gnu: Add mojoshader-cs.

* gnu/packages/gl.scm (mojoshader-cs): New variable.

gnu/packages/gl.scm

@@ -42,6 +42,7 @@ (define-module (gnu packages gl)
   #:use-module (gnu packages image)
   #:use-module (gnu packages linux)
   #:use-module (gnu packages llvm)
+  #:use-module (gnu packages mono)
   #:use-module (gnu packages pkg-config)
   #:use-module (gnu packages python)
   #:use-module (gnu packages python-xyz)
@@ -889,3 +890,41 @@ (define-public mojoshader-with-viewport-flip
       (description "This is the last version of the mojoshader library with
 the glProgramViewportFlip before it was replaced with glProgramViewportInfo.")
       (license license:zlib))))
+
+(define-public mojoshader-cs
+  (let ((commit "10d0dba21ff1cfe332eb7de328a2adce01286bd7"))
+    (package
+      (name "mojoshader-cs")
+      (version (git-version "20191205" "1" commit))
+      (source (origin
+                (method git-fetch)
+                (uri (git-reference
+                      (url "https://github.com/FNA-XNA/MojoShader")
+                      (commit commit)))
+                (file-name (git-file-name name version))
+                (sha256
+                 (base32
+                  "11mdhf3fmb9rsn2iv753gmb596j4dh5j2iipgw078vg0lj23rml7"))))
+      (build-system gnu-build-system)
+      (arguments
+       '(#:tests? #f  ; No tests.
+         #:phases
+         (modify-phases %standard-phases
+           (delete 'configure)
+           (replace 'build
+             (lambda _
+               (invoke "make" "-C" "csharp")))
+           (replace 'install
+             (lambda* (#:key outputs #:allow-other-keys)
+               (let ((out (assoc-ref outputs "out")))
+                 (install-file "csharp/bin/MojoShader-CS.dll" (string-append out "/lib"))
+                 #t))))))
+      (native-inputs
+       `(("mono" ,mono)))
+      (home-page "https://github.com/FNA-XNA/MojoShader")
+      (synopsis "C# wrapper for MojoShader")
+      (description
+       "Mojoshader-CS provides C# bindings for the Mojoshader library.
+The C# wrapper was written to be used for FNA's platform support.  However, this
+is written in a way that can be used for any general C# application.")
+      (license license:zlib))))