deps: Add build recipe for WebP (#4422)

As requested in #4387.

---------

Signed-off-by: Zach Lewis <[email protected]>
Signed-off-by: zachlewis <[email protected]>

Author: zachlewis

src/cmake/build_WebP.cmake

@@ -0,0 +1,46 @@
+# Copyright Contributors to the OpenImageIO project.
+# SPDX-License-Identifier: Apache-2.0
+# https://github.com/AcademySoftwareFoundation/OpenImageIO
+
+######################################################################
+# WebP by hand!
+######################################################################
+
+set_cache (WebP_BUILD_VERSION 1.4.0 "WebP version for local builds")
+set (WebP_GIT_REPOSITORY "https://github.com/webmproject/libwebp.git")
+set (WebP_GIT_TAG "v${WebP_BUILD_VERSION}")
+
+set_cache (WebP_BUILD_SHARED_LIBS OFF 
+           DOC "Should execute a local WebP build; if necessary, build shared libraries" ADVANCED)
+
+string (MAKE_C_IDENTIFIER ${WebP_BUILD_VERSION} WebP_VERSION_IDENT)
+
+build_dependency_with_cmake(WebP
+    VERSION         ${WebP_BUILD_VERSION}
+    GIT_REPOSITORY  ${WebP_GIT_REPOSITORY}
+    GIT_TAG         ${WebP_GIT_TAG}
+    CMAKE_ARGS
+        -D BUILD_SHARED_LIBS=${WebP_BUILD_SHARED_LIBS}
+        -D WEBP_BUILD_ANIM_UTILS=OFF
+        -D WEBP_BUILD_CWEBP=OFF
+        -D WEBP_BUILD_DWEBP=OFF
+        -D WEBP_BUILD_GIF2WEBP=OFF
+        -D WEBP_BUILD_IMG2WEBP=OFF
+        -D WEBP_BUILD_VWEBP=OFF
+        -D WEBP_BUILD_WEBPINFO=OFF
+        -D WEBP_BUILD_WEBPMUX=OFF
+        -D WEBP_BUILD_EXTRAS=OFF
+        -D CMAKE_INSTALL_LIBDIR=lib
+    )
+
+# Set some things up that we'll need for a subsequent find_package to work
+set (WebP_ROOT ${WebP_LOCAL_INSTALL_DIR})
+
+# Signal to caller that we need to find again at the installed location
+set (WebP_REFIND TRUE)
+set (WebP_REFIND_VERSION ${WebP_BUILD_VERSION})
+set (WebP_REFIND_ARGS CONFIG)
+
+if (WebP_BUILD_SHARED_LIBS)
+    install_local_dependency_libs (WebP WebP)
+endif ()