Add libglvnd packages/Add EGL support (#14572)

* add new package: "libglvnd-frontend"

* add +glvnd variant to opengl package

* add +glvnd variant to mesa package

* add +egl variant to paraview package

* add libglvnd-frontend entries to default packages config

* fix style

* add default providers for glvnd virtuals

add default providers for glvnd-gl, glvnd-glx, and glvnd-egl

* WIP: rough start to external OpenGL documentation

* rename libglvnd-frontend package and backend virtual dependencies

* update documentation

* fix ligvnd-be-* typos

* fix libglvnd-fe package class name

* fix doc parse error

1 files changed, 56 insertions, 0 deletions

diff --git a/var/spack/repos/builtin/packages/libglvnd-fe/package.py b/var/spack/repos/builtin/packages/libglvnd-fe/package.py
new file mode 100644
index 0000000000..6f737a9017
--- /dev/null
+++ b/var/spack/repos/builtin/packages/libglvnd-fe/package.py
@@ -0,0 +1,56 @@
+# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class LibglvndFe(BundlePackage):
+    """The GL Vendor-Neutral Dispatch library (Frontend Dummy Package)
+
+    libglvnd is a vendor-neutral dispatch layer for arbitrating OpenGL API
+    calls between multiple vendors. It allows multiple drivers from different
+    vendors to coexist on the same filesystem, and determines which vendor to
+    dispatch each API call to at runtime.
+
+    Both GLX and EGL are supported, in any combination with OpenGL and OpenGL
+    ES."""
+
+    homepage = "https://github.com/NVIDIA/libglvnd"
+
+    version('1.1.1', sha256='71918ed1261e4eece18c0b74b50dc62c0237b8d526e83277ef078554544720b9')
+
+    variant('glx', default=False, description='Provide GLX API')
+    variant('egl', default=False, description='Provide EGL API')
+
+    depends_on('libglvnd')
+
+    depends_on('libglvnd-be-gl')
+    depends_on('libglvnd-be-glx', when='+glx')
+    depends_on('libglvnd-be-egl', when='+egl')
+
+    provides('gl')
+    provides('glx', when='+glx')
+    provides('egl', when='+egl')
+
+    @property
+    def gl_libs(self):
+        return find_libraries('libOpenGL',
+                              root=self.spec['libglvnd'].prefix,
+                              shared=True,
+                              recursive=True)
+
+    @property
+    def glx_libs(self):
+        return find_libraries('libGLX',
+                              root=self.spec['libglvnd'].prefix,
+                              shared=True,
+                              recursive=True)
+
+    @property
+    def egl_libs(self):
+        return find_libraries('libEGL',
+                              root=self.spec['libglvnd'].prefix,
+                              shared=True,
+                              recursive=True)