Revert of Add metal view, shaders and renderer.

webrtc/sdk/objc/Framework/Classes/Metal/RTCMTLNV12Renderer.mm

-/*
- *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#import "RTCMTLNV12Renderer.h"
-
-#import <Metal/Metal.h>
-#import <MetalKit/MetalKit.h>
-
-#import "WebRTC/RTCLogging.h"
-#import "WebRTC/RTCVideoFrame.h"
-
-#include "webrtc/api/video/video_rotation.h"
-
-#define MTL_STRINGIFY(s) @ #s
-
-// As defined in shaderSource.
-static NSString *const vertexFunctionName = @"vertexPassthrough";
-static NSString *const fragmentFunctionName = @"fragmentColorConversion";
-
-static NSString *const pipelineDescriptorLabel = @"RTCPipeline";
-static NSString *const commandBufferLabel = @"RTCCommandBuffer";
-static NSString *const renderEncoderLabel = @"RTCEncoder";
-static NSString *const renderEncoderDebugGroup = @"RTCDrawFrame";
-
-static const float cubeVertexData[64] = {
-    -1.0, -1.0, 0.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 0.0, 0.0, 1.0, 1.0, 1.0, 0.0,
-
-    // rotation = 90, offset = 16.
-    -1.0, -1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 0.0, -1.0, 1.0, 0.0, 1.0, 1.0, 1.0, 0.0, 0.0,
-
-    // rotation = 180, offset = 32.
-    -1.0, -1.0, 1.0, 0.0, 1.0, -1.0, 0.0, 0.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.0, 1.0,
-
-    // rotation = 270, offset = 48.
-    -1.0, -1.0, 0.0, 0.0, 1.0, -1.0, 0.0, 1.0, -1.0, 1.0, 1.0, 0.0, 1.0, 1.0, 1.0, 1.0,
-};
-
-static inline int offsetForRotation(webrtc::VideoRotation rotation) {
-  switch (rotation) {
-    case webrtc::kVideoRotation_0:
-      return 0;
-    case webrtc::kVideoRotation_90:
-      return 16;
-    case webrtc::kVideoRotation_180:
-      return 32;
-    case webrtc::kVideoRotation_270:
-      return 48;
-  }
-  return 0;
-}
-
-static NSString *const shaderSource = MTL_STRINGIFY(
-    using namespace metal; typedef struct {
-      packed_float2 position;
-      packed_float2 texcoord;
-    } Vertex;
-
-    typedef struct {
-      float4 position[[position]];
-      float2 texcoord;
-    } Varyings;
-
-    vertex Varyings vertexPassthrough(device Vertex * verticies[[buffer(0)]],
-                                      unsigned int vid[[vertex_id]]) {
-      Varyings out;
-      device Vertex &v = verticies[vid];
-      out.position = float4(float2(v.position), 0.0, 1.0);
-      out.texcoord = v.texcoord;
-
-      return out;
-    }
-
-    // Receiving YCrCb textures.
-    fragment half4 fragmentColorConversion(
-        Varyings in[[stage_in]], texture2d<float, access::sample> textureY[[texture(0)]],
-        texture2d<float, access::sample> textureCbCr[[texture(1)]]) {
-      constexpr sampler s(address::clamp_to_edge, filter::linear);
-      float y;
-      float2 uv;
-      y = textureY.sample(s, in.texcoord).r;
-      uv = textureCbCr.sample(s, in.texcoord).rg - float2(0.5, 0.5);
-
-      // Conversion for YUV to rgb from http://www.fourcc.org/fccyvrgb.php
-      float4 out = float4(y + 1.403 * uv.y, y - 0.344 * uv.x - 0.714 * uv.y, y + 1.770 * uv.x, 1.0);
-
-      return half4(out);
-    });
-
-// The max number of command buffers in flight (submitted to GPU).
-// For now setting it up to 1.
-// In future we might use triple buffering method if it improves performance.
-static const NSInteger kMaxInflightBuffers = 1;
-
-@implementation RTCMTLNV12Renderer {
-  __kindof MTKView *_view;
-
-  // Controller.
-  dispatch_semaphore_t _inflight_semaphore;
-
-  // Renderer.
-  id<MTLDevice> _device;
-  id<MTLCommandQueue> _commandQueue;
-  id<MTLLibrary> _defaultLibrary;
-  id<MTLRenderPipelineState> _pipelineState;
-
-  // Textures.
-  CVMetalTextureCacheRef _textureCache;
-  id<MTLTexture> _yTexture;
-  id<MTLTexture> _CrCbTexture;
-
-  // Buffers.
-  id<MTLBuffer> _vertexBuffer;
-
-  // RTC Frame parameters.
-  int _offset;
-}
-
-- (instancetype)init {
-  if (self = [super init]) {
-    // _offset of 0 is equal to rotation of 0.
-    _offset = 0;
-    _inflight_semaphore = dispatch_semaphore_create(kMaxInflightBuffers);
-  }
-
-  return self;
-}
-
-- (BOOL)addRenderingDestination:(__kindof MTKView *)view {
-  return [self setupWithView:view];
-}
-
-#pragma mark - Private
-
-- (BOOL)setupWithView:(__kindof MTKView *)view {
-  BOOL success = NO;
-  if ([self setupMetal]) {
-    [self setupView:view];
-    [self loadAssets];
-    [self setupBuffers];
-    [self initializeTextureCache];
-    success = YES;
-  }
-  return success;
-}
-
-#pragma mark - GPU methods
-
-- (BOOL)setupMetal {
-  // Set the view to use the default device.
-  _device = MTLCreateSystemDefaultDevice();
-  if (!_device) {
-    return NO;
-  }
-
-  // Create a new command queue.
-  _commandQueue = [_device newCommandQueue];
-
-  // Load metal library from source.
-  NSError *libraryError = nil;
-
-  id<MTLLibrary> sourceLibrary =
-      [_device newLibraryWithSource:shaderSource options:NULL error:&libraryError];
-
-  if (libraryError) {
-    RTCLogError(@"Metal: Library with source failed\n%@", libraryError);
-    return NO;
-  }
-
-  if (!sourceLibrary) {
-    RTCLogError(@"Metal: Failed to load library. %@", libraryError);
-    return NO;
-  }
-  _defaultLibrary = sourceLibrary;
-
-  return YES;
-}
-
-- (void)setupView:(__kindof MTKView *)view {
-  view.device = _device;
-
-  view.preferredFramesPerSecond = 30;
-  view.autoResizeDrawable = NO;
-
-  // We need to keep reference to the view as it's needed down the rendering pipeline.
-  _view = view;
-}
-
-- (void)loadAssets {
-  id<MTLFunction> vertexFunction = [_defaultLibrary newFunctionWithName:vertexFunctionName];
-  id<MTLFunction> fragmentFunction =
-      [_defaultLibrary newFunctionWithName:fragmentFunctionName];
-
-  MTLRenderPipelineDescriptor *pipelineDescriptor = [[MTLRenderPipelineDescriptor alloc] init];
-  pipelineDescriptor.label = pipelineDescriptorLabel;
-  pipelineDescriptor.vertexFunction = vertexFunction;
-  pipelineDescriptor.fragmentFunction = fragmentFunction;
-  pipelineDescriptor.colorAttachments[0].pixelFormat = _view.colorPixelFormat;
-  pipelineDescriptor.depthAttachmentPixelFormat = MTLPixelFormatInvalid;
-  NSError *error = nil;
-  _pipelineState = [_device newRenderPipelineStateWithDescriptor:pipelineDescriptor error:&error];
-
-  if (!_pipelineState) {
-    RTCLogError(@"Metal: Failed to create pipeline state. %@", error);
-  }
-}
-
-- (void)setupBuffers {
-  _vertexBuffer = [_device newBufferWithBytes:cubeVertexData
-                                       length:sizeof(cubeVertexData)
-                                      options:MTLResourceOptionCPUCacheModeDefault];
-}
-
-- (void)initializeTextureCache {
-  CVReturn status =
-      CVMetalTextureCacheCreate(kCFAllocatorDefault, nil, _device, nil, &_textureCache);
-  if (status != kCVReturnSuccess) {
-    RTCLogError(@"Metal: Failed to initialize metal texture cache. Return status is %d", status);
-  }
-}
-
-- (void)render {
-  // Wait until the inflight (curently sent to GPU) command buffer
-  // has completed the GPU work.
-  dispatch_semaphore_wait(_inflight_semaphore, DISPATCH_TIME_FOREVER);
-
-  id<MTLCommandBuffer> commandBuffer = [_commandQueue commandBuffer];
-  commandBuffer.label = commandBufferLabel;
-
-  __block dispatch_semaphore_t block_semaphore = _inflight_semaphore;
-  [commandBuffer addCompletedHandler:^(id<MTLCommandBuffer> _Nonnull) {
-    // GPU work completed.
-    dispatch_semaphore_signal(block_semaphore);
-  }];
-
-  MTLRenderPassDescriptor *_renderPassDescriptor = _view.currentRenderPassDescriptor;
-  if (_renderPassDescriptor) {  // Valid drawable.
-    id<MTLRenderCommandEncoder> renderEncoder =
-        [commandBuffer renderCommandEncoderWithDescriptor:_renderPassDescriptor];
-    renderEncoder.label = renderEncoderLabel;
-
-    // Set context state.
-    [renderEncoder pushDebugGroup:renderEncoderDebugGroup];
-    [renderEncoder setRenderPipelineState:_pipelineState];
-    [renderEncoder setVertexBuffer:_vertexBuffer offset:_offset * sizeof(float) atIndex:0];
-    [renderEncoder setFragmentTexture:_yTexture atIndex:0];
-    [renderEncoder setFragmentTexture:_CrCbTexture atIndex:1];
-
-    [renderEncoder drawPrimitives:MTLPrimitiveTypeTriangleStrip
-                      vertexStart:0
-                      vertexCount:4
-                    instanceCount:1];
-    [renderEncoder popDebugGroup];
-    [renderEncoder endEncoding];
-
-    [commandBuffer presentDrawable:_view.currentDrawable];
-  }
-
-  // CPU work is completed, GPU work can be started.
-  [commandBuffer commit];
-}
-
-#pragma mark - RTCMTLRenderer
-
-- (void)drawFrame:(RTCVideoFrame *)frame {
-  [self setupTexturesForFrame:frame];
-  @autoreleasepool {
-    [self render];
-  }
-}
-
-- (void)setupTexturesForFrame:(nonnull RTCVideoFrame *)frame {
-  CVPixelBufferRef pixelBuffer = frame.nativeHandle;
-
-  id<MTLTexture> lumaTexture = nil;
-  id<MTLTexture> chromaTexture = nil;
-  CVMetalTextureRef outTexture = nullptr;
-
-  // Luma (y) texture.
-  int lumaWidth = CVPixelBufferGetWidthOfPlane(pixelBuffer, 0);
-  int lumaHeight = CVPixelBufferGetHeightOfPlane(pixelBuffer, 0);
-
-  int indexPlane = 0;
-  CVReturn result = CVMetalTextureCacheCreateTextureFromImage(
-      kCFAllocatorDefault, _textureCache, pixelBuffer, nil, MTLPixelFormatR8Unorm, lumaWidth,
-      lumaHeight, indexPlane, &outTexture);
-
-  if (result == kCVReturnSuccess) {
-    lumaTexture = CVMetalTextureGetTexture(outTexture);
-  }
-
-  // Same as CFRelease except it can be passed NULL without crashing.
-  CVBufferRelease(outTexture);
-  outTexture = nullptr;
-
-  // Chroma (CrCb) texture.
-  indexPlane = 1;
-  result = CVMetalTextureCacheCreateTextureFromImage(
-      kCFAllocatorDefault, _textureCache, pixelBuffer, nil, MTLPixelFormatRG8Unorm, lumaWidth / 2,
-      lumaHeight / 2, indexPlane, &outTexture);
-  if (result == kCVReturnSuccess) {
-    chromaTexture = CVMetalTextureGetTexture(outTexture);
-  }
-  CVBufferRelease(outTexture);
-
-  if (lumaTexture != nil && chromaTexture != nil) {
-    _yTexture = lumaTexture;
-    _CrCbTexture = chromaTexture;
-    _offset = offsetForRotation((webrtc::VideoRotation)frame.rotation);
-  }
-}
-
-@end