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