/src/qtbase/src/gui/kernel/qplatformgraphicsbuffer.cpp

Source
// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:significant reason:default

#include "qplatformgraphicsbuffer.h"
#include <QtGui/QOpenGLContext>
#include <QtGui/QOpenGLFunctions>
#include <QtGui/qopengl.h>
#include <QtCore/QDebug>

QT_BEGIN_NAMESPACE
/*!
    \class QPlatformGraphicsBuffer
    \inmodule QtGui
    \since 5.5
    \brief The QPlatformGraphicsBuffer is a windowsystem abstraction for native graphics buffers

    Different platforms have different ways of representing graphics buffers. On
    some platforms, it is possible to create one graphics buffer that you can bind
    to a texture and also get main memory access to the image bits. On the
    other hand, on some platforms all graphics buffer abstraction is completely
    hidden.

    QPlatformGraphicsBuffer is an abstraction of a single Graphics Buffer.

    There is no public constructor nor any public factory function.

    \internal
*/

/*!
    \enum QPlatformGraphicsBuffer::AccessType

    This enum describes the access that is desired or granted for the graphics
    buffer.

    \value None
    \value SWReadAccess
    \value SWWriteAccess
    \value TextureAccess
    \value HWCompositor
*/

/*!
    \enum QPlatformGraphicsBuffer::Origin

    This enum describes the origin of the content of the buffer.

    \value OriginTopLeft
    \value OriginBottomLeft
*/

/*!
    Protected constructor to initialize the private members.

    \a size is the size of the buffer.
    \a format is the format of the buffer.

    \sa size() format()
*/
QPlatformGraphicsBuffer::QPlatformGraphicsBuffer(const QSize &size, const QPixelFormat &format)
    : m_size(size)
    , m_format(format)
{
}


/*!
    Virtual destructor.
*/
QPlatformGraphicsBuffer::~QPlatformGraphicsBuffer()
{
}

/*!
    Binds the content of this graphics buffer into the currently bound texture.

    This function should fail for buffers not capable of locking to TextureAccess.

    \a rect is the subrect which is desired to be bounded to the texture. This
    argument has a no less than semantic, meaning more (if not all) of the buffer
    can be bounded to the texture. An empty QRect is interpreted as entire buffer
    should be bound.

    This function only supports binding buffers to the GL_TEXTURE_2D texture
    target.

    Returns true on success, otherwise false.
*/
bool QPlatformGraphicsBuffer::bindToTexture(const QRect &rect) const
{
    Q_UNUSED(rect);
    return false;
}

/*!
    \fn QPlatformGraphicsBuffer::AccessTypes QPlatformGraphicsBuffer::isLocked() const
    Function to check if the buffer is locked.

    \sa lock()
*/

/*!
    Before the data can be retrieved or before a buffer can be bound to a
    texture it needs to be locked. This is a separate function call since this
    operation might be time consuming, and it would not be satisfactory to do
    it per function call.

    \a access is the access type wanted.

    \a rect is the subrect which is desired to be locked. This
    argument has a no less than semantic, meaning more (if not all) of the buffer
    can be locked. An empty QRect is interpreted as entire buffer should be locked.

    Return true on successfully locking all AccessTypes specified \a access
    otherwise returns false and no locks have been granted.
*/
bool QPlatformGraphicsBuffer::lock(AccessTypes access, const QRect &rect)
{
    bool locked = doLock(access, rect);
    if (locked)
        m_lock_access |= access;

    return locked;
}

/*!
    Unlocks the current buffer lock.

    This function calls doUnlock, and then emits the unlocked signal with the
    AccessTypes from before doUnlock was called.
*/
void QPlatformGraphicsBuffer::unlock()
{
    if (m_lock_access == None)
        return;
    AccessTypes previous = m_lock_access;
    doUnlock();
    m_lock_access = None;
    emit unlocked(previous);
}


/*!
    \fn QPlatformGraphicsBuffer::doLock(AccessTypes access, const QRect &rect = QRect())

    This function should be reimplemented by subclasses. If one of the \a
    access types specified cannot be locked, then all should fail and this
    function should return false.

    \a rect is the subrect which is desired to be locked. This
    argument has a no less than semantic, meaning more (if not all) of the
    buffer can be locked. An empty QRect should be interpreted as the entire buffer
    should be locked.

    It is safe to call isLocked() to verify the current lock state.
*/

/*!
    \fn QPlatformGraphicsBuffer::doUnlock()

    This function should remove all locks set on the buffer.

    It is safe to call isLocked() to verify the current lock state.
*/

/*!
    \fn QPlatformGraphicsBuffer::unlocked(AccessTypes previousAccessTypes)

    Signal that is emitted after unlocked has been called.

    \a previousAccessTypes is the access types locked before unlock was called.
*/

/*!
    Accessor for the bytes of the buffer. This function needs to be called on a
    buffer with SWReadAccess access lock. Behavior is undefined for modifying
    the memory returned when not having a SWWriteAccess.
*/
const uchar *QPlatformGraphicsBuffer::data() const
{ return nullptr; }

/*!
    Accessor for the bytes of the buffer. This function needs to be called on a
    buffer with SWReadAccess access lock. Behavior is undefined for modifying
    the memory returned when not having a SWWriteAccess.
*/
uchar *QPlatformGraphicsBuffer::data()
{
    return nullptr;
}

/*!
    Accessor for the length of the data buffer. This function is a convenience
    function multiplying height of buffer with bytesPerLine().

    \sa data() bytesPerLine() size()
*/
int QPlatformGraphicsBuffer::byteCount() const
{
    return size().height() * bytesPerLine();
}

/*!
    Accessor for bytes per line in the graphics buffer.
*/
int QPlatformGraphicsBuffer::bytesPerLine() const
{
    return 0;
}


/*!
    In origin of the content of the graphics buffer.

    Default implementation is OriginTopLeft, as this is the coordinate
    system default for Qt. However, for most regular OpenGL textures
    this will be OriginBottomLeft.
*/
QPlatformGraphicsBuffer::Origin QPlatformGraphicsBuffer::origin() const
{
    return OriginTopLeft;
}

/*!
    \fn QPlatformGraphicsBuffer::size() const

    Accessor for content size.
*/

/*!
    \fn QPlatformGraphicsBuffer::format() const

    Accessor for the pixel format of the buffer.
*/

QT_END_NAMESPACE

#include "moc_qplatformgraphicsbuffer.cpp"

Coverage Report

Created: 2026-05-31 06:50

Line	Count	Source
1		// Copyright (C) 2016 The Qt Company Ltd.
2		// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3		// Qt-Security score:significant reason:default
4
5		#include "qplatformgraphicsbuffer.h"
6		#include <QtGui/QOpenGLContext>
7		#include <QtGui/QOpenGLFunctions>
8		#include <QtGui/qopengl.h>
9		#include <QtCore/QDebug>
10
11		QT_BEGIN_NAMESPACE
12		/*!
13		\class QPlatformGraphicsBuffer
14		\inmodule QtGui
15		\since 5.5
16		\brief The QPlatformGraphicsBuffer is a windowsystem abstraction for native graphics buffers
17
18		Different platforms have different ways of representing graphics buffers. On
19		some platforms, it is possible to create one graphics buffer that you can bind
20		to a texture and also get main memory access to the image bits. On the
21		other hand, on some platforms all graphics buffer abstraction is completely
22		hidden.
23
24		QPlatformGraphicsBuffer is an abstraction of a single Graphics Buffer.
25
26		There is no public constructor nor any public factory function.
27
28		\internal
29		*/
30
31		/*!
32		\enum QPlatformGraphicsBuffer::AccessType
33
34		This enum describes the access that is desired or granted for the graphics
35		buffer.
36
37		\value None
38		\value SWReadAccess
39		\value SWWriteAccess
40		\value TextureAccess
41		\value HWCompositor
42		*/
43
44		/*!
45		\enum QPlatformGraphicsBuffer::Origin
46
47		This enum describes the origin of the content of the buffer.
48
49		\value OriginTopLeft
50		\value OriginBottomLeft
51		*/
52
53		/*!
54		Protected constructor to initialize the private members.
55
56		\a size is the size of the buffer.
57		\a format is the format of the buffer.
58
59		\sa size() format()
60		*/
61		QPlatformGraphicsBuffer::QPlatformGraphicsBuffer(const QSize &size, const QPixelFormat &format)
62	0	: m_size(size)
63	0	, m_format(format)
64	0	{
65	0	}
66
67
68		/*!
69		Virtual destructor.
70		*/
71		QPlatformGraphicsBuffer::~QPlatformGraphicsBuffer()
72	0	{
73	0	}
74
75		/*!
76		Binds the content of this graphics buffer into the currently bound texture.
77
78		This function should fail for buffers not capable of locking to TextureAccess.
79
80		\a rect is the subrect which is desired to be bounded to the texture. This
81		argument has a no less than semantic, meaning more (if not all) of the buffer
82		can be bounded to the texture. An empty QRect is interpreted as entire buffer
83		should be bound.
84
85		This function only supports binding buffers to the GL_TEXTURE_2D texture
86		target.
87
88		Returns true on success, otherwise false.
89		*/
90		bool QPlatformGraphicsBuffer::bindToTexture(const QRect &rect) const
91	0	{
92	0	Q_UNUSED(rect);
93	0	return false;
94	0	}
95
96		/*!
97		\fn QPlatformGraphicsBuffer::AccessTypes QPlatformGraphicsBuffer::isLocked() const
98		Function to check if the buffer is locked.
99
100		\sa lock()
101		*/
102
103		/*!
104		Before the data can be retrieved or before a buffer can be bound to a
105		texture it needs to be locked. This is a separate function call since this
106		operation might be time consuming, and it would not be satisfactory to do
107		it per function call.
108
109		\a access is the access type wanted.
110
111		\a rect is the subrect which is desired to be locked. This
112		argument has a no less than semantic, meaning more (if not all) of the buffer
113		can be locked. An empty QRect is interpreted as entire buffer should be locked.
114
115		Return true on successfully locking all AccessTypes specified \a access
116		otherwise returns false and no locks have been granted.
117		*/
118		bool QPlatformGraphicsBuffer::lock(AccessTypes access, const QRect &rect)
119	0	{
120	0	bool locked = doLock(access, rect);
121	0	if (locked)
122	0	m_lock_access \|= access;
123
124	0	return locked;
125	0	}
126
127		/*!
128		Unlocks the current buffer lock.
129
130		This function calls doUnlock, and then emits the unlocked signal with the
131		AccessTypes from before doUnlock was called.
132		*/
133		void QPlatformGraphicsBuffer::unlock()
134	0	{
135	0	if (m_lock_access == None)
136	0	return;
137	0	AccessTypes previous = m_lock_access;
138	0	doUnlock();
139	0	m_lock_access = None;
140	0	emit unlocked(previous);
141	0	}
142
143
144		/*!
145		\fn QPlatformGraphicsBuffer::doLock(AccessTypes access, const QRect &rect = QRect())
146
147		This function should be reimplemented by subclasses. If one of the \a
148		access types specified cannot be locked, then all should fail and this
149		function should return false.
150
151		\a rect is the subrect which is desired to be locked. This
152		argument has a no less than semantic, meaning more (if not all) of the
153		buffer can be locked. An empty QRect should be interpreted as the entire buffer
154		should be locked.
155
156		It is safe to call isLocked() to verify the current lock state.
157		*/
158
159		/*!
160		\fn QPlatformGraphicsBuffer::doUnlock()
161
162		This function should remove all locks set on the buffer.
163
164		It is safe to call isLocked() to verify the current lock state.
165		*/
166
167		/*!
168		\fn QPlatformGraphicsBuffer::unlocked(AccessTypes previousAccessTypes)
169
170		Signal that is emitted after unlocked has been called.
171
172		\a previousAccessTypes is the access types locked before unlock was called.
173		*/
174
175		/*!
176		Accessor for the bytes of the buffer. This function needs to be called on a
177		buffer with SWReadAccess access lock. Behavior is undefined for modifying
178		the memory returned when not having a SWWriteAccess.
179		*/
180		const uchar *QPlatformGraphicsBuffer::data() const
181	0	{ return nullptr; }
182
183		/*!
184		Accessor for the bytes of the buffer. This function needs to be called on a
185		buffer with SWReadAccess access lock. Behavior is undefined for modifying
186		the memory returned when not having a SWWriteAccess.
187		*/
188		uchar *QPlatformGraphicsBuffer::data()
189	0	{
190	0	return nullptr;
191	0	}
192
193		/*!
194		Accessor for the length of the data buffer. This function is a convenience
195		function multiplying height of buffer with bytesPerLine().
196
197		\sa data() bytesPerLine() size()
198		*/
199		int QPlatformGraphicsBuffer::byteCount() const
200	0	{
201	0	return size().height() * bytesPerLine();
202	0	}
203
204		/*!
205		Accessor for bytes per line in the graphics buffer.
206		*/
207		int QPlatformGraphicsBuffer::bytesPerLine() const
208	0	{
209	0	return 0;
210	0	}
211
212
213		/*!
214		In origin of the content of the graphics buffer.
215
216		Default implementation is OriginTopLeft, as this is the coordinate
217		system default for Qt. However, for most regular OpenGL textures
218		this will be OriginBottomLeft.
219		*/
220		QPlatformGraphicsBuffer::Origin QPlatformGraphicsBuffer::origin() const
221	0	{
222	0	return OriginTopLeft;
223	0	}
224
225		/*!
226		\fn QPlatformGraphicsBuffer::size() const
227
228		Accessor for content size.
229		*/
230
231		/*!
232		\fn QPlatformGraphicsBuffer::format() const
233
234		Accessor for the pixel format of the buffer.
235		*/
236
237		QT_END_NAMESPACE
238
239		#include "moc_qplatformgraphicsbuffer.cpp"