From f2ea2014c16a232c905b84056bdb6830c6e29f39 Mon Sep 17 00:00:00 2001
From: tetrapod00 <145553014+tetrapod00@users.noreply.github.com>
Date: Thu, 17 Oct 2024 12:48:04 -0700
Subject: [PATCH] Add warning about uninitialized variables in shaders

Adds a warning note to shading_language.rst. GDShader does not
initialize local variables to 0, and an uninitialized local variable can
contain an arbitrary value.
---
 tutorials/shaders/shader_reference/shading_language.rst | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tutorials/shaders/shader_reference/shading_language.rst b/tutorials/shaders/shader_reference/shading_language.rst
index ba2ca01d7..f9913a9a0 100644
--- a/tutorials/shaders/shader_reference/shading_language.rst
+++ b/tutorials/shaders/shader_reference/shading_language.rst
@@ -86,6 +86,14 @@ Most GLSL ES 3.0 datatypes are supported:
 |                      | Only supported in Forward+ and Mobile, not Compatibility.                       |
 +----------------------+---------------------------------------------------------------------------------+
 
+.. warning::
+
+    Local variables are not initialized to a default value such as ``0.0``. If
+    you use a variable without assigning it first, it will contain whatever
+    value was already present at that memory location, and unpredictable visual
+    glitches will appear. However, uniforms and varyings are initialized to a
+    default value.
+
 Comments
 ~~~~~~~~