C++ Vector3d::isZero方法代码示例

void Head::Joint::orientTowards(bool entering, const Math::Vector3d &point, float rate, const Math::Matrix4 &matrix,
	float maxPitch, float maxYaw, float maxRoll, float constrain) {
	float step = g_grim->getPerSecond(rate);
	float yawStep = step;
	float pitchStep = step / 3.0f;
	float rollStep = step / 3.0f;

	if (!_node)
		return;

	// Make sure we have up-to-date world transform matrices computed for the joint nodes of this character.
	_node->_needsUpdate = true;
	ModelNode *p = _node;
	while (p->_parent) {
		p = p->_parent;
		p->_needsUpdate = true;
	}
	p->setMatrix(matrix);
	p->update();

	Math::Vector3d modelFront; // the modeling convention for the forward direction.
	Math::Vector3d modelUp; // the modeling convention for the upward direction.
	Math::Vector3d frontDir; // Character front facing direction vector in world space (global scene coordinate space)

	// the character head coordinate frame is: +Y forward, +Z up, +X right.
	frontDir = Math::Vector3d(_node->_matrix(0,1), _node->_matrix(1,1), _node->_matrix(2,1)); // Look straight ahead. (+Y)
	modelFront = Math::Vector3d(0,1,0);
	modelUp = Math::Vector3d(0,0,1);

	// v is the world space direction vector this character should be looking towards.
	Math::Vector3d targetDir = point - _node->_pivotMatrix.getPosition();
	if (!entering)
		targetDir = frontDir;
	if (targetDir.isZero())
		return;

	targetDir.normalize();

	// The vector v is in world space, so generate the world space lookat matrix for the desired head facing
	// orientation.
	Math::Matrix4 lookAtTM;
	lookAtTM.setToIdentity();
	const Math::Vector3d worldUp(0,0,1); // The Residual scene convention: +Z is world space up.
	if (Math::Vector3d::dotProduct(targetDir, worldUp) >= 0.98f) // Avoid singularity if trying to look straight up.
		lookAtTM.buildFromTargetDir(modelFront, targetDir, modelUp, -frontDir); // Instead of orienting head towards scene up, orient head towards character "back",
	                                                                // i.e. when you look straight up, your head up vector tilts/arches to point straight backwards.
	else if (Math::Vector3d::dotProduct(targetDir, worldUp) <= -0.98f) // Avoid singularity if trying to look straight down.
		lookAtTM.buildFromTargetDir(modelFront, targetDir, modelUp, frontDir); // Instead of orienting head towards scene down, orient head towards character "front",
																   // i.e. when you look straight down, your head up vector tilts/arches to point straight forwards.
	else
		lookAtTM.buildFromTargetDir(modelFront, targetDir, modelUp, worldUp);
	// The above specifies the world space orientation of this bone, but we need to output
	// the orientation in parent space (as yaw/pitch/roll).

	// Get the coordinate frame in which we need to produce the character head yaw/pitch/roll values.
	Math::Matrix4 parentWorldTM;
	if (_node->_parent)
		parentWorldTM = _node->_parent->_matrix;

	// While we could compute the desired lookat direction directly in the above coordinate frame,
	// it is preferrable to compute the lookat direction with respect to the head orientation in
	// the keyframe animation. This is because the LUA scripts specify the maximum head yaw, pitch and
	// roll values with respect to those keyframe animations. If the lookat was simply computed
	// directly in the space of the parent, we couldn't apply the head maxYaw/Pitch/Roll constraints
	// properly. So, compute the coordinate frame of this bone in the keyframe animation.
	Math::Matrix4 animFrame = _node->_localMatrix;
	parentWorldTM = parentWorldTM * animFrame;
	parentWorldTM.invertAffineOrthonormal();

	// Convert lookAtTM orientation from world space to parent-with-keyframe-animation space.
	lookAtTM = parentWorldTM * lookAtTM;

	// Decompose to yaw-pitch-roll (+Z, +X, +Y).
	// In this space, Yaw is +Z. Pitch is +X. Roll is +Y.
	Math::Angle y, pt, r;
	lookAtTM.getPitchYawRoll(&pt, &y, &r);

	y = y * constrain;
	pt = pt * constrain;
	r = r * constrain;

	// Constrain the maximum head movement, as desired by the game LUA scripts.
	y.clampDegrees(maxYaw);
	pt.clampDegrees(maxPitch);
	r.clampDegrees(maxRoll);

	// Also limit yaw, pitch and roll to make at most a movement as large as the given max step size during this frame.
	// This will produce a slow head-turning animation instead of immediately snapping to the
	// target lookat orientation.
	if (y - _yaw > yawStep)
		y = _yaw + yawStep;
	if (_yaw - y > yawStep)
		y = _yaw - yawStep;

	if (pt - _pitch > pitchStep)
		pt = _pitch + pitchStep;
	if (_pitch - pt > pitchStep)
		pt = _pitch - pitchStep;

	if (r - _roll > rollStep)
//.........这里部分代码省略.........

void Head::lookAt(bool entering, const Math::Vector3d &point, float rate, const Math::Matrix4 &matrix) {
	if (_joint1Node) {
		float step = g_grim->getPerSecond(rate);
		float yawStep = step;
		float pitchStep = step / 3.f;
		if (!entering) {
			//animate yaw
			if (_headYaw > yawStep) {
				_headYaw -= yawStep;
			} else if (_headYaw < -yawStep) {
				_headYaw += yawStep;
			} else {
				_headYaw = 0;
			}
			//animate pitch
			if (_headPitch > pitchStep) {
				_headPitch -= pitchStep;
			} else if (_headPitch < -pitchStep) {
				_headPitch += pitchStep;
			} else {
				_headPitch = 0;
			}
			_joint1Node->_animYaw = _headYaw;
			Math::Angle pi = _headPitch / 3.f;
			_joint1Node->_animPitch += pi;
			_joint2Node->_animPitch += pi;
			_joint3Node->_animPitch += pi;
			_joint1Node->_animRoll = (_joint1Node->_animYaw.getDegrees() / 20.f) *
			_headPitch.getDegrees() / -5.f;

			if (_joint1Node->_animRoll > _maxRoll)
				_joint1Node->_animRoll = _maxRoll;
			if (_joint1Node->_animRoll < -_maxRoll)
				_joint1Node->_animRoll = -_maxRoll;
			return;
		}

		ModelNode *p = _joint3Node;
		while (p->_parent) {
			p = p->_parent;
		}
		p->setMatrix(matrix);
		p->update();

		Math::Vector3d v = point - _joint3Node->_matrix.getPosition();
		if (v.isZero()) {
			return;
		}

		float magnitude = sqrt(v.x() * v.x() + v.y() * v.y());
		float a = v.x() / magnitude;
		float b = v.y() / magnitude;
		float yaw;
		yaw = acos(a) * (180.0f / LOCAL_PI);
		if (b < 0.0f)
			yaw = 360.0f - yaw;

		Math::Angle bodyYaw = matrix.getYaw();
		p = _joint1Node->_parent;
		while (p) {
			bodyYaw += p->_yaw + p->_animYaw;
			p = p->_parent;
		}

		_joint1Node->_animYaw = (- 90 + yaw - bodyYaw);
		if (_joint1Node->_animYaw < -180.) {
			_joint1Node->_animYaw += 360;
		}
		if (_joint1Node->_animYaw > 180.) {
			_joint1Node->_animYaw -= 360;
		}

		if (_joint1Node->_animYaw > _maxYaw)
			_joint1Node->_animYaw = _maxYaw;
		if (_joint1Node->_animYaw < -_maxYaw)
			_joint1Node->_animYaw = -_maxYaw;

		float sqLenght = v.x() * v.x() + v.y() * v.y();
		float h;
		if (sqLenght > 0) {
			h = sqrt(sqLenght);
		} else {
			h = -sqrt(sqLenght);
		}
		magnitude = sqrt(v.z() * v.z() + h * h);
		a = h / magnitude;
		b = v.z() / magnitude;
		Math::Angle pitch;
		pitch = acos(a) * (180.0f / LOCAL_PI);

		if (b < 0.0f)
			pitch = 360.0f - pitch;

		if (pitch > 180)
			pitch -= 360;

		if (pitch > _maxPitch)
			pitch = _maxPitch;
		if (pitch < -_maxPitch)
			pitch = -_maxPitch;
//.........这里部分代码省略.........