Differential D14308 Diff 39519 thumbnail/icoutils_common.cpp

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thumbnail/icoutils_common.cpp

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16	#include "icoutils.h"	16		#include "icoutils.h"
17		17
18	#include <QList>	18		#include <QList>
19	#include <QString>	19		#include <QString>
20	#include <QTemporaryFile>	20		#include <QTemporaryFile>
21	#include <QImage>	21		#include <QImage>
22	#include <QImageReader>	22		#include <QImageReader>
23		23
24	#define abs(n) ( ( n < 0 ) ? -n : n )	24		#include <algorithm>
		25
		26		qreal distance(int width, int height, int desiredWidth, int desiredHeight, int depth)
		27		{
		28		// We want as high of a depth as possible (32-bit)
			brunsUnsubmitted Not Done Can not see an area calculation here ... bruns: Can not see an area calculation here ...
		29		auto targetSamples = desiredWidth * desiredHeight * 32;
		30		auto xscale = (1.0 * desiredWidth) / width;
		31		auto yscale = (1.0 * desiredHeight) / height;
		32
		33		// clamp to the lower of the two scales
			ngrahamUnsubmitted Not Done Where does this magic number come from? ngraham: Where does this magic number come from?
			broulikAuthorUnsubmitted Not Done No idea, really. broulik: No idea, really.
			brunsUnsubmitted Not Done I think the formula is a little bit to ad-hoc, and actually wrong. We have 2 different notable cases. `desiredAspectRatio` obviously is a constant, this leaves us with `candidateAspectRatio` and `delta` all candiates have exactly the same aspect ratio. The difference below is constant, thus has no influence on the sorting. Sorting is determined by `delta`alone (good). candidates have different aspect ratios. Any candidate with a slightly different aspect ratio is immediately heavily penalized, and thus discarded (bad). Think of e.g. a requested size of 96x96, and two candidates, 32x32 and 128x64. The small one has a `distance` of 128, while the second one has a distance 25032. I don't think that's wanted here. bruns: I think the formula is a little bit to ad-hoc, and actually wrong. We have 2 different notable…
			broulikAuthorUnsubmitted Not Done I'm open to suggestions … also technically you cannot assume the icon is square broulik: I'm open to suggestions … also technically you cannot assume the icon is square
			brunsUnsubmitted Not Done Where do you see any assumption about square icons? bruns: Where do you see any assumption about square icons?
			anthonyfieroniUnsubmitted Not Done It should be qFuzzyIsNull no? anthonyfieroni: It should be qFuzzyIsNull no?
			brunsUnsubmitted Not Done @anthonyfieroni Why? bruns: @anthonyfieroni Why?
			anthonyfieroniUnsubmitted Not Done Comparing doubles should be done by epsilon not by <= 0.0 anthonyfieroni: Comparing doubles should be done by epsilon not by <= 0.0
			brunsUnsubmitted Not Done Not in general. There is nothing inexact here. Also, if difference ~= 0, it does not matter if you scale by 1, 2, -1 or -2. bruns: Not in general. There is nothing inexact here. Also, if difference ~= 0, it does not matter if…
		34		// also clamp to one, as scaling up adds no effective
		35		// samples, only interpolated samples
		36		auto sampleScale = std::min(1.0, std::min(xscale, yscale));
		37
		38		// number of effective source samles in the target
		39		auto effectiveSamples = width * height * sampleScale * sampleScale * depth;
		40		// scale down another time, to account for loss of fidelity when
		41		// using a downscaled image, biases towards smaller downscaling ratios
		42		effectiveSamples *= sampleScale;
		43
		44		return targetSamples - effectiveSamples;
		45		}
25		46
26	bool IcoUtils::loadIcoImageFromExe(QIODevice * inputDevice, QImage &image, int needWidth, int needHeight, const qint32 iconNumber)	47		bool IcoUtils::loadIcoImageFromExe(QIODevice * inputDevice, QImage &image, int needWidth, int needHeight, const qint32 iconNumber)
27	{	48		{
28		49
29	QTemporaryFile inputFile;	50		QTemporaryFile inputFile;
30		51
31	if ( ! inputFile.open() )	52		if ( ! inputFile.open() )
32	return false;	53		return false;
Show All 30 Lines		80	{
63		84
64	QList <QImage> icons;	85		QList <QImage> icons;
65	do icons << reader.read();	86		do icons << reader.read();
66	while ( reader.jumpToNextImage() );	87		while ( reader.jumpToNextImage() );
67		88
68	if ( icons.empty() )	89		if ( icons.empty() )
69	return false;	90		return false;
70		91
71	int min_w = 1024;
72	int min_h = 1024;
73	int index = icons.size() - 1;	92		int index = icons.size() - 1;
		93		qreal best = std::numeric_limits<qreal>::max();
74		94
		95		for (int i = 0; i < icons.size(); ++i) {
		96		const QImage &icon = icons.at(i);
75		97
76	// we loop in reverse order because QtIcoHandler converts all images to 32-bit depth, and resources are ordered from lower depth to higher depth	98		// QtIcoHandler converts all images to 32-bit depth
			brunsUnsubmitted Not Done either Qt handler for "Ico" files or qicohandler bruns: either Qt handler for "Ico" files or qicohandler
77	for ( int i_index = icons.size() - 1; i_index >= 0 ; --i_index )	99		// but they store the actual depth of the icon extracted in custom text:
			brunsUnsubmitted Not Done grammatical nitpick: QtIcoHandler converts all images to 32 bit depth, but it stores the actual depth of the icon extracted in custom text: i.e. missing `,` in the first line, and third person otherwise it's good to go bruns: grammatical nitpick: > // QtIcoHandler converts all images to 32 bit depth, > // but **it…
78	{	100		// qtbase/src/plugins/imageformats/ico/qiconhandler.cpp:455
			brunsUnsubmitted Not Done qico_handler.cpp (no "n") bruns: qico_handler.cpp (no "n")
			broulikAuthorUnsubmitted Not Done No, that is the actual file name on qtbase git dev broulik: No, that is the actual file name on qtbase git dev
			brunsUnsubmitted Not Done https://github.com/qt/qtbase/blob/5.11/src/plugins/imageformats/ico/qicohandler.cpp bruns: https://github.com/qt/qtbase/blob/5.11/src/plugins/imageformats/ico/qicohandler.cpp
79		101		int depth = icon.text(QStringLiteral("_q_icoOrigDepth")).toInt();
80	const QImage &icon = icons.at(i_index);	102		if (depth == 0) {
81	int i_width = icon.width();	103		depth = icon.depth();
82	int i_height = icon.height();	104		}
83	int i_w = abs(i_width - needWidth);
84	int i_h = abs(i_height - needHeight);
85
86	if ( i_w < min_w \|\| ( i_w == min_w && i_h < min_h ) )
87	{
88		105
89	min_w = i_w;	106		const qreal dist = distance(icon.width(), icon.height(), needWidth, needHeight, depth);
90	min_h = i_h;
91	index = i_index;
92		107
		108		if (dist < best) {
		109		index = i;
		110		best = dist;
93	}	111		}
94
95	}	112		}
96		113
97	image = icons.at(index);	114		image = icons.at(index);
98	return true;	115		return true;
99		116
100	}	117		}
101		118
102	bool IcoUtils::loadIcoImage(QIODevice * inputDevice, QImage &image, int needWidth, int needHeight)	119		bool IcoUtils::loadIcoImage(QIODevice * inputDevice, QImage &image, int needWidth, int needHeight)
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