[ChangeLog][General] The QtOpenglExtensions module has been
discontinued. It provided only convenience functionality for certain
direct OpenGL usage. With the new RHI graphics API abstraction, that
is no longer a primary use case. Applications that still need to
access that API have a number of alternative options, including
QOpenGLExtraFunctions.
Fixes: QTBUG-84085
Change-Id: I272af61c69ebcec207b576d67d08b59623d485ec
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
This patch provides a code generator that can be executed offline
to generate a few classes for enhancing Qt's support for OpenGL.
The generated code effectively provides all the benefits of GLEW
in its multi-context form but for all platforms and even for ES2.
The code generator takes as input the official Khronos gl.spec
specification and gl.tm typemap files. These provide all of the
information required to create the OpenGL Desktop related classes.
The classes for ES2 are hand-crafted as no similar spec files have
been published.
The generated code supports all OpenGL extensions listed in the
Khronos registry for both Desktop OpenGL and ES 2.
There is a helper factory class generated which are used by
QOpenGLContext::versionFunctions().
This allows code like the following to be written:
QOpenGLFunctions_3_3_Core* m_funcs = 0;
m_funcs = m_context->versionFunctions<QOpenGLFunctions_3_3_Core>();
if (!m_funcs) {
qWarning() << "Could not obtain required OpenGL context version";
exit(1);
}
if (!m_funcs->initializeOpenGLFunctions()) {
qWarning() << "Failed to resolve entry points";
exit(2);
}
// Get an extension object
QOpenGLExtension_ARB_draw_buffers* ext = 0;
if (m_context->hasExtension("GL_ARB_draw_buffers")) {
ext = new QOpenGLExtension_ARB_draw_buffers();
ext->initializeOpenGLFunctions(m_context);
}
Such usage will allow much easier and rigorous use of features in
modern OpenGL and extensions both in Qt itself and by users of Qt.
Follow-up patches will import the generated files and then use
these to reinstate OpenGL geometry shaders, add tessellation
shaders, and other OpenGL constructs.
Change-Id: Id0172e8aa1fd57eb4e6979a96d10fb5a34826426
Reviewed-by: Samuel Rødal <samuel.rodal@digia.com>
Reviewed-by: James Turner <james.turner@kdab.com>
