SDL_image: Enable APNG support in official Apple builds

From 833dbcb21ffdea57f421f1e9abd295cbb945ca57 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Mon, 5 Jan 2026 12:31:55 -0800
Subject: [PATCH] Enable APNG support in official Apple builds

---
 Xcode/pkg-support/build.xcconfig | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Xcode/pkg-support/build.xcconfig b/Xcode/pkg-support/build.xcconfig
index 28fc15781..66389bf72 100644
--- a/Xcode/pkg-support/build.xcconfig
+++ b/Xcode/pkg-support/build.xcconfig
@@ -15,6 +15,11 @@ AVIF_FRAMEWORK_LDFLAGS = -weak_framework avif
 JXL_PREPROCESSOR_DEFINITIONS = LOAD_JXL
 JXL_FRAMEWORK_LDFLAGS = -weak_framework jxl
 
+// Uncomment these lines to enable libpng support
+// If you do this, you should run external/download.sh to download the decode libraries and add png.framework to your application bundle.
+PNG_PREPROCESSOR_DEFINITIONS = SDL_IMAGE_LIBPNG INCLUDE_PNG_FRAMEWORK
+PNG_FRAMEWORK_LDFLAGS = -weak_framework png
+
 // Uncomment these lines to enable WebP support
 // If you do this, you should run external/download.sh to download the decode libraries and add webp.framework to your application bundle.
 WEBP_PREPROCESSOR_DEFINITIONS = LOAD_WEBP