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39
40#ifndef QOUTLINEMAPPER_P_H
41#define QOUTLINEMAPPER_P_H
42
43//
44// W A R N I N G
45// -------------
46//
47// This file is not part of the Qt API. It exists purely as an
48// implementation detail. This header file may change from version to
49// version without notice, or even be removed.
50//
51// We mean it.
52//
53
54#include <QtGui/private/qtguiglobal_p.h>
55#include <QtCore/qrect.h>
56
57#include <QtGui/qtransform.h>
58#include <QtGui/qpainterpath.h>
59
60#define QT_FT_BEGIN_HEADER
61#define QT_FT_END_HEADER
62
63#include <private/qrasterdefs_p.h>
64#include <private/qdatabuffer_p.h>
65#include "qpaintengineex_p.h"
66
67QT_BEGIN_NAMESPACE
68
69// This limitations comes from qgrayraster.c. Any higher and
70// rasterization of shapes will produce incorrect results.
71const int QT_RASTER_COORD_LIMIT = 32767;
72
73//#define QT_DEBUG_CONVERT
74
75Q_GUI_EXPORT bool qt_scaleForTransform(const QTransform &transform, qreal *scale);
76
77/********************************************************************************
78 * class QOutlineMapper
79 *
80 * Used to map between QPainterPath and the QT_FT_Outline structure used by the
81 * freetype scanconvertor.
82 *
83 * The outline mapper uses a path iterator to get points from the path,
84 * so that it is possible to transform the points as they are converted. The
85 * callback can be a noop, translate or full-fledged xform. (Tests indicated
86 * that using a C callback was low cost).
87 */
88class QOutlineMapper
89{
90public:
91 QOutlineMapper() :
92 m_element_types(0),
93 m_elements(0),
94 m_points(0),
95 m_tags(0),
96 m_contours(0),
97 m_in_clip_elements(false)
98 {
99 }
100
101 /*!
102 Sets up the matrix to be used for conversion. This also
103 sets up the qt_path_iterator function that is used as a callback
104 to get points.
105 */
106 void setMatrix(const QTransform &m)
107 {
108 m_transform = m;
109
110 qreal scale;
111 qt_scaleForTransform(transform: m, scale: &scale);
112 m_curve_threshold = scale == 0 ? qreal(0.25) : (qreal(0.25) / scale);
113 }
114
115 void beginOutline(Qt::FillRule fillRule)
116 {
117#ifdef QT_DEBUG_CONVERT
118 printf("QOutlineMapper::beginOutline rule=%d\n", fillRule);
119#endif
120 m_valid = true;
121 m_elements.reset();
122 m_element_types.reset();
123 m_points.reset();
124 m_tags.reset();
125 m_contours.reset();
126 m_outline.flags = fillRule == Qt::WindingFill
127 ? QT_FT_OUTLINE_NONE
128 : QT_FT_OUTLINE_EVEN_ODD_FILL;
129 m_subpath_start = 0;
130 }
131
132 void endOutline();
133
134 void clipElements(const QPointF *points, const QPainterPath::ElementType *types, int count);
135
136 void convertElements(const QPointF *points, const QPainterPath::ElementType *types, int count);
137
138 inline void moveTo(const QPointF &pt) {
139#ifdef QT_DEBUG_CONVERT
140 printf("QOutlineMapper::moveTo() (%f, %f)\n", pt.x(), pt.y());
141#endif
142 closeSubpath();
143 m_subpath_start = m_elements.size();
144 m_elements << pt;
145 m_element_types << QPainterPath::MoveToElement;
146 }
147
148 inline void lineTo(const QPointF &pt) {
149#ifdef QT_DEBUG_CONVERT
150 printf("QOutlineMapper::lineTo() (%f, %f)\n", pt.x(), pt.y());
151#endif
152 m_elements.add(t: pt);
153 m_element_types << QPainterPath::LineToElement;
154 }
155
156 void curveTo(const QPointF &cp1, const QPointF &cp2, const QPointF &ep);
157
158 inline void closeSubpath() {
159 int element_count = m_elements.size();
160 if (element_count > 0) {
161 if (m_elements.at(i: element_count-1) != m_elements.at(i: m_subpath_start)) {
162#ifdef QT_DEBUG_CONVERT
163 printf(" - implicitly closing\n");
164#endif
165 // Put the object on the stack to avoid the odd case where
166 // lineTo reallocs the databuffer and the QPointF & will
167 // be invalidated.
168 QPointF pt = m_elements.at(i: m_subpath_start);
169
170 // only do lineTo if we have element_type array...
171 if (m_element_types.size())
172 lineTo(pt);
173 else
174 m_elements << pt;
175
176 }
177 }
178 }
179
180 QT_FT_Outline *outline() {
181 if (m_valid)
182 return &m_outline;
183 return nullptr;
184 }
185
186 QT_FT_Outline *convertPath(const QPainterPath &path);
187 QT_FT_Outline *convertPath(const QVectorPath &path);
188
189 inline QPainterPath::ElementType *elementTypes() const { return m_element_types.size() == 0 ? nullptr : m_element_types.data(); }
190
191public:
192 QDataBuffer<QPainterPath::ElementType> m_element_types;
193 QDataBuffer<QPointF> m_elements;
194 QDataBuffer<QT_FT_Vector> m_points;
195 QDataBuffer<char> m_tags;
196 QDataBuffer<int> m_contours;
197
198 QRect m_clip_rect;
199 QRectF controlPointRect; // only valid after endOutline()
200
201 QT_FT_Outline m_outline;
202
203 int m_subpath_start;
204
205 QTransform m_transform;
206
207 qreal m_curve_threshold;
208
209 bool m_valid;
210 bool m_in_clip_elements;
211};
212
213QT_END_NAMESPACE
214
215#endif // QOUTLINEMAPPER_P_H
216

source code of qtbase/src/gui/painting/qoutlinemapper_p.h