diff -r 000000000000 -r 1918ee327afb tests/auto/qtessellator/utils.cpp --- /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 +#include + +#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 &traps) +{ + double area = 0; + + for (int i = 0; i < traps.size(); ++i) { + XTrapezoid trap = traps[i]; + area += compute_area(&trap); + } + return area; +}