Re: [Mingw-cross-env-list] Qt / Angle / OpenGL

[SEAiq]

We do use the normal OpenGL interface and when it works it works great.  However, our app (a marine navigation app used by pilots to navigate large seagoing vessels) makes use of OpenGL shaders so it will not work with the Microsoft OpenGL 1.1 fall-back library.  Expecting users to have up to date OpenGL libraries is (very) problematic.

I believe it is exactly for this reason that Google and Firefox invested the effort in developing ANGLE… its avoids the hassles with OpenGL libraries not working or being out of date.  I believe it is also for this reason that QT has embedded ANGLE in their distribution.

Does anyone have any experience with using ANGLE as part of or in conjunction with MXE?

best, Mark

On Jan 21, 2015, at 8:32 PM, Timothy Gu <address@hidden> wrote:

My question is, why can't you just use the existing OpenGL interface and have to use ANGLE?

Timothy

On Wed Jan 21 2015 at 6:30:37 PM SEAiq <address@hidden> wrote:

I’m using the development version of MXE.

The ANGLE library that is included in qtbase does not appear to be getting built.  I suspect that is because the configure command in qtbase.mk has “—opengl desktop” in the configure command.

I tried running XXXXXXX-qmake in the src/angle directory.  Then run “make”.

I get the feeling no one has attempted to cross-compile angle like this before because:

(1) the build tries to use “win_flex” rather than “flex”, as though it were on Windows

(2) a file Internal.h is included with lower-case name, “internal.h” in qtbase’s src/3rdPart/angle

(3) there is a deprecated flex feature used that cause flex output files to not compile

I worked past these issues until the build started running an FXC.EXE command which I’m not familiar with.  Again, the commands were issued as though intended to run on windows rather than cross-compiled.

So, I’m wondering if cross compiling the ANGLE library included in qtbase is going to work and if anyone has any success with this.

I’m now considering building ANGLE separately on Windows (not cross compiling) and seeing if my QT-based application can simply be linked to the ANGLE OpenGL libraries at the last step of our build.\.

It seems to me that problems with OpenGL driver libraries on Windows are so common that the approach to using ANGLE to use Direct3D makes a great deal of sense.

I hope this provides the information you were looking for.  Any comments, suggestions, etc would be greatly appreciated.  Especially from someone who has attempted/succeeded at this.

best, Mark

On Jan 21, 2015, at 8:12 PM, Timothy Gu <address@hidden> wrote:

What problem are you having?

On Wed Jan 21 2015 at 8:23:07 AM SEAiq <address@hidden> wrote:

We are having problems with users OpenGL libraries on Windows.

Google’s Angle library is supposed to avoid this by translating OpenGL to native Direct3D calls.

The Qt5 qtbase package includes the Angle library but MXE does not build it.

Is anyone using Qt5 with Angle?  Any advice on how to build Angle for MXE?

thanks, Mark