SbMatrix(3IV)
SbMatrix (SbMx) - 4x4 matrix class
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NAME SbMatrix (SbMx) - 4x4 matrix class INHERITS FROM SbMatrix SYNOPSIS #include <Inventor_c/SbLinear.h> typedef SbMatrix SbMx Functions from class SbMatrix: void SbMxMakeIdent(SbMx *this) SbMatrix SbMxIdent() void SbMxSetRot(SbMx *this, const SbRotation *q) void SbMxSetScale(SbMx *this, float s) void SbMxScaleVec(SbMx *this, const SbVec3f *s) void SbMxSetXlate(SbMx *this, const SbVec3f *t) void SbMxSetXform(SbMx *this, const SbVec3f *translation, const SbRotation *rotation, const SbVec3f *scaleFactor, const SbRotation *scaleOrientation, const SbVec3f *center) void SbMxGetXform(const SbMx *this, SbVec3f *translation, SbRotation *rotation, SbVec3f *scaleFactor, SbRotation *scaleOrientation, const SbVec3f *center) float SbMxDet3Mx(const SbMx *this, int r1, int r2, int r3, int c1, int c2, int c3) float SbMxDet3(const SbMx *this) float SbMxDet4(const SbMx *this) SbBool SbMxFactor(const SbMx *this, SbMatrix *r, SbVec3f *s, SbMatrix *u, SbVec3f *t, SbMatrix *proj) SbMatrix SbMxInverse(const SbMx *this) SbBool SbMxLUDecomp(SbMx *this, int index[4], float *d) void SbMxLUBackSub(const SbMx *this, int index[4], float b[4]) SbMatrix SbMxTranspose(const SbMx *this) SbMatrix * SbMxMultRight(SbMx *this, const SbMatrix *m) SbMatrix * SbMxMultLeft(SbMx *this, const SbMatrix *m) void SbMxMultMxVec(const SbMx *this, const SbVec3f *src, SbVec3f *dst) void SbMxMultVecMx(const SbMx *this, const SbVec3f *src, SbVec3f *dst) void SbMxMultDirMx(const SbMx *this, const SbVec3f *src, SbVec3f *dst) void SbMxMultLineMx(const SbMx *this, const SbLine *src, SbLine *dst) void SbMxPrint(const SbMx *this, FILE *fp) SbMatrix * SbMxCopy(SbMx *this, const SbMatrix *m) SbMatrix * SbMxMultBy(SbMx *this, const SbMatrix *m) SbMatrix SbMxMult(SbMx *this, const SbMatrix *m1, const SbMatrix *m2) int SbMxIsEq(SbMx *this, const SbMatrix *m1, const SbMatrix *m2) int SbMxIsNEq(SbMx *this, const SbMatrix *m1, const SbMatrix *m2) SbBool SbMxEquals(const SbMx *this, const SbMatrix *m, float tolerance) DESCRIPTION 4x4 matrix class/datatype used by many Inventor node and action classes. The matrices are stored in row-major order. Note that this class should be declared and/or malloc'd as an standard C struct: /* This is defined in Inventor_c/SbMatrix.h: */ struct SbMatrix { float mx[4][4]; }; typedef SbMatrix SbMx /* Your code should look like this: */ SbMx mx, mx_t; mx = SbMxIdent(); mx.mx[0][0] = mx.mx[1][1] = mx.mx[2][2] = 3.0; mx_t = SbMxTranspose( &mx ); FUNCTIONS void SbMxMakeIdent(SbMx *this) Sets matrix to be identity. SbMatrix SbMxIdent() Returns an identity matrix. void SbMxSetRot(SbMx *this, const SbRotation *q) Sets matrix to rotate by given rotation. void SbMxSetScale(SbMx *this, float s) Sets matrix to scale by given uniform factor. void SbMxScaleVec(SbMx *this, const SbVec3f *s) Sets matrix to scale by given vector. void SbMxSetXlate(SbMx *this, const SbVec3f *t) Sets matrix to translate by given vector. void SbMxSetXform(SbMx *this, const SbVec3f *translation, const SbRotation *rotation, const SbVec3f *scaleFactor, const SbRotation *scaleOrientation, const SbVec3f *center) Composes the matrix based on a translation, rotation, scale, orientation for scale, and center. The center is the center point for scaling and rotation. The scaleOrientation chooses the primary axes for the scale. void SbMxGetXform(const SbMx *this, SbVec3f *translation, SbRotation *rotation, SbVec3f *scaleFactor, SbRotation *scaleOrientation, const SbVec3f *center) Decomposes the matrix into a translation, rotation, scale, and scale orientation. Any projection information is discarded. The decomposition depends upon choice of center point for rotation and scaling, which is optional as the last parameter. Note that if the center is 0, decompose() is the same as factor() where t is translation, u is rotation, s is scaleFactor, and r is ScaleOrientation. float SbMxDet3Mx(const SbMx *this, int r1, int r2, int r3, int c1, int c2, int c3) Returns determinant of 3x3 submatrix composed of given row and column indices (0-3 for each). float SbMxDet3(const SbMx *this) Returns determinant of upper-left 3x3 submatrix. float SbMxDet4(const SbMx *this) Returns determinant of entire matrix. SbBool SbMxFactor(const SbMx *this, SbMatrix *r, SbVec3f *s, SbMatrix *u, SbVec3f *t, SbMatrix *proj) Factors a matrix m into 5 pieces: m = r s r^ u t, where r^ means transpose of r, and r and u are rotations, s is a scale, and t is a translation. Any projection information is returned in proj. NOTE: the projection matrix is always set to identity. SbMatrix SbMxInverse(const SbMx *this) Returns inverse of matrix. Results are undefined for singular matrices. Uses LU decomposition. SbBool SbMxLUDecomp(SbMx *this, int index[4], float *d) Perform in-place LU decomposition of matrix. index is index of rows in matrix. d is the parity of row swaps. Returns FALSE if singular. void SbMxLUBackSub(const SbMx *this, int index[4], float b[4]) Perform back-substitution on LU-decomposed matrix. Index is permutation of rows from original matrix. SbMatrix SbMxTranspose(const SbMx *this) Returns transpose of matrix. SbMatrix * SbMxMultRight(SbMx *this, const SbMatrix *m) SbMatrix * SbMxMultLeft(SbMx *this, const SbMatrix *m) Multiplies matrix by given matrix on right or left. void SbMxMultMxVec(const SbMx *this, const SbVec3f *src, SbVec3f *dst) Multiplies matrix by given column vector, giving vector result. void SbMxMultVecMx(const SbMx *this, const SbVec3f *src, SbVec3f *dst) Multiplies given row vector by matrix, giving vector result. void SbMxMultDirMx(const SbMx *this, const SbVec3f *src, SbVec3f *dst) Multiplies given row vector by matrix, giving vector result. src is assumed to be a direction vector, so translation part of matrix is ignored. Note: if you wish to transform surface points and normals by a matrix, call SbMxMultVecMatrix() for the points and call SbMxMultDirMatrix() on the inverse transpose of the matrix for the normals. void SbMxMultLineMx(const SbMx *this, const SbLine *src, SbLine *dst) Multiplies the given line's origin by the matrix, and the line's direction by the rotation portion of the matrix. void SbMxPrint(const SbMx *this, FILE *fp) Prints a formatted version of the matrix to the given file pointer. SbMatrix * SbMxCopy(SbMx *this, const SbMatrix *m) Set the matrix from another SbMatrix. SbMatrix * SbMxMultBy(SbMx *this, const SbMatrix *m) Performs right multiplication with another matrix. SbMatrix SbMxMult(SbMx *this, const SbMatrix *m1, const SbMatrix *m2) Binary multiplication of matrices. int SbMxIsEq(SbMx *this, const SbMatrix *m1, const SbMatrix *m2) int SbMxIsNEq(SbMx *this, const SbMatrix *m1, const SbMatrix *m2) Equality comparison operators. SbBool SbMxEquals(const SbMx *this, const SbMatrix *m, float tolerance) Equality comparison within given tolerance, for each component. FILE FORMAT/DEFAULTS Matrix { } SEE ALSO SbVec3f, SbRotation