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| |
| /*! |
| \class QGLColormap |
| \brief The QGLColormap class is used for installing custom colormaps into |
| a QGLWidget. |
| |
| \module OpenGL |
| \ingroup painting-3D |
| \ingroup shared |
| |
| QGLColormap provides a platform independent way of specifying and |
| installing indexed colormaps for a QGLWidget. QGLColormap 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_qglcolormap.cpp 0 |
| |
| \sa QGLWidget::setColormap(), QGLWidget::colormap() |
| */ |
| |
| /*! |
| \fn Qt::HANDLE QGLColormap::handle() |
| |
| \internal |
| |
| Returns the handle for this color map. |
| */ |
| |
| /*! |
| \fn void QGLColormap::setHandle(Qt::HANDLE handle) |
| |
| \internal |
| |
| Sets the handle for this color map to \a handle. |
| */ |
| |
| #include "qglcolormap.h" |
| |
| QT_BEGIN_NAMESPACE |
| |
| QGLColormap::QGLColormapData QGLColormap::shared_null = { Q_BASIC_ATOMIC_INITIALIZER(1), 0, 0 }; |
| |
| /*! |
| Construct a QGLColormap. |
| */ |
| QGLColormap::QGLColormap() |
| : d(&shared_null) |
| { |
| d->ref.ref(); |
| } |
| |
| |
| /*! |
| Construct a shallow copy of \a map. |
| */ |
| QGLColormap::QGLColormap(const QGLColormap &map) |
| : d(map.d) |
| { |
| d->ref.ref(); |
| } |
| |
| /*! |
| Dereferences the QGLColormap and deletes it if this was the last |
| reference to it. |
| */ |
| QGLColormap::~QGLColormap() |
| { |
| if (!d->ref.deref()) |
| cleanup(d); |
| } |
| |
| void QGLColormap::cleanup(QGLColormap::QGLColormapData *x) |
| { |
| delete x->cells; |
| x->cells = 0; |
| delete x; |
| } |
| |
| /*! |
| Assign a shallow copy of \a map to this QGLColormap. |
| */ |
| QGLColormap & QGLColormap::operator=(const QGLColormap &map) |
| { |
| map.d->ref.ref(); |
| if (!d->ref.deref()) |
| cleanup(d); |
| d = map.d; |
| return *this; |
| } |
| |
| /*! |
| \fn void QGLColormap::detach() |
| \internal |
| |
| Detaches this QGLColormap from the shared block. |
| */ |
| |
| void QGLColormap::detach_helper() |
| { |
| QGLColormapData *x = new QGLColormapData; |
| 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 QGLColormap::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 QGLColormap::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(), "QGLColormap::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 QGLColormap::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 QGLColormap::setEntry(int idx, const QColor &color) |
| { |
| setEntry(idx, color.rgb()); |
| } |
| |
| /*! |
| Returns the QRgb value in the colorcell with index \a idx. |
| */ |
| QColor QGLColormap::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 QGLWidget; 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 QGLWidget is also considered empty. |
| |
| Compare size() with zero to determine if the colormap is empty |
| regardless of whether it is in use by a QGLWidget or not. |
| |
| \sa size() |
| */ |
| bool QGLColormap::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 QGLColormap::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 QGLColormap::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 QGLColormap::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 |