From 2b9a8b8d6973363d35b381bb5ec7e7ceb53cbae4 Mon Sep 17 00:00:00 2001
From: Allan Sandfeld Jensen <allan.jensen@qt.io>
Date: Fri, 4 Dec 2020 11:38:06 +0100
Subject: [PATCH] Add generic rb swap for RGB64 formats

Will also be needed by half-float formats.

Change-Id: Ia735b29b65287c63da5f1b5ec25428562d743800
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
---
 src/gui/image/qimage.cpp          | 31 +------------------------------
 src/gui/painting/qpixellayout.cpp | 27 ++++++++++++++++++++++++---
 2 files changed, 25 insertions(+), 33 deletions(-)

diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp
index 70b958c177e..2787be53d09 100644
--- a/src/gui/image/qimage.cpp
+++ b/src/gui/image/qimage.cpp
@@ -3408,25 +3408,9 @@ QImage QImage::rgbSwapped_helper() const
             }
         }
         break;
-    case Format_RGBX64:
-    case Format_RGBA64:
-    case Format_RGBA64_Premultiplied:
-        res = QImage(d->width, d->height, d->format);
-        QIMAGE_SANITYCHECK_MEMORY(res);
-        for (int i = 0; i < d->height; i++) {
-            QRgba64 *q = reinterpret_cast<QRgba64 *>(res.scanLine(i));
-            const QRgba64 *p = reinterpret_cast<const QRgba64 *>(constScanLine(i));
-            const QRgba64 *end = p + d->width;
-            while (p < end) {
-                QRgba64 c = *p;
-                *q = QRgba64::fromRgba64(c.blue(), c.green(), c.red(), c.alpha());
-                p++;
-                q++;
-            }
-        }
-        break;
     default:
         res = QImage(d->width, d->height, d->format);
+        QIMAGE_SANITYCHECK_MEMORY(res);
         rgbSwapped_generic(d->width, d->height, this, &res, &qPixelLayouts[d->format]);
         break;
     }
@@ -3520,19 +3504,6 @@ void QImage::rgbSwapped_inplace()
             }
         }
         break;
-    case Format_RGBX64:
-    case Format_RGBA64:
-    case Format_RGBA64_Premultiplied:
-        for (int i = 0; i < d->height; i++) {
-            QRgba64 *p = reinterpret_cast<QRgba64 *>(scanLine(i));
-            QRgba64 *end = p + d->width;
-            while (p < end) {
-                QRgba64 c = *p;
-                *p = QRgba64::fromRgba64(c.blue(), c.green(), c.red(), c.alpha());
-                p++;
-            }
-        }
-        break;
     default:
         rgbSwapped_generic(d->width, d->height, this, this, &qPixelLayouts[d->format]);
         break;
diff --git a/src/gui/painting/qpixellayout.cpp b/src/gui/painting/qpixellayout.cpp
index 0b1e736ec86..3bc0d3333dd 100644
--- a/src/gui/painting/qpixellayout.cpp
+++ b/src/gui/painting/qpixellayout.cpp
@@ -568,6 +568,27 @@ static void QT_FASTCALL rbSwap_rgb30(uchar *d, const uchar *s, int count)
     UNALIASED_CONVERSION_LOOP(dest, src, count, qRgbSwapRgb30);
 }
 
+static void QT_FASTCALL rbSwap_4x16(uchar *d, const uchar *s, int count)
+{
+    const ushort *src = reinterpret_cast<const ushort *>(s);
+    ushort *dest = reinterpret_cast<ushort *>(d);
+    if (src != dest) {
+        for (int i = 0; i < count; ++i) {
+            dest[i * 4 + 0] = src[i * 4 + 2];
+            dest[i * 4 + 1] = src[i * 4 + 1];
+            dest[i * 4 + 2] = src[i * 4 + 0];
+            dest[i * 4 + 3] = src[i * 4 + 3];
+        }
+    } else {
+        for (int i = 0; i < count; ++i) {
+            const ushort r = src[i * 4 + 0];
+            const ushort b = src[i * 4 + 2];
+            dest[i * 4 + 0] = b;
+            dest[i * 4 + 2] = r;
+        }
+    }
+}
+
 template<QImage::Format Format> constexpr static inline QPixelLayout pixelLayoutRGB()
 {
     return QPixelLayout{
@@ -1405,15 +1426,15 @@ QPixelLayout qPixelLayouts[QImage::NImageFormats] = {
       convertGrayscale8ToRGB32, convertGrayscale8ToRGB64,
       fetchGrayscale8ToRGB32, fetchGrayscale8ToRGB64,
       storeGrayscale8FromARGB32PM, storeGrayscale8FromRGB32 }, // Format_Grayscale8
-    { false, false, QPixelLayout::BPP64, nullptr,
+    { false, false, QPixelLayout::BPP64, rbSwap_4x16,
       convertPassThrough, nullptr,
       fetchRGB64ToRGB32, fetchPassThrough64,
       storeRGB64FromRGB32, storeRGB64FromRGB32 }, // Format_RGBX64
-    { true, false, QPixelLayout::BPP64, nullptr,
+    { true, false, QPixelLayout::BPP64, rbSwap_4x16,
       convertARGB32ToARGB32PM, nullptr,
       fetchRGBA64ToARGB32PM, fetchRGBA64ToRGBA64PM,
       storeRGBA64FromARGB32PM, storeRGB64FromRGB32 }, // Format_RGBA64
-    { true, true, QPixelLayout::BPP64, nullptr,
+    { true, true, QPixelLayout::BPP64, rbSwap_4x16,
       convertPassThrough, nullptr,
       fetchRGB64ToRGB32, fetchPassThrough64,
       storeRGB64FromRGB32, storeRGB64FromRGB32 }, // Format_RGBA64_Premultiplied