qt5base-lts/mkspecs/win32-icc/qmake.conf
Laszlo Agocs 97c187da3c Dynamic GL switch on Windows
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>
2014-02-14 10:51:44 +01:00

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#
# qmake configuration for win32-icc
#
# Written for Intel C++
#
load(qt_config)
MAKEFILE_GENERATOR = MSVC.NET
QMAKE_PLATFORM = win32
CONFIG += incremental flat debug_and_release debug_and_release_target
DEFINES += UNICODE
QMAKE_COMPILER_DEFINES += __INTEL_COMPILER WIN32
QMAKE_COMPILER = msvc intel_icl # icl pretends to be msvc
QMAKE_CC = icl
QMAKE_LEX = flex
QMAKE_LEXFLAGS =
QMAKE_YACC = byacc
QMAKE_YACCFLAGS = -d
QMAKE_CFLAGS = -nologo -Zm200 /Qprec /Qwd1744,1738
QMAKE_CFLAGS_WARN_ON = -W3 /Qwd673
QMAKE_CFLAGS_WARN_OFF = -W0 /Qwd673
QMAKE_CFLAGS_RELEASE = -O2 -MD
# Giving -O2 to debug builds should make icc 9.1 happy, but it might make debugging harder, so it might be reverted.
# This is actually a workaround for a bug in icc 9.1.
QMAKE_CFLAGS_DEBUG = -Zi -MDd -O2
QMAKE_CFLAGS_YACC =
QMAKE_CXX = $$QMAKE_CC
QMAKE_CXXFLAGS = $$QMAKE_CFLAGS /Zc:forScope
QMAKE_CXXFLAGS_WARN_ON = $$QMAKE_CFLAGS_WARN_ON
QMAKE_CXXFLAGS_WARN_OFF = $$QMAKE_CFLAGS_WARN_OFF
QMAKE_CXXFLAGS_RELEASE = $$QMAKE_CFLAGS_RELEASE
QMAKE_CXXFLAGS_DEBUG = $$QMAKE_CFLAGS_DEBUG
QMAKE_CXXFLAGS_YACC = $$QMAKE_CFLAGS_YACC
QMAKE_CXXFLAGS_STL_ON = -GX
QMAKE_CXXFLAGS_STL_OFF =
QMAKE_CXXFLAGS_RTTI_ON = -GR
QMAKE_CXXFLAGS_RTTI_OFF =
QMAKE_CXXFLAGS_EXCEPTIONS_ON = -GX
QMAKE_CXXFLAGS_EXCEPTIONS_OFF =
QMAKE_INCDIR =
QMAKE_RUN_CC = $(CC) -c $(CFLAGS) $(INCPATH) -Fo$obj $src
QMAKE_RUN_CC_IMP = $(CC) -c $(CFLAGS) $(INCPATH) -Fo$@ $<
QMAKE_RUN_CC_IMP_BATCH = $(CC) -c $(CFLAGS) $(INCPATH) -Fo$@ @<<
QMAKE_RUN_CXX = $(CXX) -c $(CXXFLAGS) $(INCPATH) -Fo$obj $src
QMAKE_RUN_CXX_IMP = $(CXX) -c $(CXXFLAGS) $(INCPATH) -Fo$@ $<
QMAKE_RUN_CXX_IMP_BATCH = $(CXX) -c $(CXXFLAGS) $(INCPATH) -Fo$@ @<<
QMAKE_LINK = xilink
QMAKE_LFLAGS = /NOLOGO
QMAKE_LFLAGS_RELEASE =
QMAKE_LFLAGS_DEBUG = /DEBUG
QMAKE_LFLAGS_CONSOLE = /SUBSYSTEM:console
QMAKE_LFLAGS_WINDOWS = /SUBSYSTEM:windows
QMAKE_LFLAGS_DLL = /DLL
QMAKE_LIBS =
QMAKE_LIBS_CORE = kernel32.lib user32.lib shell32.lib uuid.lib ole32.lib advapi32.lib ws2_32.lib
QMAKE_LIBS_GUI = gdi32.lib comdlg32.lib oleaut32.lib imm32.lib winmm.lib ws2_32.lib ole32.lib user32.lib advapi32.lib
QMAKE_LIBS_NETWORK = ws2_32.lib
!contains(QT_CONFIG, dynamicgl): QMAKE_LIBS_OPENGL = glu32.lib opengl32.lib gdi32.lib user32.lib delayimp.lib
QMAKE_LIBS_COMPAT = advapi32.lib shell32.lib comdlg32.lib user32.lib gdi32.lib ws2_32.lib
QMAKE_LIBS_QT_ENTRY = -lqtmain
QMAKE_IDL = midl
QMAKE_LIB = xilib /NOLOGO
QMAKE_RC = rc
include(../common/shell-win32.conf)
DSP_EXTENSION = .dsp