Change Cocoa SDL_VideoData and SDL_WindowData implementations from C structs to Objective-C objects, since bridging between C and ObjC is easier that way.
Caleb Cornett
For a window created with SDL_WINDOW_ALLOW_HIGHDPI, SDL_GL_GetDrawableSize will return the high-dpi drawable size even before any GL context creation happens. But SDL_Metal_GetDrawableSize will return the size of the window if the Metal view has not been created. This is confusing and inconsistent behavior.
An easy way to test this is to build testgl2 and testvulkan on macOS with the SDL_WINDOW_ALLOW_HIGHDPI flag enabled during window creation. The GL2 program will report a drawable size of 2x window width and 2x window height, while the Vulkan program will report the window size.
This patch addresses the issue by falling back to using the content view dimensions if no Metal view exists in the window. (The code for this was taken directly from Cocoa_GL_GetDrawableSize.) With this change, the testvulkan behavior matches that of testgl2.
Note that I haven't tested for this issue on UIKit. It's possible a similar change will need to be made there too.
SDL_cocoametalview was consuming the first click rather than passing it
through to the SDLView underneath which overrides [NSView acceptsFirstMouse]
based on the user's SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH preference.
Caleb Cornett's comments:
"A few weeks ago, Alex added a partial Metal API to SDL2:
https://hg.libsdl.org/SDL/rev/22c8e7cd8d38
I noticed it was missing a few features that would help Metal become a
first-class citizen in SDL, so I went ahead and wrote them! Here are the new
APIs:
1. SDL_WINDOW_METAL flag for SDL_CreateWindow(). This allows the programmer
to specify that they intend to create a window for use with SDL_MetalView.
The flag is used to ensure correct usage of the API and to prevent
accidentally defaulting to OpenGL on iOS.
2. SDL_Metal_GetLayer(). This function takes a SDL_MetalView and returns a
pointer to the view's backing CAMetalLayer. This simplifies things
considerably, since in the current version of the SDL_Metal API the
programmer is required to bridge-cast a SDL_MetalView handle to an NSView or
UIView (depending on the platform) and then extract the layer from there.
SDL_Metal_GetLayer automatically handles all of that, making the operation
simple and cross-platform.
3. SDL_Metal_GetDrawableSize(). This function already exists in the current
SDL_Metal API (and is used behind-the-scenes for SDL_Vulkan_GetDrawableSize
on Apple platforms) but was not publicly exposed. My patch exposes this
function for public use. It works just like you'd expect.
Tested on macOS 10.14 and iOS 12.4."
Fixes Bugzilla #4796.
Ozkan Sezer
Since the Vulkan merge, building against a Mac OS X SDM older than
10.11 fails in SDL_cocoametalview.m because Metal.framework is not
present. There is no conditional compiling in SDL_cocoametalview.m
either, so --disable-video-vulkan doesn't help with anything. (The
configury doesn't check darwin for x86_64 either, but it's another
story.)
I cross-build against 10.8 SDK on linux using clang-3.4.2 and this
is a problem for me. Will this be fixed?
Error message was:
[mvk-info] MoltenVK version 0.18.2. Vulkan version 1.0.51.
[***MoltenVK ERROR***] VK_ERROR_INITIALIZATION_FAILED: On-screen rendering requires a view that is backed by a layer of type CAMetalLayer.
2017-08-28 02:17:29.579 testvulkan[95627:1716939] ERROR: SDL_Vulkan_CreateSurface(): vkCreateMacOSSurfaceMVK failed: VK_ERROR_INITIALIZATION_FAILED