SDL: Document that new surfaces are initialized to zero.

From 03ace96e5bc8c8466bac25f90d37813b830dc1ab Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Thu, 22 Aug 2024 06:27:56 -0700
Subject: [PATCH] Document that new surfaces are initialized to zero.

Fixes https://github.com/libsdl-org/SDL/issues/10577
---
 include/SDL3/SDL_surface.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/SDL3/SDL_surface.h b/include/SDL3/SDL_surface.h
index 57745ac0f90b2..8ca4ea2533441 100644
--- a/include/SDL3/SDL_surface.h
+++ b/include/SDL3/SDL_surface.h
@@ -125,6 +125,8 @@ typedef struct SDL_Surface
 /**
  * Allocate a new surface with a specific pixel format.
  *
+ * The pixels of the new surface are initialized to zero.
+ *
  * \param width the width of the surface.
  * \param height the height of the surface.
  * \param format the SDL_PixelFormat for the new surface's pixel format.