/**
* pango_matrix_rotate:
* @matrix: a #PangoMatrix
* @degrees: degrees to rotate counter-clockwise
*
* Changes the transformation represented by @matrix to be the
* transformation given by first rotating by @degrees degrees
* counter-clockwise then applying the original transformation.
*
* Since: 1.6
**/
void
pango_matrix_rotate (PangoMatrix *matrix,
double degrees)
{
PangoMatrix tmp;
gdouble r, s, c;
g_return_if_fail (matrix != NULL);
r = degrees * (G_PI / 180.);
s = sin (r);
c = cos (r);
tmp.xx = c;
tmp.xy = s;
tmp.yx = -s;
tmp.yy = c;
tmp.x0 = 0;
tmp.y0 = 0;
pango_matrix_concat (matrix, &tmp);
}
static VALUE
rg_concat_bang(VALUE self, VALUE new_matrix)
{
pango_matrix_concat(_SELF(self), _SELF(new_matrix));
return self;
}
