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50
51#include "extrafiltersplugin.h"
52
53#include <QInputDialog>
54
55QStringList ExtraFiltersPlugin::filters() const
56{
57 return {tr(s: "Flip Horizontally"), tr(s: "Flip Vertically"),
58 tr(s: "Smudge..."), tr(s: "Threshold...")};
59}
60
61QImage ExtraFiltersPlugin::filterImage(const QString &filter,
62 const QImage &image, QWidget *parent)
63{
64 QImage original = image.convertToFormat(f: QImage::Format_RGB32);
65 QImage result = original;
66
67 if (filter == tr(s: "Flip Horizontally")) {
68 for (int y = 0; y < original.height(); ++y) {
69 for (int x = 0; x < original.width(); ++x) {
70 QRgb pixel = original.pixel(x: original.width() - x - 1, y);
71 result.setPixel(x, y, index_or_rgb: pixel);
72 }
73 }
74 } else if (filter == tr(s: "Flip Vertically")) {
75 for (int y = 0; y < original.height(); ++y) {
76 for (int x = 0; x < original.width(); ++x) {
77 QRgb pixel = original.pixel(x, y: original.height() - y - 1);
78 result.setPixel(x, y, index_or_rgb: pixel);
79 }
80 }
81 } else if (filter == tr(s: "Smudge...")) {
82 bool ok;
83 int numIters = QInputDialog::getInt(parent, title: tr(s: "Smudge Filter"),
84 label: tr(s: "Enter number of iterations:"),
85 value: 5, minValue: 1, maxValue: 20, step: 1, ok: &ok);
86 if (ok) {
87 for (int i = 0; i < numIters; ++i) {
88 for (int y = 1; y < original.height() - 1; ++y) {
89 for (int x = 1; x < original.width() - 1; ++x) {
90 QRgb p1 = original.pixel(x, y);
91 QRgb p2 = original.pixel(x, y: y + 1);
92 QRgb p3 = original.pixel(x, y: y - 1);
93 QRgb p4 = original.pixel(x: x + 1, y);
94 QRgb p5 = original.pixel(x: x - 1, y);
95
96 int red = (qRed(rgb: p1) + qRed(rgb: p2) + qRed(rgb: p3) + qRed(rgb: p4)
97 + qRed(rgb: p5)) / 5;
98 int green = (qGreen(rgb: p1) + qGreen(rgb: p2) + qGreen(rgb: p3)
99 + qGreen(rgb: p4) + qGreen(rgb: p5)) / 5;
100 int blue = (qBlue(rgb: p1) + qBlue(rgb: p2) + qBlue(rgb: p3)
101 + qBlue(rgb: p4) + qBlue(rgb: p5)) / 5;
102 int alpha = (qAlpha(rgb: p1) + qAlpha(rgb: p2) + qAlpha(rgb: p3)
103 + qAlpha(rgb: p4) + qAlpha(rgb: p5)) / 5;
104
105 result.setPixel(x, y, index_or_rgb: qRgba(r: red, g: green, b: blue, a: alpha));
106 }
107 }
108 }
109 }
110 } else if (filter == tr(s: "Threshold...")) {
111 bool ok;
112 int threshold = QInputDialog::getInt(parent, title: tr(s: "Threshold Filter"),
113 label: tr(s: "Enter threshold:"),
114 value: 10, minValue: 1, maxValue: 256, step: 1, ok: &ok);
115 if (ok) {
116 int factor = 256 / threshold;
117 for (int y = 0; y < original.height(); ++y) {
118 for (int x = 0; x < original.width(); ++x) {
119 QRgb pixel = original.pixel(x, y);
120 result.setPixel(x, y, index_or_rgb: qRgba(r: qRed(rgb: pixel) / factor * factor,
121 g: qGreen(rgb: pixel) / factor * factor,
122 b: qBlue(rgb: pixel) / factor * factor,
123 a: qAlpha(rgb: pixel)));
124 }
125 }
126 }
127 }
128 return result;
129}
130

source code of qtbase/examples/widgets/tools/plugandpaint/plugins/extrafilters/extrafiltersplugin.cpp