1 files changed, 89 insertions, 0 deletions
diff --git a/debian/fireflies/fireflies-2.08/libgfx/src/mat2.cxx b/debian/fireflies/fireflies-2.08/libgfx/src/mat2.cxx
new file mode 100644
index 00000000..42ed3e1a
--- /dev/null
+++ b/debian/fireflies/fireflies-2.08/libgfx/src/mat2.cxx
@@ -0,0 +1,89 @@
+/************************************************************************
+
+  2x2 Matrix class
+
+  $Id: mat2.cxx 427 2004-09-27 04:45:31Z garland $
+
+ ************************************************************************/
+
+#include <gfx/gfx.h>
+#include <gfx/mat2.h>
+
+namespace gfx
+{
+
+Mat2 Mat2::I() { return Mat2(1,0,  0,1); }
+
+Mat2 &Mat2::diag(double d)
+{
+    row[0][0] = d;   row[0][1] = 0;
+    row[1][0] = 0;   row[1][1] = d;
+
+    return *this;
+}
+
+Mat2 operator*(const Mat2 &n, const Mat2& m)
+{
+    Mat2 A;
+    int i,j;
+
+    for(i=0;i<2;i++)
+	for(j=0;j<2;j++)
+	    A(i,j) = n[i]*m.col(j);
+
+    return A;
+}
+
+double invert(Mat2 &inv, const Mat2 &m)
+{
+    double d = det(m);
+
+    if( d==0.0 )
+	return 0.0;
+
+    inv(0, 0) =  m(1,1)/d;
+    inv(0, 1) = -m(0,1)/d;
+    inv(1, 0) = -m(1,0)/d;
+    inv(1, 1) =  m(0,0)/d;
+
+    return d;
+}
+
+bool eigenvalues(const Mat2& M, Vec2& evals)
+{
+    double B = -M(0,0)-M(1,1);
+    double C = det(M);
+
+    double dis = B*B - 4.0*C;
+    if( dis<FEQ_EPS )
+	return false;
+    else
+    {
+	double s = sqrt(dis);
+
+	evals[0] = 0.5*(-B + s);
+	evals[1] = 0.5*(-B - s);
+	return true;
+    }
+}
+
+bool eigenvectors(const Mat2& M, const Vec2& evals, Vec2 evecs[2])
+{
+    evecs[0] = Vec2(-M(0,1), M(0,0)-evals[0]);
+    evecs[1] = Vec2(-M(0,1), M(0,0)-evals[1]);
+
+    unitize(evecs[0]);
+    unitize(evecs[1]);
+
+    return true;
+}
+
+bool eigen(const Mat2& M, Vec2& evals, Vec2 evecs[2])
+{
+    bool result = eigenvalues(M, evals);
+    if( result )
+	eigenvectors(M, evals, evecs);
+    return result;
+}
+
+} // namespace gfx