Aaron Barany
I realized I made a minor mistake in my patch: I changed the constructor prototype for SDL_DisplayData, but didn't update the declaration in the .h file. The compiler and linker don't complain, but it would probably be best to fix in case a later change runs into a problem from the mismatch. I have attached a patch to fix this.
Aaron Barany
There appears to be no way to directly access the display DPI on iOS, so as an approximation the DPI for the iPhone 1 is used as a base value and is multiplied by the screen's scale. This should at least give a ballpark number for the various screen scales. (based on https://stackoverflow.com/questions/25756087/detecting-iphone-6-6-screen-sizes-in-point-values it appears that both 2x and 3x are used)
I have updated the patch to use a table of current devices and use a computation as a fallback. I have also updated the fallback computation to be more accurate.
Aaron Barany
Since OpenGL is deprecated on iOS, it is advantageous to be able to remove all OpenGL related code when building SDL for iOS. This patch adds the necessary #if checks to compile in this case.
Caleb Cornett
SDL_ShowMessageBox on UIKit doesn't do anything special with buttons that are marked with the flag SDL_MESSAGEBOX_BUTTON_RETURNKEY_DEFAULT. According to Apple's documentation on UIAlertController, a button can respond to a return key if it's marked as the preferredAction of the controller. SDL doesn't set a preferredAction currently, so I've attached a patch to fix that.
It was originally added to work around an input event problem in the code of a specific app which mixed SDL and native UIViews, but that app solved its problems in a better manner since then.
Dzmitry Malyshau
Current code, search paths, and error messages are written to only consider MoltenVK on macOS as a Vulkan Portability implementation. It's not the only implementation available to the users. gfx-portability [1] has been shown to run a number of titles well, including Dota2, Dolphin Emulator, and vkQuake3, often out-performing MoltenVK in frame rate and stability (see Dolphin benchmark [2]).
There is no reason for SDL to be that specific, it's not using any MVK-specific functions other than the WSI initialization ("VK_MVK_macos_surface"). gfx-portability exposes this extension as well, and a more generic WSI extension is in process. It would be good if SDL was written in a more generic way that expect a Vulkan Portability library as opposed to MoltenVK specifically.
[1] https://github.com/gfx-rs/portability
[2] https://gfx-rs.github.io/2019/03/22/dolphin-macos-performance.html
Caleb Cornett
On iOS 12, creating a window with the SDL_WINDOW_FULLSCREEN flag does not dim the home indicator or defer system gestures. The same goes for setting the SDL_HINT_IOS_HIDE_HOME_INDICATOR to "2" -- it has no effect at all.
I've tracked down the source of this misbehavior to a timing issue. The initial `setNeedsUpdate...` calls were happening too early and getting applied to the launch screen by mistake. In the attached patch, I've added a call to those functions right after the launch screen is hidden so that they apply to the main view controller instead. This appears to fix the issue, at least on my iPhone 6s Plus.
SDL_GetWindowDisplayMode was returning an incorrect result on iPhone Plus devices (tested on iOS 12.1/12.2). The problem was that the value returned by UIScreenMode was assumed to be the physical pixels on the display, rather than the scaled retina pixels. The fix is to use the scale returned by UIScreen.scale rather than the nativeScale.
Touch device types include SDL_TOUCH_DEVICE_DIRECT (a touch screen with window-relative coordinates for touches), SDL_TOUCH_DEVICE_INDIRECT_ABSOLUTE (a trackpad-style device with absolute device coordinates), and SDL_TOUCH_DEVICE_INDIRECT_RELATIVE (a trackpad-style device with screen cursor-relative coordinates).
Phone screens are an example of a direct device type. Mac trackpads are the indirect-absolute touch device type. The Apple TV remote is an indirect-relative touch device type.
This variable can be set to the following values:
"0" - The indicator bar is not hidden (default for windowed applications)
"1" - The indicator bar is hidden and is shown when the screen is touched (useful for movie playback applications)
"2" - The indicator bar is dim and the first swipe makes it visible and the second swipe performs the "home" action (default for fullscreen applications)
SDL now builds with gcc 7.2 with the following command line options:
-Wall -pedantic-errors -Wno-deprecated-declarations -Wno-overlength-strings --std=c99
