--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/auto/qtessellator/utils.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,93 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include "utils.h"
+
+#include <assert.h>
+#include <qglobal.h>
+
+#include "qnum.h"
+
+#define FloatToXFixed(i) (int)((i) * 65536)
+#define IntToXFixed(i) ((i) << 16)
+
+static double compute_x_at(XFixed y, XPointFixed p1, XPointFixed p2)
+{
+    double d = XFixedToDouble(p2.x - p1.x);
+    return
+        XFixedToDouble(p1.x) + d*XFixedToDouble(y - p1.y)/XFixedToDouble(p2.y - p1.y);
+}
+
+double compute_area(XTrapezoid *trap)
+{
+    double x1 = compute_x_at(trap->top, trap->left.p1, trap->left.p2);
+    double x2 = compute_x_at(trap->top, trap->right.p1, trap->right.p2);
+    double x3 = compute_x_at(trap->bottom, trap->left.p1, trap->left.p2);
+    double x4 = compute_x_at(trap->bottom, trap->right.p1, trap->right.p2);
+
+    double top = XFixedToDouble(trap->top);
+    double bottom = XFixedToDouble(trap->bottom);
+    double h = bottom - top;
+
+    double top_base = x2 - x1;
+    double bottom_base = x4 - x3;
+
+    if ((top_base < 0 && bottom_base > 0)
+        || (top_base > 0 && bottom_base < 0)) {
+        double y0 = top_base*h/(top_base - bottom_base) + top;
+        double area = qAbs(top_base * (y0 - top) / 2.);
+        area += qAbs(bottom_base * (bottom - y0) /2.);
+        return area;
+    }
+
+
+    return 0.5 * h * qAbs(top_base + bottom_base);
+}
+
+double compute_area_for_x(const QVector<XTrapezoid> &traps)
+{
+    double area = 0;
+
+    for (int i = 0; i < traps.size(); ++i) {
+        XTrapezoid trap = traps[i];
+        area += compute_area(&trap);
+    }
+    return area;
+}