# [cairo-commit] cairo/src cairo-matrix.c, 1.31, 1.32 cairoint.h, 1.203, 1.204

Bertram Felgenhauer commit at pdx.freedesktop.org
Mon Aug 22 16:52:42 PDT 2005

```Committed by: inte

Update of /cvs/cairo/cairo/src
In directory gabe:/tmp/cvs-serv14591/src

Modified Files:
cairo-matrix.c cairoint.h
Log Message:
2005-08-22  Bertram Felgenhauer  <int-e at gmx.de>

* src/cairoint.h, src/cairo-matrix.c
(_cairo_matrix_compute_eigen_values): remove.

Index: cairo-matrix.c
===================================================================
RCS file: /cvs/cairo/cairo/src/cairo-matrix.c,v
retrieving revision 1.31
retrieving revision 1.32
diff -u -d -r1.31 -r1.32
--- cairo-matrix.c	22 Aug 2005 23:48:28 -0000	1.31
+++ cairo-matrix.c	22 Aug 2005 23:52:40 -0000	1.32
@@ -484,37 +484,6 @@
*det = a*d - b*c;
}

-void
-_cairo_matrix_compute_eigen_values (const cairo_matrix_t *matrix,
-				    double *lambda1, double *lambda2)
-{
-    /* The eigenvalues of an NxN matrix M are found by solving the polynomial:
-
-       det (M - lI) = 0
-
-       The zeros in our homogeneous 3x3 matrix make this equation equal
-       to that formed by the sub-matrix:
-
-       M = a b
-           c d
-
-       by which:
-
-       l^2 - (a+d)l + (ad - bc) = 0
-
-       l = (a+d +/- sqrt (a^2 + 2ad + d^2 - 4 (ad-bc))) / 2;
-    */
-
-    double a, b, c, d, rad;
-
-    a = matrix->xx; b = matrix->yx;
-    c = matrix->xy; d = matrix->yy;
-
-    rad = sqrt (a*a + 2*a*d + d*d - 4*(a*d - b*c));
-    *lambda1 = (a + d + rad) / 2.0;
-    *lambda2 = (a + d - rad) / 2.0;
-}
-
/* Compute the amount that each basis vector is scaled by. */
cairo_status_t
_cairo_matrix_compute_scale_factors (const cairo_matrix_t *matrix,

Index: cairoint.h
===================================================================
RCS file: /cvs/cairo/cairo/src/cairoint.h,v
retrieving revision 1.203
retrieving revision 1.204
diff -u -d -r1.203 -r1.204
--- cairoint.h	22 Aug 2005 23:48:28 -0000	1.203
+++ cairoint.h	22 Aug 2005 23:52:40 -0000	1.204
@@ -1854,10 +1854,6 @@
cairo_private void
_cairo_matrix_compute_determinant (const cairo_matrix_t *matrix, double *det);

-cairo_private void
-_cairo_matrix_compute_eigen_values (const cairo_matrix_t *matrix,
-				    double *lambda1, double *lambda2);
-
cairo_private cairo_status_t
_cairo_matrix_compute_scale_factors (const cairo_matrix_t *matrix,
double *sx, double *sy, int x_major);

```