Make convert_generic_to_rgb64 more generic

This makes it possible to get rid of specialized functions for
converting to RGBA64PM, while at the same time making the conversion
faster as the painter routines are better optimized.

Change-Id: I3e73856b2c1411977450e72af1741aab0ecf537e
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

3 files changed, 35 insertions, 110 deletions

diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp
index 4c00c7705a..efef5eee58 100644
--- a/src/gui/image/qimage.cpp
+++ b/src/gui/image/qimage.cpp
@@ -2062,13 +2062,7 @@ QImage QImage::convertToFormat_helper(Format format, Qt::ImageConversionFlags fl
     Image_Converter converter = qimage_converter_map[d->format][format];
     if (!converter && format > QImage::Format_Indexed8 && d->format > QImage::Format_Indexed8) {
         if (highColorPrecision(format) && highColorPrecision(d->format)) {
-            // Convert over RGBA64_Premultiplied
-            if (format == QImage::Format_RGBA64_Premultiplied)
-                converter = convert_generic_to_rgb64;
-            else {
-                Q_ASSERT(d->format != QImage::Format_RGBA64_Premultiplied);
-                return convertToFormat(Format_RGBA64_Premultiplied, flags).convertToFormat(format, flags);
-            }
+            converter = convert_generic_to_rgb64;
         } else
             converter = convert_generic;
     }
diff --git a/src/gui/image/qimage_conversions.cpp b/src/gui/image/qimage_conversions.cpp
index ea9347183e..82ffb8af8b 100644
--- a/src/gui/image/qimage_conversions.cpp
+++ b/src/gui/image/qimage_conversions.cpp
@@ -223,18 +223,29 @@ void convert_generic(QImageData *dest, const QImageData *src, Qt::ImageConversio
 
 void convert_generic_to_rgb64(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags)
 {
-    Q_ASSERT(dest->format == QImage::Format_RGBA64_Premultiplied);
+    Q_ASSERT(dest->format > QImage::Format_Indexed8);
     Q_ASSERT(src->format > QImage::Format_Indexed8);
+    QRgba64 buf[BufferSize];
+    QRgba64 *buffer = buf;
     const QPixelLayout *srcLayout = &qPixelLayouts[src->format];
+    const QPixelLayout *destLayout = &qPixelLayouts[dest->format];
     const uchar *srcData = src->data;
     uchar *destData = dest->data;
 
     const FetchAndConvertPixelsFunc64 fetch = srcLayout->fetchToRGBA64PM;
+    const ConvertAndStorePixelsFunc64 store = qStoreFromRGBA64PM[dest->format];
 
     for (int y = 0; y < src->height; ++y) {
-        const QRgba64 *ptr = fetch((QRgba64*)destData, srcData, 0, src->width, nullptr, nullptr);
-        if (ptr != (const QRgba64*)destData) {
-            memcpy(destData, ptr, dest->bytes_per_line);
+        int x = 0;
+        while (x < src->width) {
+            int l = src->width - x;
+            if (destLayout->bpp == QPixelLayout::BPP64)
+                buffer = reinterpret_cast<QRgba64 *>(destData) + x;
+            else
+                l = qMin(l, BufferSize);
+            const QRgba64 *ptr = fetch(buffer, srcData, x, l, nullptr, nullptr);
+            store(destData, ptr, x, l, nullptr, nullptr);
+            x += l;
         }
         srcData += src->bytes_per_line;
         destData += dest->bytes_per_line;
@@ -1205,33 +1216,6 @@ static void convert_RGBA64_to_ARGB32(QImageData *dest, const QImageData *src, Qt
 }
 
 template<bool RGBA>
-static void convert_RGBA64PM_to_ARGB32(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags)
-{
-    Q_ASSERT(src->format == QImage::Format_RGBA64_Premultiplied);
-    Q_ASSERT(RGBA || dest->format == QImage::Format_ARGB32);
-    Q_ASSERT(!RGBA || dest->format == QImage::Format_RGBA8888);
-    Q_ASSERT(src->width == dest->width);
-    Q_ASSERT(src->height == dest->height);
-
-    const int src_pad = (src->bytes_per_line >> 3) - src->width;
-    const int dest_pad = (dest->bytes_per_line >> 2) - dest->width;
-    const QRgba64 *src_data = reinterpret_cast<const QRgba64 *>(src->data);
-    uint *dest_data = reinterpret_cast<uint *>(dest->data);
-
-    for (int i = 0; i < src->height; ++i) {
-        const QRgba64 *end = src_data + src->width;
-        while (src_data < end) {
-            QRgba64 s = src_data->unpremultiplied();
-            *dest_data = RGBA ? ARGB2RGBA(s.toArgb32()) : s.toArgb32();
-            ++src_data;
-            ++dest_data;
-        }
-        src_data += src_pad;
-        dest_data += dest_pad;
-    }
-}
-
-template<bool RGBA>
 static void convert_ARGB32_to_RGBA64(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags)
 {
     Q_ASSERT(RGBA || src->format == QImage::Format_ARGB32);
@@ -1240,74 +1224,14 @@ static void convert_ARGB32_to_RGBA64(QImageData *dest, const QImageData *src, Qt
     Q_ASSERT(src->width == dest->width);
     Q_ASSERT(src->height == dest->height);
 
-    const int src_pad = (src->bytes_per_line >> 2) - src->width;
-    const int dest_pad = (dest->bytes_per_line >> 3) - dest->width;
-    const uint *src_data = reinterpret_cast<const uint *>(src->data);
-    QRgba64 *dest_data = reinterpret_cast<QRgba64 *>(dest->data);
-
-    for (int i = 0; i < src->height; ++i) {
-        const uint *end = src_data + src->width;
-        while (src_data < end) {
-            if (RGBA)
-                *dest_data = QRgba64::fromArgb32(RGBA2ARGB(*src_data));
-            else
-                *dest_data = QRgba64::fromArgb32(*src_data);
-            ++src_data;
-            ++dest_data;
-        }
-        src_data += src_pad;
-        dest_data += dest_pad;
-    }
-}
-
-template<QtPixelOrder PixelOrder>
-static void convert_RGBA64PM_to_RGB30(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags)
-{
-    Q_ASSERT(src->format == QImage::Format_RGBA64_Premultiplied);
-    Q_ASSERT(dest->format == QImage::Format_RGB30 || dest->format == QImage::Format_BGR30);
-    Q_ASSERT(src->width == dest->width);
-    Q_ASSERT(src->height == dest->height);
-
-    const int src_pad = (src->bytes_per_line >> 3) - src->width;
-    const int dest_pad = (dest->bytes_per_line >> 2) - dest->width;
-    const QRgba64 *src_data = reinterpret_cast<const QRgba64 *>(src->data);
-    uint *dest_data = reinterpret_cast<uint *>(dest->data);
-
-    for (int i = 0; i < src->height; ++i) {
-        const QRgba64 *end = src_data + src->width;
-        while (src_data < end) {
-            *dest_data = 0xc0000000 | qConvertRgb64ToRgb30<PixelOrder>(src_data->unpremultiplied());
-            ++src_data;
-            ++dest_data;
-        }
-        src_data += src_pad;
-        dest_data += dest_pad;
-    }
-}
-
-template<QtPixelOrder PixelOrder>
-static void convert_RGBA64PM_to_A2RGB30(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags)
-{
-    Q_ASSERT(src->format == QImage::Format_RGBA64_Premultiplied);
-    Q_ASSERT(dest->format == QImage::Format_A2RGB30_Premultiplied
-          || dest->format == QImage::Format_A2BGR30_Premultiplied);
-    Q_ASSERT(src->width == dest->width);
-    Q_ASSERT(src->height == dest->height);
-
-    const int src_pad = (src->bytes_per_line >> 3) - src->width;
-    const int dest_pad = (dest->bytes_per_line >> 2) - dest->width;
-    const QRgba64 *src_data = reinterpret_cast<const QRgba64 *>(src->data);
-    uint *dest_data = reinterpret_cast<uint *>(dest->data);
+    const uchar *src_data = src->data;
+    uchar *dest_data = dest->data;
+    const FetchAndConvertPixelsFunc64 fetch = qPixelLayouts[src->format + 1].fetchToRGBA64PM;
 
     for (int i = 0; i < src->height; ++i) {
-        const QRgba64 *end = src_data + src->width;
-        while (src_data < end) {
-            *dest_data = qConvertRgb64ToRgb30<PixelOrder>(*src_data);
-            ++src_data;
-            ++dest_data;
-        }
-        src_data += src_pad;
-        dest_data += dest_pad;
+        fetch(reinterpret_cast<QRgba64 *>(dest_data), src_data, 0, src->width, nullptr, nullptr);
+        src_data += src->bytes_per_line;;
+        dest_data += dest->bytes_per_line;
     }
 }
 
@@ -2958,7 +2882,6 @@ Image_Converter qimage_converter_map[QImage::NImageFormats][QImage::NImageFormat
         0,
         0,
         0,
-        convert_RGBA64PM_to_ARGB32<false>,
         0,
         0,
         0,
@@ -2970,12 +2893,10 @@ Image_Converter qimage_converter_map[QImage::NImageFormats][QImage::NImageFormat
         0,
         0,
         0,
-        convert_RGBA64PM_to_ARGB32<true>,
         0,
-        convert_RGBA64PM_to_RGB30<PixelOrderBGR>,
-        convert_RGBA64PM_to_A2RGB30<PixelOrderBGR>,
-        convert_RGBA64PM_to_RGB30<PixelOrderRGB>,
-        convert_RGBA64PM_to_A2RGB30<PixelOrderRGB>,
+        0,
+        0,
+        0, 0, 0, 0,
         0, 0,
         convert_RGBA64PM_to_RGBA64<true>,
         convert_RGBA64PM_to_RGBA64<false>,
diff --git a/tests/benchmarks/gui/image/qimageconversion/tst_qimageconversion.cpp b/tests/benchmarks/gui/image/qimageconversion/tst_qimageconversion.cpp
index e0f69bee11..605df100ee 100644
--- a/tests/benchmarks/gui/image/qimageconversion/tst_qimageconversion.cpp
+++ b/tests/benchmarks/gui/image/qimageconversion/tst_qimageconversion.cpp
@@ -200,6 +200,8 @@ void tst_QImageConversion::convertRgb32_data()
     QTest::newRow("argb32 -> argb8565pm") << argb32 << QImage::Format_ARGB8565_Premultiplied;
     QTest::newRow("argb32 -> argb4444pm") << argb32 << QImage::Format_ARGB4444_Premultiplied;
     QTest::newRow("argb32 -> argb6666pm") << argb32 << QImage::Format_ARGB6666_Premultiplied;
+    QTest::newRow("argb32 -> rgba64") << argb32 << QImage::Format_RGBA64;
+    QTest::newRow("argb32 -> rgba64pm") << argb32 << QImage::Format_RGBA64_Premultiplied;
 
     QTest::newRow("argb32pm -> rgb16") << argb32pm << QImage::Format_RGB16;
     QTest::newRow("argb32pm -> rgb32") << argb32pm << QImage::Format_RGB32;
@@ -239,6 +241,7 @@ void tst_QImageConversion::convertGeneric_data()
     QImage a2rgb30 = argb32.convertToFormat(QImage::Format_A2RGB30_Premultiplied);
     QImage rgb666 = rgb32.convertToFormat(QImage::Format_RGB666);
     QImage argb4444 = argb32.convertToFormat(QImage::Format_ARGB4444_Premultiplied);
+    QImage rgba64pm = argb32.convertToFormat(QImage::Format_RGBA64_Premultiplied);
 
     QTest::newRow("indexed8 -> rgb32") << i8 << QImage::Format_RGB32;
     QTest::newRow("indexed8 -> argb32") << i8 << QImage::Format_ARGB32;
@@ -289,6 +292,13 @@ void tst_QImageConversion::convertGeneric_data()
     QTest::newRow("argb4444pm -> rgba8888pm") << argb4444 << QImage::Format_RGBA8888_Premultiplied;
     QTest::newRow("argb4444pm -> rgb30") << argb4444 << QImage::Format_RGB30;
     QTest::newRow("argb4444pm -> a2bgr30") << argb4444 << QImage::Format_A2BGR30_Premultiplied;
+
+    QTest::newRow("rgba64pm -> argb32") << rgba64pm << QImage::Format_ARGB32;
+    QTest::newRow("rgba64pm -> rgbx8888") << rgba64pm << QImage::Format_RGBX8888;
+    QTest::newRow("rgba64pm -> rgba8888pm") << rgba64pm << QImage::Format_RGBA8888_Premultiplied;
+    QTest::newRow("rgba64pm -> rgb30") << rgba64pm << QImage::Format_RGB30;
+    QTest::newRow("rgba64pm -> a2bgr30") << rgba64pm << QImage::Format_A2BGR30_Premultiplied;
+    QTest::newRow("rgba64pm -> rgba64") << rgba64pm << QImage::Format_RGBA64;
 }
 
 void tst_QImageConversion::convertGeneric()