src/video/cocoa/SDL_cocoametalview.m
author Sam Lantinga <slouken@libsdl.org>
Fri, 04 Jan 2019 22:01:14 -0800
changeset 12503 806492103856
parent 12320 758d4e1222a7
child 12797 a7ce9dc7a31f
permissions -rw-r--r--
Updated copyright for 2019
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2019 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  * @author Mark Callow, www.edgewise-consulting.com.
    23  *
    24  * Thanks to Alex Szpakowski, @slime73 on GitHub, for his gist showing
    25  * how to add a CAMetalLayer backed view.
    26  */
    27 
    28 #import "SDL_cocoametalview.h"
    29 
    30 #if SDL_VIDEO_DRIVER_COCOA && (SDL_VIDEO_VULKAN || SDL_VIDEO_RENDER_METAL)
    31 
    32 #include "SDL_assert.h"
    33 
    34 @implementation SDL_cocoametalview
    35 
    36 /* Return a Metal-compatible layer. */
    37 + (Class)layerClass
    38 {
    39     return NSClassFromString(@"CAMetalLayer");
    40 }
    41 
    42 /* Indicate the view wants to draw using a backing layer instead of drawRect. */
    43 - (BOOL)wantsUpdateLayer
    44 {
    45     return YES;
    46 }
    47 
    48 /* When the wantsLayer property is set to YES, this method will be invoked to
    49  * return a layer instance.
    50  */
    51 - (CALayer*)makeBackingLayer
    52 {
    53     return [self.class.layerClass layer];
    54 }
    55 
    56 - (instancetype)initWithFrame:(NSRect)frame
    57                       highDPI:(BOOL)highDPI
    58 {
    59     if ((self = [super initWithFrame:frame])) {
    60         self.highDPI = highDPI;
    61         self.wantsLayer = YES;
    62 
    63         /* Allow resize. */
    64         self.autoresizingMask = NSViewWidthSizable | NSViewHeightSizable;
    65 
    66         [self updateDrawableSize];
    67     }
    68   
    69     return self;
    70 }
    71 
    72 - (NSInteger)tag
    73 {
    74     return METALVIEW_TAG;
    75 }
    76 
    77 - (void)updateDrawableSize
    78 {
    79     CAMetalLayer *metalLayer = (CAMetalLayer *)self.layer;
    80     CGSize size = self.bounds.size;
    81     CGSize backingSize = size;
    82 
    83     if (self.highDPI) {
    84         /* Note: NSHighResolutionCapable must be set to true in the app's
    85          * Info.plist in order for the backing size to be high res.
    86          */
    87         backingSize = [self convertSizeToBacking:size];
    88     }
    89 
    90     metalLayer.contentsScale = backingSize.height / size.height;
    91     metalLayer.drawableSize = backingSize;
    92 }
    93 
    94 /* Set the size of the metal drawables when the view is resized. */
    95 - (void)resizeWithOldSuperviewSize:(NSSize)oldSize
    96 {
    97     [super resizeWithOldSuperviewSize:oldSize];
    98     [self updateDrawableSize];
    99 }
   100 
   101 @end
   102 
   103 SDL_cocoametalview*
   104 Cocoa_Mtl_AddMetalView(SDL_Window* window)
   105 {
   106     SDL_WindowData* data = (__bridge SDL_WindowData *)window->driverdata;
   107     NSView *view = data->nswindow.contentView;
   108     BOOL highDPI = (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) != 0;
   109     SDL_cocoametalview *metalview;
   110 
   111     metalview = [[SDL_cocoametalview alloc] initWithFrame:view.frame highDPI:highDPI];
   112     [view addSubview:metalview];
   113     return metalview;
   114 }
   115 
   116 void
   117 Cocoa_Mtl_GetDrawableSize(SDL_Window * window, int * w, int * h)
   118 {
   119     SDL_WindowData *data = (__bridge SDL_WindowData *)window->driverdata;
   120     NSView *view = data->nswindow.contentView;
   121     SDL_cocoametalview* metalview = [view viewWithTag:METALVIEW_TAG];
   122     if (metalview) {
   123         CAMetalLayer *layer = (CAMetalLayer*)metalview.layer;
   124         assert(layer != NULL);
   125         if (w) {
   126             *w = layer.drawableSize.width;
   127         }
   128         if (h) {
   129             *h = layer.drawableSize.height;
   130         }
   131     } else {
   132         SDL_GetWindowSize(window, w, h);
   133     }
   134 }
   135 
   136 #endif /* SDL_VIDEO_DRIVER_COCOA && (SDL_VIDEO_VULKAN || SDL_VIDEO_RENDER_METAL) */
   137 
   138 /* vi: set ts=4 sw=4 expandtab: */