From f38935459bd13f2d01d0575507e8ed20d99cdb97 Mon Sep 17 00:00:00 2001
From: Maciej Suminski <maciej.suminski@cern.ch>
Date: Mon, 1 Jul 2013 15:47:44 +0200
Subject: [PATCH] Headers are regenerated only if shaders' source code was
 modified.

---
 common/gal/opengl/make_shader_src_h.sh | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/common/gal/opengl/make_shader_src_h.sh b/common/gal/opengl/make_shader_src_h.sh
index 19f6a410f2..9bb4ce4de8 100755
--- a/common/gal/opengl/make_shader_src_h.sh
+++ b/common/gal/opengl/make_shader_src_h.sh
@@ -8,6 +8,20 @@ SHADER_SRC=( "shader.vert" "shader.frag" )
 # Number of shaders
 SHADERS_NUMBER=${#SHADER_SRC[@]}
 OUTPUT="shader_src.h"
+UPDATE=false
+
+# Check if it is necessary to regenerate headers
+for filename in "${SHADER_SRC[@]}"
+do
+	if [[ $filename -nt $OUTPUT ]]; then
+	    UPDATE=true
+	fi
+done
+
+if [[ $UPDATE == false ]]; then
+    echo "Headers are up-to-date."
+    exit
+fi
 
 # Prepare GLSL source to be included in C array
 function processSrc {