MACOSX_USE_GLX has been renamed to HAVE_XLIB and now configurable on Linux target.
Xw_Window.hxx now export class on non-Linux platforms.
OpenGl_Window now creates an off-screen EGL surface also in case of
window-less desktop setup (e.g. with disabled Xlib on Linux).
Draw_Window - code has been cleaned up.
Class definition has been unified across platforms when possible.
Unusued constructors have been removed.
Internal header files (MainWindow.h, init.h, etc.) have been renamed to .pxx
to avoid their unexpected distribution in "inc".
Handled __EMSCRIPTEN__ macros to:
- Workaround atomics (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 is undefined, but GCC atomics are provided).
- Suppress non-standard header <sys/signal.h> warning.
- Return OSD_LinuxREDHAT.
- Avoid inclusion of XLib headers.
- Skip fontconfig library.
- Enable EGL+GLES path (translated by Emscripten into WebGL).
- Skip eglCreatePbufferSurface() not implemented by Emscripten EGL.
Fixed Graphic3d_Vec4.hxx usage within Quantity_ColorRGBA.hxx.
OpenGl_ShaderManager::defaultGlslVersion() now prefers GLSL 300 es when WebGL 2.0 is available,
as there no any OpenGL ES greater than 3.0 emulation so far.
Shaders_Declarations.glsl - added workaround for GLSL compilation on WebGL 1.0
by defining Light properties accessors as macros instead of functions
('[]' : Index expression must be constant).
OpenGl_FrameBuffer::Init() - added workaround for initialization of GL_DEPTH24_STENCIL8
depth-stencil attachment on WebGL 1.0 + GL_WEBGL_depth_texture extension.
OpenGl_Context::Vec4FromQuantityColor() now considers myIsSRgbActive flag
to handle use case, when Immediate Layer is drawn directly into window buffer,
which is not sRGB-ready.
Added new sample - OCCT WebGL viewer.
Aspect_Window::NativeFBConfig() - extend interface with new method.
Xw_Window - add Aspect_FBConfig option to constructors,
use glXChooseFBConfig() instead of glXChooseVisual() on GLX1.3+.
OpenGl_Window - create context using glXCreateContextAttribsARB()
when GLXFBConfig is provided by Aspect_Window.
This procedure now handles Core Profile and Debug Context options on Linux.
OpenGl_Window - drop code implicitly creating child window
when window XVisual is incomplete for OpenGL context.
This should eliminate event-handling issues at application side,
but would require window to be properly created by application.
