From af0ec13fc325110edc85d4241422558e31f36d70 Mon Sep 17 00:00:00 2001
From: Sasha Szpakowski <[EMAIL REDACTED]>
Date: Sat, 28 Jan 2023 17:09:24 -0400
Subject: [PATCH] iOS: fix display modes to have accurate pixel sizes and
screen scales.
---
src/video/uikit/SDL_uikitmodes.m | 31 +++++++++++++++++++++++++++----
1 file changed, 27 insertions(+), 4 deletions(-)
diff --git a/src/video/uikit/SDL_uikitmodes.m b/src/video/uikit/SDL_uikitmodes.m
index 60b55551165f..896b747f1c0a 100644
--- a/src/video/uikit/SDL_uikitmodes.m
+++ b/src/video/uikit/SDL_uikitmodes.m
@@ -271,7 +271,7 @@ static int UIKit_AddSingleDisplayMode(SDL_VideoDisplay *display, int w, int h,
mode.pixel_w = w;
mode.pixel_h = h;
- mode.display_scale = uiscreen.scale;
+ mode.display_scale = uiscreen.nativeScale;
mode.refresh_rate = UIKit_GetDisplayModeRefreshRate(uiscreen);
mode.format = SDL_PIXELFORMAT_ABGR8888;
@@ -300,10 +300,32 @@ static int UIKit_AddDisplayMode(SDL_VideoDisplay *display, int w, int h,
return 0;
}
+static CGSize GetUIScreenModePixelSize(UIScreen *uiscreen, UIScreenMode *mode)
+{
+ /* For devices such as iPhone 6/7/8 Plus, the UIScreenMode reported by iOS
+ * isn't the physical pixels of the display, but rather the point size times
+ * the scale. For example, on iOS 12.2 on iPhone 8 Plus the physical pixel
+ * resolution is 1080x1920, the size reported by mode.size is 1242x2208,
+ * the size in points is 414x736, the scale property is 3.0, and the
+ * nativeScale property is ~2.6087 (ie 1920.0 / 736.0). So we need a bit of
+ * math to convert from retina pixels (point size multiplied by scale) to
+ * real pixels.
+ * Note that the iOS Simulator doesn't have this behavior for those devices.
+ * https://github.com/libsdl-org/SDL/issues/3220
+ */
+ CGSize size = mode.size;
+ CGFloat scale = uiscreen.nativeScale / uiscreen.scale;
+
+ size.width = SDL_round(size.width * scale);
+ size.height = SDL_round(size.height * scale);
+
+ return size;
+}
+
int UIKit_AddDisplay(UIScreen *uiscreen, SDL_bool send_event)
{
UIScreenMode *uiscreenmode = uiscreen.currentMode;
- CGSize size = uiscreenmode.size;
+ CGSize size = GetUIScreenModePixelSize(uiscreen, uiscreenmode);
SDL_VideoDisplay display;
SDL_DisplayMode mode;
@@ -406,8 +428,9 @@ void UIKit_GetDisplayModes(_THIS, SDL_VideoDisplay *display)
#endif
for (UIScreenMode *uimode in availableModes) {
- int w = uimode.size.width;
- int h = uimode.size.height;
+ CGSize size = GetUIScreenModePixelSize(data.uiscreen, uimode);
+ int w = size.width;
+ int h = size.height;
/* Make sure the width/height are oriented correctly */
if (isLandscape != (w > h)) {