From cd06d901af2b7c707db430293ab6efae354f4742 Mon Sep 17 00:00:00 2001 From: Allan Sandfeld Jensen Date: Thu, 25 Feb 2016 16:29:49 +0100 Subject: Implement ordered dithering for image format conversions QImage::convertToFormat was ignoring its conversion flag argument, only performing dithering when converting to indexed formats. This patch updates the documentation and implements ordered dithering for other conversions. Change-Id: I807353d61669694185b7e595ef262d80d9fbb3f1 Reviewed-by: Gunnar Sletta --- src/gui/image/qimage_conversions.cpp | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) (limited to 'src/gui/image/qimage_conversions.cpp') diff --git a/src/gui/image/qimage_conversions.cpp b/src/gui/image/qimage_conversions.cpp index d2f92dbe73..41b4807671 100644 --- a/src/gui/image/qimage_conversions.cpp +++ b/src/gui/image/qimage_conversions.cpp @@ -128,7 +128,7 @@ extern const uint *QT_FASTCALL convertRGB32FromARGB32PM_sse4(uint *buffer, const const QVector *, QDitherInfo *); #endif -void convert_generic(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags) +void convert_generic(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags flags) { // Cannot be used with indexed formats. Q_ASSERT(dest->format > QImage::Format_Indexed8); @@ -159,14 +159,20 @@ void convert_generic(QImageData *dest, const QImageData *src, Qt::ImageConversio convertFromARGB32PM = convertRGB32FromARGB32PM; } } + QDitherInfo dither; + QDitherInfo *ditherPtr = 0; + if ((flags & Qt::PreferDither) && (flags & Qt::Dither_Mask) != Qt::ThresholdDither) + ditherPtr = &dither; for (int y = 0; y < src->height; ++y) { + dither.y = y; int x = 0; while (x < src->width) { + dither.x = x; int l = qMin(src->width - x, buffer_size); const uint *ptr = fetch(buffer, srcData, x, l); - ptr = convertToARGB32PM(buffer, ptr, l, 0, 0); - ptr = convertFromARGB32PM(buffer, ptr, l, 0, 0); + ptr = convertToARGB32PM(buffer, ptr, l, 0, ditherPtr); + ptr = convertFromARGB32PM(buffer, ptr, l, 0, ditherPtr); store(destData, ptr, x, l); x += l; } @@ -175,7 +181,7 @@ void convert_generic(QImageData *dest, const QImageData *src, Qt::ImageConversio } } -bool convert_generic_inplace(QImageData *data, QImage::Format dst_format, Qt::ImageConversionFlags) +bool convert_generic_inplace(QImageData *data, QImage::Format dst_format, Qt::ImageConversionFlags flags) { // Cannot be used with indexed formats or between formats with different pixel depths. Q_ASSERT(dst_format > QImage::Format_Indexed8); @@ -208,14 +214,20 @@ bool convert_generic_inplace(QImageData *data, QImage::Format dst_format, Qt::Im convertFromARGB32PM = convertRGB32FromARGB32PM; } } + QDitherInfo dither; + QDitherInfo *ditherPtr = 0; + if ((flags & Qt::PreferDither) && (flags & Qt::Dither_Mask) != Qt::ThresholdDither) + ditherPtr = &dither; for (int y = 0; y < data->height; ++y) { + dither.y = y; int x = 0; while (x < data->width) { + dither.x = x; int l = qMin(data->width - x, buffer_size); const uint *ptr = fetch(buffer, srcData, x, l); - ptr = convertToARGB32PM(buffer, ptr, l, 0, 0); - ptr = convertFromARGB32PM(buffer, ptr, l, 0, 0); + ptr = convertToARGB32PM(buffer, ptr, l, 0, ditherPtr); + ptr = convertFromARGB32PM(buffer, ptr, l, 0, ditherPtr); // The conversions might be passthrough and not use the buffer, in that case we are already done. if (srcData != (const uchar*)ptr) store(srcData, ptr, x, l); -- cgit v1.2.3