From 7d8c7dd70ab9ed41226f89d9bf7e477108a99a24 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Rydg=C3=A5rd?= <hrydgard@gmail.com>
Date: Thu, 20 Feb 2025 13:54:50 -0600
Subject: [PATCH] macOS SDL: Set the metal layer resolution properly, remove
 DPI hacks.

Fixes #19183

Thanks to @schm1dtmac for the fix.

@shm1dtmac also mentions that this may have issues when moving the window between displays, but this should still be an improvement for most people.
---
 SDL/SDLCocoaMetalLayer.mm |  1 +
 SDL/SDLMain.cpp           | 16 ++--------------
 2 files changed, 3 insertions(+), 14 deletions(-)

diff --git a/SDL/SDLCocoaMetalLayer.mm b/SDL/SDLCocoaMetalLayer.mm
index cb7bd551923e..539a91c7f878 100644
--- a/SDL/SDLCocoaMetalLayer.mm
+++ b/SDL/SDLCocoaMetalLayer.mm
@@ -17,6 +17,7 @@
 	if (![view.layer isKindOfClass:[CAMetalLayer class]])
 	{
 		[view setLayer:[CAMetalLayer layer]];
+		[[view layer] setContentsScale:[window backingScaleFactor]];
 	}
 	return view.layer;
 #else
diff --git a/SDL/SDLMain.cpp b/SDL/SDLMain.cpp
index 0ee28bec6dd4..7a553df63e28 100644
--- a/SDL/SDLMain.cpp
+++ b/SDL/SDLMain.cpp
@@ -185,8 +185,8 @@ static void StopSDLAudioDevice() {
 }
 
 static void UpdateScreenDPI(SDL_Window *window) {
-	int drawable_width, window_width;
-	SDL_GetWindowSize(window, &window_width, NULL);
+	int drawable_width, window_width, window_height;
+	SDL_GetWindowSize(window, &window_width, &window_height);
 
 	if (g_Config.iGPUBackend == (int)GPUBackend::OPENGL)
 		SDL_GL_GetDrawableSize(window, &drawable_width, NULL);
@@ -200,13 +200,6 @@ static void UpdateScreenDPI(SDL_Window *window) {
 	// Round up a little otherwise there would be a gap sometimes
 	// in fractional scaling
 	g_DesktopDPI = ((float) drawable_width + 1.0f) / window_width;
-
-	// Temporary hack
-#if PPSSPP_PLATFORM(MAC) || PPSSPP_PLATFORM(IOS)
-	if (g_Config.iGPUBackend == (int)GPUBackend::VULKAN) {
-		g_DesktopDPI = 1.0f;
-	}
-#endif
 }
 
 // Simple implementations of System functions
@@ -1438,11 +1431,6 @@ int main(int argc, char *argv[]) {
 		}
 #endif
 	}
-#if PPSSPP_PLATFORM(MAC) || PPSSPP_PLATFORM(IOS)
-	if (g_Config.iGPUBackend == (int)GPUBackend::VULKAN) {
-		g_ForcedDPI = 1.0f;
-	}
-#endif
 
 	UpdateScreenDPI(window);