1 files changed, 177 insertions, 0 deletions
diff --git a/src/imageplugins/perspective/matrix.cpp b/src/imageplugins/perspective/matrix.cpp
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+/* ============================================================
+ *
+ * This file is a part of digiKam project
+ * http://www.digikam.org
+ *
+ * Date        : 2005-02-17
+ * Description : a matrix implementation for image
+ *               perspective adjustment.
+ * 
+ * Copyright (C) 2005-2007 by Gilles Caulier <caulier dot gilles at gmail dot com>
+ * Copyright (C) 2006-2007 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
+ *
+ * Matrix3 implementation inspired from gimp 2.0
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ * 
+ * This program is free software; you can redistribute it
+ * and/or modify it under the terms of the GNU General
+ * Public License as published by the Free Software Foundation;
+ * either version 2, or (at your option)
+ * any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * ============================================================ */
+
+// C++ includes.
+
+#include <cstring>
+
+// Local includes.
+
+#include "matrix.h"
+
+namespace DigikamPerspectiveImagesPlugin
+{
+
+static double identityMatrix[3][3] = { { 1.0, 0.0, 0.0 },
+                                       { 0.0, 1.0, 0.0 },
+                                       { 0.0, 0.0, 1.0 } };
+
+Matrix::Matrix()
+{
+    memcpy(coeff, identityMatrix, sizeof(coeff));
+}
+
+void Matrix::translate (double x, double y)
+{
+    double g, h, i;
+
+    g = coeff[2][0];
+    h = coeff[2][1];
+    i = coeff[2][2];
+
+    coeff[0][0] += x * g;
+    coeff[0][1] += x * h;
+    coeff[0][2] += x * i;
+    coeff[1][0] += y * g;
+    coeff[1][1] += y * h;
+    coeff[1][2] += y * i;
+}
+
+void Matrix::scale(double x, double y)
+{
+    coeff[0][0] *= x;
+    coeff[0][1] *= x;
+    coeff[0][2] *= x;
+
+    coeff[1][0] *= y;
+    coeff[1][1] *= y;
+    coeff[1][2] *= y;
+}
+
+void Matrix::multiply(const Matrix &matrix)
+{
+    int      i, j;
+    Matrix   tmp;
+    double   t1, t2, t3;
+
+    for (i = 0; i < 3; i++)
+    {
+        t1 = matrix.coeff[i][0];
+        t2 = matrix.coeff[i][1];
+        t3 = matrix.coeff[i][2];
+
+        for (j = 0; j < 3; j++)
+        {
+            tmp.coeff[i][j]  = t1 * coeff[0][j];
+            tmp.coeff[i][j] += t2 * coeff[1][j];
+            tmp.coeff[i][j] += t3 * coeff[2][j];
+        }
+    }
+
+    *this = tmp;
+}
+
+void Matrix::transformPoint(double x, double y, double *newx, double *newy) const
+{
+    double  w;
+
+    w = coeff[2][0] * x + coeff[2][1] * y + coeff[2][2];
+
+    if (w == 0.0)
+       w = 1.0;
+    else
+       w = 1.0/w;
+
+    *newx = (coeff[0][0] * x +
+             coeff[0][1] * y +
+             coeff[0][2]) * w;
+    *newy = (coeff[1][0] * x +
+             coeff[1][1] * y +
+             coeff[1][2]) * w;
+}
+
+void Matrix::invert()
+{
+    Matrix  inv;
+    double  det;
+
+    det = determinant();
+
+    if (det == 0.0)
+       return;
+
+    det = 1.0 / det;
+
+    inv.coeff[0][0] =   (coeff[1][1] * coeff[2][2] -
+                         coeff[1][2] * coeff[2][1]) * det;
+
+    inv.coeff[1][0] = - (coeff[1][0] * coeff[2][2] -
+                         coeff[1][2] * coeff[2][0]) * det;
+
+    inv.coeff[2][0] =   (coeff[1][0] * coeff[2][1] -
+                         coeff[1][1] * coeff[2][0]) * det;
+
+    inv.coeff[0][1] = - (coeff[0][1] * coeff[2][2] -
+                         coeff[0][2] * coeff[2][1]) * det;
+
+    inv.coeff[1][1] =   (coeff[0][0] * coeff[2][2] -
+                         coeff[0][2] * coeff[2][0]) * det;
+
+    inv.coeff[2][1] = - (coeff[0][0] * coeff[2][1] -
+                         coeff[0][1] * coeff[2][0]) * det;
+
+    inv.coeff[0][2] =   (coeff[0][1] * coeff[1][2] -
+                         coeff[0][2] * coeff[1][1]) * det;
+
+    inv.coeff[1][2] = - (coeff[0][0] * coeff[1][2] -
+                         coeff[0][2] * coeff[1][0]) * det;
+
+    inv.coeff[2][2] =   (coeff[0][0] * coeff[1][1] -
+                         coeff[0][1] * coeff[1][0]) * det;
+
+    *this = inv;
+}
+
+double Matrix::determinant() const
+{
+    double determinant;
+
+    determinant  = (coeff[0][0] *
+                   (coeff[1][1] * coeff[2][2] -
+                    coeff[1][2] * coeff[2][1]));
+    determinant -= (coeff[1][0] *
+                   (coeff[0][1] * coeff[2][2] -
+                    coeff[0][2] * coeff[2][1]));
+    determinant += (coeff[2][0] *
+                   (coeff[0][1] * coeff[1][2] -
+                    coeff[0][2] * coeff[1][1]));
+
+    return determinant;
+}
+
+}  // namespace DigikamPerspectiveImagesPlugin