Changeset 70424 in webkit

Timestamp:

Oct 24, 2010 2:08:20 PM (13 years ago)

Author:

andreas.kling@nokia.com

Message:

2010-10-24 Andreas Kling <​kling@webkit.org>

Reviewed by Kenneth Rohde Christiansen.

[Qt] ImageBuffer::platformTransformColorSpace is unnecessarily slow
​https://bugs.webkit.org/show_bug.cgi?id=48211

Grab the QImage::bits() and do direct access instead of going through
QImage::pixel() and QImage::setPixel().

This is a performance optimization, so no new tests.

• platform/graphics/qt/ImageBufferQt.cpp: (WebCore::ImageBuffer::platformTransformColorSpace):

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/qt/ImageBufferQt.cpp (modified) (1 diff)

trunk/WebCore/ChangeLog

@@ +1 @@
+2010-10-24  Andreas Kling  <kling@webkit.org>
+
+        Reviewed by Kenneth Rohde Christiansen.
+
+        [Qt] ImageBuffer::platformTransformColorSpace is unnecessarily slow
+        https://bugs.webkit.org/show_bug.cgi?id=48211
+
+        Grab the QImage::bits() and do direct access instead of going through
+        QImage::pixel() and QImage::setPixel().
+
+        This is a performance optimization, so no new tests.
+
+        * platform/graphics/qt/ImageBufferQt.cpp:
+        (WebCore::ImageBuffer::platformTransformColorSpace):
+
 2010-10-24  Dirk Schulze  <krit@webkit.org>
 

trunk/WebCore/platform/graphics/qt/ImageBufferQt.cpp

@@ -158 +158 @@
     ASSERT(!image.isNull());
 
+    uchar* bits = image.bits();
+    const int bytesPerLine = image.bytesPerLine();
+
     for (int y = 0; y < m_size.height(); ++y) {
-        for (int x = 0; x < m_size.width(); x++) {
-            QRgb value = image.pixel(x, y);
-            value = qRgba(lookUpTable[qRed(value)],
-                          lookUpTable[qGreen(value)],
-                          lookUpTable[qBlue(value)],
-                          qAlpha(value));
-            image.setPixel(x, y, value);
+        quint32* scanLine = reinterpret_cast_ptr<quint32*>(bits + y * bytesPerLine);
+        for (int x = 0; x < m_size.width(); ++x) {
+            QRgb& pixel = scanLine[x];
+            pixel = qRgba(lookUpTable[qRed(pixel)],
+                          lookUpTable[qGreen(pixel)],
+                          lookUpTable[qBlue(pixel)],
+                          qAlpha(pixel));
         }
     }