summaryrefslogtreecommitdiffstats
path: root/src/opengl/gl2paintengineex/qgl2pexvertexarray.cpp
blob: 560ad3a88a80ca8df454a25a7fd0ab0149b72dfe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Qt Software Information (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 either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** 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 1.0, 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.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at qt-sales@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::addPath(const QVectorPath &path, GLfloat curveInverseScale)
{
    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;
    }

    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:
//                qDebug("element[%d] is a MoveToElement", i);
                vertexArrayStops.append(vertexArray.size());
                vertexArray.add(points[i]); // 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);

    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