src/opengl/gl2paintengineex/qgl2pexvertexarray.cpp
changeset 0 1918ee327afb
child 3 41300fa6a67c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/opengl/gl2paintengineex/qgl2pexvertexarray.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,201 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtOpenGL module 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.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qgl2pexvertexarray_p.h"
+
+#include <private/qbezier_p.h>
+
+QT_BEGIN_NAMESPACE
+
+void QGL2PEXVertexArray::clear()
+{
+    vertexArray.reset();
+    vertexArrayStops.clear();
+    boundingRectDirty = true;
+}
+
+
+QGLRect QGL2PEXVertexArray::boundingRect() const
+{
+    if (boundingRectDirty)
+        return QGLRect(0.0, 0.0, 0.0, 0.0);
+    else
+        return QGLRect(minX, minY, maxX, maxY);
+}
+
+void QGL2PEXVertexArray::addRect(const QRectF &rect)
+{
+    vertexArray << rect.topLeft() << rect.topRight() << rect.bottomRight()
+                << rect.bottomRight() << rect.bottomLeft() << rect.topLeft();
+}
+
+void QGL2PEXVertexArray::addClosingLine(int index)
+{
+    if (QPointF(vertexArray.at(index)) != QPointF(vertexArray.last()))
+        vertexArray.add(vertexArray.at(index));
+}
+
+void QGL2PEXVertexArray::addCentroid(const QVectorPath &path, int subPathIndex)
+{
+    const QPointF *const points = reinterpret_cast<const QPointF *>(path.points());
+    const QPainterPath::ElementType *const elements = path.elements();
+
+    QPointF sum = points[subPathIndex];
+    int count = 1;
+
+    for (int i = subPathIndex + 1; i < path.elementCount() && (!elements || elements[i] != QPainterPath::MoveToElement); ++i) {
+        sum += points[i];
+        ++count;
+    }
+
+    const QPointF centroid = sum / qreal(count);
+    vertexArray.add(centroid);
+}
+
+void QGL2PEXVertexArray::addPath(const QVectorPath &path, GLfloat curveInverseScale, bool outline)
+{
+    const QPointF* const points = reinterpret_cast<const QPointF*>(path.points());
+    const QPainterPath::ElementType* const elements = path.elements();
+
+    if (boundingRectDirty) {
+        minX = maxX = points[0].x();
+        minY = maxY = points[0].y();
+        boundingRectDirty = false;
+    }
+
+    if (!outline)
+        addCentroid(path, 0);
+
+    int lastMoveTo = vertexArray.size();
+    vertexArray.add(points[0]); // The first element is always a moveTo
+
+    do {
+        if (!elements) {
+//             qDebug("QVectorPath has no elements");
+            // If the path has a null elements pointer, the elements implicitly
+            // start with a moveTo (already added) and continue with lineTos:
+            for (int i=1; i<path.elementCount(); ++i)
+                lineToArray(points[i].x(), points[i].y());
+
+            break;
+        }
+//         qDebug("QVectorPath has element types");
+
+        for (int i=1; i<path.elementCount(); ++i) {
+            const QPainterPath::ElementType elementType = elements[i];
+            switch (elementType) {
+            case QPainterPath::MoveToElement:
+                if (!outline)
+                    addClosingLine(lastMoveTo);
+//                qDebug("element[%d] is a MoveToElement", i);
+                vertexArrayStops.append(vertexArray.size());
+                if (!outline) {
+                    addCentroid(path, i);
+                    lastMoveTo = vertexArray.size();
+                }
+                lineToArray(points[i].x(), points[i].y()); // Add the moveTo as a new vertex
+                break;
+            case QPainterPath::LineToElement:
+//                qDebug("element[%d] is a LineToElement", i);
+                lineToArray(points[i].x(), points[i].y());
+                break;
+            case QPainterPath::CurveToElement:
+//                qDebug("element[%d] is a CurveToElement", i);
+                curveToArray(points[i], points[i+1], points[i+2], curveInverseScale);
+                i+=2;
+                break;
+            default:
+                break;
+            }
+        }
+    } while (0);
+
+    if (!outline)
+        addClosingLine(lastMoveTo);
+    vertexArrayStops.append(vertexArray.size());
+}
+
+void QGL2PEXVertexArray::lineToArray(const GLfloat x, const GLfloat y)
+{
+    vertexArray.add(QGLPoint(x, y));
+
+    if (x > maxX)
+        maxX = x;
+    else if (x < minX)
+        minX = x;
+    if (y > maxY)
+        maxY = y;
+    else if (y < minY)
+        minY = y;
+}
+
+void QGL2PEXVertexArray::curveToArray(const QGLPoint &cp1, const QGLPoint &cp2, const QGLPoint &ep, GLfloat inverseScale)
+{
+    qreal inverseScaleHalf = inverseScale / 2;
+
+    QBezier beziers[32];
+    beziers[0] = QBezier::fromPoints(vertexArray.last(), cp1, cp2, ep);
+    QBezier *b = beziers;
+    while (b >= beziers) {
+        // check if we can pop the top bezier curve from the stack
+        qreal l = qAbs(b->x4 - b->x1) + qAbs(b->y4 - b->y1);
+        qreal d;
+        if (l > inverseScale) {
+            d = qAbs( (b->x4 - b->x1)*(b->y1 - b->y2) - (b->y4 - b->y1)*(b->x1 - b->x2) )
+                + qAbs( (b->x4 - b->x1)*(b->y1 - b->y3) - (b->y4 - b->y1)*(b->x1 - b->x3) );
+            d /= l;
+        } else {
+            d = qAbs(b->x1 - b->x2) + qAbs(b->y1 - b->y2) +
+                qAbs(b->x1 - b->x3) + qAbs(b->y1 - b->y3);
+        }
+        if (d < inverseScaleHalf || b == beziers + 31) {
+            // good enough, we pop it off and add the endpoint
+            lineToArray(b->x4, b->y4);
+            --b;
+        } else {
+            // split, second half of the polygon goes lower into the stack
+            b->split(b+1, b);
+           ++b;
+        }
+    }
+}
+
+QT_END_NAMESPACE