diff --git a/shaders/glava/util/pass.frag b/shaders/glava/util/pass.frag
new file mode 100644
index 0000000..c0b8d48
--- /dev/null
+++ b/shaders/glava/util/pass.frag
@@ -0,0 +1,9 @@
+uniform sampler1D tex;
+
+out vec4 fragment;
+in vec4 gl_FragCoord;
+
+/* 1D texture mapping */
+void main() {
+    fragment.r = texelFetch(tex, int(gl_FragCoord.x), 0).r;
+}