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author | Lars Knoll <lars.knoll@nokia.com> | 2009-03-23 09:18:55 (GMT) |
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committer | Simon Hausmann <simon.hausmann@nokia.com> | 2009-03-23 09:18:55 (GMT) |
commit | e5fcad302d86d316390c6b0f62759a067313e8a9 (patch) | |
tree | c2afbf6f1066b6ce261f14341cf6d310e5595bc1 /tests/auto/qtessellator/utils.cpp | |
download | Qt-e5fcad302d86d316390c6b0f62759a067313e8a9.zip Qt-e5fcad302d86d316390c6b0f62759a067313e8a9.tar.gz Qt-e5fcad302d86d316390c6b0f62759a067313e8a9.tar.bz2 |
Long live Qt 4.5!
Diffstat (limited to 'tests/auto/qtessellator/utils.cpp')
-rw-r--r-- | tests/auto/qtessellator/utils.cpp | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/tests/auto/qtessellator/utils.cpp b/tests/auto/qtessellator/utils.cpp new file mode 100644 index 0000000..8a9dc1e --- /dev/null +++ b/tests/auto/qtessellator/utils.cpp @@ -0,0 +1,93 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (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 either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** 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 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@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; +} |