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+/**
+ @file Matrix3.cpp
+
+ 3x3 matrix class
+
+ @author Morgan McGuire, graphics3d.com
+
+ @created 2001-06-02
+ @edited 2009-11-15
+
+ Copyright 2000-2009, Morgan McGuire.
+ All rights reserved.
+*/
+
+#include "G3D/platform.h"
+#include <memory.h>
+#include <assert.h>
+#include "G3D/Matrix3.h"
+#include "G3D/g3dmath.h"
+#include "G3D/BinaryInput.h"
+#include "G3D/BinaryOutput.h"
+#include "G3D/Quat.h"
+#include "G3D/Any.h"
+
+namespace G3D {
+
+const float Matrix3::EPSILON = 1e-06f;
+
+Matrix3::Matrix3(const Any& any) {
+ any.verifyName("Matrix3");
+ any.verifyType(Any::ARRAY);
+ any.verifySize(9);
+
+ for (int r = 0; r < 3; ++r) {
+ for (int c = 0; c < 3; ++c) {
+ elt[r][c] = any[r * 3 + c];
+ }
+ }
+}
+
+
+Matrix3::operator Any() const {
+ Any any(Any::ARRAY, "Matrix3");
+ any.resize(9);
+ for (int r = 0; r < 3; ++r) {
+ for (int c = 0; c < 3; ++c) {
+ any[r * 3 + c] = elt[r][c];
+ }
+ }
+
+ return any;
+}
+
+const Matrix3& Matrix3::zero() {
+ static Matrix3 m(0, 0, 0, 0, 0, 0, 0, 0, 0);
+ return m;
+}
+
+const Matrix3& Matrix3::identity() {
+ static Matrix3 m(1, 0, 0, 0, 1, 0, 0, 0, 1);
+ return m;
+}
+
+
+const float Matrix3::ms_fSvdEpsilon = 1e-04f;
+const int Matrix3::ms_iSvdMaxIterations = 32;
+
+Matrix3::Matrix3(BinaryInput& b) {
+ deserialize(b);
+}
+
+bool Matrix3::fuzzyEq(const Matrix3& b) const {
+ for (int r = 0; r < 3; ++r) {
+ for (int c = 0; c < 3; ++c) {
+ if (! G3D::fuzzyEq(elt[r][c], b[r][c])) {
+ return false;
+ }
+ }
+ }
+ return true;
+}
+
+
+bool Matrix3::isRightHanded() const{
+
+ const Vector3& X = column(0);
+ const Vector3& Y = column(1);
+ const Vector3& Z = column(2);
+
+ const Vector3& W = X.cross(Y);
+
+ return W.dot(Z) > 0.0f;
+}
+
+
+bool Matrix3::isOrthonormal() const {
+ const Vector3& X = column(0);
+ const Vector3& Y = column(1);
+ const Vector3& Z = column(2);
+
+ return
+ (G3D::fuzzyEq(X.dot(Y), 0.0f) &&
+ G3D::fuzzyEq(Y.dot(Z), 0.0f) &&
+ G3D::fuzzyEq(X.dot(Z), 0.0f) &&
+ G3D::fuzzyEq(X.squaredMagnitude(), 1.0f) &&
+ G3D::fuzzyEq(Y.squaredMagnitude(), 1.0f) &&
+ G3D::fuzzyEq(Z.squaredMagnitude(), 1.0f));
+}
+
+//----------------------------------------------------------------------------
+Matrix3::Matrix3(const Quat& _q) {
+ // Implementation from Watt and Watt, pg 362
+ // See also http://www.flipcode.com/documents/matrfaq.html#Q54
+ Quat q = _q;
+ q.unitize();
+ float xx = 2.0f * q.x * q.x;
+ float xy = 2.0f * q.x * q.y;
+ float xz = 2.0f * q.x * q.z;
+ float xw = 2.0f * q.x * q.w;
+
+ float yy = 2.0f * q.y * q.y;
+ float yz = 2.0f * q.y * q.z;
+ float yw = 2.0f * q.y * q.w;
+
+ float zz = 2.0f * q.z * q.z;
+ float zw = 2.0f * q.z * q.w;
+
+ set(1.0f - yy - zz, xy - zw, xz + yw,
+ xy + zw, 1.0f - xx - zz, yz - xw,
+ xz - yw, yz + xw, 1.0f - xx - yy);
+}
+
+//----------------------------------------------------------------------------
+
+Matrix3::Matrix3 (const float aafEntry[3][3]) {
+ memcpy(elt, aafEntry, 9*sizeof(float));
+}
+
+//----------------------------------------------------------------------------
+Matrix3::Matrix3 (const Matrix3& rkMatrix) {
+ memcpy(elt, rkMatrix.elt, 9*sizeof(float));
+}
+
+//----------------------------------------------------------------------------
+Matrix3::Matrix3(
+ float fEntry00, float fEntry01, float fEntry02,
+ float fEntry10, float fEntry11, float fEntry12,
+ float fEntry20, float fEntry21, float fEntry22) {
+ set(fEntry00, fEntry01, fEntry02,
+ fEntry10, fEntry11, fEntry12,
+ fEntry20, fEntry21, fEntry22);
+}
+
+void Matrix3::set(
+ float fEntry00, float fEntry01, float fEntry02,
+ float fEntry10, float fEntry11, float fEntry12,
+ float fEntry20, float fEntry21, float fEntry22) {
+
+ elt[0][0] = fEntry00;
+ elt[0][1] = fEntry01;
+ elt[0][2] = fEntry02;
+ elt[1][0] = fEntry10;
+ elt[1][1] = fEntry11;
+ elt[1][2] = fEntry12;
+ elt[2][0] = fEntry20;
+ elt[2][1] = fEntry21;
+ elt[2][2] = fEntry22;
+}
+
+
+void Matrix3::deserialize(BinaryInput& b) {
+ int r,c;
+ for (c = 0; c < 3; ++c) {
+ for (r = 0; r < 3; ++r) {
+ elt[r][c] = b.readFloat32();
+ }
+ }
+}
+
+
+void Matrix3::serialize(BinaryOutput& b) const {
+ int r,c;
+ for (c = 0; c < 3; ++c) {
+ for (r = 0; r < 3; ++r) {
+ b.writeFloat32(elt[r][c]);
+ }
+ }
+}
+
+
+//----------------------------------------------------------------------------
+Vector3 Matrix3::column (int iCol) const {
+ assert((0 <= iCol) && (iCol < 3));
+ return Vector3(elt[0][iCol], elt[1][iCol],
+ elt[2][iCol]);
+}
+
+
+const Vector3& Matrix3::row (int iRow) const {
+ assert((0 <= iRow) && (iRow < 3));
+ return *reinterpret_cast<const Vector3*>(elt[iRow]);
+}
+
+
+void Matrix3::setColumn(int iCol, const Vector3 &vector) {
+ debugAssert((iCol >= 0) && (iCol < 3));
+ elt[0][iCol] = vector.x;
+ elt[1][iCol] = vector.y;
+ elt[2][iCol] = vector.z;
+}
+
+
+void Matrix3::setRow(int iRow, const Vector3 &vector) {
+ debugAssert((iRow >= 0) && (iRow < 3));
+ elt[iRow][0] = vector.x;
+ elt[iRow][1] = vector.y;
+ elt[iRow][2] = vector.z;
+}
+
+
+//----------------------------------------------------------------------------
+bool Matrix3::operator== (const Matrix3& rkMatrix) const {
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ if ( elt[iRow][iCol] != rkMatrix.elt[iRow][iCol] )
+ return false;
+ }
+ }
+
+ return true;
+}
+
+//----------------------------------------------------------------------------
+bool Matrix3::operator!= (const Matrix3& rkMatrix) const {
+ return !operator==(rkMatrix);
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::operator+ (const Matrix3& rkMatrix) const {
+ Matrix3 kSum;
+
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ kSum.elt[iRow][iCol] = elt[iRow][iCol] +
+ rkMatrix.elt[iRow][iCol];
+ }
+ }
+
+ return kSum;
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::operator- (const Matrix3& rkMatrix) const {
+ Matrix3 kDiff;
+
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ kDiff.elt[iRow][iCol] = elt[iRow][iCol] -
+ rkMatrix.elt[iRow][iCol];
+ }
+ }
+
+ return kDiff;
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::operator* (const Matrix3& rkMatrix) const {
+ Matrix3 kProd;
+
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ kProd.elt[iRow][iCol] =
+ elt[iRow][0] * rkMatrix.elt[0][iCol] +
+ elt[iRow][1] * rkMatrix.elt[1][iCol] +
+ elt[iRow][2] * rkMatrix.elt[2][iCol];
+ }
+ }
+
+ return kProd;
+}
+
+Matrix3& Matrix3::operator+= (const Matrix3& rkMatrix) {
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ elt[iRow][iCol] = elt[iRow][iCol] + rkMatrix.elt[iRow][iCol];
+ }
+ }
+
+ return *this;
+}
+
+Matrix3& Matrix3::operator-= (const Matrix3& rkMatrix) {
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ elt[iRow][iCol] = elt[iRow][iCol] - rkMatrix.elt[iRow][iCol];
+ }
+ }
+
+ return *this;
+}
+
+Matrix3& Matrix3::operator*= (const Matrix3& rkMatrix) {
+ Matrix3 mulMat;
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ mulMat.elt[iRow][iCol] =
+ elt[iRow][0] * rkMatrix.elt[0][iCol] +
+ elt[iRow][1] * rkMatrix.elt[1][iCol] +
+ elt[iRow][2] * rkMatrix.elt[2][iCol];
+ }
+ }
+
+ *this = mulMat;
+ return *this;
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::operator- () const {
+ Matrix3 kNeg;
+
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ kNeg[iRow][iCol] = -elt[iRow][iCol];
+ }
+ }
+
+ return kNeg;
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::operator* (float fScalar) const {
+ Matrix3 kProd;
+
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ kProd[iRow][iCol] = fScalar * elt[iRow][iCol];
+ }
+ }
+
+ return kProd;
+}
+
+Matrix3& Matrix3::operator/= (float fScalar) {
+ return *this *= (1.0f / fScalar);
+}
+
+Matrix3& Matrix3::operator*= (float fScalar) {
+
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ elt[iRow][iCol] *= fScalar;
+ }
+ }
+
+ return *this;
+}
+
+//----------------------------------------------------------------------------
+Matrix3 operator* (double fScalar, const Matrix3& rkMatrix) {
+ Matrix3 kProd;
+
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ kProd[iRow][iCol] = fScalar * rkMatrix.elt[iRow][iCol];
+ }
+ }
+
+ return kProd;
+}
+
+Matrix3 operator* (float fScalar, const Matrix3& rkMatrix) {
+ return (double)fScalar * rkMatrix;
+}
+
+
+Matrix3 operator* (int fScalar, const Matrix3& rkMatrix) {
+ return (double)fScalar * rkMatrix;
+}
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::transpose () const {
+ Matrix3 kTranspose;
+
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ kTranspose[iRow][iCol] = elt[iCol][iRow];
+ }
+ }
+
+ return kTranspose;
+}
+
+//----------------------------------------------------------------------------
+bool Matrix3::inverse (Matrix3& rkInverse, float fTolerance) const {
+ // Invert a 3x3 using cofactors. This is about 8 times faster than
+ // the Numerical Recipes code which uses Gaussian elimination.
+
+ rkInverse[0][0] = elt[1][1] * elt[2][2] -
+ elt[1][2] * elt[2][1];
+ rkInverse[0][1] = elt[0][2] * elt[2][1] -
+ elt[0][1] * elt[2][2];
+ rkInverse[0][2] = elt[0][1] * elt[1][2] -
+ elt[0][2] * elt[1][1];
+ rkInverse[1][0] = elt[1][2] * elt[2][0] -
+ elt[1][0] * elt[2][2];
+ rkInverse[1][1] = elt[0][0] * elt[2][2] -
+ elt[0][2] * elt[2][0];
+ rkInverse[1][2] = elt[0][2] * elt[1][0] -
+ elt[0][0] * elt[1][2];
+ rkInverse[2][0] = elt[1][0] * elt[2][1] -
+ elt[1][1] * elt[2][0];
+ rkInverse[2][1] = elt[0][1] * elt[2][0] -
+ elt[0][0] * elt[2][1];
+ rkInverse[2][2] = elt[0][0] * elt[1][1] -
+ elt[0][1] * elt[1][0];
+
+ float fDet =
+ elt[0][0] * rkInverse[0][0] +
+ elt[0][1] * rkInverse[1][0] +
+ elt[0][2] * rkInverse[2][0];
+
+ if ( G3D::abs(fDet) <= fTolerance )
+ return false;
+
+ float fInvDet = 1.0 / fDet;
+
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++)
+ rkInverse[iRow][iCol] *= fInvDet;
+ }
+
+ return true;
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::inverse (float fTolerance) const {
+ Matrix3 kInverse = Matrix3::zero();
+ inverse(kInverse, fTolerance);
+ return kInverse;
+}
+
+//----------------------------------------------------------------------------
+float Matrix3::determinant () const {
+ float fCofactor00 = elt[1][1] * elt[2][2] -
+ elt[1][2] * elt[2][1];
+ float fCofactor10 = elt[1][2] * elt[2][0] -
+ elt[1][0] * elt[2][2];
+ float fCofactor20 = elt[1][0] * elt[2][1] -
+ elt[1][1] * elt[2][0];
+
+ float fDet =
+ elt[0][0] * fCofactor00 +
+ elt[0][1] * fCofactor10 +
+ elt[0][2] * fCofactor20;
+
+ return fDet;
+}
+
+//----------------------------------------------------------------------------
+void Matrix3::bidiagonalize (Matrix3& kA, Matrix3& kL,
+ Matrix3& kR) {
+ float afV[3], afW[3];
+ float fLength, fSign, fT1, fInvT1, fT2;
+ bool bIdentity;
+
+ // map first column to (*,0,0)
+ fLength = sqrt(kA[0][0] * kA[0][0] + kA[1][0] * kA[1][0] +
+ kA[2][0] * kA[2][0]);
+
+ if ( fLength > 0.0 ) {
+ fSign = (kA[0][0] > 0.0 ? 1.0 : -1.0);
+ fT1 = kA[0][0] + fSign * fLength;
+ fInvT1 = 1.0 / fT1;
+ afV[1] = kA[1][0] * fInvT1;
+ afV[2] = kA[2][0] * fInvT1;
+
+ fT2 = -2.0 / (1.0 + afV[1] * afV[1] + afV[2] * afV[2]);
+ afW[0] = fT2 * (kA[0][0] + kA[1][0] * afV[1] + kA[2][0] * afV[2]);
+ afW[1] = fT2 * (kA[0][1] + kA[1][1] * afV[1] + kA[2][1] * afV[2]);
+ afW[2] = fT2 * (kA[0][2] + kA[1][2] * afV[1] + kA[2][2] * afV[2]);
+ kA[0][0] += afW[0];
+ kA[0][1] += afW[1];
+ kA[0][2] += afW[2];
+ kA[1][1] += afV[1] * afW[1];
+ kA[1][2] += afV[1] * afW[2];
+ kA[2][1] += afV[2] * afW[1];
+ kA[2][2] += afV[2] * afW[2];
+
+ kL[0][0] = 1.0 + fT2;
+ kL[0][1] = kL[1][0] = fT2 * afV[1];
+ kL[0][2] = kL[2][0] = fT2 * afV[2];
+ kL[1][1] = 1.0 + fT2 * afV[1] * afV[1];
+ kL[1][2] = kL[2][1] = fT2 * afV[1] * afV[2];
+ kL[2][2] = 1.0 + fT2 * afV[2] * afV[2];
+ bIdentity = false;
+ } else {
+ kL = Matrix3::identity();
+ bIdentity = true;
+ }
+
+ // map first row to (*,*,0)
+ fLength = sqrt(kA[0][1] * kA[0][1] + kA[0][2] * kA[0][2]);
+
+ if ( fLength > 0.0 ) {
+ fSign = (kA[0][1] > 0.0 ? 1.0 : -1.0);
+ fT1 = kA[0][1] + fSign * fLength;
+ afV[2] = kA[0][2] / fT1;
+
+ fT2 = -2.0 / (1.0 + afV[2] * afV[2]);
+ afW[0] = fT2 * (kA[0][1] + kA[0][2] * afV[2]);
+ afW[1] = fT2 * (kA[1][1] + kA[1][2] * afV[2]);
+ afW[2] = fT2 * (kA[2][1] + kA[2][2] * afV[2]);
+ kA[0][1] += afW[0];
+ kA[1][1] += afW[1];
+ kA[1][2] += afW[1] * afV[2];
+ kA[2][1] += afW[2];
+ kA[2][2] += afW[2] * afV[2];
+
+ kR[0][0] = 1.0;
+ kR[0][1] = kR[1][0] = 0.0;
+ kR[0][2] = kR[2][0] = 0.0;
+ kR[1][1] = 1.0 + fT2;
+ kR[1][2] = kR[2][1] = fT2 * afV[2];
+ kR[2][2] = 1.0 + fT2 * afV[2] * afV[2];
+ } else {
+ kR = Matrix3::identity();
+ }
+
+ // map second column to (*,*,0)
+ fLength = sqrt(kA[1][1] * kA[1][1] + kA[2][1] * kA[2][1]);
+
+ if ( fLength > 0.0 ) {
+ fSign = (kA[1][1] > 0.0 ? 1.0 : -1.0);
+ fT1 = kA[1][1] + fSign * fLength;
+ afV[2] = kA[2][1] / fT1;
+
+ fT2 = -2.0 / (1.0 + afV[2] * afV[2]);
+ afW[1] = fT2 * (kA[1][1] + kA[2][1] * afV[2]);
+ afW[2] = fT2 * (kA[1][2] + kA[2][2] * afV[2]);
+ kA[1][1] += afW[1];
+ kA[1][2] += afW[2];
+ kA[2][2] += afV[2] * afW[2];
+
+ float fA = 1.0 + fT2;
+ float fB = fT2 * afV[2];
+ float fC = 1.0 + fB * afV[2];
+
+ if ( bIdentity ) {
+ kL[0][0] = 1.0;
+ kL[0][1] = kL[1][0] = 0.0;
+ kL[0][2] = kL[2][0] = 0.0;
+ kL[1][1] = fA;
+ kL[1][2] = kL[2][1] = fB;
+ kL[2][2] = fC;
+ } else {
+ for (int iRow = 0; iRow < 3; iRow++) {
+ float fTmp0 = kL[iRow][1];
+ float fTmp1 = kL[iRow][2];
+ kL[iRow][1] = fA * fTmp0 + fB * fTmp1;
+ kL[iRow][2] = fB * fTmp0 + fC * fTmp1;
+ }
+ }
+ }
+}
+
+//----------------------------------------------------------------------------
+void Matrix3::golubKahanStep (Matrix3& kA, Matrix3& kL,
+ Matrix3& kR) {
+ float fT11 = kA[0][1] * kA[0][1] + kA[1][1] * kA[1][1];
+ float fT22 = kA[1][2] * kA[1][2] + kA[2][2] * kA[2][2];
+ float fT12 = kA[1][1] * kA[1][2];
+ float fTrace = fT11 + fT22;
+ float fDiff = fT11 - fT22;
+ float fDiscr = sqrt(fDiff * fDiff + 4.0 * fT12 * fT12);
+ float fRoot1 = 0.5 * (fTrace + fDiscr);
+ float fRoot2 = 0.5 * (fTrace - fDiscr);
+
+ // adjust right
+ float fY = kA[0][0] - (G3D::abs(fRoot1 - fT22) <=
+ G3D::abs(fRoot2 - fT22) ? fRoot1 : fRoot2);
+ float fZ = kA[0][1];
+ float fInvLength = 1.0 / sqrt(fY * fY + fZ * fZ);
+ float fSin = fZ * fInvLength;
+ float fCos = -fY * fInvLength;
+
+ float fTmp0 = kA[0][0];
+ float fTmp1 = kA[0][1];
+ kA[0][0] = fCos * fTmp0 - fSin * fTmp1;
+ kA[0][1] = fSin * fTmp0 + fCos * fTmp1;
+ kA[1][0] = -fSin * kA[1][1];
+ kA[1][1] *= fCos;
+
+ int iRow;
+
+ for (iRow = 0; iRow < 3; iRow++) {
+ fTmp0 = kR[0][iRow];
+ fTmp1 = kR[1][iRow];
+ kR[0][iRow] = fCos * fTmp0 - fSin * fTmp1;
+ kR[1][iRow] = fSin * fTmp0 + fCos * fTmp1;
+ }
+
+ // adjust left
+ fY = kA[0][0];
+
+ fZ = kA[1][0];
+
+ fInvLength = 1.0 / sqrt(fY * fY + fZ * fZ);
+
+ fSin = fZ * fInvLength;
+
+ fCos = -fY * fInvLength;
+
+ kA[0][0] = fCos * kA[0][0] - fSin * kA[1][0];
+
+ fTmp0 = kA[0][1];
+
+ fTmp1 = kA[1][1];
+
+ kA[0][1] = fCos * fTmp0 - fSin * fTmp1;
+
+ kA[1][1] = fSin * fTmp0 + fCos * fTmp1;
+
+ kA[0][2] = -fSin * kA[1][2];
+
+ kA[1][2] *= fCos;
+
+ int iCol;
+
+ for (iCol = 0; iCol < 3; iCol++) {
+ fTmp0 = kL[iCol][0];
+ fTmp1 = kL[iCol][1];
+ kL[iCol][0] = fCos * fTmp0 - fSin * fTmp1;
+ kL[iCol][1] = fSin * fTmp0 + fCos * fTmp1;
+ }
+
+ // adjust right
+ fY = kA[0][1];
+
+ fZ = kA[0][2];
+
+ fInvLength = 1.0 / sqrt(fY * fY + fZ * fZ);
+
+ fSin = fZ * fInvLength;
+
+ fCos = -fY * fInvLength;
+
+ kA[0][1] = fCos * kA[0][1] - fSin * kA[0][2];
+
+ fTmp0 = kA[1][1];
+
+ fTmp1 = kA[1][2];
+
+ kA[1][1] = fCos * fTmp0 - fSin * fTmp1;
+
+ kA[1][2] = fSin * fTmp0 + fCos * fTmp1;
+
+ kA[2][1] = -fSin * kA[2][2];
+
+ kA[2][2] *= fCos;
+
+ for (iRow = 0; iRow < 3; iRow++) {
+ fTmp0 = kR[1][iRow];
+ fTmp1 = kR[2][iRow];
+ kR[1][iRow] = fCos * fTmp0 - fSin * fTmp1;
+ kR[2][iRow] = fSin * fTmp0 + fCos * fTmp1;
+ }
+
+ // adjust left
+ fY = kA[1][1];
+
+ fZ = kA[2][1];
+
+ fInvLength = 1.0 / sqrt(fY * fY + fZ * fZ);
+
+ fSin = fZ * fInvLength;
+
+ fCos = -fY * fInvLength;
+
+ kA[1][1] = fCos * kA[1][1] - fSin * kA[2][1];
+
+ fTmp0 = kA[1][2];
+
+ fTmp1 = kA[2][2];
+
+ kA[1][2] = fCos * fTmp0 - fSin * fTmp1;
+
+ kA[2][2] = fSin * fTmp0 + fCos * fTmp1;
+
+ for (iCol = 0; iCol < 3; iCol++) {
+ fTmp0 = kL[iCol][1];
+ fTmp1 = kL[iCol][2];
+ kL[iCol][1] = fCos * fTmp0 - fSin * fTmp1;
+ kL[iCol][2] = fSin * fTmp0 + fCos * fTmp1;
+ }
+}
+
+//----------------------------------------------------------------------------
+void Matrix3::singularValueDecomposition (Matrix3& kL, Vector3& kS,
+ Matrix3& kR) const {
+ int iRow, iCol;
+
+ Matrix3 kA = *this;
+ bidiagonalize(kA, kL, kR);
+
+ for (int i = 0; i < ms_iSvdMaxIterations; i++) {
+ float fTmp, fTmp0, fTmp1;
+ float fSin0, fCos0, fTan0;
+ float fSin1, fCos1, fTan1;
+
+ bool bTest1 = (G3D::abs(kA[0][1]) <=
+ ms_fSvdEpsilon * (G3D::abs(kA[0][0]) + G3D::abs(kA[1][1])));
+ bool bTest2 = (G3D::abs(kA[1][2]) <=
+ ms_fSvdEpsilon * (G3D::abs(kA[1][1]) + G3D::abs(kA[2][2])));
+
+ if ( bTest1 ) {
+ if ( bTest2 ) {
+ kS[0] = kA[0][0];
+ kS[1] = kA[1][1];
+ kS[2] = kA[2][2];
+ break;
+ } else {
+ // 2x2 closed form factorization
+ fTmp = (kA[1][1] * kA[1][1] - kA[2][2] * kA[2][2] +
+ kA[1][2] * kA[1][2]) / (kA[1][2] * kA[2][2]);
+ fTan0 = 0.5 * (fTmp + sqrt(fTmp * fTmp + 4.0));
+ fCos0 = 1.0 / sqrt(1.0 + fTan0 * fTan0);
+ fSin0 = fTan0 * fCos0;
+
+ for (iCol = 0; iCol < 3; iCol++) {
+ fTmp0 = kL[iCol][1];
+ fTmp1 = kL[iCol][2];
+ kL[iCol][1] = fCos0 * fTmp0 - fSin0 * fTmp1;
+ kL[iCol][2] = fSin0 * fTmp0 + fCos0 * fTmp1;
+ }
+
+ fTan1 = (kA[1][2] - kA[2][2] * fTan0) / kA[1][1];
+ fCos1 = 1.0 / sqrt(1.0 + fTan1 * fTan1);
+ fSin1 = -fTan1 * fCos1;
+
+ for (iRow = 0; iRow < 3; iRow++) {
+ fTmp0 = kR[1][iRow];
+ fTmp1 = kR[2][iRow];
+ kR[1][iRow] = fCos1 * fTmp0 - fSin1 * fTmp1;
+ kR[2][iRow] = fSin1 * fTmp0 + fCos1 * fTmp1;
+ }
+
+ kS[0] = kA[0][0];
+ kS[1] = fCos0 * fCos1 * kA[1][1] -
+ fSin1 * (fCos0 * kA[1][2] - fSin0 * kA[2][2]);
+ kS[2] = fSin0 * fSin1 * kA[1][1] +
+ fCos1 * (fSin0 * kA[1][2] + fCos0 * kA[2][2]);
+ break;
+ }
+ } else {
+ if ( bTest2 ) {
+ // 2x2 closed form factorization
+ fTmp = (kA[0][0] * kA[0][0] + kA[1][1] * kA[1][1] -
+ kA[0][1] * kA[0][1]) / (kA[0][1] * kA[1][1]);
+ fTan0 = 0.5 * ( -fTmp + sqrt(fTmp * fTmp + 4.0));
+ fCos0 = 1.0 / sqrt(1.0 + fTan0 * fTan0);
+ fSin0 = fTan0 * fCos0;
+
+ for (iCol = 0; iCol < 3; iCol++) {
+ fTmp0 = kL[iCol][0];
+ fTmp1 = kL[iCol][1];
+ kL[iCol][0] = fCos0 * fTmp0 - fSin0 * fTmp1;
+ kL[iCol][1] = fSin0 * fTmp0 + fCos0 * fTmp1;
+ }
+
+ fTan1 = (kA[0][1] - kA[1][1] * fTan0) / kA[0][0];
+ fCos1 = 1.0 / sqrt(1.0 + fTan1 * fTan1);
+ fSin1 = -fTan1 * fCos1;
+
+ for (iRow = 0; iRow < 3; iRow++) {
+ fTmp0 = kR[0][iRow];
+ fTmp1 = kR[1][iRow];
+ kR[0][iRow] = fCos1 * fTmp0 - fSin1 * fTmp1;
+ kR[1][iRow] = fSin1 * fTmp0 + fCos1 * fTmp1;
+ }
+
+ kS[0] = fCos0 * fCos1 * kA[0][0] -
+ fSin1 * (fCos0 * kA[0][1] - fSin0 * kA[1][1]);
+ kS[1] = fSin0 * fSin1 * kA[0][0] +
+ fCos1 * (fSin0 * kA[0][1] + fCos0 * kA[1][1]);
+ kS[2] = kA[2][2];
+ break;
+ } else {
+ golubKahanStep(kA, kL, kR);
+ }
+ }
+ }
+
+ // positize diagonal
+ for (iRow = 0; iRow < 3; iRow++) {
+ if ( kS[iRow] < 0.0 ) {
+ kS[iRow] = -kS[iRow];
+
+ for (iCol = 0; iCol < 3; iCol++)
+ kR[iRow][iCol] = -kR[iRow][iCol];
+ }
+ }
+}
+
+//----------------------------------------------------------------------------
+void Matrix3::singularValueComposition (const Matrix3& kL,
+ const Vector3& kS, const Matrix3& kR) {
+ int iRow, iCol;
+ Matrix3 kTmp;
+
+ // product S*R
+ for (iRow = 0; iRow < 3; iRow++) {
+ for (iCol = 0; iCol < 3; iCol++)
+ kTmp[iRow][iCol] = kS[iRow] * kR[iRow][iCol];
+ }
+
+ // product L*S*R
+ for (iRow = 0; iRow < 3; iRow++) {
+ for (iCol = 0; iCol < 3; iCol++) {
+ elt[iRow][iCol] = 0.0;
+
+ for (int iMid = 0; iMid < 3; iMid++)
+ elt[iRow][iCol] += kL[iRow][iMid] * kTmp[iMid][iCol];
+ }
+ }
+}
+
+//----------------------------------------------------------------------------
+void Matrix3::orthonormalize () {
+ // Algorithm uses Gram-Schmidt orthogonalization. If 'this' matrix is
+ // M = [m0|m1|m2], then orthonormal output matrix is Q = [q0|q1|q2],
+ //
+ // q0 = m0/|m0|
+ // q1 = (m1-(q0*m1)q0)/|m1-(q0*m1)q0|
+ // q2 = (m2-(q0*m2)q0-(q1*m2)q1)/|m2-(q0*m2)q0-(q1*m2)q1|
+ //
+ // where |V| indicates length of vector V and A*B indicates dot
+ // product of vectors A and B.
+
+ // compute q0
+ float fInvLength = 1.0 / sqrt(elt[0][0] * elt[0][0]
+ + elt[1][0] * elt[1][0] +
+ elt[2][0] * elt[2][0]);
+
+ elt[0][0] *= fInvLength;
+ elt[1][0] *= fInvLength;
+ elt[2][0] *= fInvLength;
+
+ // compute q1
+ float fDot0 =
+ elt[0][0] * elt[0][1] +
+ elt[1][0] * elt[1][1] +
+ elt[2][0] * elt[2][1];
+
+ elt[0][1] -= fDot0 * elt[0][0];
+ elt[1][1] -= fDot0 * elt[1][0];
+ elt[2][1] -= fDot0 * elt[2][0];
+
+ fInvLength = 1.0 / sqrt(elt[0][1] * elt[0][1] +
+ elt[1][1] * elt[1][1] +
+ elt[2][1] * elt[2][1]);
+
+ elt[0][1] *= fInvLength;
+ elt[1][1] *= fInvLength;
+ elt[2][1] *= fInvLength;
+
+ // compute q2
+ float fDot1 =
+ elt[0][1] * elt[0][2] +
+ elt[1][1] * elt[1][2] +
+ elt[2][1] * elt[2][2];
+
+ fDot0 =
+ elt[0][0] * elt[0][2] +
+ elt[1][0] * elt[1][2] +
+ elt[2][0] * elt[2][2];
+
+ elt[0][2] -= fDot0 * elt[0][0] + fDot1 * elt[0][1];
+ elt[1][2] -= fDot0 * elt[1][0] + fDot1 * elt[1][1];
+ elt[2][2] -= fDot0 * elt[2][0] + fDot1 * elt[2][1];
+
+ fInvLength = 1.0 / sqrt(elt[0][2] * elt[0][2] +
+ elt[1][2] * elt[1][2] +
+ elt[2][2] * elt[2][2]);
+
+ elt[0][2] *= fInvLength;
+ elt[1][2] *= fInvLength;
+ elt[2][2] *= fInvLength;
+}
+
+//----------------------------------------------------------------------------
+void Matrix3::qDUDecomposition (Matrix3& kQ,
+ Vector3& kD, Vector3& kU) const {
+ // Factor M = QR = QDU where Q is orthogonal, D is diagonal,
+ // and U is upper triangular with ones on its diagonal. Algorithm uses
+ // Gram-Schmidt orthogonalization (the QR algorithm).
+ //
+ // If M = [ m0 | m1 | m2 ] and Q = [ q0 | q1 | q2 ], then
+ //
+ // q0 = m0/|m0|
+ // q1 = (m1-(q0*m1)q0)/|m1-(q0*m1)q0|
+ // q2 = (m2-(q0*m2)q0-(q1*m2)q1)/|m2-(q0*m2)q0-(q1*m2)q1|
+ //
+ // where |V| indicates length of vector V and A*B indicates dot
+ // product of vectors A and B. The matrix R has entries
+ //
+ // r00 = q0*m0 r01 = q0*m1 r02 = q0*m2
+ // r10 = 0 r11 = q1*m1 r12 = q1*m2
+ // r20 = 0 r21 = 0 r22 = q2*m2
+ //
+ // so D = diag(r00,r11,r22) and U has entries u01 = r01/r00,
+ // u02 = r02/r00, and u12 = r12/r11.
+
+ // Q = rotation
+ // D = scaling
+ // U = shear
+
+ // D stores the three diagonal entries r00, r11, r22
+ // U stores the entries U[0] = u01, U[1] = u02, U[2] = u12
+
+ // build orthogonal matrix Q
+ float fInvLength = 1.0 / sqrt(elt[0][0] * elt[0][0]
+ + elt[1][0] * elt[1][0] +
+ elt[2][0] * elt[2][0]);
+ kQ[0][0] = elt[0][0] * fInvLength;
+ kQ[1][0] = elt[1][0] * fInvLength;
+ kQ[2][0] = elt[2][0] * fInvLength;
+
+ float fDot = kQ[0][0] * elt[0][1] + kQ[1][0] * elt[1][1] +
+ kQ[2][0] * elt[2][1];
+ kQ[0][1] = elt[0][1] - fDot * kQ[0][0];
+ kQ[1][1] = elt[1][1] - fDot * kQ[1][0];
+ kQ[2][1] = elt[2][1] - fDot * kQ[2][0];
+ fInvLength = 1.0 / sqrt(kQ[0][1] * kQ[0][1] + kQ[1][1] * kQ[1][1] +
+ kQ[2][1] * kQ[2][1]);
+ kQ[0][1] *= fInvLength;
+ kQ[1][1] *= fInvLength;
+ kQ[2][1] *= fInvLength;
+
+ fDot = kQ[0][0] * elt[0][2] + kQ[1][0] * elt[1][2] +
+ kQ[2][0] * elt[2][2];
+ kQ[0][2] = elt[0][2] - fDot * kQ[0][0];
+ kQ[1][2] = elt[1][2] - fDot * kQ[1][0];
+ kQ[2][2] = elt[2][2] - fDot * kQ[2][0];
+ fDot = kQ[0][1] * elt[0][2] + kQ[1][1] * elt[1][2] +
+ kQ[2][1] * elt[2][2];
+ kQ[0][2] -= fDot * kQ[0][1];
+ kQ[1][2] -= fDot * kQ[1][1];
+ kQ[2][2] -= fDot * kQ[2][1];
+ fInvLength = 1.0 / sqrt(kQ[0][2] * kQ[0][2] + kQ[1][2] * kQ[1][2] +
+ kQ[2][2] * kQ[2][2]);
+ kQ[0][2] *= fInvLength;
+ kQ[1][2] *= fInvLength;
+ kQ[2][2] *= fInvLength;
+
+ // guarantee that orthogonal matrix has determinant 1 (no reflections)
+ float fDet = kQ[0][0] * kQ[1][1] * kQ[2][2] + kQ[0][1] * kQ[1][2] * kQ[2][0] +
+ kQ[0][2] * kQ[1][0] * kQ[2][1] - kQ[0][2] * kQ[1][1] * kQ[2][0] -
+ kQ[0][1] * kQ[1][0] * kQ[2][2] - kQ[0][0] * kQ[1][2] * kQ[2][1];
+
+ if ( fDet < 0.0 ) {
+ for (int iRow = 0; iRow < 3; iRow++)
+ for (int iCol = 0; iCol < 3; iCol++)
+ kQ[iRow][iCol] = -kQ[iRow][iCol];
+ }
+
+ // build "right" matrix R
+ Matrix3 kR;
+
+ kR[0][0] = kQ[0][0] * elt[0][0] + kQ[1][0] * elt[1][0] +
+ kQ[2][0] * elt[2][0];
+
+ kR[0][1] = kQ[0][0] * elt[0][1] + kQ[1][0] * elt[1][1] +
+ kQ[2][0] * elt[2][1];
+
+ kR[1][1] = kQ[0][1] * elt[0][1] + kQ[1][1] * elt[1][1] +
+ kQ[2][1] * elt[2][1];
+
+ kR[0][2] = kQ[0][0] * elt[0][2] + kQ[1][0] * elt[1][2] +
+ kQ[2][0] * elt[2][2];
+
+ kR[1][2] = kQ[0][1] * elt[0][2] + kQ[1][1] * elt[1][2] +
+ kQ[2][1] * elt[2][2];
+
+ kR[2][2] = kQ[0][2] * elt[0][2] + kQ[1][2] * elt[1][2] +
+ kQ[2][2] * elt[2][2];
+
+ // the scaling component
+ kD[0] = kR[0][0];
+
+ kD[1] = kR[1][1];
+
+ kD[2] = kR[2][2];
+
+ // the shear component
+ float fInvD0 = 1.0 / kD[0];
+
+ kU[0] = kR[0][1] * fInvD0;
+
+ kU[1] = kR[0][2] * fInvD0;
+
+ kU[2] = kR[1][2] / kD[1];
+}
+
+//----------------------------------------------------------------------------
+void Matrix3::polarDecomposition(Matrix3 &R, Matrix3 &S) const{
+ /*
+ Polar decomposition of a matrix. Based on pseudocode from
+ Nicholas J Higham, "Computing the Polar Decomposition -- with
+ Applications Siam Journal of Science and Statistical Computing, Vol 7, No. 4,
+ October 1986.
+
+ Decomposes A into R*S, where R is orthogonal and S is symmetric.
+
+ Ken Shoemake's "Matrix animation and polar decomposition"
+ in Proceedings of the conference on Graphics interface '92
+ seems to be better known in the world of graphics, but Higham's version
+ uses a scaling constant that can lead to faster convergence than
+ Shoemake's when the initial matrix is far from orthogonal.
+ */
+
+ Matrix3 X = *this;
+ Matrix3 tmp = X.inverse();
+ Matrix3 Xit = tmp.transpose();
+ int iter = 0;
+
+ const int MAX_ITERS = 100;
+
+ const double eps = 50 * std::numeric_limits<float>::epsilon();
+ const float BigEps = 50 * eps;
+
+ /* Higham suggests using OneNorm(Xit-X) < eps * OneNorm(X)
+ * as the convergence criterion, but OneNorm(X) should quickly
+ * settle down to something between 1 and 1.7, so just comparing
+ * with eps seems sufficient.
+ *--------------------------------------------------------------- */
+
+ double resid = X.diffOneNorm(Xit);
+ while (resid > eps && iter < MAX_ITERS) {
+
+ tmp = X.inverse();
+ Xit = tmp.transpose();
+
+ if (resid < BigEps) {
+ // close enough use simple iteration
+ X += Xit;
+ X *= 0.5f;
+ }
+ else {
+ // not close to convergence, compute acceleration factor
+ float gamma = sqrt( sqrt(
+ (Xit.l1Norm()* Xit.lInfNorm())/(X.l1Norm()*X.lInfNorm()) ) );
+
+ X *= 0.5f * gamma;
+ tmp = Xit;
+ tmp *= 0.5f / gamma;
+ X += tmp;
+ }
+
+ resid = X.diffOneNorm(Xit);
+ iter++;
+ }
+
+ R = X;
+ tmp = R.transpose();
+
+ S = tmp * (*this);
+
+ // S := (S + S^t)/2 one more time to make sure it is symmetric
+ tmp = S.transpose();
+
+ S += tmp;
+ S *= 0.5f;
+
+#ifdef G3D_DEBUG
+ // Check iter limit
+ assert(iter < MAX_ITERS);
+
+ // Check A = R*S
+ tmp = R*S;
+ resid = tmp.diffOneNorm(*this);
+ assert(resid < eps);
+
+ // Check R is orthogonal
+ tmp = R*R.transpose();
+ resid = tmp.diffOneNorm(Matrix3::identity());
+ assert(resid < eps);
+
+ // Check that S is symmetric
+ tmp = S.transpose();
+ resid = tmp.diffOneNorm(S);
+ assert(resid < eps);
+#endif
+}
+
+//----------------------------------------------------------------------------
+float Matrix3::maxCubicRoot (float afCoeff[3]) {
+ // Spectral norm is for A^T*A, so characteristic polynomial
+ // P(x) = c[0]+c[1]*x+c[2]*x^2+x^3 has three positive float roots.
+ // This yields the assertions c[0] < 0 and c[2]*c[2] >= 3*c[1].
+
+ // quick out for uniform scale (triple root)
+ const float fOneThird = 1.0f / 3.0f;
+ const float fEpsilon = 1e-06f;
+ float fDiscr = afCoeff[2] * afCoeff[2] - 3.0f * afCoeff[1];
+
+ if ( fDiscr <= fEpsilon )
+ return -fOneThird*afCoeff[2];
+
+ // Compute an upper bound on roots of P(x). This assumes that A^T*A
+ // has been scaled by its largest entry.
+ float fX = 1.0f;
+
+ float fPoly = afCoeff[0] + fX * (afCoeff[1] + fX * (afCoeff[2] + fX));
+
+ if ( fPoly < 0.0f ) {
+ // uses a matrix norm to find an upper bound on maximum root
+ fX = G3D::abs(afCoeff[0]);
+ float fTmp = 1.0 + G3D::abs(afCoeff[1]);
+
+ if ( fTmp > fX )
+ fX = fTmp;
+
+ fTmp = 1.0 + G3D::abs(afCoeff[2]);
+
+ if ( fTmp > fX )
+ fX = fTmp;
+ }
+
+ // Newton's method to find root
+ float fTwoC2 = 2.0f * afCoeff[2];
+
+ for (int i = 0; i < 16; i++) {
+ fPoly = afCoeff[0] + fX * (afCoeff[1] + fX * (afCoeff[2] + fX));
+
+ if ( G3D::abs(fPoly) <= fEpsilon )
+ return fX;
+
+ float fDeriv = afCoeff[1] + fX * (fTwoC2 + 3.0f * fX);
+
+ fX -= fPoly / fDeriv;
+ }
+
+ return fX;
+}
+
+//----------------------------------------------------------------------------
+float Matrix3::spectralNorm () const {
+ Matrix3 kP;
+ int iRow, iCol;
+ float fPmax = 0.0;
+
+ for (iRow = 0; iRow < 3; iRow++) {
+ for (iCol = 0; iCol < 3; iCol++) {
+ kP[iRow][iCol] = 0.0;
+
+ for (int iMid = 0; iMid < 3; iMid++) {
+ kP[iRow][iCol] +=
+ elt[iMid][iRow] * elt[iMid][iCol];
+ }
+
+ if ( kP[iRow][iCol] > fPmax )
+ fPmax = kP[iRow][iCol];
+ }
+ }
+
+ float fInvPmax = 1.0 / fPmax;
+
+ for (iRow = 0; iRow < 3; iRow++) {
+ for (iCol = 0; iCol < 3; iCol++)
+ kP[iRow][iCol] *= fInvPmax;
+ }
+
+ float afCoeff[3];
+ afCoeff[0] = -(kP[0][0] * (kP[1][1] * kP[2][2] - kP[1][2] * kP[2][1]) +
+ kP[0][1] * (kP[2][0] * kP[1][2] - kP[1][0] * kP[2][2]) +
+ kP[0][2] * (kP[1][0] * kP[2][1] - kP[2][0] * kP[1][1]));
+ afCoeff[1] = kP[0][0] * kP[1][1] - kP[0][1] * kP[1][0] +
+ kP[0][0] * kP[2][2] - kP[0][2] * kP[2][0] +
+ kP[1][1] * kP[2][2] - kP[1][2] * kP[2][1];
+ afCoeff[2] = -(kP[0][0] + kP[1][1] + kP[2][2]);
+
+ float fRoot = maxCubicRoot(afCoeff);
+ float fNorm = sqrt(fPmax * fRoot);
+ return fNorm;
+}
+
+//----------------------------------------------------------------------------
+float Matrix3::squaredFrobeniusNorm() const {
+ float norm2 = 0;
+ const float* e = &elt[0][0];
+
+ for (int i = 0; i < 9; ++i){
+ norm2 += (*e) * (*e);
+ }
+
+ return norm2;
+}
+
+//----------------------------------------------------------------------------
+float Matrix3::frobeniusNorm() const {
+ return sqrtf(squaredFrobeniusNorm());
+}
+
+//----------------------------------------------------------------------------
+float Matrix3::l1Norm() const {
+ // The one norm of a matrix is the max column sum in absolute value.
+ float oneNorm = 0;
+ for (int c = 0; c < 3; ++c) {
+
+ float f = fabs(elt[0][c])+ fabs(elt[1][c]) + fabs(elt[2][c]);
+
+ if (f > oneNorm) {
+ oneNorm = f;
+ }
+ }
+ return oneNorm;
+}
+
+//----------------------------------------------------------------------------
+float Matrix3::lInfNorm() const {
+ // The infinity norm of a matrix is the max row sum in absolute value.
+ float infNorm = 0;
+
+ for (int r = 0; r < 3; ++r) {
+
+ float f = fabs(elt[r][0]) + fabs(elt[r][1])+ fabs(elt[r][2]);
+
+ if (f > infNorm) {
+ infNorm = f;
+ }
+ }
+ return infNorm;
+}
+
+//----------------------------------------------------------------------------
+float Matrix3::diffOneNorm(const Matrix3 &y) const{
+ float oneNorm = 0;
+
+ for (int c = 0; c < 3; ++c){
+
+ float f = fabs(elt[0][c] - y[0][c]) + fabs(elt[1][c] - y[1][c])
+ + fabs(elt[2][c] - y[2][c]);
+
+ if (f > oneNorm) {
+ oneNorm = f;
+ }
+ }
+ return oneNorm;
+}
+
+//----------------------------------------------------------------------------
+void Matrix3::toAxisAngle (Vector3& rkAxis, float& rfRadians) const {
+ //
+ // Let (x,y,z) be the unit-length axis and let A be an angle of rotation.
+ // The rotation matrix is R = I + sin(A)*P + (1-cos(A))*P^2 (Rodrigues' formula) where
+ // I is the identity and
+ //
+ // +- -+
+ // P = | 0 -z +y |
+ // | +z 0 -x |
+ // | -y +x 0 |
+ // +- -+
+ //
+ // If A > 0, R represents a counterclockwise rotation about the axis in
+ // the sense of looking from the tip of the axis vector towards the
+ // origin. Some algebra will show that
+ //
+ // cos(A) = (trace(R)-1)/2 and R - R^t = 2*sin(A)*P
+ //
+ // In the event that A = pi, R-R^t = 0 which prevents us from extracting
+ // the axis through P. Instead note that R = I+2*P^2 when A = pi, so
+ // P^2 = (R-I)/2. The diagonal entries of P^2 are x^2-1, y^2-1, and
+ // z^2-1. We can solve these for axis (x,y,z). Because the angle is pi,
+ // it does not matter which sign you choose on the square roots.
+
+ float fTrace = elt[0][0] + elt[1][1] + elt[2][2];
+ float fCos = 0.5f * (fTrace - 1.0f);
+ rfRadians = G3D::aCos(fCos); // in [0,PI]
+
+ if ( rfRadians > 0.0 ) {
+ if ( rfRadians < pi() ) {
+ rkAxis.x = elt[2][1] - elt[1][2];
+ rkAxis.y = elt[0][2] - elt[2][0];
+ rkAxis.z = elt[1][0] - elt[0][1];
+ rkAxis.unitize();
+ } else {
+ // angle is PI
+ float fHalfInverse;
+
+ if ( elt[0][0] >= elt[1][1] ) {
+ // r00 >= r11
+ if ( elt[0][0] >= elt[2][2] ) {
+ // r00 is maximum diagonal term
+ rkAxis.x = 0.5 * sqrt(elt[0][0] -
+ elt[1][1] - elt[2][2] + 1.0);
+ fHalfInverse = 0.5 / rkAxis.x;
+ rkAxis.y = fHalfInverse * elt[0][1];
+ rkAxis.z = fHalfInverse * elt[0][2];
+ } else {
+ // r22 is maximum diagonal term
+ rkAxis.z = 0.5 * sqrt(elt[2][2] -
+ elt[0][0] - elt[1][1] + 1.0);
+ fHalfInverse = 0.5 / rkAxis.z;
+ rkAxis.x = fHalfInverse * elt[0][2];
+ rkAxis.y = fHalfInverse * elt[1][2];
+ }
+ } else {
+ // r11 > r00
+ if ( elt[1][1] >= elt[2][2] ) {
+ // r11 is maximum diagonal term
+ rkAxis.y = 0.5 * sqrt(elt[1][1] -
+ elt[0][0] - elt[2][2] + 1.0);
+ fHalfInverse = 0.5 / rkAxis.y;
+ rkAxis.x = fHalfInverse * elt[0][1];
+ rkAxis.z = fHalfInverse * elt[1][2];
+ } else {
+ // r22 is maximum diagonal term
+ rkAxis.z = 0.5 * sqrt(elt[2][2] -
+ elt[0][0] - elt[1][1] + 1.0);
+ fHalfInverse = 0.5 / rkAxis.z;
+ rkAxis.x = fHalfInverse * elt[0][2];
+ rkAxis.y = fHalfInverse * elt[1][2];
+ }
+ }
+ }
+ } else {
+ // The angle is 0 and the matrix is the identity. Any axis will
+ // work, so just use the x-axis.
+ rkAxis.x = 1.0;
+ rkAxis.y = 0.0;
+ rkAxis.z = 0.0;
+ }
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::fromAxisAngle (const Vector3& _axis, float fRadians) {
+ Vector3 axis = _axis.direction();
+
+ Matrix3 m;
+ float fCos = cos(fRadians);
+ float fSin = sin(fRadians);
+ float fOneMinusCos = 1.0 - fCos;
+ float fX2 = square(axis.x);
+ float fY2 = square(axis.y);
+ float fZ2 = square(axis.z);
+ float fXYM = axis.x * axis.y * fOneMinusCos;
+ float fXZM = axis.x * axis.z * fOneMinusCos;
+ float fYZM = axis.y * axis.z * fOneMinusCos;
+ float fXSin = axis.x * fSin;
+ float fYSin = axis.y * fSin;
+ float fZSin = axis.z * fSin;
+
+ m.elt[0][0] = fX2 * fOneMinusCos + fCos;
+ m.elt[0][1] = fXYM - fZSin;
+ m.elt[0][2] = fXZM + fYSin;
+
+ m.elt[1][0] = fXYM + fZSin;
+ m.elt[1][1] = fY2 * fOneMinusCos + fCos;
+ m.elt[1][2] = fYZM - fXSin;
+
+ m.elt[2][0] = fXZM - fYSin;
+ m.elt[2][1] = fYZM + fXSin;
+ m.elt[2][2] = fZ2 * fOneMinusCos + fCos;
+
+ return m;
+}
+
+//----------------------------------------------------------------------------
+bool Matrix3::toEulerAnglesXYZ (float& rfXAngle, float& rfYAngle,
+ float& rfZAngle) const {
+ // rot = cy*cz -cy*sz sy
+ // cz*sx*sy+cx*sz cx*cz-sx*sy*sz -cy*sx
+ // -cx*cz*sy+sx*sz cz*sx+cx*sy*sz cx*cy
+
+ if ( elt[0][2] < 1.0f ) {
+ if ( elt[0][2] > -1.0f ) {
+ rfXAngle = G3D::aTan2( -elt[1][2], elt[2][2]);
+ rfYAngle = (float) G3D::aSin(elt[0][2]);
+ rfZAngle = G3D::aTan2( -elt[0][1], elt[0][0]);
+ return true;
+ } else {
+ // WARNING. Not unique. XA - ZA = -atan2(r10,r11)
+ rfXAngle = -G3D::aTan2(elt[1][0], elt[1][1]);
+ rfYAngle = -(float)halfPi();
+ rfZAngle = 0.0f;
+ return false;
+ }
+ } else {
+ // WARNING. Not unique. XAngle + ZAngle = atan2(r10,r11)
+ rfXAngle = G3D::aTan2(elt[1][0], elt[1][1]);
+ rfYAngle = (float)halfPi();
+ rfZAngle = 0.0f;
+ return false;
+ }
+}
+
+//----------------------------------------------------------------------------
+bool Matrix3::toEulerAnglesXZY (float& rfXAngle, float& rfZAngle,
+ float& rfYAngle) const {
+ // rot = cy*cz -sz cz*sy
+ // sx*sy+cx*cy*sz cx*cz -cy*sx+cx*sy*sz
+ // -cx*sy+cy*sx*sz cz*sx cx*cy+sx*sy*sz
+
+ if ( elt[0][1] < 1.0f ) {
+ if ( elt[0][1] > -1.0f ) {
+ rfXAngle = G3D::aTan2(elt[2][1], elt[1][1]);
+ rfZAngle = (float) asin( -elt[0][1]);
+ rfYAngle = G3D::aTan2(elt[0][2], elt[0][0]);
+ return true;
+ } else {
+ // WARNING. Not unique. XA - YA = atan2(r20,r22)
+ rfXAngle = G3D::aTan2(elt[2][0], elt[2][2]);
+ rfZAngle = (float)halfPi();
+ rfYAngle = 0.0;
+ return false;
+ }
+ } else {
+ // WARNING. Not unique. XA + YA = atan2(-r20,r22)
+ rfXAngle = G3D::aTan2( -elt[2][0], elt[2][2]);
+ rfZAngle = -(float)halfPi();
+ rfYAngle = 0.0f;
+ return false;
+ }
+}
+
+//----------------------------------------------------------------------------
+bool Matrix3::toEulerAnglesYXZ (float& rfYAngle, float& rfXAngle,
+ float& rfZAngle) const {
+ // rot = cy*cz+sx*sy*sz cz*sx*sy-cy*sz cx*sy
+ // cx*sz cx*cz -sx
+ // -cz*sy+cy*sx*sz cy*cz*sx+sy*sz cx*cy
+
+ if ( elt[1][2] < 1.0 ) {
+ if ( elt[1][2] > -1.0 ) {
+ rfYAngle = G3D::aTan2(elt[0][2], elt[2][2]);
+ rfXAngle = (float) asin( -elt[1][2]);
+ rfZAngle = G3D::aTan2(elt[1][0], elt[1][1]);
+ return true;
+ } else {
+ // WARNING. Not unique. YA - ZA = atan2(r01,r00)
+ rfYAngle = G3D::aTan2(elt[0][1], elt[0][0]);
+ rfXAngle = (float)halfPi();
+ rfZAngle = 0.0;
+ return false;
+ }
+ } else {
+ // WARNING. Not unique. YA + ZA = atan2(-r01,r00)
+ rfYAngle = G3D::aTan2( -elt[0][1], elt[0][0]);
+ rfXAngle = -(float)halfPi();
+ rfZAngle = 0.0f;
+ return false;
+ }
+}
+
+//----------------------------------------------------------------------------
+bool Matrix3::toEulerAnglesYZX (float& rfYAngle, float& rfZAngle,
+ float& rfXAngle) const {
+ // rot = cy*cz sx*sy-cx*cy*sz cx*sy+cy*sx*sz
+ // sz cx*cz -cz*sx
+ // -cz*sy cy*sx+cx*sy*sz cx*cy-sx*sy*sz
+
+ if ( elt[1][0] < 1.0 ) {
+ if ( elt[1][0] > -1.0 ) {
+ rfYAngle = G3D::aTan2( -elt[2][0], elt[0][0]);
+ rfZAngle = (float) asin(elt[1][0]);
+ rfXAngle = G3D::aTan2( -elt[1][2], elt[1][1]);
+ return true;
+ } else {
+ // WARNING. Not unique. YA - XA = -atan2(r21,r22);
+ rfYAngle = -G3D::aTan2(elt[2][1], elt[2][2]);
+ rfZAngle = -(float)halfPi();
+ rfXAngle = 0.0;
+ return false;
+ }
+ } else {
+ // WARNING. Not unique. YA + XA = atan2(r21,r22)
+ rfYAngle = G3D::aTan2(elt[2][1], elt[2][2]);
+ rfZAngle = (float)halfPi();
+ rfXAngle = 0.0f;
+ return false;
+ }
+}
+
+//----------------------------------------------------------------------------
+bool Matrix3::toEulerAnglesZXY (float& rfZAngle, float& rfXAngle,
+ float& rfYAngle) const {
+ // rot = cy*cz-sx*sy*sz -cx*sz cz*sy+cy*sx*sz
+ // cz*sx*sy+cy*sz cx*cz -cy*cz*sx+sy*sz
+ // -cx*sy sx cx*cy
+
+ if ( elt[2][1] < 1.0 ) {
+ if ( elt[2][1] > -1.0 ) {
+ rfZAngle = G3D::aTan2( -elt[0][1], elt[1][1]);
+ rfXAngle = (float) asin(elt[2][1]);
+ rfYAngle = G3D::aTan2( -elt[2][0], elt[2][2]);
+ return true;
+ } else {
+ // WARNING. Not unique. ZA - YA = -atan(r02,r00)
+ rfZAngle = -G3D::aTan2(elt[0][2], elt[0][0]);
+ rfXAngle = -(float)halfPi();
+ rfYAngle = 0.0f;
+ return false;
+ }
+ } else {
+ // WARNING. Not unique. ZA + YA = atan2(r02,r00)
+ rfZAngle = G3D::aTan2(elt[0][2], elt[0][0]);
+ rfXAngle = (float)halfPi();
+ rfYAngle = 0.0f;
+ return false;
+ }
+}
+
+//----------------------------------------------------------------------------
+bool Matrix3::toEulerAnglesZYX (float& rfZAngle, float& rfYAngle,
+ float& rfXAngle) const {
+ // rot = cy*cz cz*sx*sy-cx*sz cx*cz*sy+sx*sz
+ // cy*sz cx*cz+sx*sy*sz -cz*sx+cx*sy*sz
+ // -sy cy*sx cx*cy
+
+ if ( elt[2][0] < 1.0 ) {
+ if ( elt[2][0] > -1.0 ) {
+ rfZAngle = atan2f(elt[1][0], elt[0][0]);
+ rfYAngle = asinf(-(double)elt[2][1]);
+ rfXAngle = atan2f(elt[2][1], elt[2][2]);
+ return true;
+ } else {
+ // WARNING. Not unique. ZA - XA = -atan2(r01,r02)
+ rfZAngle = -G3D::aTan2(elt[0][1], elt[0][2]);
+ rfYAngle = (float)halfPi();
+ rfXAngle = 0.0f;
+ return false;
+ }
+ } else {
+ // WARNING. Not unique. ZA + XA = atan2(-r01,-r02)
+ rfZAngle = G3D::aTan2( -elt[0][1], -elt[0][2]);
+ rfYAngle = -(float)halfPi();
+ rfXAngle = 0.0f;
+ return false;
+ }
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::fromEulerAnglesXYZ (float fYAngle, float fPAngle,
+ float fRAngle) {
+ float fCos, fSin;
+
+ fCos = cosf(fYAngle);
+ fSin = sinf(fYAngle);
+ Matrix3 kXMat(1.0f, 0.0f, 0.0f, 0.0f, fCos, -fSin, 0.0, fSin, fCos);
+
+ fCos = cosf(fPAngle);
+ fSin = sinf(fPAngle);
+ Matrix3 kYMat(fCos, 0.0f, fSin, 0.0f, 1.0f, 0.0f, -fSin, 0.0f, fCos);
+
+ fCos = cosf(fRAngle);
+ fSin = sinf(fRAngle);
+ Matrix3 kZMat(fCos, -fSin, 0.0f, fSin, fCos, 0.0f, 0.0f, 0.0f, 1.0f);
+
+ return kXMat * (kYMat * kZMat);
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::fromEulerAnglesXZY (float fYAngle, float fPAngle,
+ float fRAngle) {
+
+ float fCos, fSin;
+
+ fCos = cosf(fYAngle);
+ fSin = sinf(fYAngle);
+ Matrix3 kXMat(1.0, 0.0, 0.0, 0.0, fCos, -fSin, 0.0, fSin, fCos);
+
+ fCos = cosf(fPAngle);
+ fSin = sinf(fPAngle);
+ Matrix3 kZMat(fCos, -fSin, 0.0, fSin, fCos, 0.0, 0.0, 0.0, 1.0);
+
+ fCos = cosf(fRAngle);
+ fSin = sinf(fRAngle);
+ Matrix3 kYMat(fCos, 0.0, fSin, 0.0, 1.0, 0.0, -fSin, 0.0, fCos);
+
+ return kXMat * (kZMat * kYMat);
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::fromEulerAnglesYXZ(
+ float fYAngle,
+ float fPAngle,
+ float fRAngle) {
+
+ float fCos, fSin;
+
+ fCos = cos(fYAngle);
+ fSin = sin(fYAngle);
+ Matrix3 kYMat(fCos, 0.0f, fSin, 0.0f, 1.0f, 0.0f, -fSin, 0.0f, fCos);
+
+ fCos = cos(fPAngle);
+ fSin = sin(fPAngle);
+ Matrix3 kXMat(1.0f, 0.0f, 0.0f, 0.0f, fCos, -fSin, 0.0f, fSin, fCos);
+
+ fCos = cos(fRAngle);
+ fSin = sin(fRAngle);
+ Matrix3 kZMat(fCos, -fSin, 0.0f, fSin, fCos, 0.0f, 0.0f, 0.0f, 1.0f);
+
+ return kYMat * (kXMat * kZMat);
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::fromEulerAnglesYZX(
+ float fYAngle,
+ float fPAngle,
+ float fRAngle) {
+
+ float fCos, fSin;
+
+ fCos = cos(fYAngle);
+ fSin = sin(fYAngle);
+ Matrix3 kYMat(fCos, 0.0f, fSin, 0.0f, 1.0f, 0.0f, -fSin, 0.0f, fCos);
+
+ fCos = cos(fPAngle);
+ fSin = sin(fPAngle);
+ Matrix3 kZMat(fCos, -fSin, 0.0f, fSin, fCos, 0.0f, 0.0f, 0.0f, 1.0f);
+
+ fCos = cos(fRAngle);
+ fSin = sin(fRAngle);
+ Matrix3 kXMat(1.0f, 0.0f, 0.0f, 0.0f, fCos, -fSin, 0.0f, fSin, fCos);
+
+ return kYMat * (kZMat * kXMat);
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::fromEulerAnglesZXY (float fYAngle, float fPAngle,
+ float fRAngle) {
+ float fCos, fSin;
+
+ fCos = cos(fYAngle);
+ fSin = sin(fYAngle);
+ Matrix3 kZMat(fCos, -fSin, 0.0, fSin, fCos, 0.0, 0.0, 0.0, 1.0);
+
+ fCos = cos(fPAngle);
+ fSin = sin(fPAngle);
+ Matrix3 kXMat(1.0, 0.0, 0.0, 0.0, fCos, -fSin, 0.0, fSin, fCos);
+
+ fCos = cos(fRAngle);
+ fSin = sin(fRAngle);
+ Matrix3 kYMat(fCos, 0.0, fSin, 0.0, 1.0, 0.0, -fSin, 0.0, fCos);
+
+ return kZMat * (kXMat * kYMat);
+}
+
+//----------------------------------------------------------------------------
+Matrix3 Matrix3::fromEulerAnglesZYX (float fYAngle, float fPAngle,
+ float fRAngle) {
+ float fCos, fSin;
+
+ fCos = cos(fYAngle);
+ fSin = sin(fYAngle);
+ Matrix3 kZMat(fCos, -fSin, 0.0, fSin, fCos, 0.0, 0.0, 0.0, 1.0);
+
+ fCos = cos(fPAngle);
+ fSin = sin(fPAngle);
+ Matrix3 kYMat(fCos, 0.0, fSin, 0.0, 1.0, 0.0, -fSin, 0.0, fCos);
+
+ fCos = cos(fRAngle);
+ fSin = sin(fRAngle);
+ Matrix3 kXMat(1.0, 0.0, 0.0, 0.0, fCos, -fSin, 0.0, fSin, fCos);
+
+ return kZMat * (kYMat * kXMat);
+}
+
+//----------------------------------------------------------------------------
+void Matrix3::tridiagonal (float afDiag[3], float afSubDiag[3]) {
+ // Householder reduction T = Q^t M Q
+ // Input:
+ // mat, symmetric 3x3 matrix M
+ // Output:
+ // mat, orthogonal matrix Q
+ // diag, diagonal entries of T
+ // subd, subdiagonal entries of T (T is symmetric)
+
+ float fA = elt[0][0];
+ float fB = elt[0][1];
+ float fC = elt[0][2];
+ float fD = elt[1][1];
+ float fE = elt[1][2];
+ float fF = elt[2][2];
+
+ afDiag[0] = fA;
+ afSubDiag[2] = 0.0;
+
+ if ( G3D::abs(fC) >= EPSILON ) {
+ float fLength = sqrt(fB * fB + fC * fC);
+ float fInvLength = 1.0 / fLength;
+ fB *= fInvLength;
+ fC *= fInvLength;
+ float fQ = 2.0 * fB * fE + fC * (fF - fD);
+ afDiag[1] = fD + fC * fQ;
+ afDiag[2] = fF - fC * fQ;
+ afSubDiag[0] = fLength;
+ afSubDiag[1] = fE - fB * fQ;
+ elt[0][0] = 1.0;
+ elt[0][1] = 0.0;
+ elt[0][2] = 0.0;
+ elt[1][0] = 0.0;
+ elt[1][1] = fB;
+ elt[1][2] = fC;
+ elt[2][0] = 0.0;
+ elt[2][1] = fC;
+ elt[2][2] = -fB;
+ } else {
+ afDiag[1] = fD;
+ afDiag[2] = fF;
+ afSubDiag[0] = fB;
+ afSubDiag[1] = fE;
+ elt[0][0] = 1.0;
+ elt[0][1] = 0.0;
+ elt[0][2] = 0.0;
+ elt[1][0] = 0.0;
+ elt[1][1] = 1.0;
+ elt[1][2] = 0.0;
+ elt[2][0] = 0.0;
+ elt[2][1] = 0.0;
+ elt[2][2] = 1.0;
+ }
+}
+
+//----------------------------------------------------------------------------
+bool Matrix3::qLAlgorithm (float afDiag[3], float afSubDiag[3]) {
+ // QL iteration with implicit shifting to reduce matrix from tridiagonal
+ // to diagonal
+
+ for (int i0 = 0; i0 < 3; i0++) {
+ const int iMaxIter = 32;
+ int iIter;
+
+ for (iIter = 0; iIter < iMaxIter; iIter++) {
+ int i1;
+
+ for (i1 = i0; i1 <= 1; i1++) {
+ float fSum = G3D::abs(afDiag[i1]) +
+ G3D::abs(afDiag[i1 + 1]);
+
+ if ( G3D::abs(afSubDiag[i1]) + fSum == fSum )
+ break;
+ }
+
+ if ( i1 == i0 )
+ break;
+
+ float fTmp0 = (afDiag[i0 + 1] - afDiag[i0]) / (2.0 * afSubDiag[i0]);
+
+ float fTmp1 = sqrt(fTmp0 * fTmp0 + 1.0);
+
+ if ( fTmp0 < 0.0 )
+ fTmp0 = afDiag[i1] - afDiag[i0] + afSubDiag[i0] / (fTmp0 - fTmp1);
+ else
+ fTmp0 = afDiag[i1] - afDiag[i0] + afSubDiag[i0] / (fTmp0 + fTmp1);
+
+ float fSin = 1.0;
+
+ float fCos = 1.0;
+
+ float fTmp2 = 0.0;
+
+ for (int i2 = i1 - 1; i2 >= i0; i2--) {
+ float fTmp3 = fSin * afSubDiag[i2];
+ float fTmp4 = fCos * afSubDiag[i2];
+
+ if (G3D::abs(fTmp3) >= G3D::abs(fTmp0)) {
+ fCos = fTmp0 / fTmp3;
+ fTmp1 = sqrt(fCos * fCos + 1.0);
+ afSubDiag[i2 + 1] = fTmp3 * fTmp1;
+ fSin = 1.0 / fTmp1;
+ fCos *= fSin;
+ } else {
+ fSin = fTmp3 / fTmp0;
+ fTmp1 = sqrt(fSin * fSin + 1.0);
+ afSubDiag[i2 + 1] = fTmp0 * fTmp1;
+ fCos = 1.0 / fTmp1;
+ fSin *= fCos;
+ }
+
+ fTmp0 = afDiag[i2 + 1] - fTmp2;
+ fTmp1 = (afDiag[i2] - fTmp0) * fSin + 2.0 * fTmp4 * fCos;
+ fTmp2 = fSin * fTmp1;
+ afDiag[i2 + 1] = fTmp0 + fTmp2;
+ fTmp0 = fCos * fTmp1 - fTmp4;
+
+ for (int iRow = 0; iRow < 3; iRow++) {
+ fTmp3 = elt[iRow][i2 + 1];
+ elt[iRow][i2 + 1] = fSin * elt[iRow][i2] +
+ fCos * fTmp3;
+ elt[iRow][i2] = fCos * elt[iRow][i2] -
+ fSin * fTmp3;
+ }
+ }
+
+ afDiag[i0] -= fTmp2;
+ afSubDiag[i0] = fTmp0;
+ afSubDiag[i1] = 0.0;
+ }
+
+ if ( iIter == iMaxIter ) {
+ // should not get here under normal circumstances
+ return false;
+ }
+ }
+
+ return true;
+}
+
+//----------------------------------------------------------------------------
+void Matrix3::eigenSolveSymmetric (float afEigenvalue[3],
+ Vector3 akEigenvector[3]) const {
+ Matrix3 kMatrix = *this;
+ float afSubDiag[3];
+ kMatrix.tridiagonal(afEigenvalue, afSubDiag);
+ kMatrix.qLAlgorithm(afEigenvalue, afSubDiag);
+
+ for (int i = 0; i < 3; i++) {
+ akEigenvector[i][0] = kMatrix[0][i];
+ akEigenvector[i][1] = kMatrix[1][i];
+ akEigenvector[i][2] = kMatrix[2][i];
+ }
+
+ // make eigenvectors form a right--handed system
+ Vector3 kCross = akEigenvector[1].cross(akEigenvector[2]);
+
+ float fDet = akEigenvector[0].dot(kCross);
+
+ if ( fDet < 0.0 ) {
+ akEigenvector[2][0] = - akEigenvector[2][0];
+ akEigenvector[2][1] = - akEigenvector[2][1];
+ akEigenvector[2][2] = - akEigenvector[2][2];
+ }
+}
+
+//----------------------------------------------------------------------------
+void Matrix3::tensorProduct (const Vector3& rkU, const Vector3& rkV,
+ Matrix3& rkProduct) {
+ for (int iRow = 0; iRow < 3; iRow++) {
+ for (int iCol = 0; iCol < 3; iCol++) {
+ rkProduct[iRow][iCol] = rkU[iRow] * rkV[iCol];
+ }
+ }
+}
+
+//----------------------------------------------------------------------------
+
+// Runs in 52 cycles on AMD, 76 cycles on Intel Centrino
+//
+// The loop unrolling is necessary for performance.
+// I was unable to improve performance further by flattening the matrices
+// into float*'s instead of 2D arrays.
+//
+// -morgan
+void Matrix3::_mul(const Matrix3& A, const Matrix3& B, Matrix3& out) {
+ const float* ARowPtr = A.elt[0];
+ float* outRowPtr = out.elt[0];
+ outRowPtr[0] =
+ ARowPtr[0] * B.elt[0][0] +
+ ARowPtr[1] * B.elt[1][0] +
+ ARowPtr[2] * B.elt[2][0];
+ outRowPtr[1] =
+ ARowPtr[0] * B.elt[0][1] +
+ ARowPtr[1] * B.elt[1][1] +
+ ARowPtr[2] * B.elt[2][1];
+ outRowPtr[2] =
+ ARowPtr[0] * B.elt[0][2] +
+ ARowPtr[1] * B.elt[1][2] +
+ ARowPtr[2] * B.elt[2][2];
+
+ ARowPtr = A.elt[1];
+ outRowPtr = out.elt[1];
+
+ outRowPtr[0] =
+ ARowPtr[0] * B.elt[0][0] +
+ ARowPtr[1] * B.elt[1][0] +
+ ARowPtr[2] * B.elt[2][0];
+ outRowPtr[1] =
+ ARowPtr[0] * B.elt[0][1] +
+ ARowPtr[1] * B.elt[1][1] +
+ ARowPtr[2] * B.elt[2][1];
+ outRowPtr[2] =
+ ARowPtr[0] * B.elt[0][2] +
+ ARowPtr[1] * B.elt[1][2] +
+ ARowPtr[2] * B.elt[2][2];
+
+ ARowPtr = A.elt[2];
+ outRowPtr = out.elt[2];
+
+ outRowPtr[0] =
+ ARowPtr[0] * B.elt[0][0] +
+ ARowPtr[1] * B.elt[1][0] +
+ ARowPtr[2] * B.elt[2][0];
+ outRowPtr[1] =
+ ARowPtr[0] * B.elt[0][1] +
+ ARowPtr[1] * B.elt[1][1] +
+ ARowPtr[2] * B.elt[2][1];
+ outRowPtr[2] =
+ ARowPtr[0] * B.elt[0][2] +
+ ARowPtr[1] * B.elt[1][2] +
+ ARowPtr[2] * B.elt[2][2];
+}
+
+//----------------------------------------------------------------------------
+void Matrix3::_transpose(const Matrix3& A, Matrix3& out) {
+ out[0][0] = A.elt[0][0];
+ out[0][1] = A.elt[1][0];
+ out[0][2] = A.elt[2][0];
+ out[1][0] = A.elt[0][1];
+ out[1][1] = A.elt[1][1];
+ out[1][2] = A.elt[2][1];
+ out[2][0] = A.elt[0][2];
+ out[2][1] = A.elt[1][2];
+ out[2][2] = A.elt[2][2];
+}
+
+//-----------------------------------------------------------------------------
+std::string Matrix3::toString() const {
+ return G3D::format("[%g, %g, %g; %g, %g, %g; %g, %g, %g]",
+ elt[0][0], elt[0][1], elt[0][2],
+ elt[1][0], elt[1][1], elt[1][2],
+ elt[2][0], elt[2][1], elt[2][2]);
+}
+
+
+
+} // namespace
+