1/*
2 * Copyright (C) Research In Motion Limited 2010. All rights reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB.  If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 */
19
20#include "config.h"
21
22#include "core/svg/SVGPathByteStreamBuilder.h"
23
24#include "core/svg/SVGPathSeg.h"
25#include "wtf/OwnPtr.h"
26
27namespace blink {
28
29// Helper class that coalesces writes to a SVGPathByteStream to a local buffer.
30class CoalescingBuffer {
31public:
32    CoalescingBuffer(SVGPathByteStream* byteStream)
33        : m_currentOffset(0)
34        , m_byteStream(byteStream)
35    {
36        ASSERT(byteStream);
37    }
38    ~CoalescingBuffer()
39    {
40        for (size_t i = 0; i < m_currentOffset; ++i)
41            m_byteStream->append(m_bytes[i]);
42    }
43
44    template<typename DataType>
45    void writeType(DataType value)
46    {
47        ByteType<DataType> data;
48        data.value = value;
49        size_t typeSize = sizeof(ByteType<DataType>);
50        ASSERT(m_currentOffset + typeSize <= sizeof(m_bytes));
51        memcpy(m_bytes + m_currentOffset, data.bytes, typeSize);
52        m_currentOffset += typeSize;
53    }
54
55    void writeFlag(bool value) { writeType<bool>(value); }
56    void writeFloat(float value) { writeType<float>(value); }
57    void writeFloatPoint(const FloatPoint& point)
58    {
59        writeType<float>(point.x());
60        writeType<float>(point.y());
61    }
62    void writeSegmentType(unsigned short value) { writeType<unsigned short>(value); }
63
64private:
65    // Adjust size to fit the largest command (in serialized/byte-stream format).
66    // Currently a cubic segment.
67    size_t m_currentOffset;
68    unsigned char m_bytes[sizeof(unsigned short) + sizeof(FloatPoint) * 3];
69    SVGPathByteStream* m_byteStream;
70};
71
72SVGPathByteStreamBuilder::SVGPathByteStreamBuilder()
73    : m_byteStream(0)
74{
75}
76
77void SVGPathByteStreamBuilder::moveTo(const FloatPoint& targetPoint, bool, PathCoordinateMode mode)
78{
79    CoalescingBuffer buffer(m_byteStream);
80    buffer.writeSegmentType(mode == RelativeCoordinates ?  PathSegMoveToRel : PathSegMoveToAbs);
81    buffer.writeFloatPoint(targetPoint);
82}
83
84void SVGPathByteStreamBuilder::lineTo(const FloatPoint& targetPoint, PathCoordinateMode mode)
85{
86    CoalescingBuffer buffer(m_byteStream);
87    buffer.writeSegmentType(mode == RelativeCoordinates ? PathSegLineToRel : PathSegLineToAbs);
88    buffer.writeFloatPoint(targetPoint);
89}
90
91void SVGPathByteStreamBuilder::lineToHorizontal(float x, PathCoordinateMode mode)
92{
93    CoalescingBuffer buffer(m_byteStream);
94    buffer.writeSegmentType(mode == RelativeCoordinates ? PathSegLineToHorizontalRel : PathSegLineToHorizontalAbs);
95    buffer.writeFloat(x);
96}
97
98void SVGPathByteStreamBuilder::lineToVertical(float y, PathCoordinateMode mode)
99{
100    CoalescingBuffer buffer(m_byteStream);
101    buffer.writeSegmentType(mode == RelativeCoordinates ? PathSegLineToVerticalRel : PathSegLineToVerticalAbs);
102    buffer.writeFloat(y);
103}
104
105void SVGPathByteStreamBuilder::curveToCubic(const FloatPoint& point1, const FloatPoint& point2, const FloatPoint& targetPoint, PathCoordinateMode mode)
106{
107    CoalescingBuffer buffer(m_byteStream);
108    buffer.writeSegmentType(mode == RelativeCoordinates ? PathSegCurveToCubicRel : PathSegCurveToCubicAbs);
109    buffer.writeFloatPoint(point1);
110    buffer.writeFloatPoint(point2);
111    buffer.writeFloatPoint(targetPoint);
112}
113
114void SVGPathByteStreamBuilder::curveToCubicSmooth(const FloatPoint& point2, const FloatPoint& targetPoint, PathCoordinateMode mode)
115{
116    CoalescingBuffer buffer(m_byteStream);
117    buffer.writeSegmentType(mode == RelativeCoordinates ? PathSegCurveToCubicSmoothRel : PathSegCurveToCubicSmoothAbs);
118    buffer.writeFloatPoint(point2);
119    buffer.writeFloatPoint(targetPoint);
120}
121
122void SVGPathByteStreamBuilder::curveToQuadratic(const FloatPoint& point1, const FloatPoint& targetPoint, PathCoordinateMode mode)
123{
124    CoalescingBuffer buffer(m_byteStream);
125    buffer.writeSegmentType(mode == RelativeCoordinates ? PathSegCurveToQuadraticRel : PathSegCurveToQuadraticAbs);
126    buffer.writeFloatPoint(point1);
127    buffer.writeFloatPoint(targetPoint);
128}
129
130void SVGPathByteStreamBuilder::curveToQuadraticSmooth(const FloatPoint& targetPoint, PathCoordinateMode mode)
131{
132    CoalescingBuffer buffer(m_byteStream);
133    buffer.writeSegmentType(mode == RelativeCoordinates ? PathSegCurveToQuadraticSmoothRel : PathSegCurveToQuadraticSmoothAbs);
134    buffer.writeFloatPoint(targetPoint);
135}
136
137void SVGPathByteStreamBuilder::arcTo(float r1, float r2, float angle, bool largeArcFlag, bool sweepFlag, const FloatPoint& targetPoint, PathCoordinateMode mode)
138{
139    CoalescingBuffer buffer(m_byteStream);
140    buffer.writeSegmentType(mode == RelativeCoordinates ? PathSegArcRel : PathSegArcAbs);
141    buffer.writeFloat(r1);
142    buffer.writeFloat(r2);
143    buffer.writeFloat(angle);
144    buffer.writeFlag(largeArcFlag);
145    buffer.writeFlag(sweepFlag);
146    buffer.writeFloatPoint(targetPoint);
147}
148
149void SVGPathByteStreamBuilder::closePath()
150{
151    CoalescingBuffer buffer(m_byteStream);
152    buffer.writeSegmentType(PathSegClosePath);
153}
154
155} // namespace blink
156