1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2020 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#include "../../SDL_internal.h"
30
31#if SDL_VIDEO_DRIVER_UIKIT && (SDL_VIDEO_VULKAN || SDL_VIDEO_METAL)
32
33#import "../SDL_sysvideo.h"
34#import "SDL_uikitwindow.h"
35#import "SDL_uikitmetalview.h"
36
37#include "SDL_assert.h"
38
39@implementation SDL_uikitmetalview
40
41/* Returns a Metal-compatible layer. */
42+ (Class)layerClass
43{
44    return [CAMetalLayer class];
45}
46
47- (instancetype)initWithFrame:(CGRect)frame
48                        scale:(CGFloat)scale
49{
50    if ((self = [super initWithFrame:frame])) {
51        self.tag = METALVIEW_TAG;
52        self.layer.contentsScale = scale;
53        [self updateDrawableSize];
54    }
55
56    return self;
57}
58
59/* Set the size of the metal drawables when the view is resized. */
60- (void)layoutSubviews
61{
62    [super layoutSubviews];
63    [self updateDrawableSize];
64}
65
66- (void)updateDrawableSize
67{
68    CGSize size = self.bounds.size;
69    size.width *= self.layer.contentsScale;
70    size.height *= self.layer.contentsScale;
71    ((CAMetalLayer *)self.layer).drawableSize = size;
72}
73
74@end
75
76SDL_MetalView
77UIKit_Metal_CreateView(_THIS, SDL_Window * window)
78{ @autoreleasepool {
79    SDL_WindowData *data = (__bridge SDL_WindowData *)window->driverdata;
80    CGFloat scale = 1.0;
81    SDL_uikitmetalview *metalview;
82
83    if (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
84        /* Set the scale to the natural scale factor of the screen - then
85         * the backing dimensions of the Metal view will match the pixel
86         * dimensions of the screen rather than the dimensions in points
87         * yielding high resolution on retine displays.
88         */
89        if ([data.uiwindow.screen respondsToSelector:@selector(nativeScale)]) {
90            scale = data.uiwindow.screen.nativeScale;
91        } else {
92            scale = data.uiwindow.screen.scale;
93        }
94    }
95
96    metalview = [[SDL_uikitmetalview alloc] initWithFrame:data.uiwindow.bounds
97                                                    scale:scale];
98    [metalview setSDLWindow:window];
99
100    return (void*)CFBridgingRetain(metalview);
101}}
102
103void
104UIKit_Metal_DestroyView(_THIS, SDL_MetalView view)
105{ @autoreleasepool {
106    SDL_uikitmetalview *metalview = CFBridgingRelease(view);
107
108    if ([metalview isKindOfClass:[SDL_uikitmetalview class]]) {
109        [metalview setSDLWindow:NULL];
110    }
111}}
112
113void *
114UIKit_Metal_GetLayer(_THIS, SDL_MetalView view)
115{ @autoreleasepool {
116    SDL_uikitview *uiview = (__bridge SDL_uikitview *)view;
117    return (__bridge void *)uiview.layer;
118}}
119
120void
121UIKit_Metal_GetDrawableSize(_THIS, SDL_Window * window, int * w, int * h)
122{
123    @autoreleasepool {
124        SDL_WindowData *data = (__bridge SDL_WindowData *)window->driverdata;
125        SDL_uikitview *view = (SDL_uikitview*)data.uiwindow.rootViewController.view;
126        SDL_uikitmetalview* metalview = [view viewWithTag:METALVIEW_TAG];
127        if (metalview) {
128            CAMetalLayer *layer = (CAMetalLayer*)metalview.layer;
129            assert(layer != NULL);
130            if (w) {
131                *w = layer.drawableSize.width;
132            }
133            if (h) {
134                *h = layer.drawableSize.height;
135            }
136        } else {
137            SDL_GetWindowSize(window, w, h);
138        }
139    }
140}
141
142#endif /* SDL_VIDEO_DRIVER_UIKIT && (SDL_VIDEO_VULKAN || SDL_VIDEO_METAL) */
143