Document textureSize() should be avoided in Built-in functions

Calinou · Calinou · commit 920cfced1ecd · 2025-11-05T00:41:20.000+01:00
For performance reasons, it's best to pass the texture size
as a uniform instead.
diff --git a/tutorials/shaders/shader_reference/shader_functions.rst b/tutorials/shaders/shader_reference/shader_functions.rst
@@ -2254,9 +2254,9 @@ Texture functions
     +------------------+---------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------+
     | | ivec2          | | :ref:`textureSize<shader_func_textureSize>`\ (\ |gsampler2D| s, int lod)                              | Get the size of a texture.                                          |
     | | ivec2          | | :ref:`textureSize<shader_func_textureSize>`\ (\ samplerCube s, int lod)                               |                                                                     |
-    | | ivec2          | | :ref:`textureSize<shader_func_textureSize>`\ (\ samplerCubeArray s, int lod)                          |                                                                     |
-    | | ivec3          | | :ref:`textureSize<shader_func_textureSize>`\ (\ |gsampler2DArray| s, int lod)                         |                                                                     |
-    | | ivec3          | | :ref:`textureSize<shader_func_textureSize>`\ (\ |gsampler3D| s, int lod)                              |                                                                     |
+    | | ivec2          | | :ref:`textureSize<shader_func_textureSize>`\ (\ samplerCubeArray s, int lod)                          | For performance reasons, this function should be avoided as it      |
+    | | ivec3          | | :ref:`textureSize<shader_func_textureSize>`\ (\ |gsampler2DArray| s, int lod)                         | always performs a full texture read. When possible, you should pass |
+    | | ivec3          | | :ref:`textureSize<shader_func_textureSize>`\ (\ |gsampler3D| s, int lod)                              | the texture size as a uniform instead.                              |
     +------------------+---------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------+
     | | vec2           | | :ref:`textureQueryLod<shader_func_textureQueryLod>`\ (\ |gsampler2D| s, vec2 p)                       | Compute the level-of-detail that would be used to sample from a     |
     | | vec3           | | :ref:`textureQueryLod<shader_func_textureQueryLod>`\ (\ |gsampler2DArray| s, vec2 p)                  | texture.                                                            |
