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39
40#include "qplatformopenglcontext.h"
41
42#include <QOpenGLFunctions>
43
44QT_BEGIN_NAMESPACE
45
46/*!
47 \class QPlatformOpenGLContext
48 \since 4.8
49 \internal
50 \preliminary
51 \ingroup qpa
52
53 \brief The QPlatformOpenGLContext class provides an abstraction for native GL contexts.
54
55 In QPA the way to support OpenGL or OpenVG or other technologies that requires a native GL
56 context is through the QPlatformOpenGLContext wrapper.
57
58 There is no factory function for QPlatformOpenGLContexts, but rather only one accessor function.
59 The only place to retrieve a QPlatformOpenGLContext from is through a QPlatformWindow.
60
61 The context which is current for a specific thread can be collected by the currentContext()
62 function. This is how QPlatformOpenGLContext also makes it possible to use the Qt GUI module
63 withhout using QOpenGLWidget. When using QOpenGLContext::currentContext(), it will ask
64 QPlatformOpenGLContext for the currentContext. Then a corresponding QOpenGLContext will be returned,
65 which maps to the QPlatformOpenGLContext.
66*/
67
68/*! \fn void QPlatformOpenGLContext::swapBuffers(QPlatformSurface *surface)
69 Reimplement in subclass to native swap buffers calls
70
71 The implementation must support being called in a thread different than the gui-thread.
72*/
73
74/*! \fn QFunctionPointer QPlatformOpenGLContext::getProcAddress(const char *procName)
75
76 Reimplement in subclass to allow dynamic querying of OpenGL symbols. As opposed to e.g. the wglGetProcAddress
77 function on Windows, Qt expects this methods to be able to return valid function pointers even for standard
78 OpenGL symbols.
79*/
80
81class QPlatformOpenGLContextPrivate
82{
83public:
84 QPlatformOpenGLContextPrivate() : context(nullptr) {}
85
86 QOpenGLContext *context;
87};
88
89QPlatformOpenGLContext::QPlatformOpenGLContext()
90 : d_ptr(new QPlatformOpenGLContextPrivate)
91{
92}
93
94QPlatformOpenGLContext::~QPlatformOpenGLContext()
95{
96}
97
98/*!
99 Called after a new instance is constructed. The default implementation does nothing.
100
101 Subclasses can use this function to perform additional initialization that relies on
102 virtual functions.
103 */
104void QPlatformOpenGLContext::initialize()
105{
106}
107
108/*!
109 Reimplement in subclass if your platform uses framebuffer objects for surfaces.
110
111 The default implementation returns 0.
112*/
113GLuint QPlatformOpenGLContext::defaultFramebufferObject(QPlatformSurface *) const
114{
115 return 0;
116}
117
118QOpenGLContext *QPlatformOpenGLContext::context() const
119{
120 Q_D(const QPlatformOpenGLContext);
121 return d->context;
122}
123
124void QPlatformOpenGLContext::setContext(QOpenGLContext *context)
125{
126 Q_D(QPlatformOpenGLContext);
127 d->context = context;
128}
129
130bool QPlatformOpenGLContext::parseOpenGLVersion(const QByteArray &versionString, int &major, int &minor)
131{
132 bool majorOk = false;
133 bool minorOk = false;
134 QList<QByteArray> parts = versionString.split(sep: ' ');
135 if (versionString.startsWith(QByteArrayLiteral("OpenGL ES"))) {
136 if (parts.size() >= 3) {
137 QList<QByteArray> versionParts = parts.at(i: 2).split(sep: '.');
138 if (versionParts.size() >= 2) {
139 major = versionParts.at(i: 0).toInt(ok: &majorOk);
140 minor = versionParts.at(i: 1).toInt(ok: &minorOk);
141 // Nexus 6 has "OpenGL ES 3.0V@95.0 (GIT@I86da836d38)"
142 if (!minorOk)
143 if (int idx = versionParts.at(i: 1).indexOf(c: 'V'))
144 minor = versionParts.at(i: 1).left(len: idx).toInt(ok: &minorOk);
145 } else {
146 qWarning(msg: "Unrecognized OpenGL ES version");
147 }
148 } else {
149 // If < 3 parts to the name, it is an unrecognised OpenGL ES
150 qWarning(msg: "Unrecognised OpenGL ES version");
151 }
152 } else {
153 // Not OpenGL ES, but regular OpenGL, the version numbers are first in the string
154 QList<QByteArray> versionParts = parts.at(i: 0).split(sep: '.');
155 if (versionParts.size() >= 2) {
156 major = versionParts.at(i: 0).toInt(ok: &majorOk);
157 minor = versionParts.at(i: 1).toInt(ok: &minorOk);
158 } else {
159 qWarning(msg: "Unrecognized OpenGL version");
160 }
161 }
162
163 if (!majorOk || !minorOk)
164 qWarning(msg: "Unrecognized OpenGL version");
165 return (majorOk && minorOk);
166}
167
168QT_END_NAMESPACE
169

source code of qtbase/src/gui/kernel/qplatformopenglcontext.cpp