Unbreak QImage::rgbSwapped() for many image formats.

These formats had broken rgbSwapped() implementations:
argb8565, argb6666, rgb555, argb8555, rgb444, argb4444

Reviewed-by: Benjamin Poulain

2 files changed, 101 insertions, 41 deletions

diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp
index 30cf758..cb834c0 100644
--- a/src/gui/image/qimage.cpp
+++ b/src/gui/image/qimage.cpp
@@ -4829,7 +4829,7 @@ QImage QImage::rgbSwapped() const
         QIMAGE_SANITYCHECK_MEMORY(res);
         for (int i = 0; i < d->height; i++) {
             uint *q = (uint*)res.scanLine(i);
-            uint *p = (uint*)scanLine(i);
+            uint *p = (uint*)constScanLine(i);
             uint *end = p + d->width;
             while (p < end) {
                 *q = ((*p << 16) & 0xff0000) | ((*p >> 16) & 0xff) | (*p & 0xff00ff00);
@@ -4843,7 +4843,7 @@ QImage QImage::rgbSwapped() const
         QIMAGE_SANITYCHECK_MEMORY(res);
         for (int i = 0; i < d->height; i++) {
             ushort *q = (ushort*)res.scanLine(i);
-            const ushort *p = (const ushort*)scanLine(i);
+            const ushort *p = (const ushort*)constScanLine(i);
             const ushort *end = p + d->width;
             while (p < end) {
                 *q = ((*p << 11) & 0xf800) | ((*p >> 11) & 0x1f) | (*p & 0x07e0);
@@ -4856,12 +4856,15 @@ QImage QImage::rgbSwapped() const
         res = QImage(d->width, d->height, d->format);
         QIMAGE_SANITYCHECK_MEMORY(res);
         for (int i = 0; i < d->height; i++) {
-            quint8 *p = (quint8*)scanLine(i);
+            const quint8 *p = constScanLine(i);
+            quint8 *q = res.scanLine(i);
             const quint8 *end = p + d->width * sizeof(qargb8565);
             while (p < end) {
-                quint16 *q = reinterpret_cast<quint16*>(p + 1);
-                *q = ((*q << 11) & 0xf800) | ((*q >> 11) & 0x1f) | (*q & 0x07e0);
+                q[0] = p[0];
+                q[1] = (p[1] & 0xe0) | (p[2] >> 3);
+                q[2] = (p[2] & 0x07) | (p[1] << 3);
                 p += sizeof(qargb8565);
+                q += sizeof(qargb8565);
             }
         }
         break;
@@ -4870,7 +4873,7 @@ QImage QImage::rgbSwapped() const
         QIMAGE_SANITYCHECK_MEMORY(res);
         for (int i = 0; i < d->height; i++) {
             qrgb666 *q = reinterpret_cast<qrgb666*>(res.scanLine(i));
-            const qrgb666 *p = reinterpret_cast<const qrgb666*>(scanLine(i));
+            const qrgb666 *p = reinterpret_cast<const qrgb666*>(constScanLine(i));
             const qrgb666 *end = p + d->width;
             while (p < end) {
                 const QRgb rgb = quint32(*p++);
@@ -4882,12 +4885,15 @@ QImage QImage::rgbSwapped() const
         res = QImage(d->width, d->height, d->format);
         QIMAGE_SANITYCHECK_MEMORY(res);
         for (int i = 0; i < d->height; i++) {
-            qargb6666 *q = reinterpret_cast<qargb6666*>(res.scanLine(i));
-            const qargb6666 *p = reinterpret_cast<const qargb6666*>(scanLine(i));
-            const qargb6666 *end = p + d->width;
+            const quint8 *p = constScanLine(i);
+            const quint8 *end = p + d->width * sizeof(qargb6666);
+            quint8 *q = res.scanLine(i);
             while (p < end) {
-                const QRgb rgb = quint32(*p++);
-                *q++ = qRgba(qBlue(rgb), qGreen(rgb), qRed(rgb), qAlpha(rgb));
+                q[0] = (p[1] >> 4) | ((p[2] & 0x3) << 4) | (p[0] & 0xc0);
+                q[1] = (p[1] & 0xf) | (p[0] << 4);
+                q[2] = (p[2] & 0xfc) | ((p[0] >> 4) & 0x3);
+                p += sizeof(qargb6666);
+                q += sizeof(qargb6666);
             }
         }
         break;
@@ -4895,11 +4901,11 @@ QImage QImage::rgbSwapped() const
         res = QImage(d->width, d->height, d->format);
         QIMAGE_SANITYCHECK_MEMORY(res);
         for (int i = 0; i < d->height; i++) {
-            ushort *q = (ushort*)res.scanLine(i);
-            const ushort *p = (const ushort*)scanLine(i);
-            const ushort *end = p + d->width;
+            quint16 *q = (quint16*)res.scanLine(i);
+            const quint16 *p = (const quint16*)constScanLine(i);
+            const quint16 *end = p + d->width;
             while (p < end) {
-                *q = ((*p << 10) & 0x7800) | ((*p >> 10) & 0x1f) | (*p & 0x83e0);
+                *q = ((*p << 10) & 0x7c00) | ((*p >> 10) & 0x1f) | (*p & 0x3e0);
                 p++;
                 q++;
             }
@@ -4909,12 +4915,15 @@ QImage QImage::rgbSwapped() const
         res = QImage(d->width, d->height, d->format);
         QIMAGE_SANITYCHECK_MEMORY(res);
         for (int i = 0; i < d->height; i++) {
-            quint8 *p = (quint8*)scanLine(i);
+            const quint8 *p = constScanLine(i);
+            quint8 *q = res.scanLine(i);
             const quint8 *end = p + d->width * sizeof(qargb8555);
             while (p < end) {
-                quint16 *q = reinterpret_cast<quint16*>(p + 1);
-                *q = ((*q << 10) & 0x7800) | ((*q >> 10) & 0x1f) | (*q & 0x83e0);
+                q[0] = p[0];
+                q[1] = (p[1] & 0xe0) | (p[2] >> 2);
+                q[2] = (p[2] & 0x03) | ((p[1] << 2) & 0x7f);
                 p += sizeof(qargb8555);
+                q += sizeof(qargb8555);
             }
         }
         break;
@@ -4922,8 +4931,8 @@ QImage QImage::rgbSwapped() const
         res = QImage(d->width, d->height, d->format);
         QIMAGE_SANITYCHECK_MEMORY(res);
         for (int i = 0; i < d->height; i++) {
-            quint8 *q = reinterpret_cast<quint8*>(res.scanLine(i));
-            const quint8 *p = reinterpret_cast<const quint8*>(scanLine(i));
+            quint8 *q = res.scanLine(i);
+            const quint8 *p = constScanLine(i);
             const quint8 *end = p + d->width * sizeof(qrgb888);
             while (p < end) {
                 q[0] = p[2];
@@ -4935,32 +4944,17 @@ QImage QImage::rgbSwapped() const
         }
         break;
     case Format_RGB444:
-        res = QImage(d->width, d->height, d->format);
-        QIMAGE_SANITYCHECK_MEMORY(res);
-        for (int i = 0; i < d->height; i++) {
-            quint8 *q = reinterpret_cast<quint8*>(res.scanLine(i));
-            const quint8 *p = reinterpret_cast<const quint8*>(scanLine(i));
-            const quint8 *end = p + d->width * sizeof(qrgb444);
-            while (p < end) {
-                q[0] = (p[0] & 0xf0) | ((p[1] & 0x0f) << 8);
-                q[1] = ((p[0] & 0x0f) >> 8) | (p[1] & 0xf0);
-                q += sizeof(qrgb444);
-                p += sizeof(qrgb444);
-            }
-        }
-        break;
     case Format_ARGB4444_Premultiplied:
         res = QImage(d->width, d->height, d->format);
         QIMAGE_SANITYCHECK_MEMORY(res);
         for (int i = 0; i < d->height; i++) {
-            quint8 *q = reinterpret_cast<quint8*>(res.scanLine(i));
-            const quint8 *p = reinterpret_cast<const quint8*>(scanLine(i));
-            const quint8 *end = p + d->width * sizeof(qargb4444);
+            quint16 *q = reinterpret_cast<quint16*>(res.scanLine(i));
+            const quint16 *p = reinterpret_cast<const quint16*>(constScanLine(i));
+            const quint16 *end = p + d->width;
             while (p < end) {
-                q[0] = (p[0] & 0xf0) | ((p[1] & 0x0f) << 8);
-                q[1] = ((p[0] & 0x0f) >> 8) | (p[1] & 0xf0);
-                q += sizeof(qargb4444);
-                p += sizeof(qargb4444);
+                *q = (*p & 0xf0f0) | ((*p & 0x0f) << 8) | ((*p & 0xf00) >> 8);
+                p++;
+                q++;
             }
         }
         break;
diff --git a/tests/auto/qimage/tst_qimage.cpp b/tests/auto/qimage/tst_qimage.cpp
index 1330d96..49514dc 100644
--- a/tests/auto/qimage/tst_qimage.cpp
+++ b/tests/auto/qimage/tst_qimage.cpp
@@ -139,6 +139,9 @@ private slots:
     void premultipliedAlphaConsistency();
 
     void compareIndexed();
+
+    void rgbSwapped_data();
+    void rgbSwapped();
 };
 
 tst_QImage::tst_QImage()
@@ -1820,5 +1823,68 @@ void tst_QImage::compareIndexed()
     QCOMPARE(img, imgInverted);
 }
 
+void tst_QImage::rgbSwapped_data()
+{
+    QTest::addColumn<QImage::Format>("format");
+
+    QTest::newRow("Format_Indexed8") << QImage::Format_Indexed8;
+    QTest::newRow("Format_RGB32") << QImage::Format_RGB32;
+    QTest::newRow("Format_ARGB32") << QImage::Format_ARGB32;
+    QTest::newRow("Format_ARGB32_Premultiplied") << QImage::Format_ARGB32_Premultiplied;
+    QTest::newRow("Format_RGB16") << QImage::Format_RGB16;
+    QTest::newRow("Format_ARGB8565_Premultiplied") << QImage::Format_ARGB8565_Premultiplied;
+    QTest::newRow("Format_ARGB6666_Premultiplied") << QImage::Format_ARGB6666_Premultiplied;
+    QTest::newRow("Format_ARGB4444_Premultiplied") << QImage::Format_ARGB4444_Premultiplied;
+    QTest::newRow("Format_RGB666") << QImage::Format_RGB666;
+    QTest::newRow("Format_RGB555") << QImage::Format_RGB555;
+    QTest::newRow("Format_ARGB8555_Premultiplied") << QImage::Format_ARGB8555_Premultiplied;
+    QTest::newRow("Format_RGB888") << QImage::Format_RGB888;
+    QTest::newRow("Format_RGB444") << QImage::Format_RGB444;
+}
+
+void tst_QImage::rgbSwapped()
+{
+    QFETCH(QImage::Format, format);
+
+    QImage image(100, 1, format);
+    image.fill(0);
+
+    QVector<QColor> testColor(image.width());
+
+    for (int i = 0; i < image.width(); ++i)
+        testColor[i] = QColor(i, 10 + i, 20 + i * 2, 30 + i);
+
+    if (format != QImage::Format_Indexed8) {
+        QPainter p(&image);
+        p.setCompositionMode(QPainter::CompositionMode_Source);
+        for (int i = 0; i < image.width(); ++i)
+            p.fillRect(QRect(i, 0, 1, 1), testColor[i].rgb());
+    } else {
+        image.setColorCount(image.width());
+        for (int i = 0; i < image.width(); ++i) {
+            image.setColor(0, testColor[i].rgba());
+            image.setPixel(i, 0, i);
+        }
+    }
+
+    QImage imageSwapped = image.rgbSwapped();
+
+    for (int i = 0; i < image.width(); ++i) {
+        QColor referenceColor = QColor(image.pixel(i, 0));
+        QColor swappedColor = QColor(imageSwapped.pixel(i, 0));
+
+        QCOMPARE(swappedColor.alpha(), referenceColor.alpha());
+        QCOMPARE(swappedColor.red(), referenceColor.blue());
+        QCOMPARE(swappedColor.green(), referenceColor.green());
+        QCOMPARE(swappedColor.blue(), referenceColor.red());
+    }
+
+    QImage imageSwappedTwice = imageSwapped.rgbSwapped();
+
+    QCOMPARE(image, imageSwappedTwice);
+
+    QCOMPARE(memcmp(image.constBits(), imageSwappedTwice.constBits(), image.numBytes()), 0);
+}
+
 QTEST_MAIN(tst_QImage)
 #include "tst_qimage.moc"