorldSpaceSwingLimitYRotationAxis.Length();
|
|
if (len != 0.0f)
|
|
{
|
|
mWorldSpaceSwingLimitYRotationAxis /= len;
|
|
mSwingLimitYConstraintPart.CalculateConstraintProperties(inBody1, inBody2, mWorldSpaceSwingLimitYRotationAxis);
|
|
}
|
|
else
|
|
mSwingLimitYConstraintPart.Deactivate();
|
|
}
|
|
else
|
|
mSwingLimitYConstraintPart.Deactivate();
|
|
mSwingLimitZConstraintPart.Deactivate();
|
|
}
|
|
else
|
|
{
|
|
// No swing limits
|
|
mSwingLimitYConstraintPart.Deactivate();
|
|
mSwingLimitZConstraintPart.Deactivate();
|
|
}
|
|
|
|
if (mRotationFlags & TwistXLocked)
|
|
{
|
|
// Twist locked, always activate constraint
|
|
mWorldSpaceTwistLimitRotationAxis = (inConstraintToWorld * q_swing).RotateAxisX();
|
|
mTwistLimitConstraintPart.CalculateConstraintProperties(inBody1, inBody2, mWorldSpaceTwistLimitRotationAxis);
|
|
}
|
|
else if ((mRotationFlags & TwistXFree) == 0)
|
|
{
|
|
// Twist has limits
|
|
if ((clamped_axis & (cClampedTwistMin | cClampedTwistMax)) != 0)
|
|
{
|
|
mWorldSpaceTwistLimitRotationAxis = (inConstraintToWorld * q_swing).RotateAxisX();
|
|
if ((clamped_axis & cClampedTwistMin) != 0)
|
|
mWorldSpaceTwistLimitRotationAxis = -mWorldSpaceTwistLimitRotationAxis; // Flip axis if hitting min limit because the impulse limit is going to be between [-FLT_MAX, 0]
|
|
mTwistLimitConstraintPart.CalculateConstraintProperties(inBody1, inBody2, mWorldSpaceTwistLimitRotationAxis);
|
|
}
|
|
else
|
|
mTwistLimitConstraintPart.Deactivate();
|
|
}
|
|
else
|
|
{
|
|
// No twist limits
|
|
mTwistLimitConstraintPart.Deactivate();
|
|
}
|
|
}
|
|
|
|
/// Deactivate this constraint
|
|
void Deactivate()
|
|
{
|
|
mSwingLimitYConstraintPart.Deactivate();
|
|
mSwingLimitZConstraintPart.Deactivate();
|
|
mTwistLimitConstraintPart.Deactivate();
|
|
}
|
|
|
|
/// Check if constraint is active
|
|
inline bool IsActive() const
|
|
{
|
|
return mSwingLimitYConstraintPart.IsActive() || mSwingLimitZConstraintPart.IsActive() || mTwistLimitConstraintPart.IsActive();
|
|
}
|
|
|
|
/// Must be called from the WarmStartVelocityConstraint call to apply the previous frame's impulses
|
|
inline void WarmStart(Body &ioBody1, Body &ioBody2, float inWarmStartImpulseRatio)
|
|
{
|
|
mSwingLimitYConstraintPart.WarmStart(ioBody1, ioBody2, inWarmStartImpulseRatio);
|
|
mSwingLimitZConstraintPart.WarmStart(ioBody1, ioBody2, inWarmStartImpulseRatio);
|
|
mTwistLimitConstraintPart.WarmStart(ioBody1, ioBody2, inWarmStartImpulseRatio);
|
|
}
|
|
|
|
/// Iteratively update the velocity constraint. Makes sure d/dt C(...) = 0, where C is the constraint equation.
|
|
inline bool SolveVelocityConstraint(Body &ioBody1, Body &ioBody2)
|
|
{
|
|
bool impulse = false;
|
|
|
|
// Solve swing constraint
|
|
if (mSwingLimitYConstraintPart.IsActive())
|
|
impulse |= mSwingLimitYConstraintPart.SolveVelocityConstraint(ioBody1, ioBody2, mWorldSpaceSwingLimitYRotationAxis, -FLT_MAX, mSinSwingYHalfMinAngle == mSinSwingYHalfMaxAngle? FLT_MAX : 0.0f);
|
|
|
|
if (mSwingLimitZConstraintPart.IsActive())
|
|
impulse |= mSwingLimitZConstraintPart.SolveVelocityConstraint(ioBody1, ioBody2, mWorldSpaceSwingLimitZRotationAxis, -FLT_MAX, mSinSwingZHalfMinAngle == mSinSwingZHalfMaxAngle? FLT_MAX : 0.0f);
|
|
|
|
// Solve twist constraint
|
|
if (mTwistLimitConstraintPart.IsActive())
|
|
impulse |= mTwistLimitConstraintPart.SolveVelocityConstraint(ioBody1, ioBody2, mWorldSpaceTwistLimitRotationAxis, -FLT_MAX, mSinTwistHalfMinAngle == mSinTwistHalfMaxAngle? FLT_MAX : 0.0f);
|
|
|
|
return impulse;
|
|
}
|
|
|
|
/// Iteratively update the position constraint. Makes sure C(...) = 0.
|
|
/// @param ioBody1 The first body that this constraint is attached to
|
|
/// @param ioBody2 The second body that this constraint is attached to
|
|
/// @param inConstraintRotation The current rotation of the constraint in constraint space
|
|
/// @param inConstraintToBody1 , inConstraintToBody2 Rotates from constraint space to body 1/2 space
|
|
/// @param inBaumgarte Baumgarte constant (fraction of the error to correct)
|
|
inline bool SolvePositionConstraint(Body &ioBody1, Body &ioBody2, QuatArg inConstraintRotation, QuatArg inConstraintToBody1, QuatArg inConstraintToBody2, float inBaumgarte) const
|
|
{
|
|
Quat q_swing, q_twist;
|
|
inConstraintRotation.GetSwingTwist(q_swing, q_twist);
|
|
|
|
uint clamped_axis;
|
|
ClampSwingTwist(q_swing, q_twist, clamped_axis);
|
|
|
|
// Solve rotation violations
|
|
if (clamped_axis != 0)
|
|
{
|
|
RotationEulerConstraintPart part;
|
|
Quat inv_initial_orientation = inConstraintToBody2 * (inConstraintToBody1 * q_swing * q_twist).Conjugated();
|
|
part.CalculateConstraintProperties(ioBody1, Mat44::sRotation(ioBody1.GetRotation()), ioBody2, Mat44::sRotation(ioBody2.GetRotation()));
|
|
return part.SolvePositionConstraint(ioBody1, ioBody2, inv_initial_orientation, inBaumgarte);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/// Return lagrange multiplier for swing
|
|
inline float GetTotalSwingYLambda() const
|
|
{
|
|
return mSwingLimitYConstraintPart.GetTotalLambda();
|
|
}
|
|
|
|
inline float GetTotalSwingZLambda() const
|
|
{
|
|
return mSwingLimitZConstraintPart.GetTotalLambda();
|
|
}
|
|
|
|
/// Return lagrange multiplier for twist
|
|
inline float GetTotalTwistLambda() const
|
|
{
|
|
return mTwistLimitConstraintPart.GetTotalLambda();
|
|
}
|
|
|
|
/// Save state of this constraint part
|
|
void SaveState(StateRecorder &inStream) const
|
|
{
|
|
mSwingLimitYConstraintPart.SaveState(inStream);
|
|
mSwingLimitZConstraintPart.SaveState(inStream);
|
|
mTwistLimitConstraintPart.SaveState(inStream);
|
|
}
|
|
|
|
/// Restore state of this constraint part
|
|
void RestoreState(StateRecorder &inStream)
|
|
{
|
|
mSwingLimitYConstraintPart.RestoreState(inStream);
|
|
mSwingLimitZConstraintPart.RestoreState(inStream);
|
|
mTwistLimitConstraintPart.RestoreState(inStream);
|
|
}
|
|
|
|
private:
|
|
// CONFIGURATION PROPERTIES FOLLOW
|
|
|
|
enum ERotationFlags
|
|
{
|
|
/// Indicates that axis is completely locked (cannot rotate around this axis)
|
|
TwistXLocked = 1 << 0,
|
|
SwingYLocked = 1 << 1,
|
|
SwingZLocked = 1 << 2,
|
|
|
|
/// Indicates that axis is completely free (can rotate around without limits)
|
|
TwistXFree = 1 << 3,
|
|
SwingYFree = 1 << 4,
|
|
SwingZFree = 1 << 5,
|
|
SwingYZFree = SwingYFree | SwingZFree
|
|
};
|
|
|
|
uint8 mRotationFlags;
|
|
|
|
// Constants
|
|
ESwingType mSwingType = ESwingType::Cone;
|
|
float mSinTwistHalfMinAngle;
|
|
float mSinTwistHalfMaxAngle;
|
|
float mCosTwistHalfMinAngle;
|
|
float mCosTwistHalfMaxAngle;
|
|
float mSwingYHalfMinAngle;
|
|
float mSwingYHalfMaxAngle;
|
|
float mSwingZHalfMinAngle;
|
|
float mSwingZHalfMaxAngle;
|
|
float mSinSwingYHalfMinAngle;
|
|
float mSinSwingYHalfMaxAngle;
|
|
float mSinSwingZHalfMinAngle;
|
|
float mSinSwingZHalfMaxAngle;
|
|
float mCosSwingYHalfMinAngle;
|
|
float mCosSwingYHalfMaxAngle;
|
|
float mCosSwingZHalfMinAngle;
|
|
float mCosSwingZHalfMaxAngle;
|
|
|
|
// RUN TIME PROPERTIES FOLLOW
|
|
|
|
/// Rotation axis for the angle constraint parts
|
|
Vec3 mWorldSpaceSwingLimitYRotationAxis;
|
|
Vec3 mWorldSpaceSwingLimitZRotationAxis;
|
|
Vec3 mWorldSpaceTwistLimitRotationAxis;
|
|
|
|
/// The constraint parts
|
|
AngleConstraintPart mSwingLimitYConstraintPart;
|
|
AngleConstraintPart mSwingLimitZConstraintPart;
|
|
AngleConstraintPart mTwistLimitConstraintPart;
|
|
};
|
|
|
|
JPH_NAMESPACE_END
|