src/video/cocoa/SDL_cocoametalview.m
author Alex Szpakowski <slime73@gmail.com>
Sun, 31 Dec 2017 15:21:25 -0400
changeset 11797 4da70548aa06
parent 11507 071deb801690
child 11809 4b858abfb24d
permissions -rw-r--r--
macOS: Fix MoltenVK Metal view resizing, and allow the metal view to be used without vulkan.
     1 /*
     2  Simple DirectMedia Layer
     3  Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
     4  
     5  This software is provided 'as-is', without any express or implied
     6  warranty.  In no event will the authors be held liable for any damages
     7  arising from the use of this software.
     8  
     9  Permission is granted to anyone to use this software for any purpose,
    10  including commercial applications, and to alter it and redistribute it
    11  freely, subject to the following restrictions:
    12  
    13  1. The origin of this software must not be misrepresented; you must not
    14  claim that you wrote the original software. If you use this software
    15  in a product, an acknowledgment in the product documentation would be
    16  appreciated but is not required.
    17  2. Altered source versions must be plainly marked as such, and must not be
    18  misrepresented as being the original software.
    19  3. This notice may not be removed or altered from any source distribution.
    20  */
    21 
    22 /*
    23  * @author Mark Callow, www.edgewise-consulting.com.
    24  *
    25  * Thanks to Alex Szpakowski, @slime73 on GitHub, for his gist showing
    26  * how to add a CAMetalLayer backed view.
    27  */
    28 
    29 #import "SDL_cocoametalview.h"
    30 
    31 #if SDL_VIDEO_DRIVER_COCOA && (SDL_VIDEO_VULKAN || SDL_VIDEO_RENDER_METAL)
    32 
    33 #include "SDL_assert.h"
    34 
    35 @implementation SDL_cocoametalview
    36 
    37 /* The synthesized getter should be called by super's viewWithTag. */
    38 @synthesize tag = _tag;
    39 
    40 /* Return a Metal-compatible layer. */
    41 + (Class)layerClass
    42 {
    43 	return NSClassFromString(@"CAMetalLayer");
    44 }
    45 
    46 /* Indicate the view wants to draw using a backing layer instead of drawRect. */
    47 - (BOOL)wantsUpdateLayer
    48 {
    49     return YES;
    50 }
    51 
    52 /* When the wantsLayer property is set to YES, this method will be invoked to
    53  * return a layer instance.
    54  */
    55 - (CALayer*)makeBackingLayer
    56 {
    57     return [self.class.layerClass layer];
    58 }
    59 
    60 - (instancetype)initWithFrame:(NSRect)frame
    61                    useHighDPI:(bool)useHighDPI
    62 {
    63 	if ((self = [super initWithFrame:frame])) {
    64     
    65         /* Allow resize. */
    66         self.autoresizingMask = NSViewWidthSizable | NSViewHeightSizable;
    67         _tag = METALVIEW_TAG;
    68       
    69         _useHighDPI = useHighDPI;
    70         [self updateDrawableSize];
    71 	}
    72   
    73 	return self;
    74 }
    75 
    76 /* Set the size of the metal drawables when the view is resized. */
    77 - (void)resizeWithOldSuperviewSize:(NSSize)oldSize
    78 {
    79     [super resizeWithOldSuperviewSize:oldSize];
    80     [self updateDrawableSize];
    81 }
    82 
    83 - (void)updateDrawableSize
    84 {
    85     NSRect bounds = [self bounds];
    86     if (_useHighDPI) {
    87         bounds = [self convertRectToBacking:bounds];
    88     }
    89     ((CAMetalLayer *) self.layer).drawableSize = NSSizeToCGSize(bounds.size);
    90 }
    91 
    92 @end
    93 
    94 SDL_cocoametalview*
    95 Cocoa_Mtl_AddMetalView(SDL_Window* window)
    96 {
    97     SDL_WindowData *data = (SDL_WindowData *)window->driverdata;
    98     NSView *view = data->nswindow.contentView;
    99 
   100     SDL_cocoametalview *metalview
   101         = [[SDL_cocoametalview alloc] initWithFrame:view.frame
   102                        useHighDPI:(window->flags & SDL_WINDOW_ALLOW_HIGHDPI)];
   103     // Instantiate the CAMetalLayer
   104     metalview.wantsLayer = YES;
   105     [view addSubview:metalview];
   106     return metalview;
   107 }
   108 
   109 void
   110 Cocoa_Mtl_GetDrawableSize(SDL_Window * window, int * w, int * h)
   111 {
   112     SDL_WindowData *data = (__bridge SDL_WindowData *)window->driverdata;
   113     NSView *view = data->nswindow.contentView;
   114     SDL_cocoametalview* metalview = [view viewWithTag:METALVIEW_TAG];
   115     if (metalview) {
   116         CAMetalLayer *layer = (CAMetalLayer*)metalview.layer;
   117         assert(layer != NULL);
   118         if (w) {
   119             *w = layer.drawableSize.width;
   120         }
   121         if (h) {
   122             *h = layer.drawableSize.height;
   123         }
   124     }
   125 }
   126 
   127 #endif /* SDL_VIDEO_DRIVER_COCOA && (SDL_VIDEO_VULKAN || SDL_VIDEO_RENDER_METAL) */
   128 
   129 /* vi: set ts=4 sw=4 expandtab: */