qt5base-lts/examples/opengl/legacy/README

This directory contains legacy examples that use the fixed pipeline
and thus are not compatible with OpenGL ES 2.0+ and the core profile of
OpenGL 3.0+. They also rely on the Qt OpenGL module (e.g. QGLWidget) which
is not advisable in new application.
Modernize the OpenGL examples Change them to use QOpenGLWidget and QOpenGLTexture. Advocate also the usage of VBOs. Hopeless examples, that rely on the fixed pipeline and will not compile or work in ES and dynamic builds, are moved to a "legacy" directory. The documentation pages for these are removed. This long due change avoids the confusion newcomers experience when trying to get started with Qt 5 and OpenGL. hellowindow's behavior is changed to open a single window only by default. The old default behavior, that opened three windows on platforms that supported both MultipleWindows & ThreadedOpenGL, can be requested by passing --multiple. --single is removed since it is the default now. This plays much nicer with drivers that have issues with threading. In addition, say hello to hellogl2. This is the old hellogl example updated to use QOpenGLWidget and OpenGL 2. It also has a mainwindow with multiple (un)dockable widgets containing the OpenGL widgets. This helps testing the behavior when the top-level of the QOpenGLWidget changes and provides a very important example of how to do proper resource management in this case. (must use aboutToBeDestroyed() of the context, since the context goes away and is replaced by a new one on every dock/undock) As a bonus, the logo is now real 3D, no more orthographic nonsense. Launch with --multisample to request 4x MSAA. Launch with --coreprofile to request 3.2 Core. In this particular example the shaders are present in both versions and there is a VAO so the application is functional with core profile contexts. Change-Id: Id780a80cb0708ef164cc172450ed74050f065596 Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com> 2014-08-02 17:42:15 +00:00			`This directory contains legacy examples that use the fixed pipeline`
			`and thus are not compatible with OpenGL ES 2.0+ and the core profile of`
			`OpenGL 3.0+. They also rely on the Qt OpenGL module (e.g. QGLWidget) which`
			`is not advisable in new application.`