src/video/cocoa/SDL_cocoametalview.m
author Alex Szpakowski <slime73@gmail.com>
Tue, 02 Jan 2018 21:44:28 -0400
changeset 11809 4b858abfb24d
parent 11797 4da70548aa06
child 11811 5d94cb6b24d3
permissions -rw-r--r--
metal and moltenvk: fix highdpi.
     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         self.wantsLayer = YES;
    65 
    66         /* Allow resize. */
    67         self.autoresizingMask = NSViewWidthSizable | NSViewHeightSizable;
    68         _tag = METALVIEW_TAG;
    69 
    70         _useHighDPI = useHighDPI;
    71         [self updateDrawableSize];
    72 	}
    73   
    74 	return self;
    75 }
    76 
    77 /* Set the size of the metal drawables when the view is resized. */
    78 - (void)resizeWithOldSuperviewSize:(NSSize)oldSize
    79 {
    80     [super resizeWithOldSuperviewSize:oldSize];
    81     [self updateDrawableSize];
    82 }
    83 
    84 - (void)updateDrawableSize
    85 {
    86     NSRect bounds = [self bounds];
    87     if (_useHighDPI) {
    88         bounds = [self convertRectToBacking:bounds];
    89     }
    90     ((CAMetalLayer *) self.layer).drawableSize = NSSizeToCGSize(bounds.size);
    91 }
    92 
    93 @end
    94 
    95 SDL_cocoametalview*
    96 Cocoa_Mtl_AddMetalView(SDL_Window* window)
    97 {
    98     SDL_WindowData *data = (SDL_WindowData *)window->driverdata;
    99     NSView *view = data->nswindow.contentView;
   100 
   101     SDL_cocoametalview *metalview
   102         = [[SDL_cocoametalview alloc] initWithFrame:view.frame
   103                        useHighDPI:(window->flags & SDL_WINDOW_ALLOW_HIGHDPI)];
   104     [view addSubview:metalview];
   105     return metalview;
   106 }
   107 
   108 void
   109 Cocoa_Mtl_GetDrawableSize(SDL_Window * window, int * w, int * h)
   110 {
   111     SDL_WindowData *data = (__bridge SDL_WindowData *)window->driverdata;
   112     NSView *view = data->nswindow.contentView;
   113     SDL_cocoametalview* metalview = [view viewWithTag:METALVIEW_TAG];
   114     if (metalview) {
   115         CAMetalLayer *layer = (CAMetalLayer*)metalview.layer;
   116         assert(layer != NULL);
   117         if (w) {
   118             *w = layer.drawableSize.width;
   119         }
   120         if (h) {
   121             *h = layer.drawableSize.height;
   122         }
   123     }
   124 }
   125 
   126 #endif /* SDL_VIDEO_DRIVER_COCOA && (SDL_VIDEO_VULKAN || SDL_VIDEO_RENDER_METAL) */
   127 
   128 /* vi: set ts=4 sw=4 expandtab: */