diff options
Diffstat (limited to 'src/gui/image/qimage.cpp')
-rw-r--r-- | src/gui/image/qimage.cpp | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp index 558d574..14e8b8f 100644 --- a/src/gui/image/qimage.cpp +++ b/src/gui/image/qimage.cpp @@ -1691,8 +1691,12 @@ void QImage::setColorTable(const QVector<QRgb> colors) d->colortable = colors; d->has_alpha_clut = false; - for (int i = 0; i < d->colortable.size(); ++i) - d->has_alpha_clut |= (qAlpha(d->colortable.at(i)) != 255); + for (int i = 0; i < d->colortable.size(); ++i) { + if (qAlpha(d->colortable.at(i)) != 255) { + d->has_alpha_clut = true; + break; + } + } } /*! @@ -3607,6 +3611,9 @@ int QImage::pixelIndex(int x, int y) const If the \a position is not valid, the results are undefined. + \warning This function is expensive when used for massive pixel + manipulations. + \sa setPixel(), valid(), {QImage#Pixel Manipulation}{Pixel Manipulation} */ @@ -4937,10 +4944,12 @@ int QImage::dotsPerMeterY() const meter, to \a x. Together with dotsPerMeterY(), this number defines the intended - scale and aspect ratio of the image. + scale and aspect ratio of the image, and determines the scale + at which QPainter will draw graphics on the image. It does not + change the scale or aspect ratio of the image when it is rendered + on other paint devices. - \sa dotsPerMeterX(), {QImage#Image Information}{Image - Information} + \sa dotsPerMeterX(), {QImage#Image Information}{Image Information} */ void QImage::setDotsPerMeterX(int x) { @@ -4957,10 +4966,12 @@ void QImage::setDotsPerMeterX(int x) to \a y. Together with dotsPerMeterX(), this number defines the intended - scale and aspect ratio of the image. + scale and aspect ratio of the image, and determines the scale + at which QPainter will draw graphics on the image. It does not + change the scale or aspect ratio of the image when it is rendered + on other paint devices. - \sa dotsPerMeterY(), {QImage#Image Information}{Image - Information} + \sa dotsPerMeterY(), {QImage#Image Information}{Image Information} */ void QImage::setDotsPerMeterY(int y) { @@ -5577,6 +5588,8 @@ bool QImage::isDetached() const Use one of the composition mods in QPainter::CompositionMode instead. + \warning This function is expensive. + \sa alphaChannel(), {QImage#Image Transformations}{Image Transformations}, {QImage#Image Formats}{Image Formats} */ @@ -5659,6 +5672,11 @@ void QImage::setAlphaChannel(const QImage &alphaChannel) \l{QPixmap::}{alphaChannel()}, which works in the same way as this function on QPixmaps. + Most usecases for this function can be replaced with QPainter and + using composition modes. + + \warning This is an expensive function. + \sa setAlphaChannel(), hasAlphaChannel(), {QPixmap#Pixmap Information}{Pixmap}, {QImage#Image Transformations}{Image Transformations} |