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Diffstat (limited to 'src/gui/opengl/qopenglcolormap.cpp')
| -rw-r--r-- | src/gui/opengl/qopenglcolormap.cpp | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/src/gui/opengl/qopenglcolormap.cpp b/src/gui/opengl/qopenglcolormap.cpp new file mode 100644 index 0000000000..386358ac23 --- /dev/null +++ b/src/gui/opengl/qopenglcolormap.cpp @@ -0,0 +1,297 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtGui module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** GNU Lesser General Public License Usage +** 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. +** +** 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. +** +** Other Usage +** Alternatively, this file may be used in accordance with the terms and +** conditions contained in a signed written agreement between you and Nokia. +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \class QOpenGLColormap + \brief The QOpenGLColormap class is used for installing custom colormaps into + a QOpenGLWidget. + + \module OpenGL + \ingroup painting-3D + \ingroup shared + + QOpenGLColormap provides a platform independent way of specifying and + installing indexed colormaps for a QOpenGLWidget. QOpenGLColormap is + especially useful when using the OpenGL color-index mode. + + Under X11 you must use an X server that supports either a \c + PseudoColor or \c DirectColor visual class. If your X server + currently only provides a \c GrayScale, \c TrueColor, \c + StaticColor or \c StaticGray visual, you will not be able to + allocate colorcells for writing. If this is the case, try setting + your X server to 8 bit mode. It should then provide you with at + least a \c PseudoColor visual. Note that you may experience + colormap flashing if your X server is running in 8 bit mode. + + The size() of the colormap is always set to 256 + colors. Note that under Windows you can also install colormaps + in child widgets. + + This class uses \l{implicit sharing} as a memory and speed + optimization. + + Example of use: + \snippet doc/src/snippets/code/src_opengl_qopenglcolormap.cpp 0 + + \sa QOpenGLWidget::setColormap(), QOpenGLWidget::colormap() +*/ + +/*! + \fn Qt::HANDLE QOpenGLColormap::handle() + + \internal + + Returns the handle for this color map. +*/ + +/*! + \fn void QOpenGLColormap::setHandle(Qt::HANDLE handle) + + \internal + + Sets the handle for this color map to \a handle. +*/ + +#include "qopenglcolormap.h" + +QT_BEGIN_NAMESPACE + +QOpenGLColormap::QOpenGLColormapData QOpenGLColormap::shared_null = { Q_BASIC_ATOMIC_INITIALIZER(1), 0, 0 }; + +/*! + Construct a QOpenGLColormap. +*/ +QOpenGLColormap::QOpenGLColormap() + : d(&shared_null) +{ + d->ref.ref(); +} + + +/*! + Construct a shallow copy of \a map. +*/ +QOpenGLColormap::QOpenGLColormap(const QOpenGLColormap &map) + : d(map.d) +{ + d->ref.ref(); +} + +/*! + Dereferences the QOpenGLColormap and deletes it if this was the last + reference to it. +*/ +QOpenGLColormap::~QOpenGLColormap() +{ + if (!d->ref.deref()) + cleanup(d); +} + +void QOpenGLColormap::cleanup(QOpenGLColormap::QOpenGLColormapData *x) +{ + delete x->cells; + x->cells = 0; + delete x; +} + +/*! + Assign a shallow copy of \a map to this QOpenGLColormap. +*/ +QOpenGLColormap & QOpenGLColormap::operator=(const QOpenGLColormap &map) +{ + map.d->ref.ref(); + if (!d->ref.deref()) + cleanup(d); + d = map.d; + return *this; +} + +/*! + \fn void QOpenGLColormap::detach() + \internal + + Detaches this QOpenGLColormap from the shared block. +*/ + +void QOpenGLColormap::detach_helper() +{ + QOpenGLColormapData *x = new QOpenGLColormapData; + x->ref = 1; + x->cmapHandle = 0; + x->cells = 0; + if (d->cells) { + x->cells = new QVector<QRgb>(256); + *x->cells = *d->cells; + } + if (!d->ref.deref()) + cleanup(d); + d = x; +} + +/*! + Set cell at index \a idx in the colormap to color \a color. +*/ +void QOpenGLColormap::setEntry(int idx, QRgb color) +{ + detach(); + if (!d->cells) + d->cells = new QVector<QRgb>(256); + d->cells->replace(idx, color); +} + +/*! + Set an array of cells in this colormap. \a count is the number of + colors that should be set, \a colors is the array of colors, and + \a base is the starting index. The first element in \a colors + is set at \a base in the colormap. +*/ +void QOpenGLColormap::setEntries(int count, const QRgb *colors, int base) +{ + detach(); + if (!d->cells) + d->cells = new QVector<QRgb>(256); + + Q_ASSERT_X(colors && base >= 0 && (base + count) <= d->cells->size(), "QOpenGLColormap::setEntries", + "preconditions not met"); + for (int i = 0; i < count; ++i) + setEntry(base + i, colors[i]); +} + +/*! + Returns the QRgb value in the colorcell with index \a idx. +*/ +QRgb QOpenGLColormap::entryRgb(int idx) const +{ + if (d == &shared_null || !d->cells) + return 0; + else + return d->cells->at(idx); +} + +/*! + \overload + + Set the cell with index \a idx in the colormap to color \a color. +*/ +void QOpenGLColormap::setEntry(int idx, const QColor &color) +{ + setEntry(idx, color.rgb()); +} + +/*! + Returns the QRgb value in the colorcell with index \a idx. +*/ +QColor QOpenGLColormap::entryColor(int idx) const +{ + if (d == &shared_null || !d->cells) + return QColor(); + else + return QColor(d->cells->at(idx)); +} + +/*! + Returns true if the colormap is empty or it is not in use + by a QOpenGLWidget; otherwise returns false. + + A colormap with no color values set is considered to be empty. + For historical reasons, a colormap that has color values set + but which is not in use by a QOpenGLWidget is also considered empty. + + Compare size() with zero to determine if the colormap is empty + regardless of whether it is in use by a QOpenGLWidget or not. + + \sa size() +*/ +bool QOpenGLColormap::isEmpty() const +{ + return d == &shared_null || d->cells == 0 || d->cells->size() == 0 || d->cmapHandle == 0; +} + + +/*! + Returns the number of colorcells in the colormap. +*/ +int QOpenGLColormap::size() const +{ + return d->cells ? d->cells->size() : 0; +} + +/*! + Returns the index of the color \a color. If \a color is not in the + map, -1 is returned. +*/ +int QOpenGLColormap::find(QRgb color) const +{ + if (d->cells) + return d->cells->indexOf(color); + return -1; +} + +/*! + Returns the index of the color that is the closest match to color + \a color. +*/ +int QOpenGLColormap::findNearest(QRgb color) const +{ + int idx = find(color); + if (idx >= 0) + return idx; + int mapSize = size(); + int mindist = 200000; + int r = qRed(color); + int g = qGreen(color); + int b = qBlue(color); + int rx, gx, bx, dist; + for (int i = 0; i < mapSize; ++i) { + QRgb ci = d->cells->at(i); + rx = r - qRed(ci); + gx = g - qGreen(ci); + bx = b - qBlue(ci); + dist = rx * rx + gx * gx + bx * bx; // calculate distance + if (dist < mindist) { // minimal? + mindist = dist; + idx = i; + } + } + return idx; +} + +QT_END_NAMESPACE |