From c45155d6b7dcda450016a548fd399628efd5063b Mon Sep 17 00:00:00 2001
From: alexanderWatanabe <alex.watanabe@gmail.com>
Date: Mon, 13 Apr 2020 01:22:45 +0900
Subject: [PATCH] added cuda cmake flags (allows GPU acceleration of some of
 the libraries functions)

---
 pkgs/development/libraries/dlib/default.nix | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/libraries/dlib/default.nix b/pkgs/development/libraries/dlib/default.nix
index e4259e1686c8..e7cc12e0db51 100644
--- a/pkgs/development/libraries/dlib/default.nix
+++ b/pkgs/development/libraries/dlib/default.nix
@@ -3,6 +3,7 @@
 
   # see http://dlib.net/compile.html
 , avxSupport ? true
+, cudaSupport ? true
 }:
 
 stdenv.mkDerivation rec {
@@ -20,7 +21,9 @@ stdenv.mkDerivation rec {
     rm -rf dlib/external
   '';
 
-  cmakeFlags = [ "-DUSE_AVX_INSTRUCTIONS=${if avxSupport then "yes" else "no"}" ];
+  cmakeFlags = [ 
+    "-DUSE_DLIB_USE_CUDA=${if cudaSupport then "1" else "0"}"
+    "-DUSE_AVX_INSTRUCTIONS=${if avxSupport then "yes" else "no"}" ];
 
   enableParallelBuilding = true;
   nativeBuildInputs = [ cmake pkgconfig ];