Add distance field generation functions from Scenegraph

Since we may use distance field text rendering in raster, these
functions need to be moved from declarative to QtGui.

Change-Id: I158bc3bae02b5590ae812f06ad7a78a5914bcb9e
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@nokia.com>

1 files changed, 762 insertions, 0 deletions

diff --git a/src/gui/text/qdistancefield.cpp b/src/gui/text/qdistancefield.cpp
new file mode 100644
index 0000000000..fb06a26c8f
--- /dev/null
+++ b/src/gui/text/qdistancefield.cpp
@@ -0,0 +1,762 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/
+**
+** This file is part of the QtDeclarative module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** 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.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qdistancefield_p.h"
+#include <qmath.h>
+#include <private/qdatabuffer_p.h>
+#include <private/qpathsimplifier_p.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace
+{
+    enum FillHDir
+    {
+        LeftToRight,
+        RightToLeft
+    };
+
+    enum FillVDir
+    {
+        TopDown,
+        BottomUp
+    };
+
+    enum FillClip
+    {
+        NoClip,
+        Clip
+    };
+}
+
+template <FillClip clip, FillHDir dir>
+inline void fillLine(qint32 *, int, int, int, qint32, qint32)
+{
+}
+
+template <>
+inline void fillLine<Clip, LeftToRight>(qint32 *line, int width, int lx, int rx, qint32 d, qint32 dd)
+{
+    int fromX = qMax(0, lx >> 8);
+    int toX = qMin(width, rx >> 8);
+    int x = toX - fromX;
+    if (x <= 0)
+        return;
+    qint32 val = d + (((fromX << 8) + 0xff - lx) * dd >> 8);
+    line += fromX;
+    do {
+        *line = abs(val) < abs(*line) ? val : *line;
+        val += dd;
+        ++line;
+    } while (--x);
+}
+
+template <>
+inline void fillLine<Clip, RightToLeft>(qint32 *line, int width, int lx, int rx, qint32 d, qint32 dd)
+{
+    int fromX = qMax(0, lx >> 8);
+    int toX = qMin(width, rx >> 8);
+    int x = toX - fromX;
+    if (x <= 0)
+        return;
+    qint32 val = d + (((toX << 8) + 0xff - rx) * dd >> 8);
+    line += toX;
+    do {
+        val -= dd;
+        --line;
+        *line = abs(val) < abs(*line) ? val : *line;
+    } while (--x);
+}
+
+template <>
+inline void fillLine<NoClip, LeftToRight>(qint32 *line, int, int lx, int rx, qint32 d, qint32 dd)
+{
+    int fromX = lx >> 8;
+    int toX = rx >> 8;
+    int x = toX - fromX;
+    if (x <= 0)
+        return;
+    qint32 val = d + ((~lx & 0xff) * dd >> 8);
+    line += fromX;
+    do {
+        *line = abs(val) < abs(*line) ? val : *line;
+        val += dd;
+        ++line;
+    } while (--x);
+}
+
+template <>
+inline void fillLine<NoClip, RightToLeft>(qint32 *line, int, int lx, int rx, qint32 d, qint32 dd)
+{
+    int fromX = lx >> 8;
+    int toX = rx >> 8;
+    int x = toX - fromX;
+    if (x <= 0)
+        return;
+    qint32 val = d + ((~rx & 0xff) * dd >> 8);
+    line += toX;
+    do {
+        val -= dd;
+        --line;
+        *line = abs(val) < abs(*line) ? val : *line;
+    } while (--x);
+}
+
+template <FillClip clip, FillVDir vDir, FillHDir hDir>
+inline void fillLines(qint32 *bits, int width, int height, int upperY, int lowerY,
+                      int &lx, int ldx, int &rx, int rdx, qint32 &d, qint32 ddy, qint32 ddx)
+{
+    Q_UNUSED(height);
+    Q_ASSERT(upperY < lowerY);
+    int y = lowerY - upperY;
+    if (vDir == TopDown) {
+        qint32 *line = bits + upperY * width;
+        do {
+            fillLine<clip, hDir>(line, width, lx, rx, d, ddx);
+            lx += ldx;
+            d += ddy;
+            rx += rdx;
+            line += width;
+        } while (--y);
+    } else {
+        qint32 *line = bits + lowerY * width;
+        do {
+            lx -= ldx;
+            d -= ddy;
+            rx -= rdx;
+            line -= width;
+            fillLine<clip, hDir>(line, width, lx, rx, d, ddx);
+        } while (--y);
+    }
+}
+
+template <FillClip clip>
+void drawTriangle(qint32 *bits, int width, int height, const QPoint *center,
+                  const QPoint *v1, const QPoint *v2, qint32 value)
+{
+    const int y1 = clip == Clip ? qBound(0, v1->y() >> 8, height) : v1->y() >> 8;
+    const int y2 = clip == Clip ? qBound(0, v2->y() >> 8, height) : v2->y() >> 8;
+    const int yC = clip == Clip ? qBound(0, center->y() >> 8, height) : center->y() >> 8;
+
+    const int v1Frac = clip == Clip ? (y1 << 8) + 0xff - v1->y() : ~v2->y() & 0xff;
+    const int v2Frac = clip == Clip ? (y2 << 8) + 0xff - v2->y() : ~v1->y() & 0xff;
+    const int centerFrac = clip == Clip ? (yC << 8) + 0xff - center->y() : ~center->y() & 0xff;
+
+    int dx1 = 0, x1 = 0, dx2 = 0, x2 = 0;
+    qint32 dd1, d1, dd2, d2;
+    if (v1->y() != center->y()) {
+        dx1 = ((v1->x() - center->x()) << 8) / (v1->y() - center->y());
+        x1 = center->x() + centerFrac * (v1->x() - center->x()) / (v1->y() - center->y());
+    }
+    if (v2->y() != center->y()) {
+        dx2 = ((v2->x() - center->x()) << 8) / (v2->y() - center->y());
+        x2 = center->x() + centerFrac * (v2->x() - center->x()) / (v2->y() - center->y());
+    }
+
+    const qint32 div = (v2->x() - center->x()) * (v1->y() - center->y())
+                     - (v2->y() - center->y()) * (v1->x() - center->x());
+    const qint32 dd = div ? qint32((qint64(value * (v1->y() - v2->y())) << 8) / div) : 0;
+
+    if (y2 < yC) {
+        if (y1 < yC) {
+            // Center at the bottom.
+            if (y2 < y1) {
+                // y2 < y1 < yC
+                // Long right edge.
+                d1 = centerFrac * value / (v1->y() - center->y());
+                dd1 = ((value << 8) / (v1->y() - center->y()));
+                fillLines<clip, BottomUp, LeftToRight>(bits, width, height, y1, yC, x1, dx1,
+                                                       x2, dx2, d1, dd1, dd);
+                dx1 = ((v1->x() - v2->x()) << 8) / (v1->y() - v2->y());
+                x1 = v1->x() + v1Frac * (v1->x() - v2->x()) / (v1->y() - v2->y());
+                fillLines<clip, BottomUp, LeftToRight>(bits, width, height, y2, y1, x1, dx1,
+                                                       x2, dx2, value, 0, dd);
+            } else {
+                // y1 <= y2 < yC
+                // Long left edge.
+                d2 = centerFrac * value / (v2->y() - center->y());
+                dd2 = ((value << 8) / (v2->y() - center->y()));
+                fillLines<clip, BottomUp, RightToLeft>(bits, width, height, y2, yC, x1, dx1,
+                                                       x2, dx2, d2, dd2, dd);
+                if (y1 != y2) {
+                    dx2 = ((v1->x() - v2->x()) << 8) / (v1->y() - v2->y());
+                    x2 = v2->x() + v2Frac * (v1->x() - v2->x()) / (v1->y() - v2->y());
+                    fillLines<clip, BottomUp, RightToLeft>(bits, width, height, y1, y2, x1, dx1,
+                                                           x2, dx2, value, 0, dd);
+                }
+            }
+        } else {
+            // y2 < yC <= y1
+            // Center to the right.
+            int dx = ((v1->x() - v2->x()) << 8) / (v1->y() - v2->y());
+            int xUp, xDn;
+            xUp = xDn = v2->x() + (clip == Clip ? (yC << 8) + 0xff - v2->y()
+                                                : (center->y() | 0xff) - v2->y())
+                        * (v1->x() - v2->x()) / (v1->y() - v2->y());
+            fillLines<clip, BottomUp, LeftToRight>(bits, width, height, y2, yC, xUp, dx,
+                                                   x2, dx2, value, 0, dd);
+            if (yC != y1)
+                fillLines<clip, TopDown, LeftToRight>(bits, width, height, yC, y1, xDn, dx,
+                                                      x1, dx1, value, 0, dd);
+        }
+    } else {
+        if (y1 < yC) {
+            // y1 < yC <= y2
+            // Center to the left.
+            int dx = ((v1->x() - v2->x()) << 8) / (v1->y() - v2->y());
+            int xUp, xDn;
+            xUp = xDn = v1->x() + (clip == Clip ? (yC << 8) + 0xff - v1->y()
+                                                : (center->y() | 0xff) - v1->y())
+                        * (v1->x() - v2->x()) / (v1->y() - v2->y());
+            fillLines<clip, BottomUp, RightToLeft>(bits, width, height, y1, yC, x1, dx1,
+                                                   xUp, dx, value, 0, dd);
+            if (yC != y2)
+                fillLines<clip, TopDown, RightToLeft>(bits, width, height, yC, y2, x2, dx2,
+                                                      xDn, dx, value, 0, dd);
+        } else {
+            // Center at the top.
+            if (y2 < y1) {
+                // yC <= y2 < y1
+                // Long right edge.
+                if (yC != y2) {
+                    d2 = centerFrac * value / (v2->y() - center->y());
+                    dd2 = ((value << 8) / (v2->y() - center->y()));
+                    fillLines<clip, TopDown, LeftToRight>(bits, width, height, yC, y2, x2, dx2,
+                                                          x1, dx1, d2, dd2, dd);
+                }
+                dx2 = ((v1->x() - v2->x()) << 8) / (v1->y() - v2->y());
+                x2 = v2->x() + v2Frac * (v1->x() - v2->x()) / (v1->y() - v2->y());
+                fillLines<clip, TopDown, LeftToRight>(bits, width, height, y2, y1, x2, dx2,
+                                                      x1, dx1, value, 0, dd);
+            } else {
+                // Long left edge.
+                // yC <= y1 <= y2
+                if (yC != y1) {
+                    d1 = centerFrac * value / (v1->y() - center->y());
+                    dd1 = ((value << 8) / (v1->y() - center->y()));
+                    fillLines<clip, TopDown, RightToLeft>(bits, width, height, yC, y1, x2, dx2,
+                                                          x1, dx1, d1, dd1, dd);
+                }
+                if (y1 != y2) {
+                    dx1 = ((v1->x() - v2->x()) << 8) / (v1->y() - v2->y());
+                    x1 = v1->x() + v1Frac * (v1->x() - v2->x()) / (v1->y() - v2->y());
+                    fillLines<clip, TopDown, RightToLeft>(bits, width, height, y1, y2, x2, dx2,
+                                                          x1, dx1, value, 0, dd);
+                }
+            }
+        }
+    }
+}
+
+template <FillClip clip>
+void drawRectangle(qint32 *bits, int width, int height,
+                   const QPoint *int1, const QPoint *center1, const QPoint *ext1,
+                   const QPoint *int2, const QPoint *center2, const QPoint *ext2,
+                   qint32 extValue)
+{
+    if (center1->y() > center2->y()) {
+        qSwap(center1, center2);
+        qSwap(int1, ext2);
+        qSwap(ext1, int2);
+        extValue = -extValue;
+    }
+
+    Q_ASSERT(ext1->x() - center1->x() == center1->x() - int1->x());
+    Q_ASSERT(ext1->y() - center1->y() == center1->y() - int1->y());
+    Q_ASSERT(ext2->x() - center2->x() == center2->x() - int2->x());
+    Q_ASSERT(ext2->y() - center2->y() == center2->y() - int2->y());
+
+    const int yc1 = clip == Clip ? qBound(0, center1->y() >> 8, height) : center1->y() >> 8;
+    const int yc2 = clip == Clip ? qBound(0, center2->y() >> 8, height) : center2->y() >> 8;
+    const int yi1 = clip == Clip ? qBound(0, int1->y() >> 8, height) : int1->y() >> 8;
+    const int yi2 = clip == Clip ? qBound(0, int2->y() >> 8, height) : int2->y() >> 8;
+    const int ye1 = clip == Clip ? qBound(0, ext1->y() >> 8, height) : ext1->y() >> 8;
+    const int ye2 = clip == Clip ? qBound(0, ext2->y() >> 8, height) : ext2->y() >> 8;
+
+    const int center1Frac = clip == Clip ? (yc1 << 8) + 0xff - center1->y() : ~center1->y() & 0xff;
+    const int center2Frac = clip == Clip ? (yc2 << 8) + 0xff - center2->y() : ~center2->y() & 0xff;
+    const int int1Frac = clip == Clip ? (yi1 << 8) + 0xff - int1->y() : ~int1->y() & 0xff;
+    const int ext1Frac = clip == Clip ? (ye1 << 8) + 0xff - ext1->y() : ~ext1->y() & 0xff;
+
+    int dxC = 0, dxE = 0; // cap slope, edge slope
+    qint32 ddC = 0;
+    if (ext1->y() != int1->y()) {
+        dxC = ((ext1->x() - int1->x()) << 8) / (ext1->y() - int1->y());
+        ddC = (extValue << 9) / (ext1->y() - int1->y());
+    }
+    if (ext1->y() != ext2->y())
+        dxE = ((ext1->x() - ext2->x()) << 8) / (ext1->y() - ext2->y());
+
+    const qint32 div = (ext1->x() - int1->x()) * (ext2->y() - int1->y())
+                     - (ext1->y() - int1->y()) * (ext2->x() - int1->x());
+    const qint32 dd = div ? qint32((qint64(extValue * (ext2->y() - ext1->y())) << 9) / div) : 0;
+
+    int xe1, xe2, xc1, xc2;
+    qint32 d;
+
+    qint32 intValue = -extValue;
+
+    if (center2->x() < center1->x()) {
+        // Leaning to the right. '/'
+        if (int1->y() < ext2->y()) {
+            // Mostly vertical.
+            Q_ASSERT(ext1->y() != ext2->y());
+            xe1 = ext1->x() + ext1Frac * (ext1->x() - ext2->x()) / (ext1->y() - ext2->y());
+            xe2 = int1->x() + int1Frac * (ext1->x() - ext2->x()) / (ext1->y() - ext2->y());
+            if (ye1 != yi1) {
+                xc2 = center1->x() + center1Frac * (ext1->x() - int1->x()) / (ext1->y() - int1->y());
+                xc2 += (ye1 - yc1) * dxC;
+                fillLines<clip, TopDown, LeftToRight>(bits, width, height, ye1, yi1, xe1, dxE,
+                                                      xc2, dxC, extValue, 0, dd);
+            }
+            if (yi1 != ye2)
+                fillLines<clip, TopDown, LeftToRight>(bits, width, height, yi1, ye2, xe1, dxE,
+                                                      xe2, dxE, extValue, 0, dd);
+            if (ye2 != yi2) {
+                xc1 = center2->x() + center2Frac * (ext1->x() - int1->x()) / (ext1->y() - int1->y());
+                xc1 += (ye2 - yc2) * dxC;
+                fillLines<clip, TopDown, RightToLeft>(bits, width, height, ye2, yi2, xc1, dxC,
+                                                      xe2, dxE, intValue, 0, dd);
+            }
+        } else {
+            // Mostly horizontal.
+            Q_ASSERT(ext1->y() != int1->y());
+            xc1 = center2->x() + center2Frac * (ext1->x() - int1->x()) / (ext1->y() - int1->y());
+            xc2 = center1->x() + center1Frac * (ext1->x() - int1->x()) / (ext1->y() - int1->y());
+            xc1 += (ye2 - yc2) * dxC;
+            xc2 += (ye1 - yc1) * dxC;
+            if (ye1 != ye2) {
+                xe1 = ext1->x() + ext1Frac * (ext1->x() - ext2->x()) / (ext1->y() - ext2->y());
+                fillLines<clip, TopDown, LeftToRight>(bits, width, height, ye1, ye2, xe1, dxE,
+                                                      xc2, dxC, extValue, 0, dd);
+            }
+            if (ye2 != yi1) {
+                d = (clip == Clip ? (ye2 << 8) + 0xff - center2->y()
+                                  : (ext2->y() | 0xff) - center2->y())
+                    * 2 * extValue / (ext1->y() - int1->y());
+                fillLines<clip, TopDown, LeftToRight>(bits, width, height, ye2, yi1, xc1, dxC,
+                                                      xc2, dxC, d, ddC, dd);
+            }
+            if (yi1 != yi2) {
+                xe2 = int1->x() + int1Frac * (ext1->x() - ext2->x()) / (ext1->y() - ext2->y());
+                fillLines<clip, TopDown, RightToLeft>(bits, width, height, yi1, yi2, xc1, dxC,
+                                                      xe2, dxE, intValue, 0, dd);
+            }
+        }
+    } else {
+        // Leaning to the left. '\'
+        if (ext1->y() < int2->y()) {
+            // Mostly vertical.
+            Q_ASSERT(ext1->y() != ext2->y());
+            xe1 = ext1->x() + ext1Frac * (ext1->x() - ext2->x()) / (ext1->y() - ext2->y());
+            xe2 = int1->x() + int1Frac * (ext1->x() - ext2->x()) / (ext1->y() - ext2->y());
+            if (yi1 != ye1) {
+                xc1 = center1->x() + center1Frac * (ext1->x() - int1->x()) / (ext1->y() - int1->y());
+                xc1 += (yi1 - yc1) * dxC;
+                fillLines<clip, TopDown, RightToLeft>(bits, width, height, yi1, ye1, xc1, dxC,
+                                                      xe2, dxE, intValue, 0, dd);
+            }
+            if (ye1 != yi2)
+                fillLines<clip, TopDown, RightToLeft>(bits, width, height, ye1, yi2, xe1, dxE,
+                                                      xe2, dxE, intValue, 0, dd);
+            if (yi2 != ye2) {
+                xc2 = center2->x() + center2Frac * (ext1->x() - int1->x()) / (ext1->y() - int1->y());
+                xc2 += (yi2 - yc2) * dxC;
+                fillLines<clip, TopDown, LeftToRight>(bits, width, height, yi2, ye2, xe1, dxE,
+                                                      xc2, dxC, extValue, 0, dd);
+            }
+        } else {
+            // Mostly horizontal.
+            Q_ASSERT(ext1->y() != int1->y());
+            xc1 = center1->x() + center1Frac * (ext1->x() - int1->x()) / (ext1->y() - int1->y());
+            xc2 = center2->x() + center2Frac * (ext1->x() - int1->x()) / (ext1->y() - int1->y());
+            xc1 += (yi1 - yc1) * dxC;
+            xc2 += (yi2 - yc2) * dxC;
+            if (yi1 != yi2) {
+                xe2 = int1->x() + int1Frac * (ext1->x() - ext2->x()) / (ext1->y() - ext2->y());
+                fillLines<clip, TopDown, RightToLeft>(bits, width, height, yi1, yi2, xc1, dxC,
+                                                      xe2, dxE, intValue, 0, dd);
+            }
+            if (yi2 != ye1) {
+                d = (clip == Clip ? (yi2 << 8) + 0xff - center2->y()
+                                  : (int2->y() | 0xff) - center2->y())
+                    * 2 * extValue / (ext1->y() - int1->y());
+                fillLines<clip, TopDown, RightToLeft>(bits, width, height, yi2, ye1, xc1, dxC,
+                                                      xc2, dxC, d, ddC, dd);
+            }
+            if (ye1 != ye2) {
+                xe1 = ext1->x() + ext1Frac * (ext1->x() - ext2->x()) / (ext1->y() - ext2->y());
+                fillLines<clip, TopDown, LeftToRight>(bits, width, height, ye1, ye2, xe1, dxE,
+                                                      xc2, dxC, extValue, 0, dd);
+            }
+        }
+    }
+}
+
+static void drawPolygons(qint32 *bits, int width, int height, const QPoint *vertices,
+                         const quint32 *indices, int indexCount, qint32 value)
+{
+    Q_ASSERT(indexCount != 0);
+    Q_ASSERT(height <= 128);
+    QVarLengthArray<quint8, 16> scans[128];
+    int first = 0;
+    for (int i = 1; i < indexCount; ++i) {
+        quint32 idx1 = indices[i - 1];
+        quint32 idx2 = indices[i];
+        Q_ASSERT(idx1 != quint32(-1));
+        if (idx2 == quint32(-1)) {
+            idx2 = indices[first];
+            Q_ASSERT(idx2 != quint32(-1));
+            first = ++i;
+        }
+        const QPoint *v1 = &vertices[idx1];
+        const QPoint *v2 = &vertices[idx2];
+        if (v2->y() < v1->y())
+            qSwap(v1, v2);
+        int fromY = qMax(0, v1->y() >> 8);
+        int toY = qMin(height, v2->y() >> 8);
+        if (fromY >= toY)
+            continue;
+        int dx = ((v2->x() - v1->x()) << 8) / (v2->y() - v1->y());
+        int x = v1->x() + ((fromY << 8) + 0xff - v1->y()) * (v2->x() - v1->x()) / (v2->y() - v1->y());
+        for (int y = fromY; y < toY; ++y) {
+            quint32 c = quint32(x >> 8);
+            if (c < quint32(width))
+                scans[y].append(quint8(c));
+            x += dx;
+        }
+    }
+    for (int i = 0; i < height; ++i) {
+        quint8 *scanline = scans[i].data();
+        int size = scans[i].size();
+        for (int j = 1; j < size; ++j) {
+            int k = j;
+            quint8 value = scanline[k];
+            for (; k != 0 && value < scanline[k - 1]; --k)
+                scanline[k] = scanline[k - 1];
+            scanline[k] = value;
+        }
+        qint32 *line = bits + i * width;
+        int j = 0;
+        for (; j + 1 < size; j += 2) {
+            for (quint8 x = scanline[j]; x < scanline[j + 1]; ++x)
+                line[x] = value;
+        }
+        if (j < size) {
+            for (int x = scanline[j]; x < width; ++x)
+                line[x] = value;
+        }
+    }
+}
+
+static QImage makeDistanceField(int imgSize, const QPainterPath &path, int dfScale, int offs)
+{
+    QImage image(imgSize, imgSize, QImage::Format_Indexed8);
+
+    if (path.isEmpty()) {
+        image.fill(0);
+        return image;
+    }
+
+    QTransform transform;
+    transform.translate(offs, offs);
+    transform.scale(qreal(1) / dfScale, qreal(1) / dfScale);
+
+    QDataBuffer<quint32> pathIndices(0);
+    QDataBuffer<QPoint> pathVertices(0);
+    qSimplifyPath(path, pathVertices, pathIndices, transform);
+
+    const qint32 interiorColor = -0x7f80; // 8:8 signed format, -127.5
+    const qint32 exteriorColor = 0x7f80; // 8:8 signed format, 127.5
+
+    QScopedArrayPointer<qint32> bits(new qint32[imgSize * imgSize]);
+    for (int i = 0; i < imgSize * imgSize; ++i)
+        bits[i] = exteriorColor;
+
+    const qreal angleStep = qreal(15 * 3.141592653589793238 / 180);
+    const QPoint rotation(qRound(cos(angleStep) * 0x4000),
+                          qRound(sin(angleStep) * 0x4000)); // 2:14 signed
+
+    const quint32 *indices = pathIndices.data();
+    QVarLengthArray<QPoint> normals;
+    QVarLengthArray<QPoint> vertices;
+    QVarLengthArray<bool> isConvex;
+    QVarLengthArray<bool> needsClipping;
+
+    drawPolygons(bits.data(), imgSize, imgSize, pathVertices.data(), indices, pathIndices.size(),
+                 interiorColor);
+
+    int index = 0;
+
+    while (index < pathIndices.size()) {
+        normals.clear();
+        vertices.clear();
+        needsClipping.clear();
+
+        // Find end of polygon.
+        int end = index;
+        while (indices[end] != quint32(-1))
+            ++end;
+
+        // Calculate vertex normals.
+        for (int next = index, prev = end - 1; next < end; prev = next++) {
+            quint32 fromVertexIndex = indices[prev];
+            quint32 toVertexIndex = indices[next];
+
+            const QPoint &from = pathVertices.at(fromVertexIndex);
+            const QPoint &to = pathVertices.at(toVertexIndex);
+
+            QPoint n(to.y() - from.y(), from.x() - to.x());
+            if (n.x() == 0 && n.y() == 0)
+                continue;
+            int scale = qRound((offs << 16) / sqrt(qreal(n.x() * n.x() + n.y() * n.y()))); // 8:16
+            n.rx() = n.x() * scale >> 8;
+            n.ry() = n.y() * scale >> 8;
+            normals.append(n);
+            QPoint v(to.x() + 0x7f, to.y() + 0x7f);
+            vertices.append(v);
+            needsClipping.append((to.x() < offs << 8) || (to.x() >= (imgSize - offs) << 8)
+                                 || (to.y() < offs << 8) || (to.y() >= (imgSize - offs) << 8));
+        }
+
+        isConvex.resize(normals.count());
+        for (int next = 0, prev = normals.count() - 1; next < normals.count(); prev = next++) {
+            isConvex[prev] = normals.at(prev).x() * normals.at(next).y()
+                           - normals.at(prev).y() * normals.at(next).x() < 0;
+        }
+
+        // Draw quads.
+        for (int next = 0, prev = normals.count() - 1; next < normals.count(); prev = next++) {
+            QPoint n = normals.at(next);
+            QPoint intPrev = vertices.at(prev);
+            QPoint extPrev = vertices.at(prev);
+            QPoint intNext = vertices.at(next);
+            QPoint extNext = vertices.at(next);
+
+            extPrev.rx() -= n.x();
+            extPrev.ry() -= n.y();
+            intPrev.rx() += n.x();
+            intPrev.ry() += n.y();
+            extNext.rx() -= n.x();
+            extNext.ry() -= n.y();
+            intNext.rx() += n.x();
+            intNext.ry() += n.y();
+
+            if (needsClipping[prev] || needsClipping[next]) {
+                drawRectangle<Clip>(bits.data(), imgSize, imgSize,
+                                    &intPrev, &vertices.at(prev), &extPrev,
+                                    &intNext, &vertices.at(next), &extNext,
+                                    exteriorColor);
+            } else {
+                drawRectangle<NoClip>(bits.data(), imgSize, imgSize,
+                                      &intPrev, &vertices.at(prev), &extPrev,
+                                      &intNext, &vertices.at(next), &extNext,
+                                      exteriorColor);
+            }
+
+            if (isConvex.at(prev)) {
+                QPoint p = extPrev;
+                if (needsClipping[prev]) {
+                    for (;;) {
+                        QPoint rn((n.x() * rotation.x() - n.y() * rotation.y()) >> 14,
+                                  (n.y() * rotation.x() + n.x() * rotation.y()) >> 14);
+                        n = rn;
+                        if (n.x() * normals.at(prev).y() - n.y() * normals.at(prev).x() <= 0) {
+                            p.rx() = vertices.at(prev).x() - normals.at(prev).x();
+                            p.ry() = vertices.at(prev).y() - normals.at(prev).y();
+                            drawTriangle<Clip>(bits.data(), imgSize, imgSize, &vertices.at(prev),
+                                               &extPrev, &p, exteriorColor);
+                            break;
+                        }
+
+                        p.rx() = vertices.at(prev).x() - n.x();
+                        p.ry() = vertices.at(prev).y() - n.y();
+                        drawTriangle<Clip>(bits.data(), imgSize, imgSize, &vertices.at(prev),
+                                           &extPrev, &p, exteriorColor);
+                        extPrev = p;
+                    }
+                } else {
+                    for (;;) {
+                        QPoint rn((n.x() * rotation.x() - n.y() * rotation.y()) >> 14,
+                                  (n.y() * rotation.x() + n.x() * rotation.y()) >> 14);
+                        n = rn;
+                        if (n.x() * normals.at(prev).y() - n.y() * normals.at(prev).x() <= 0) {
+                            p.rx() = vertices.at(prev).x() - normals.at(prev).x();
+                            p.ry() = vertices.at(prev).y() - normals.at(prev).y();
+                            drawTriangle<NoClip>(bits.data(), imgSize, imgSize, &vertices.at(prev),
+                                                 &extPrev, &p, exteriorColor);
+                            break;
+                        }
+
+                        p.rx() = vertices.at(prev).x() - n.x();
+                        p.ry() = vertices.at(prev).y() - n.y();
+                        drawTriangle<NoClip>(bits.data(), imgSize, imgSize, &vertices.at(prev),
+                                             &extPrev, &p, exteriorColor);
+                        extPrev = p;
+                    }
+                }
+            } else {
+                QPoint p = intPrev;
+                if (needsClipping[prev]) {
+                    for (;;) {
+                        QPoint rn((n.x() * rotation.x() + n.y() * rotation.y()) >> 14,
+                                  (n.y() * rotation.x() - n.x() * rotation.y()) >> 14);
+                        n = rn;
+                        if (n.x() * normals.at(prev).y() - n.y() * normals.at(prev).x() >= 0) {
+                            p.rx() = vertices.at(prev).x() + normals.at(prev).x();
+                            p.ry() = vertices.at(prev).y() + normals.at(prev).y();
+                            drawTriangle<Clip>(bits.data(), imgSize, imgSize, &vertices.at(prev),
+                                               &p, &intPrev, interiorColor);
+                            break;
+                        }
+
+                        p.rx() = vertices.at(prev).x() + n.x();
+                        p.ry() = vertices.at(prev).y() + n.y();
+                        drawTriangle<Clip>(bits.data(), imgSize, imgSize, &vertices.at(prev),
+                                           &p, &intPrev, interiorColor);
+                        intPrev = p;
+                    }
+                } else {
+                    for (;;) {
+                        QPoint rn((n.x() * rotation.x() + n.y() * rotation.y()) >> 14,
+                                  (n.y() * rotation.x() - n.x() * rotation.y()) >> 14);
+                        n = rn;
+                        if (n.x() * normals.at(prev).y() - n.y() * normals.at(prev).x() >= 0) {
+                            p.rx() = vertices.at(prev).x() + normals.at(prev).x();
+                            p.ry() = vertices.at(prev).y() + normals.at(prev).y();
+                            drawTriangle<NoClip>(bits.data(), imgSize, imgSize, &vertices.at(prev),
+                                                 &p, &intPrev, interiorColor);
+                            break;
+                        }
+
+                        p.rx() = vertices.at(prev).x() + n.x();
+                        p.ry() = vertices.at(prev).y() + n.y();
+                        drawTriangle<NoClip>(bits.data(), imgSize, imgSize, &vertices.at(prev),
+                                             &p, &intPrev, interiorColor);
+                        intPrev = p;
+                    }
+                }
+            }
+        }
+
+        index = end + 1;
+    }
+
+    const qint32 *inLine = bits.data();
+    uchar *outLine = image.bits();
+    int padding = image.bytesPerLine() - image.width();
+    for (int y = 0; y < imgSize; ++y) {
+        for (int x = 0; x < imgSize; ++x, ++inLine, ++outLine)
+            *outLine = uchar((0x7f80 - *inLine) >> 8);
+        outLine += padding;
+    }
+
+    return image;
+}
+
+bool qt_fontHasNarrowOutlines(const QRawFont &f)
+{
+    QRawFont font = f;
+    font.setPixelSize(QT_DISTANCEFIELD_DEFAULT_BASEFONTSIZE);
+    Q_ASSERT(font.isValid());
+
+    QVector<quint32> glyphIndices = font.glyphIndexesForString(QLatin1String("O"));
+    if (glyphIndices.size() < 1)
+        return false;
+
+    QImage im = font.alphaMapForGlyph(glyphIndices.at(0), QRawFont::PixelAntialiasing);
+    if (im.isNull())
+        return false;
+
+    int minHThick = 999;
+    int minVThick = 999;
+
+    int thick = 0;
+    bool in = false;
+    int y = (im.height() + 1) / 2;
+    for (int x = 0; x < im.width(); ++x) {
+        int a = qAlpha(im.pixel(x, y));
+        if (a > 127) {
+            in = true;
+            ++thick;
+        } else if (in) {
+            in = false;
+            minHThick = qMin(minHThick, thick);
+            thick = 0;
+        }
+    }
+
+    thick = 0;
+    in = false;
+    int x = (im.width() + 1) / 2;
+    for (int y = 0; y < im.height(); ++y) {
+        int a = qAlpha(im.pixel(x, y));
+        if (a > 127) {
+            in = true;
+            ++thick;
+        } else if (in) {
+            in = false;
+            minVThick = qMin(minVThick, thick);
+            thick = 0;
+        }
+    }
+
+    return minHThick == 1 || minVThick == 1;
+}
+
+QImage qt_renderDistanceFieldGlyph(const QRawFont &font, glyph_t glyph, bool doubleResolution)
+{
+    QRawFont renderFont = font;
+    renderFont.setPixelSize(QT_DISTANCEFIELD_BASEFONTSIZE(doubleResolution) * QT_DISTANCEFIELD_SCALE(doubleResolution));
+
+    QPainterPath path = renderFont.pathForGlyph(glyph);
+    path.translate(-path.boundingRect().topLeft());
+    path.setFillRule(Qt::WindingFill);
+
+    QImage im = makeDistanceField(QT_DISTANCEFIELD_TILESIZE(doubleResolution),
+                                  path,
+                                  QT_DISTANCEFIELD_SCALE(doubleResolution),
+                                  QT_DISTANCEFIELD_RADIUS(doubleResolution) / QT_DISTANCEFIELD_SCALE(doubleResolution));
+    return im;
+}
+
+QT_END_NAMESPACE
+