SDL_image: Fixed libpng symbol visibility on Xcode

From f10f9a4e740af16bf265f617f9b50796e88cc7f6 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Thu, 15 Jan 2026 11:25:25 -0800
Subject: [PATCH] Fixed libpng symbol visibility on Xcode

---
 Xcode/png/png.xcodeproj/project.pbxproj | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Xcode/png/png.xcodeproj/project.pbxproj b/Xcode/png/png.xcodeproj/project.pbxproj
index 2b70de09..b2d01e73 100644
--- a/Xcode/png/png.xcodeproj/project.pbxproj
+++ b/Xcode/png/png.xcodeproj/project.pbxproj
@@ -329,6 +329,7 @@
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_OPTIMIZATION_LEVEL = 0;
 				GCC_PREPROCESSOR_DEFINITIONS = (
+					"PNG_IMPEXP=__attribute__((visibility(\\\"default\\\")))",
 					"DEBUG=1",
 					"$(inherited)",
 				);
@@ -392,6 +393,10 @@
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_C_LANGUAGE_STANDARD = gnu11;
 				GCC_NO_COMMON_BLOCKS = YES;
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"PNG_IMPEXP=__attribute__((visibility(\\\"default\\\")))",
+					"$(inherited)",
+				);
 				GCC_SYMBOLS_PRIVATE_EXTERN = YES;
 				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;