97c187da3c
The patch introduces a new build configuration on Windows which can be requested by passing -opengl dynamic to configure. Platforms other than Windows (including WinRT) are not affected. The existing Angle and desktop configurations are not affected. These continue to function as before and Angle remains the default. In the future, when all modules have added support for the dynamic path, as described below, the default configuration could be changed to be the dynamic one. This would allow providing a single set of binaries in the official builds instead of the current two. When requesting dynamic GL, Angle is built but QT_OPENGL_ES[_2] are never defined. Instead, the code path that has traditionally been desktop GL only becomes the dynamic path that has to do runtime checks. Qt modules and applications are not linked to opengl32.dll or libegl/glesv2.dll in this case. Instead, QtGui exports all necessary egl/egl/gl functions which will, under the hood, forward all requests to a dynamically loaded EGL/WGL/GL implementation. Porting guide (better said, changes needed to prepare your code to work with dynamic GL builds when the fallback to Angle is utilized): 1. In !QT_OPENGL_ES[_2] code branches use QOpenGLFunctions::isES() to differentiate between desktop and ES where needed. Keep in mind that it is the desktop GL header (plus qopenglext.h) that is included, not the GLES one. QtGui's proxy will handle some differences, for example calling glClearDepth will route to glClearDepthf when needed. The built-in eglGetProcAddress is able to retrieve pointers for standard GLES2 functions too so code resolving OpenGL 2 functions will function in any case. 2. QT_CONFIG will contain "opengl" and "dynamicgl" in dynamic builds, but never "angle" or "opengles2". 3. The preprocessor define QT_OPENGL_DYNAMIC is also available in dynamic builds. The usage of this is strongly discouraged and should not be needed anywhere except for QtGui and the platform plugin. 4. Code in need of the library handle can use QOpenGLFunctions::platformGLHandle(). The decision on which library to load is currently based on a simple test that creates a dummy window/context and tries to resolve an OpenGL 2 function. If this fails, it goes for Angle. This seems to work well on Win7 PCs for example that do not have proper graphics drivers providing OpenGL installed but are D3D9 capable using the default drivers. Setting QT_OPENGL to desktop or angle skips the test and forces usage of the given GL. There are also two new application attributes that could be used for the same purpose. If Angle is requested but the libraries are not present, desktop is tried. If desktop is requested, or if angle is requested but nothing works, the EGL/WGL functions will still be callable but will return 0. This conveniently means that eglInitialize() and such will report a failure. Debug messages can be enabled by setting QT_OPENGLPROXY_DEBUG. This will tell which implementation is chosen. The textures example application is ported to OpenGL 2, the GL 1 code path is removed. [ChangeLog][QtGui] Qt builds on Windows can now be configured for dynamic loading of the OpenGL implementation. This can be requested by passing -opengl dynamic to configure. In this mode no modules will link to opengl32.dll or Angle's libegl/libglesv2. Instead, QtGui will dynamically choose between desktop and Angle during the first GL/EGL/WGL call. This allows deploying applications with a single set of Qt libraries with the ability of transparently falling back to Angle in case the opengl32.dll is not suitable, due to missing graphics drivers for example. Task-number: QTBUG-36483 Change-Id: I716fdebbf60b355b7d9ef57d1e069eef366b4ab9 Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com> Reviewed-by: Jørgen Lind <jorgen.lind@digia.com> |
||
---|---|---|
.. | ||
auto | ||
baselineserver | ||
benchmarks | ||
global | ||
manual | ||
shared | ||
README | ||
tests.pro |
This directory contains autotests and benchmarks based on Qt Test. In order to run the autotests reliably, you need to configure a desktop to match the test environment that these tests are written for. Linux X11: * The user must be logged in to an active desktop; you can't run the autotests without a valid DISPLAY that allows X11 connections. * The tests are run against a KDE3 or KDE4 desktop. * Window manager uses "click to focus", and not "focus follows mouse". Many tests move the mouse cursor around and expect this to not affect focus and activation. * Disable "click to activate", i.e., when a window is opened, the window manager should automatically activate it (give it input focus) and not wait for the user to click the window.