SDL_image: Fixed CMake error building ImageIO support on macOS

From 61b030c759caa4cccf4be236b81ed3646b0bd420 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Wed, 22 Jan 2025 14:09:05 -0800
Subject: [PATCH] Fixed CMake error building ImageIO support on macOS

Fixes https://github.com/libsdl-org/SDL_image/issues/505
---
 CMakeLists.txt      | 1 +
 docs/INTRO-cmake.md | 5 -----
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b27db46f..c53e853b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -379,6 +379,7 @@ list(APPEND SDLIMAGE_BACKENDS IMAGEIO)
 set(SDLIMAGE_IMAGEIO_ENABLED FALSE)
 if(APPLE)
     if(SDLIMAGE_BACKEND_IMAGEIO)
+        enable_language(OBJC)
         set(SDLIMAGE_IMAGEIO_ENABLED TRUE)
         if(CMAKE_SYSTEM_NAME MATCHES ".*(Darwin|MacOS).*")
             target_link_libraries(${sdl3_image_target_name} PRIVATE -Wl,-framework,ApplicationServices)
diff --git a/docs/INTRO-cmake.md b/docs/INTRO-cmake.md
index 5f943677..a36b0707 100644
--- a/docs/INTRO-cmake.md
+++ b/docs/INTRO-cmake.md
@@ -10,11 +10,6 @@ Create the file CMakeLists.txt
 cmake_minimum_required(VERSION 3.16)
 project(hello)
 
-# Enable Objective C on Apple platforms, for ImageIO support
-if(APPLE)
-  enable_language(OBJC)
-endif()
-
 # set the output directory for built objects.
 # This makes sure that the dynamic library goes into the build directory automatically.
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/$<CONFIGURATION>")