diff --git a/src/renderer/shader/aorii_util.slang b/src/renderer/shader/aorii_util.slang
new file mode 100644
index 0000000..4606dde
--- /dev/null
+++ b/src/renderer/shader/aorii_util.slang
@@ -0,0 +1,8 @@
+
+// 将uv坐标系移动到[-1, -1] ~ [1, 1]
+float2 uv_to_ndc(float2 uv) {
+#ifdef UV_FLIP
+    uv.y = 1.0 - uv.y;
+#endif
+    return uv * 2.0 - 1.0;
+}