Merge branch '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-2 into 4.7-integration

* '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-2:
  QtDFB: Make transparent windows behave better
  For meego graphics system, use floyd-steinberg dithering when converting to 16bit.
  Added support for blitting to native child widgets in GL window surface.

11 files changed, 395 insertions, 101 deletions

diff --git a/src/opengl/qgl.cpp b/src/opengl/qgl.cpp
index 62eff6e..dbd295f 100644
--- a/src/opengl/qgl.cpp
+++ b/src/opengl/qgl.cpp
@@ -2104,7 +2104,7 @@ void QGLContextPrivate::syncGlState()
 #undef ctx
 
 #ifdef QT_NO_EGL
-void QGLContextPrivate::swapRegion(const QRegion *)
+void QGLContextPrivate::swapRegion(const QRegion &)
 {
     Q_Q(QGLContext);
     q->swapBuffers();
diff --git a/src/opengl/qgl_egl.cpp b/src/opengl/qgl_egl.cpp
index c79c4cd..27f7ad9 100644
--- a/src/opengl/qgl_egl.cpp
+++ b/src/opengl/qgl_egl.cpp
@@ -276,12 +276,12 @@ EGLSurface QGLContextPrivate::eglSurfaceForDevice() const
     return eglSurface;
 }
 
-void QGLContextPrivate::swapRegion(const QRegion *region)
+void QGLContextPrivate::swapRegion(const QRegion &region)
 {
     if (!valid || !eglContext)
         return;
 
-    eglContext->swapBuffersRegion2NOK(eglSurfaceForDevice(), region);
+    eglContext->swapBuffersRegion2NOK(eglSurfaceForDevice(), &region);
 }
 
 void QGLWidget::setMouseTracking(bool enable)
diff --git a/src/opengl/qgl_p.h b/src/opengl/qgl_p.h
index 6c494ee..f86c77f 100644
--- a/src/opengl/qgl_p.h
+++ b/src/opengl/qgl_p.h
@@ -343,7 +343,7 @@ public:
 
     void setVertexAttribArrayEnabled(int arrayIndex, bool enabled = true);
     void syncGlState(); // Makes sure the GL context's state is what we think it is
-    void swapRegion(const QRegion *region);
+    void swapRegion(const QRegion &region);
 
 #if defined(Q_WS_WIN)
     void updateFormatVersion();
diff --git a/src/opengl/qwindowsurface_gl.cpp b/src/opengl/qwindowsurface_gl.cpp
index 8157b2a..9f3dcdf 100644
--- a/src/opengl/qwindowsurface_gl.cpp
+++ b/src/opengl/qwindowsurface_gl.cpp
@@ -275,6 +275,8 @@ struct QGLWindowSurfacePrivate
     QRegion paintedRegion;
     QSize size;
 
+    QSize textureSize;
+
     QList<QImage> buffers;
     QGLWindowSurfaceGLPaintDevice glDevice;
     QGLWindowSurface* q_ptr;
@@ -316,6 +318,7 @@ QGLWindowSurface::QGLWindowSurface(QWidget *window)
     d_ptr->pb = 0;
     d_ptr->fbo = 0;
     d_ptr->ctx = 0;
+    d_ptr->tex_id = 0;
 #if defined (QT_OPENGL_ES_2)
     d_ptr->tried_fbo = true;
     d_ptr->tried_pb = true;
@@ -433,7 +436,7 @@ static void drawTexture(const QRectF &rect, GLuint tex_id, const QSize &texSize,
 
 void QGLWindowSurface::beginPaint(const QRegion &)
 {
-    if (! context())
+    if (!context())
         return;
 
     int clearFlags = 0;
@@ -457,13 +460,42 @@ void QGLWindowSurface::endPaint(const QRegion &rgn)
     d_ptr->buffers.clear();
 }
 
-void QGLWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoint &offset)
+static void blitTexture(QGLContext *ctx, GLuint texture, const QSize &viewport, const QSize &texSize, const QRect &targetRect, const QRect &sourceRect)
 {
-    if (context() && widget != window()) {
-        qWarning("No native child widget support in GL window surface without FBOs or pixel buffers");
-        return;
-    }
+    glDisable(GL_DEPTH_TEST);
+    glDisable(GL_SCISSOR_TEST);
+    glDisable(GL_BLEND);
+
+    glViewport(0, 0, viewport.width(), viewport.height());
+
+    QGLShaderProgram *blitProgram =
+        QGLEngineSharedShaders::shadersForContext(ctx)->blitProgram();
+    blitProgram->bind();
+    blitProgram->setUniformValue("imageTexture", 0 /*QT_IMAGE_TEXTURE_UNIT*/);
+
+    // The shader manager's blit program does not multiply the
+    // vertices by the pmv matrix, so we need to do the effect
+    // of the orthographic projection here ourselves.
+    QRectF r;
+    qreal w = viewport.width();
+    qreal h = viewport.height();
+    r.setLeft((targetRect.left() / w) * 2.0f - 1.0f);
+    if (targetRect.right() == (viewport.width() - 1))
+        r.setRight(1.0f);
+    else
+        r.setRight((targetRect.right() / w) * 2.0f - 1.0f);
+    r.setBottom((targetRect.top() / h) * 2.0f - 1.0f);
+    if (targetRect.bottom() == (viewport.height() - 1))
+        r.setTop(1.0f);
+    else
+        r.setTop((targetRect.bottom() / w) * 2.0f - 1.0f);
+
+    drawTexture(r, texture, texSize, sourceRect);
+}
+
 
+void QGLWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoint &offset)
+{
     //### Find out why d_ptr->geometry_updated isn't always false.
     // flush() should not be called when d_ptr->geometry_updated is true. It assumes that either
     // d_ptr->fbo or d_ptr->pb is allocated and has the correct size.
@@ -534,12 +566,29 @@ void QGLWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoint &
                 }
             }
 #endif
-            if (hasPartialUpdateSupport() &&
-                d_ptr->paintedRegion.boundingRect().width() * d_ptr->paintedRegion.boundingRect().height() <
-                geometry().width() * geometry().height() * 0.2) {
-                context()->d_func()->swapRegion(&d_ptr->paintedRegion);             
-            } else
-                context()->swapBuffers();
+            bool doingPartialUpdate = hasPartialUpdateSupport() && br.width() * br.height() < parent->geometry().width() * parent->geometry().height() * 0.2;
+            QGLContext *ctx = reinterpret_cast<QGLContext *>(parent->d_func()->extraData()->glContext);
+            if (widget != window()) {
+                if (initializeOffscreenTexture(window()->size()))
+                    qWarning() << "QGLWindowSurface: Flushing to native child widget, may lead to significant performance loss";
+                glBindTexture(target, d_ptr->tex_id);
+
+                const uint bottom = window()->height() - (br.y() + br.height());
+                glCopyTexSubImage2D(target, 0, br.x(), bottom, br.x(), bottom, br.width(), br.height());
+
+                glBindTexture(target, 0);
+
+                ctx->makeCurrent();
+                if (doingPartialUpdate)
+                    blitTexture(ctx, d_ptr->tex_id, parent->size(), window()->size(), rect, br);
+                else
+                    blitTexture(ctx, d_ptr->tex_id, parent->size(), window()->size(), parent->rect(), parent->rect().translated(offset + wOffset));
+            }
+
+            if (doingPartialUpdate)
+                ctx->d_func()->swapRegion(br);
+            else
+                ctx->swapBuffers();
 
             d_ptr->paintedRegion = QRegion();
         } else {
@@ -665,38 +714,10 @@ void QGLWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoint &
     else if (d_ptr->fbo) {
         Q_UNUSED(target);
 
-        GLuint texture = d_ptr->fbo->texture();
-
-        glDisable(GL_DEPTH_TEST);
-
         if (d_ptr->fbo->isBound())
             d_ptr->fbo->release();
 
-        glViewport(0, 0, size.width(), size.height());
-
-        QGLShaderProgram *blitProgram =
-            QGLEngineSharedShaders::shadersForContext(ctx)->blitProgram();
-        blitProgram->bind();
-        blitProgram->setUniformValue("imageTexture", 0 /*QT_IMAGE_TEXTURE_UNIT*/);
-
-        // The shader manager's blit program does not multiply the
-        // vertices by the pmv matrix, so we need to do the effect
-        // of the orthographic projection here ourselves.
-        QRectF r;
-        qreal w = size.width() ? size.width() : 1.0f;
-        qreal h = size.height() ? size.height() : 1.0f;
-        r.setLeft((rect.left() / w) * 2.0f - 1.0f);
-        if (rect.right() == (size.width() - 1))
-            r.setRight(1.0f);
-        else
-            r.setRight((rect.right() / w) * 2.0f - 1.0f);
-        r.setBottom((rect.top() / h) * 2.0f - 1.0f);
-        if (rect.bottom() == (size.height() - 1))
-            r.setTop(1.0f);
-        else
-            r.setTop((rect.bottom() / w) * 2.0f - 1.0f);
-
-        drawTexture(r, texture, window()->size(), br);
+        blitTexture(ctx, d_ptr->fbo->texture(), size, window()->size(), rect, br);
     }
 #endif
 
@@ -719,7 +740,6 @@ void QGLWindowSurface::updateGeometry() {
         return;
     d_ptr->geometry_updated = false;
 
-
     QRect rect = geometry();
     hijackWindow(window());
     QGLContext *ctx = reinterpret_cast<QGLContext *>(window()->d_func()->extraData()->glContext);
@@ -740,11 +760,8 @@ void QGLWindowSurface::updateGeometry() {
 
     if (d_ptr->ctx) {
 #ifndef QT_OPENGL_ES_2
-        if (d_ptr->destructive_swap_buffers) {
-            glBindTexture(target, d_ptr->tex_id);
-            glTexImage2D(target, 0, GL_RGBA, rect.width(), rect.height(), 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
-            glBindTexture(target, 0);
-        }
+        if (d_ptr->destructive_swap_buffers)
+            initializeOffscreenTexture(rect.size());
 #endif
         return;
     }
@@ -824,15 +841,8 @@ void QGLWindowSurface::updateGeometry() {
     ctx->makeCurrent();
 
 #ifndef QT_OPENGL_ES_2
-    if (d_ptr->destructive_swap_buffers) {
-        glGenTextures(1, &d_ptr->tex_id);
-        glBindTexture(target, d_ptr->tex_id);
-        glTexImage2D(target, 0, GL_RGBA, rect.width(), rect.height(), 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
-
-        glTexParameterf(target, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-        glTexParameterf(target, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-        glBindTexture(target, 0);
-    }
+    if (d_ptr->destructive_swap_buffers)
+        initializeOffscreenTexture(rect.size());
 #endif
 
     qDebug() << "QGLWindowSurface: Using plain widget as window surface" << this;;
@@ -840,6 +850,23 @@ void QGLWindowSurface::updateGeometry() {
     d_ptr->ctx->d_ptr->internal_context = true;
 }
 
+bool QGLWindowSurface::initializeOffscreenTexture(const QSize &size)
+{
+    if (size == d_ptr->textureSize)
+        return false;
+
+    glGenTextures(1, &d_ptr->tex_id);
+    glBindTexture(GL_TEXTURE_2D, d_ptr->tex_id);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, size.width(), size.height(), 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
+
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glBindTexture(GL_TEXTURE_2D, 0);
+
+    d_ptr->textureSize = size;
+    return true;
+}
+
 bool QGLWindowSurface::scroll(const QRegion &area, int dx, int dy)
 {
     // this code randomly fails currently for unknown reasons
diff --git a/src/opengl/qwindowsurface_gl_p.h b/src/opengl/qwindowsurface_gl_p.h
index ffc2e86..6906f35 100644
--- a/src/opengl/qwindowsurface_gl_p.h
+++ b/src/opengl/qwindowsurface_gl_p.h
@@ -107,6 +107,7 @@ private slots:
 
 private:
     void hijackWindow(QWidget *widget);
+    bool initializeOffscreenTexture(const QSize &size);
 
     QGLWindowSurfacePrivate *d_ptr;
 };
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbscreen.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbscreen.cpp
index bf6164d..f2ee6ae 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbscreen.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbscreen.cpp
@@ -1554,9 +1554,8 @@ void QDirectFBScreen::exposeRegion(QRegion r, int)
                                 : (DSBLIT_BLEND_ALPHACHANNEL|DSBLIT_BLEND_COLORALPHA);
         }
     }
-    if (!region.isEmpty()) {
-        solidFill(d_ptr->backgroundColor, region);
-    }
+
+    solidFill(d_ptr->backgroundColor, region);
 
     while (idx > 0) {
         const PaintCommand &cmd = commands[--idx];
@@ -1629,29 +1628,34 @@ void QDirectFBScreen::solidFill(const QColor &color, const QRegion &region)
     Q_UNUSED(color);
     Q_UNUSED(region);
 #else
+    QDirectFBScreen::solidFill(d_ptr->primarySurface, color, region);
+#endif
+}
+
+static inline void clearRect(IDirectFBSurface *surface, const QColor &color, const QRect &rect)
+{
+    Q_ASSERT(surface);
+    const DFBRegion region = { rect.left(), rect.top(), rect.right(), rect.bottom() };
+    // could just reinterpret_cast this to a DFBRegion
+    surface->SetClip(surface, &region);
+    surface->Clear(surface, color.red(), color.green(), color.blue(), color.alpha());
+}
+
+void QDirectFBScreen::solidFill(IDirectFBSurface *surface, const QColor &color, const QRegion &region)
+{
     if (region.isEmpty())
         return;
 
-    d_ptr->primarySurface->SetColor(d_ptr->primarySurface,
-                                    color.red(), color.green(), color.blue(),
-                                    color.alpha());
     const int n = region.rectCount();
     if (n == 1) {
-        const QRect r = region.boundingRect();
-        d_ptr->primarySurface->FillRectangle(d_ptr->primarySurface, r.x(), r.y(), r.width(), r.height());
+        clearRect(surface, color, region.boundingRect());
     } else {
         const QVector<QRect> rects = region.rects();
-        QVarLengthArray<DFBRectangle, 32> rectArray(n);
         for (int i=0; i<n; ++i) {
-            const QRect &r = rects.at(i);
-            rectArray[i].x = r.x();
-            rectArray[i].y = r.y();
-            rectArray[i].w = r.width();
-            rectArray[i].h = r.height();
+            clearRect(surface, color, rects.at(i));
         }
-        d_ptr->primarySurface->FillRectangles(d_ptr->primarySurface, rectArray.constData(), n);
     }
-#endif
+    surface->SetClip(surface, 0);
 }
 
 QImage::Format QDirectFBScreen::alphaPixmapFormat() const
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbscreen.h b/src/plugins/gfxdrivers/directfb/qdirectfbscreen.h
index c483020..1085423 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbscreen.h
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbscreen.h
@@ -159,6 +159,7 @@ public:
 
     void exposeRegion(QRegion r, int changing);
     void solidFill(const QColor &color, const QRegion &region);
+    static void solidFill(IDirectFBSurface *surface, const QColor &color, const QRegion &region);    
 
     void setMode(int width, int height, int depth);
     void blank(bool on);
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbwindowsurface.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbwindowsurface.cpp
index 51969fc..2eeee24 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbwindowsurface.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbwindowsurface.cpp
@@ -380,11 +380,18 @@ void QDirectFBWindowSurface::flush(QWidget *widget, const QRegion &region,
     flushPending = false;
 }
 
-void QDirectFBWindowSurface::beginPaint(const QRegion &)
+void QDirectFBWindowSurface::beginPaint(const QRegion &region)
 {
     if (!engine) {
         engine = new QDirectFBPaintEngine(this);
     }
+
+    if (dfbSurface) {
+        const QWidget *win = window();
+        if (win && win->testAttribute(Qt::WA_NoSystemBackground)) {
+            QDirectFBScreen::solidFill(dfbSurface, Qt::transparent, region);
+        }
+    }
     flushPending = true;
 }
 
diff --git a/src/plugins/graphicssystems/meego/dithering.cpp b/src/plugins/graphicssystems/meego/dithering.cpp
new file mode 100644
index 0000000..6eeabd3
--- /dev/null
+++ b/src/plugins/graphicssystems/meego/dithering.cpp
@@ -0,0 +1,267 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+// This is an implementation of the 32bit => 16bit Floyd-Steinberg dithering.
+// The alghorithm used here is not the fastest possible but it's prolly fast enough:
+// uses look-up tables, integer-only arthmetics and works in one pass on two lines
+// at a time. It's a high-quality dithering using 1/8 diffusion precission.
+// Two functions here to look at:
+//
+//   * convertRGBA32_to_RGB565
+//   * convertRGBA32_to_RGBA4444
+//
+// Each channel (RGBA) is diffused independently and alpha is dithered too.
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+// Gets a component (red = 1, green = 2...) from a RGBA data structure.
+// data is unsigned char. stride is the number of bytes per line.
+#define GET_RGBA_COMPONENT(data, x, y, stride, c) (data[(y * stride) + (x << 2) + c])
+
+// Writes a new pixel with r, g, b to data in 565 16bit format. Data is a short.
+#define PUT_565(data, x, y, width, r, g, b) (data[(y * width) + x] = (r << 11) | (g << 5) | b)
+
+// Writes a new pixel with r, g, b, a to data in 4444 RGBA 16bit format. Data is a short.
+#define PUT_4444(data, x, y, width, r, g, b, a) (data[(y * width) + x] = (r << 12) | (g << 8) | (b << 4) | a)
+
+// Writes(ads) a new value to the diffusion accumulator. accumulator is a short.
+// x, y is a position in the accumulation buffer. y can be 0 or 1 -- we operate on two lines at time.
+#define ACCUMULATE(accumulator, x, y, width, v) if (x < width && x > 0) accumulator[(y * width) + x] += v
+
+// Clamps a value to be in 0..255 range.
+#define CLAMP_256(v) if (v > 255) v = 255; if (v < 0) v = 0;
+
+// Converts incoming RGB32 (QImage::Format_RGB32) to RGB565. Returns the newly allocated data.
+unsigned short* convertRGB32_to_RGB565(const unsigned char *in, int width, int height, int stride)
+{
+    // Will store output
+    unsigned short *out = (unsigned short *) malloc(width * height * 2);
+
+    // Lookup tables for the 8bit => 6bit and 8bit => 5bit conversion
+    unsigned char lookup_8bit_to_5bit[256];
+    short lookup_8bit_to_5bit_diff[256];
+    unsigned char lookup_8bit_to_6bit[256];
+    short lookup_8bit_to_6bit_diff[256];
+
+    // Macros for the conversion using the lookup table.
+    #define CONVERT_8BIT_TO_5BIT(v) (lookup_8bit_to_5bit[v])
+    #define DIFF_8BIT_TO_5BIT(v) (lookup_8bit_to_5bit_diff[v])
+
+    #define CONVERT_8BIT_TO_6BIT(v) (lookup_8bit_to_6bit[v])
+    #define DIFF_8BIT_TO_6BIT(v) (lookup_8bit_to_6bit_diff[v])
+
+    int i;
+    int x, y, c; // Pixel we're processing. c is component number (0, 1, 2 for r, b, b)
+    short component[3]; // Stores the new components (r, g, b) for pixel produced during conversion
+    short diff; // The difference between the converted value and the original one. To be accumulated.
+    short accumulator[3][width * 2]; // Three acumulators for r, g, b. Each accumulator is two lines.
+
+    // Produce the conversion lookup tables.
+    for (i = 0; i < 256; i++) {
+        lookup_8bit_to_5bit[i] = round(i / 8.0);
+        if (lookup_8bit_to_5bit[i] > 31)
+            lookup_8bit_to_5bit[i] -= 1;
+
+        // Before bitshifts: (i * 8) - (... * 8 * 8)
+        lookup_8bit_to_5bit_diff[i] = (i << 3) - (lookup_8bit_to_5bit[i] << 6);
+
+        lookup_8bit_to_6bit[i] = round(i / 4.0);
+        if (lookup_8bit_to_6bit[i] > 63)
+            lookup_8bit_to_6bit[i] -= 1;
+
+        // Before bitshifts: (i * 8) - (... * 4 * 8)
+        lookup_8bit_to_6bit_diff[i] = (i << 3) - (lookup_8bit_to_6bit[i] << 5);
+    }
+
+    // Clear the accumulators
+    memset(accumulator[0], 0, width * 4);
+    memset(accumulator[1], 0, width * 4);
+    memset(accumulator[2], 0, width * 4);
+
+    // For each line...
+    for (y = 0; y < height; y++) {
+
+        // For each accumulator, move the second line (index 1) to replace the first line (index 0).
+        // Clear the second line (index 1)
+        memcpy(accumulator[0], accumulator[0] + width, width * 2);
+        memset(accumulator[0] + width, 0, width * 2);
+
+        memcpy(accumulator[1], accumulator[1] + width, width * 2);
+        memset(accumulator[1] + width, 0, width * 2);
+
+        memcpy(accumulator[2], accumulator[2] + width, width * 2);
+        memset(accumulator[2] + width, 0, width * 2);
+
+        // For each column....
+        for (x = 0; x < width; x++) {
+
+            // For each component (r, g, b)...
+            for (c = 0; c < 3; c++) {
+
+                // Get the 8bit value from the original image
+                component[c] = GET_RGBA_COMPONENT(in, x, y, stride, c);
+
+                // Add the diffusion for this pixel we stored in the accumulator.
+                // >> 7 because the values in accumulator are stored * 128
+                component[c] += accumulator[c][x] >> 7;
+
+                // Make sure we're not over the boundries.
+                CLAMP_256(component[c]);
+
+                // For green component we use 6 bits. Otherwise 5 bits.
+                // Store the difference from converting 8bit => 6 bit and the orig pixel.
+                // Convert 8bit => 6(5) bit.
+                if (c == 1) {
+                    diff = DIFF_8BIT_TO_6BIT(component[c]);
+                    component[c] = CONVERT_8BIT_TO_6BIT(component[c]);
+                } else {
+                    diff = DIFF_8BIT_TO_5BIT(component[c]);
+                    component[c] = CONVERT_8BIT_TO_5BIT(component[c]);
+                }
+
+                // Distribute the difference according to the matrix in the
+                // accumulation bufffer.
+                ACCUMULATE(accumulator[c], x + 1, 0, width, diff * 7);
+                ACCUMULATE(accumulator[c], x - 1, 1, width, diff * 3);
+                ACCUMULATE(accumulator[c], x, 1, width, diff * 5);
+                ACCUMULATE(accumulator[c], x + 1, 1, width, diff * 1);
+            }
+
+            // Write the newly produced pixel
+            PUT_565(out, x, y, width, component[2], component[1], component[0]);
+        }
+    }
+
+    return out;
+}
+
+// Converts incoming RGBA32 (QImage::Format_ARGB32_Premultiplied) to RGB565. Returns the newly allocated data.
+// This function is similiar (yet different) to the _565 variant but it makes sense to duplicate it here for simplicity.
+unsigned short* convertARGB32_to_RGBA4444(const unsigned char *in, int width, int height, int stride)
+{
+    // Will store output
+    unsigned short *out = (unsigned short *) malloc(width * height * 2);
+
+    // Lookup tables for the 8bit => 4bit conversion
+    unsigned char lookup_8bit_to_4bit[256];
+    short lookup_8bit_to_4bit_diff[256];
+
+    // Macros for the conversion using the lookup table.
+    #define CONVERT_8BIT_TO_4BIT(v) (lookup_8bit_to_4bit[v])
+    #define DIFF_8BIT_TO_4BIT(v) (lookup_8bit_to_4bit_diff[v])
+
+    int i;
+    int x, y, c; // Pixel we're processing. c is component number (0, 1, 2, 3 for r, b, b, a)
+    short component[4]; // Stores the new components (r, g, b, a) for pixel produced during conversion
+    short diff; // The difference between the converted value and the original one. To be accumulated.
+    short accumulator[4][width * 2]; // Four acumulators for r, g, b, a. Each accumulator is two lines.
+
+    // Produce the conversion lookup tables.
+    for (i = 0; i < 256; i++) {
+        lookup_8bit_to_4bit[i] = round(i / 16.0);
+        if (lookup_8bit_to_4bit[i] > 15)
+            lookup_8bit_to_4bit[i] -= 1;
+
+        // Before bitshifts: (i * 8) - (... * 16 * 8)
+        lookup_8bit_to_4bit_diff[i] = (i << 3) - (lookup_8bit_to_4bit[i] << 7);
+    }
+
+    // Clear the accumulators
+    memset(accumulator[0], 0, width * 4);
+    memset(accumulator[1], 0, width * 4);
+    memset(accumulator[2], 0, width * 4);
+    memset(accumulator[3], 0, width * 4);
+
+    // For each line...
+    for (y = 0; y < height; y++) {
+
+        // For each component (r, g, b, a)...
+        memcpy(accumulator[0], accumulator[0] + width, width * 2);
+        memset(accumulator[0] + width, 0, width * 2);
+
+        memcpy(accumulator[1], accumulator[1] + width, width * 2);
+        memset(accumulator[1] + width, 0, width * 2);
+
+        memcpy(accumulator[2], accumulator[2] + width, width * 2);
+        memset(accumulator[2] + width, 0, width * 2);
+
+        memcpy(accumulator[3], accumulator[3] + width, width * 2);
+        memset(accumulator[3] + width, 0, width * 2);
+
+        // For each column....
+        for (x = 0; x < width; x++) {
+
+            // For each component (r, g, b, a)...
+            for (c = 0; c < 4; c++) {
+
+                // Get the 8bit value from the original image
+                component[c] = GET_RGBA_COMPONENT(in, x, y, stride, c);
+
+                // Add the diffusion for this pixel we stored in the accumulator.
+                // >> 7 because the values in accumulator are stored * 128
+                component[c] += accumulator[c][x] >> 7;
+
+                // Make sure we're not over the boundries.
+                CLAMP_256(component[c]);
+
+                // Store the difference from converting 8bit => 4bit and the orig pixel.
+                // Convert 8bit => 4bit.
+                diff = DIFF_8BIT_TO_4BIT(component[c]);
+                component[c] = CONVERT_8BIT_TO_4BIT(component[c]);
+
+                // Distribute the difference according to the matrix in the
+                // accumulation bufffer.
+                ACCUMULATE(accumulator[c], x + 1, 0, width, diff * 7);
+                ACCUMULATE(accumulator[c], x - 1, 1, width, diff * 3);
+                ACCUMULATE(accumulator[c], x, 1, width, diff * 5);
+                ACCUMULATE(accumulator[c], x + 1, 1, width, diff * 1);
+            }
+
+            // Write the newly produced pixel
+            PUT_4444(out, x, y, width, component[0], component[1], component[2], component[3]);
+        }
+    }
+
+    return out;
+}
diff --git a/src/plugins/graphicssystems/meego/meego.pro b/src/plugins/graphicssystems/meego/meego.pro
index 0b157fa..0d3cce6 100644
--- a/src/plugins/graphicssystems/meego/meego.pro
+++ b/src/plugins/graphicssystems/meego/meego.pro
@@ -6,7 +6,7 @@ QT += gui opengl
 QTDIR_build:DESTDIR = $$QT_BUILD_TREE/plugins/graphicssystems
 
 HEADERS = qmeegographicssystem.h qmeegopixmapdata.h qmeegoextensions.h qmeegorasterpixmapdata.h qmeegolivepixmapdata.h
-SOURCES = qmeegographicssystem.cpp qmeegographicssystem.h qmeegographicssystemplugin.h qmeegographicssystemplugin.cpp qmeegopixmapdata.h qmeegopixmapdata.cpp qmeegoextensions.h qmeegoextensions.cpp qmeegorasterpixmapdata.h qmeegorasterpixmapdata.cpp qmeegolivepixmapdata.cpp qmeegolivepixmapdata.h
+SOURCES = qmeegographicssystem.cpp qmeegographicssystem.h qmeegographicssystemplugin.h qmeegographicssystemplugin.cpp qmeegopixmapdata.h qmeegopixmapdata.cpp qmeegoextensions.h qmeegoextensions.cpp qmeegorasterpixmapdata.h qmeegorasterpixmapdata.cpp qmeegolivepixmapdata.cpp qmeegolivepixmapdata.h dithering.cpp
 
 target.path += $$[QT_INSTALL_PLUGINS]/graphicssystems
 INSTALLS += target
diff --git a/src/plugins/graphicssystems/meego/qmeegopixmapdata.cpp b/src/plugins/graphicssystems/meego/qmeegopixmapdata.cpp
index 0899f2d..02a4273 100644
--- a/src/plugins/graphicssystems/meego/qmeegopixmapdata.cpp
+++ b/src/plugins/graphicssystems/meego/qmeegopixmapdata.cpp
@@ -48,28 +48,14 @@
 #include <private/qapplication_p.h>
 #include <private/qgraphicssystem_runtime_p.h>
 
+// from dithering.cpp
+extern unsigned short* convertRGB32_to_RGB565(const unsigned char *in, int width, int height, int stride);
+extern unsigned short* convertARGB32_to_RGBA4444(const unsigned char *in, int width, int height, int stride);
+
 static EGLint preserved_image_attribs[] = { EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, EGL_NONE };
 
 QHash <void*, QMeeGoImageInfo*> QMeeGoPixmapData::sharedImagesMap;
 
-// This helper method converts (in place) a QImage::Format_ARGB4444_Premultiplied to 
-// GL-friendly Format_RGBA4444_Premultiplied. Just swaps the bits around really.
-static void qARGBA4ToRGBA4(QImage *image)
-{
-    unsigned char *raw = static_cast <unsigned char *> (image->data_ptr()->data);
-    // FIXME image.bytesPerLine() is broken. Returns 512 for 128x128 image while it should
-    // return 256
-    int bytesPerLine = image->width() * 2;
-
-    for (int y = 0; y < image->height(); y++) {
-        for (int x = 0; x < image->width(); x++) {
-            unsigned short *target = (unsigned short *) (raw + (y * bytesPerLine + (x * 2)));
-            // FIXME Oh yeah, that's broken with endianness.
-            *target = (*target << 4) | (* target >> 12);
-        }
-    }
-}
-
 /* Public */
 
 QMeeGoPixmapData::QMeeGoPixmapData() : QGLPixmapData(QPixmapData::PixmapType)
@@ -160,12 +146,13 @@ Qt::HANDLE QMeeGoPixmapData::imageToEGLSharedImage(const QImage &image)
     glGenTextures(1, &textureId);
     glBindTexture(GL_TEXTURE_2D, textureId);
     if (image.hasAlphaChannel() && const_cast<QImage &>(image).data_ptr()->checkForAlphaPixels()) {
-        QImage convertedImage = image.convertToFormat(QImage::Format_ARGB4444_Premultiplied, Qt::DiffuseAlphaDither | Qt::DiffuseDither | Qt::PreferDither);
-        qARGBA4ToRGBA4(&convertedImage);
-        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, image.width(), image.height(), 0, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, convertedImage.bits());
+        void *converted = convertARGB32_to_RGBA4444(image.bits(), image.width(), image.height(), image.bytesPerLine());
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, image.width(), image.height(), 0, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, converted);
+        free(converted);
     } else {
-        QImage convertedImage = image.convertToFormat(QImage::Format_RGB16, Qt::DiffuseAlphaDither | Qt::DiffuseDither | Qt::PreferDither);
-        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, image.width(), image.height(), 0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, convertedImage.bits());
+        void *converted = convertRGB32_to_RGB565(image.bits(), image.width(), image.height(), image.bytesPerLine());
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, image.width(), image.height(), 0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, converted);
+        free(converted);
     }
 
     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);