[eve7][rendercore] Download the release tarball at build time instead of bundling it

.github/workflows/root-ci-config/buildconfig/global.txt

@@ -24,6 +24,7 @@ builtin_openssl=OFF
 builtin_jsroot=ON
 builtin_mathjax=ON
 builtin_openui5=ON
+builtin_rendercore=ON
 builtin_pcre=OFF
 builtin_tbb=OFF
 builtin_unuran=OFF

README/ReleaseNotes/v644/index.md

@@ -32,6 +32,10 @@ The following people have contributed to this new version:
 As announced in the 6.42 release notes, the minimum CMake version required for building ROOT 6.44 rose to 3.26. It is the version shipped with RHEL 8.10, which is the oldest Linux distribution supported by this release.
 After ROOT 6.44, the minimum may rise to 3.31 if an upgrade to LLVM 24 or later is performed, see the [minimum version of CMake required by LLVM](https://discourse.llvm.org/t/rfc-raising-minimum-required-cmake-version-to-3-31/91086), a warning will be emitted at configure time if your CMake version is older than this.
 
+### RenderCore
+
+RenderCore, the WebGL engine of the REve client, is fetched at build time as the tarball of its release, from [SPI](https://spi.web.cern.ch)'s [website](https://lcgpackages.web.cern.ch/) first and from its GitHub release second, instead of being bundled in `builtins/rendercore/`. A build without a network takes the tarball from `ROOT_DOWNLOAD_DIR`, as for every builtin. The build option `builtin_rendercore`, ON by default, controls the download. REve has no web location of RenderCore to fall back to, so the option can be OFF only when REve is not built, that is with `root7` or `webgui` OFF; otherwise the configuration stops with an error.
+
 ## Python Interface
 
 ## I/O

builtins/rendercore/CMakeLists.txt

@@ -1,11 +1,26 @@
-ExternalProject_Add(
-  RENDERCORE
-  URL ${CMAKE_SOURCE_DIR}/builtins/rendercore/RenderCore-2.3.tar.gz
-  URL_HASH SHA256=1f5ff8f33e0c381e00a0472a51d6232a4bbcede1e5cfd167889e185079b57ab9
+# Copyright (C) 1995-2026, Rene Brun and Fons Rademakers.
+# All rights reserved.
+#
+# For the licensing terms see $ROOTSYS/LICENSE.
+# For the list of contributors see $ROOTSYS/README/CREDITS.
+
+# RenderCore, the WebGL engine of the REve client, taken as the distribution
+# tarball of its release: LICENSE, the bundle REveRenderCore-min.mjs and the
+# shaders. The ROOT http server serves it from ui5/eve7/rcore, and the client
+# has no web fallback for it, so it is always built.
+set(ROOT_RENDERCORE_VERSION 2.3.2)
+set(ROOT_RENDERCORE_HASH "a9f786baa49b923f45d09c589ca2e31d927790196968d7ebd1d4fda86e63c4d8")
+
+ExternalProject_Add(RENDERCORE
+  DOWNLOAD_DIR      ${ROOT_DOWNLOAD_DIR}
+  URL               ${lcgpackages}/RenderCore-${ROOT_RENDERCORE_VERSION}.tar.gz
+                    https://github.com/UL-FRI-LGM/RenderCore/releases/download/${ROOT_RENDERCORE_VERSION}/RenderCore-${ROOT_RENDERCORE_VERSION}.tar.gz
+  URL_HASH          SHA256=${ROOT_RENDERCORE_HASH}
+  SOURCE_DIR        ${CMAKE_BINARY_DIR}/ui5/eve7/rcore
+  TIMEOUT           600
   CONFIGURE_COMMAND ""
-  BUILD_COMMAND ""
-  INSTALL_COMMAND ""
-  SOURCE_DIR ${CMAKE_BINARY_DIR}/ui5/eve7/rcore
-  TIMEOUT 600
+  BUILD_COMMAND     ""
+  INSTALL_COMMAND   ""
 )
+
 install(DIRECTORY ${CMAKE_BINARY_DIR}/ui5/eve7/rcore/ DESTINATION ${CMAKE_INSTALL_OPENUI5DIR}/eve7/rcore/ COMPONENT libraries FILES_MATCHING PATTERN "*")

cmake/modules/RootBuildOptions.cmake

@@ -107,6 +107,7 @@ ROOT_BUILD_OPTION(builtin_openssl OFF "Build OpenSSL from an automatically downl
 ROOT_BUILD_OPTION(builtin_jsroot OFF "Install JSROOT to run webgui widgets (requires network)")
 ROOT_BUILD_OPTION(builtin_mathjax OFF "Install mathjax package for mathtext rendering in JSROOT (requires network)")
 ROOT_BUILD_OPTION(builtin_openui5 OFF "Install openui5 package to run webgui widgets (requires network)")
+ROOT_BUILD_OPTION(builtin_rendercore ON "Install RenderCore to run the REve event display (requires network)")
 ROOT_BUILD_OPTION(builtin_pcre OFF "Build PCRE2 from an automatically downloaded source tarball (requires network)")
 ROOT_BUILD_OPTION(builtin_png OFF "Build libpng from an automatically downloaded source tarball (requires network)")
 ROOT_BUILD_OPTION(builtin_tbb OFF "Build TBB from an automatically downloaded source tarball (requires network)")
@@ -290,6 +291,7 @@ if(builtin_all)
   set(builtin_jsroot_defvalue ON)
   set(builtin_mathjax_defvalue ON)
   set(builtin_openui5_defvalue ON)
+  set(builtin_rendercore_defvalue ON)
   set(builtin_pcre_defvalue ON)
   set(builtin_png_defvalue ON)
   set(builtin_tbb_defvalue ON)

cmake/modules/SearchInstalledSoftware.cmake

@@ -1139,7 +1139,23 @@ if(webgui)
     message(WARNING "Without builtin_openui5 option webgui components will not work offline")
     set(OPENUI5_CUSTOM_LOCATION "https://sdk.openui5.org/1.152.0/")
   endif()
-  add_subdirectory(builtins/rendercore)
+endif()
+
+#------------------------------------------------------------------------------------
+# REve, built with webgui and root7, runs its client on RenderCore, for which there is
+# no web location to fall back to, so the builtin is required whenever REve is built.
+if(webgui AND root7)
+  if(builtin_rendercore)
+    ROOT_CHECK_CONNECTION("root7=OFF")
+    if (NO_CONNECTION)
+      message(SEND_ERROR "builtin_rendercore=ON requires internet connection, check it, place the RenderCore tarball in ROOT_DOWNLOAD_DIR or disable root7")
+      list(APPEND HOTFIX_BUILD_FLAGS -Droot7=OFF)
+    endif()
+    add_subdirectory(builtins/rendercore)
+  else()
+    message(SEND_ERROR "REve needs RenderCore: enable builtin_rendercore or disable root7")
+    list(APPEND HOTFIX_BUILD_FLAGS -Droot7=OFF)
+  endif()
 endif()
 
 #------------------------------------------------------------------------------------