qglcolormap.rar_class A_qglwidget

/*! \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