sdl

SDL_cocoametalview.m (5760B)

---

 /*
   Simple DirectMedia Layer
   Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
 
   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
   arising from the use of this software.
 
   Permission is granted to anyone to use this software for any purpose,
   including commercial applications, and to alter it and redistribute it
   freely, subject to the following restrictions:
 
   1. The origin of this software must not be misrepresented; you must not
      claim that you wrote the original software. If you use this software
      in a product, an acknowledgment in the product documentation would be
      appreciated but is not required.
   2. Altered source versions must be plainly marked as such, and must not be
      misrepresented as being the original software.
   3. This notice may not be removed or altered from any source distribution.
 */
 /*
  * @author Mark Callow, www.edgewise-consulting.com.
  *
  * Thanks to Alex Szpakowski, @slime73 on GitHub, for his gist showing
  * how to add a CAMetalLayer backed view.
  */
 #include "../../SDL_internal.h"
 
 #import "SDL_cocoametalview.h"
 
 #if SDL_VIDEO_DRIVER_COCOA && (SDL_VIDEO_VULKAN || SDL_VIDEO_METAL)
 
 #include "SDL_events.h"
 
 static int SDLCALL
 SDL_MetalViewEventWatch(void *userdata, SDL_Event *event)
 {
     /* Update the drawable size when SDL receives a size changed event for
      * the window that contains the metal view. It would be nice to use
      * - (void)resizeWithOldSuperviewSize:(NSSize)oldSize and
      * - (void)viewDidChangeBackingProperties instead, but SDL's size change
      * events don't always happen in the same frame (for example when a
      * resizable window exits a fullscreen Space via the user pressing the OS
      * exit-space button). */
     if (event->type == SDL_WINDOWEVENT && event->window.event == SDL_WINDOWEVENT_SIZE_CHANGED) {
         @autoreleasepool {
             SDL_cocoametalview *view = (__bridge SDL_cocoametalview *)userdata;
             if (view.sdlWindowID == event->window.windowID) {
                 [view updateDrawableSize];
             }
         }
     }
     return 0;
 }
 
 @implementation SDL_cocoametalview
 
 /* Return a Metal-compatible layer. */
 + (Class)layerClass
 {
     return NSClassFromString(@"CAMetalLayer");
 }
 
 /* Indicate the view wants to draw using a backing layer instead of drawRect. */
 - (BOOL)wantsUpdateLayer
 {
     return YES;
 }
 
 /* When the wantsLayer property is set to YES, this method will be invoked to
  * return a layer instance.
  */
 - (CALayer*)makeBackingLayer
 {
     return [self.class.layerClass layer];
 }
 
 - (instancetype)initWithFrame:(NSRect)frame
                       highDPI:(BOOL)highDPI
                      windowID:(Uint32)windowID;
 {
     if ((self = [super initWithFrame:frame])) {
         self.highDPI = highDPI;
         self.sdlWindowID = windowID;
         self.wantsLayer = YES;
 
         /* Allow resize. */
         self.autoresizingMask = NSViewWidthSizable | NSViewHeightSizable;
 
         SDL_AddEventWatch(SDL_MetalViewEventWatch, self);
 
         [self updateDrawableSize];
     }
   
     return self;
 }
 
 - (void)dealloc
 {
     SDL_DelEventWatch(SDL_MetalViewEventWatch, self);
     [super dealloc];
 }
 
 - (NSInteger)tag
 {
     return METALVIEW_TAG;
 }
 
 - (void)updateDrawableSize
 {
     CAMetalLayer *metalLayer = (CAMetalLayer *)self.layer;
     NSSize size = self.bounds.size;
     NSSize backingSize = size;
 
     if (self.highDPI) {
         /* Note: NSHighResolutionCapable must be set to true in the app's
          * Info.plist in order for the backing size to be high res.
          */
         backingSize = [self convertSizeToBacking:size];
     }
 
     metalLayer.contentsScale = backingSize.height / size.height;
     metalLayer.drawableSize = NSSizeToCGSize(backingSize);
 }
 
 - (NSView *)hitTest:(NSPoint)point {
     return nil;
 }
 
 @end
 
 SDL_MetalView
 Cocoa_Metal_CreateView(_THIS, SDL_Window * window)
 { @autoreleasepool {
     SDL_WindowData* data = (__bridge SDL_WindowData *)window->driverdata;
     NSView *view = data->nswindow.contentView;
     BOOL highDPI = (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) != 0;
     Uint32 windowID = SDL_GetWindowID(window);
     SDL_cocoametalview *newview;
     SDL_MetalView metalview;
 
     newview = [[SDL_cocoametalview alloc] initWithFrame:view.frame
                                                 highDPI:highDPI
                                                 windowID:windowID];
     if (newview == nil) {
         return NULL;
     }
 
     [view addSubview:newview];
 
     metalview = (SDL_MetalView)CFBridgingRetain(newview);
     [newview release];
 
     return metalview;
 }}
 
 void
 Cocoa_Metal_DestroyView(_THIS, SDL_MetalView view)
 { @autoreleasepool {
     SDL_cocoametalview *metalview = CFBridgingRelease(view);
     [metalview removeFromSuperview];
 }}
 
 void *
 Cocoa_Metal_GetLayer(_THIS, SDL_MetalView view)
 { @autoreleasepool {
     SDL_cocoametalview *cocoaview = (__bridge SDL_cocoametalview *)view;
     return (__bridge void *)cocoaview.layer;
 }}
 
 void
 Cocoa_Metal_GetDrawableSize(_THIS, SDL_Window * window, int * w, int * h)
 { @autoreleasepool {
     SDL_WindowData *data = (__bridge SDL_WindowData *)window->driverdata;
     NSView *view = data->nswindow.contentView;
     SDL_cocoametalview* metalview = [view viewWithTag:METALVIEW_TAG];
     if (metalview) {
         CAMetalLayer *layer = (CAMetalLayer*)metalview.layer;
         SDL_assert(layer != NULL);
         if (w) {
             *w = layer.drawableSize.width;
         }
         if (h) {
             *h = layer.drawableSize.height;
         }
     } else {
         SDL_GetWindowSize(window, w, h);
     }
 }}
 
 #endif /* SDL_VIDEO_DRIVER_COCOA && (SDL_VIDEO_VULKAN || SDL_VIDEO_METAL) */
 
 /* vi: set ts=4 sw=4 expandtab: */