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FlutterSurface.mm
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
6 
7 #import <Metal/Metal.h>
8 
9 @interface FlutterSurface () {
10  CGSize _size;
11  IOSurfaceRef _ioSurface;
12  id<MTLTexture> _texture;
13 }
14 @end
15 
16 @implementation FlutterSurface
17 
18 - (IOSurfaceRef)ioSurface {
19  return _ioSurface;
20 }
21 
22 - (CGSize)size {
23  return _size;
24 }
25 
26 - (int64_t)textureId {
27  return reinterpret_cast<int64_t>(_texture);
28 }
29 
30 - (instancetype)initWithSize:(CGSize)size device:(id<MTLDevice>)device {
31  if (self = [super init]) {
32  self->_size = size;
33  self->_ioSurface = [FlutterSurface createIOSurfaceWithSize:size];
34  self->_texture = [FlutterSurface createTextureForIOSurface:_ioSurface size:size device:device];
35  }
36  return self;
37 }
38 
39 static void ReleaseSurface(void* surface) {
40  if (surface != nullptr) {
41  CFBridgingRelease(surface);
42  }
43 }
44 
45 - (FlutterMetalTexture)asFlutterMetalTexture {
46  FlutterMetalTexture res;
47  memset(&res, 0, sizeof(FlutterMetalTexture));
48  res.struct_size = sizeof(FlutterMetalTexture);
49  res.texture = (__bridge void*)_texture;
50  res.texture_id = self.textureId;
51  res.user_data = (void*)CFBridgingRetain(self);
52  res.destruction_callback = ReleaseSurface;
53  return res;
54 }
55 
56 + (FlutterSurface*)fromFlutterMetalTexture:(const FlutterMetalTexture*)texture {
57  return (__bridge FlutterSurface*)texture->user_data;
58 }
59 
60 - (void)dealloc {
61  CFRelease(_ioSurface);
62 }
63 
64 + (IOSurfaceRef)createIOSurfaceWithSize:(CGSize)size {
65  unsigned pixelFormat = 'BGRA';
66  unsigned bytesPerElement = 4;
67 
68  size_t bytesPerRow = IOSurfaceAlignProperty(kIOSurfaceBytesPerRow, size.width * bytesPerElement);
69  size_t totalBytes = IOSurfaceAlignProperty(kIOSurfaceAllocSize, size.height * bytesPerRow);
70  NSDictionary* options = @{
71  (id)kIOSurfaceWidth : @(size.width),
72  (id)kIOSurfaceHeight : @(size.height),
73  (id)kIOSurfacePixelFormat : @(pixelFormat),
74  (id)kIOSurfaceBytesPerElement : @(bytesPerElement),
75  (id)kIOSurfaceBytesPerRow : @(bytesPerRow),
76  (id)kIOSurfaceAllocSize : @(totalBytes),
77  };
78 
79  IOSurfaceRef res = IOSurfaceCreate((CFDictionaryRef)options);
80  IOSurfaceSetValue(res, CFSTR("IOSurfaceColorSpace"), kCGColorSpaceSRGB);
81  return res;
82 }
83 
84 + (id<MTLTexture>)createTextureForIOSurface:(IOSurfaceRef)surface
85  size:(CGSize)size
86  device:(id<MTLDevice>)device {
87  MTLTextureDescriptor* textureDescriptor =
88  [MTLTextureDescriptor texture2DDescriptorWithPixelFormat:MTLPixelFormatBGRA8Unorm
89  width:size.width
90  height:size.height
91  mipmapped:NO];
92  textureDescriptor.usage =
93  MTLTextureUsageShaderRead | MTLTextureUsageRenderTarget | MTLTextureUsageShaderWrite;
94  // plane = 0 for BGRA.
95  return [device newTextureWithDescriptor:textureDescriptor iosurface:surface plane:0];
96 }
97 
98 @end
-[FlutterSurface asFlutterMetalTexture]
FlutterMetalTexture asFlutterMetalTexture()
Definition: FlutterSurface.mm:45
FlutterSurface(Private)::textureId
int64_t textureId
Definition: FlutterSurface.h:31
FlutterSurface()::_size
CGSize _size
Definition: FlutterSurface.mm:10
FlutterSurface(Private)::ioSurface
IOSurfaceRef ioSurface
Definition: FlutterSurface.h:29
FlutterSurface()::_ioSurface
IOSurfaceRef _ioSurface
Definition: FlutterSurface.mm:11
FlutterSurface.h
_texture
id< FlutterTexture > _texture
Definition: FlutterExternalTexture.mm:14
FlutterSurface
Definition: FlutterSurface.h:13
FlutterSurface(Private)::size
CGSize size
Definition: FlutterSurface.h:30
FlutterSurface()::_texture
id< MTLTexture > _texture
Definition: FlutterSurface.mm:12