Add EGL support to ParaView and Glew (#39800)

* Add EGL support to ParaView and Glew

add a package for egl that provides GL but also adds
EGL libs and headers for projects that need them

Fix a header problem with the opengl package

Format files using black

* better description for egl variant description

Co-authored-by: Vicente Bolea <vicente.bolea@gmail.com>

* better check/setup of non egl variant dependencies

Co-authored-by: Vicente Bolea <vicente.bolea@gmail.com>

* Add biddisco as maintainer

* Fix unused var style warning

* Add egl conflicts for other gl providers

---------

Co-authored-by: Vicente Bolea <vicente.bolea@gmail.com>

4 files changed, 137 insertions, 12 deletions

diff --git a/var/spack/repos/builtin/packages/egl/package.py b/var/spack/repos/builtin/packages/egl/package.py
new file mode 100644
index 0000000000..d79f1e30db
--- /dev/null
+++ b/var/spack/repos/builtin/packages/egl/package.py
@@ -0,0 +1,92 @@
+# Copyright 2013-2023 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)
+
+import re
+import sys
+
+from spack.package import *
+
+
+class Egl(BundlePackage):
+    """Placeholder for external EGL(OpenGL) libraries from hardware vendors"""
+
+    homepage = "https://www.khronos.org/egl"
+    maintainers("biddisco")
+
+    version("1.5")
+
+    # This should really be when='platform=linux' but can't because of a
+    # current bug in when and how ArchSpecs are constructed
+    if sys.platform.startswith("linux"):
+        provides("gl@4.5")
+
+    # conflict with GLX
+    conflicts("glx")
+
+    # not always available, but sometimes
+    executables = ["^eglinfo$"]
+
+    @classmethod
+    def determine_version(cls, exe):
+        if exe:
+            output = Executable(exe)(output=str, error=str)
+            match = re.search(r"EGL version string: (\S+)", output)
+            return match.group(1) if match else None
+        else:
+            return None
+
+    # Override the fetcher method to throw a useful error message;
+    # fixes GitHub issue (#7061) in which this package threw a
+    # generic, uninformative error during the `fetch` step,
+    @property
+    def fetcher(self):
+        msg = """This package is intended to be a placeholder for
+        system-provided EGL(OpenGL) libraries from hardware vendors.  Please
+        download and install EGL drivers/libraries for your graphics
+        hardware separately, and then set that up as an external package.
+        An example of a working packages.yaml:
+
+        packages:
+          egl:
+            buildable: False
+            externals:
+            - spec: egl@1.5.0
+              prefix: /usr/
+
+        In that case, /usr/ should contain these two folders:
+
+        include/EGL/      (egl headers, including "egl.h")
+        lib               (egl libraries, including "libEGL.so")
+
+        """
+        raise InstallError(msg)
+
+    @fetcher.setter  # Since fetcher is read-write, must override both
+    def fetcher(self):
+        _ = self.fetcher
+
+    @property
+    def headers(self):
+        return self.egl_headers
+
+    @property
+    def libs(self):
+        return self.egl_libs
+
+    @property
+    def egl_headers(self):
+        header_name = "GL/gl"
+        gl_header = find_headers(header_name, root=self.prefix, recursive=True)
+        header_name = "EGL/egl"
+        egl_header = find_headers(header_name, root=self.prefix, recursive=True)
+        return gl_header + egl_header
+
+    @property
+    def egl_libs(self):
+        lib_name = "libGL"
+        gl_lib = find_libraries(lib_name, root=self.prefix, recursive=True)
+        lib_name = "libEGL"
+        egl_lib = find_libraries(lib_name, root=self.prefix, recursive=True)
+        return gl_lib + egl_lib
diff --git a/var/spack/repos/builtin/packages/glew/package.py b/var/spack/repos/builtin/packages/glew/package.py
index a5d8d1ef3e..38c2a9c322 100644
--- a/var/spack/repos/builtin/packages/glew/package.py
+++ b/var/spack/repos/builtin/packages/glew/package.py
@@ -15,6 +15,8 @@ class Glew(CMakePackage):
     url = "https://github.com/nigels-com/glew/releases/download/glew-2.1.0/glew-2.1.0.tgz"
     root_cmakelists_dir = "build/cmake"
 
+    maintainers("biddisco")
+
     version("2.2.0", sha256="d4fc82893cfb00109578d0a1a2337fb8ca335b3ceccf97b97e5cc7f08e4353e1")
     version("2.1.0", sha256="04de91e7e6763039bc11940095cd9c7f880baba82196a7765f727ac05a993c95")
     version("2.0.0", sha256="c572c30a4e64689c342ba1624130ac98936d7af90c3103f9ce12b8a0c5736764")
@@ -22,20 +24,26 @@ class Glew(CMakePackage):
     variant(
         "gl",
         default="glx" if sys.platform.startswith("linux") else "other",
-        values=("glx", "osmesa", "other"),
+        values=("glx", "osmesa", "egl", "other"),
         multi=False,
         description="The OpenGL provider to use",
     )
     conflicts("^osmesa", when="gl=glx")
+    conflicts("^osmesa", when="gl=egl")
     conflicts("^osmesa", when="gl=other")
     conflicts("^glx", when="gl=osmesa")
     conflicts("^glx", when="gl=other")
+    conflicts("^glx", when="gl=egl")
+    conflicts("^egl", when="gl=glx")
+    conflicts("^egl", when="gl=osmesa")
+    conflicts("^egl", when="gl=other")
 
     depends_on("gl")
     depends_on("osmesa", when="gl=osmesa")
     depends_on("glx", when="gl=glx")
     depends_on("libx11", when="gl=glx")
     depends_on("xproto", when="gl=glx")
+    depends_on("egl", when="gl=egl")
 
     # glu is already forcibly disabled in the CMakeLists.txt.  This prevents
     # it from showing up in the .pc file
@@ -46,17 +54,22 @@ class Glew(CMakePackage):
         args = [
             self.define("BUILD_UTILS", True),
             self.define("GLEW_REGAL", False),
-            self.define("GLEW_EGL", False),
+            self.define("GLEW_EGL", "gl=egl" in spec),
             self.define("OpenGL_GL_PREFERENCE", "LEGACY"),
             self.define("OPENGL_INCLUDE_DIR", spec["gl"].headers.directories[0]),
             self.define("OPENGL_gl_LIBRARY", spec["gl"].libs[0]),
             self.define("OPENGL_opengl_LIBRARY", "IGNORE"),
             self.define("OPENGL_glx_LIBRARY", "IGNORE"),
-            self.define("OPENGL_egl_LIBRARY", "IGNORE"),
             self.define("OPENGL_glu_LIBRARY", "IGNORE"),
             self.define("GLEW_OSMESA", "gl=osmesa" in spec),
             self.define("GLEW_X11", "gl=glx" in spec),
             self.define("CMAKE_DISABLE_FIND_PACKAGE_X11", "gl=glx" not in spec),
         ]
+        if "gl=egl" in spec:
+            args.append(
+                self.define("OPENGL_egl_LIBRARY", [spec["egl"].libs[0], spec["egl"].libs[1]])
+            )
+        else:
+            args.append(self.define("OPENGL_egl_LIBRARY", "IGNORE"))
 
         return args
diff --git a/var/spack/repos/builtin/packages/opengl/package.py b/var/spack/repos/builtin/packages/opengl/package.py
index 21cc3b8cd7..edc6577c3b 100644
--- a/var/spack/repos/builtin/packages/opengl/package.py
+++ b/var/spack/repos/builtin/packages/opengl/package.py
@@ -13,8 +13,8 @@ class Opengl(BundlePackage):
     """Placeholder for external OpenGL libraries from hardware vendors"""
 
     homepage = "https://www.opengl.org/"
-
     version("4.5")
+    maintainers("biddisco")
 
     # This should really be when='platform=linux' but can't because of a
     # current bug in when and how ArchSpecs are constructed
@@ -83,15 +83,20 @@ class Opengl(BundlePackage):
         _ = self.fetcher
 
     @property
+    def headers(self):
+        return self.gl_headers
+
+    @property
     def libs(self):
         return self.gl_libs
 
     @property
     def gl_headers(self):
-        if "platform=darwin":
-            header_name = "OpenGL/gl.h"
+        spec = self.spec
+        if "platform=darwin" in spec:
+            header_name = "OpenGL/gl"
         else:
-            header_name = "GL/gl.h"
+            header_name = "GL/gl"
         return find_headers(header_name, root=self.prefix, recursive=True)
 
     @property
diff --git a/var/spack/repos/builtin/packages/paraview/package.py b/var/spack/repos/builtin/packages/paraview/package.py
index 1f3cd9a76f..333cc328f2 100644
--- a/var/spack/repos/builtin/packages/paraview/package.py
+++ b/var/spack/repos/builtin/packages/paraview/package.py
@@ -67,6 +67,7 @@ class Paraview(CMakePackage, CudaPackage, ROCmPackage):
     variant("fortran", default=False, description="Enable Fortran support")
     variant("mpi", default=True, description="Enable MPI support")
     variant("osmesa", default=False, description="Enable OSMesa support")
+    variant("egl", default=False, description="Enable EGL in the OpenGL library being used")
     variant("qt", default=False, description="Enable Qt (gui) support")
     variant("opengl2", default=True, description="Enable OpenGL2 backend")
     variant("examples", default=False, description="Build examples")
@@ -186,12 +187,16 @@ class Paraview(CMakePackage, CudaPackage, ROCmPackage):
 
     depends_on("gl@3.2:", when="+opengl2")
     depends_on("gl@1.2:", when="~opengl2")
-    depends_on("glew")
+    depends_on("glew", when="~egl")
+    depends_on("glew gl=egl", when="+egl")
+
     depends_on("osmesa", when="+osmesa")
     for p in ["linux", "cray"]:
-        depends_on("glx", when="~osmesa platform={}".format(p))
-        depends_on("libxt", when="~osmesa platform={}".format(p))
+        depends_on("glx", when="~egl ~osmesa platform={}".format(p))
+        depends_on("libxt", when="~egl ~osmesa platform={}".format(p))
     conflicts("+qt", when="+osmesa")
+    conflicts("+qt", when="+egl")
+    conflicts("+egl", when="+osmesa")
 
     depends_on("ospray@2.1:2", when="+raytracing")
     depends_on("openimagedenoise", when="+raytracing")
@@ -419,13 +424,20 @@ class Paraview(CMakePackage, CudaPackage, ROCmPackage):
             """Negated ternary for spec variant to OFF/ON string"""
             return variant_bool(feature, on="OFF", off="ON")
 
+        def use_x11():
+            """Return false if osmesa or egl are requested"""
+            if "+osmesa" in spec or "+egl" in spec:
+                return "OFF"
+            if spec.satisfies("platform=windows"):
+                return "OFF"
+            return "ON"
+
         rendering = variant_bool("+opengl2", "OpenGL2", "OpenGL")
         includes = variant_bool("+development_files")
-        use_x11 = nvariant_bool("+osmesa") if not spec.satisfies("platform=windows") else "OFF"
 
         cmake_args = [
             "-DVTK_OPENGL_HAS_OSMESA:BOOL=%s" % variant_bool("+osmesa"),
-            "-DVTK_USE_X:BOOL=%s" % use_x11,
+            "-DVTK_USE_X:BOOL=%s" % use_x11(),
             "-DPARAVIEW_INSTALL_DEVELOPMENT_FILES:BOOL=%s" % includes,
             "-DBUILD_TESTING:BOOL=OFF",
             "-DOpenGL_GL_PREFERENCE:STRING=LEGACY",
@@ -433,6 +445,9 @@ class Paraview(CMakePackage, CudaPackage, ROCmPackage):
             self.define_from_variant("VISIT_BUILD_READER_Silo", "visitbridge"),
         ]
 
+        if "+egl" in spec:
+            cmake_args.append("-DVTK_OPENGL_HAS_EGL:BOOL=ON")
+
         if spec.satisfies("@5.12:"):
             cmake_args.append("-DVTK_MODULE_USE_EXTERNAL_VTK_fast_float:BOOL=OFF")
             cmake_args.append("-DVTK_MODULE_USE_EXTERNAL_VTK_token:BOOL=OFF")