Fork of Ork library with SCons build support.

Following lines describes how to build Ork under Ubuntu 22.04 LTS.

• download glew library from glew page where 1.5.6 version can be downloaded here

• unpack with

tar -xaf glew-1.5.6.tgz	

command.

• install glew dependencies with

sudo apt install libxmu-dev libglu1-mesa-dev libglut-dev

command

• build with

cd glew-1.5.6
make -j8

command

note: works only with tarball (not zip glew library file)

• install with to /usr directory with

sudo make install

command. Where glew library in installed to /usr directory.

• create linker configuration for /usr/lib64 where glew was installed. Go to configuration directory with

cd /etc/ld.so.conf.d

and create usr_lib64.conf with following

$ cat usr_lib64.conf 
# linker configuration for /usr/lib64
/usr/lib64

content

• update linker cache with

sudo ldconfig

Be aware that (/usr/lib64/pkgconfig) pkg-config install directory is not searched by pkg-config command and as a result pkg-config is not aware of locally installed glew library e.g.

$ pkg-config --modversion glew
2.2.0

can return 2.2.0 (verson of glew library installed by package manager) instead of 1.5.6 version installed manually.

This can be solved by setting PKG_CONFIG_PATH environment variable from build script with

env.AppendENVPath('PKG_CONFIG_PATH', '/usr/lib64/pkgconfig')

line (see SConstruct file).

Now finally we can run

scons -j8

command to build Ork library.

1. undefined reference to glEnable

/bin/ld: libork.a(FrameBuffer.o): undefined reference to symbol 'glEnable'
/bin/ld: /lib/x86_64-linux-gnu/libGL.so.1: error adding symbols: DSO missing from command line

There are missing -lGL -lX11 -lGLU dependencies for glew library in a pkg-config configuration.

After succesfull building examples can be found in examples directory.

$ cd examples
$ ./examples minimal

other examples are render, resource, scenegraph, scenegraphresource and tessellation.

Run

./examples render .

commnad for render example or

./examples resource .

command for resource or

./examples scenegraph .

command for scenegraph or

./example scenegraphresource . cubesScene|exampleScene|postprocessScene|skyboxScene

command for scene graph from resource file sample or

./examples tessellation

command for a tessellation sample (GLSL 4.0).

TODO: how to run tests to find errors?

1. Unable to loading shared library libGLEW.so.1.5

$ ./examples
./examples: error while loading shared libraries: libGLEW.so.1.5: c/etc/ld.so.conf.dannot open shared object file: No such file or directory

The root cause is that the library in not in a linker cache.

$ ldconfig -p|grep -i glew
        libGLEW.so.2.2 (libc6,x86-64) => /lib/x86_64-linux-gnu/libGLEW.so.2.2
        libGLEW.so (libc6,x86-64) => /lib/x86_64-linux-gnu/libGLEW.so

There is missig linker configuration for /usr/lib64 in /etc/ld.so.conf.d directory.

2. OpenGL error 1282 complain for exampes

$ ./examples minimal
ERROR [RENDER] OpenGL error 1282, returned string 'invalid operation'
invalid operation
examples: ork/render/Program.cpp:660: void ork::Program::initUniforms(): Assertion `FrameBuffer::getError() == 0' failed.
Aborted (core dumped)

3. unknown sequence resource type for scenegraph example

$ ./examples scenegraph .
...
ERROR [RESOURCE] Unknown resource type 'sequence' at line 1 in sequence>

this is because implicit resource type registration mechanism is optimized out by linker in case sequence resource part of the code is not called by an application (which is the case or runtime configuration). No idea how to force linker to not optimized out local static variables so therefore we've introduced explicit initialization as ork::InitResourceTypes() in resources/InitResources.h header.

To install Ork library run

sudo scons install

command and to update linker database, run

sudo ldconfig

TODO: is linker searching in /usr/local/lib by default?

command.

The library is installed to /usr/local/lib directory.