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Diffstat (limited to 'third_party/libwebrtc/sdk/objc/components/renderer/metal/RTCMTLRenderer.mm')
| -rw-r--r-- | third_party/libwebrtc/sdk/objc/components/renderer/metal/RTCMTLRenderer.mm | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/third_party/libwebrtc/sdk/objc/components/renderer/metal/RTCMTLRenderer.mm b/third_party/libwebrtc/sdk/objc/components/renderer/metal/RTCMTLRenderer.mm new file mode 100644 index 0000000000..410590a7b1 --- /dev/null +++ b/third_party/libwebrtc/sdk/objc/components/renderer/metal/RTCMTLRenderer.mm @@ -0,0 +1,328 @@ +/* + * 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 "RTCMTLRenderer+Private.h" + +#import <Metal/Metal.h> +#import <MetalKit/MetalKit.h> + +#import "base/RTCLogging.h" +#import "base/RTCVideoFrame.h" +#import "base/RTCVideoFrameBuffer.h" + +#include "api/video/video_rotation.h" +#include "rtc_base/checks.h" + +// 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"; + +// Computes the texture coordinates given rotation and cropping. +static inline void getCubeVertexData(int cropX, + int cropY, + int cropWidth, + int cropHeight, + size_t frameWidth, + size_t frameHeight, + RTCVideoRotation rotation, + float *buffer) { + // The computed values are the adjusted texture coordinates, in [0..1]. + // For the left and top, 0.0 means no cropping and e.g. 0.2 means we're skipping 20% of the + // left/top edge. + // For the right and bottom, 1.0 means no cropping and e.g. 0.8 means we're skipping 20% of the + // right/bottom edge (i.e. render up to 80% of the width/height). + float cropLeft = cropX / (float)frameWidth; + float cropRight = (cropX + cropWidth) / (float)frameWidth; + float cropTop = cropY / (float)frameHeight; + float cropBottom = (cropY + cropHeight) / (float)frameHeight; + + // These arrays map the view coordinates to texture coordinates, taking cropping and rotation + // into account. The first two columns are view coordinates, the last two are texture coordinates. + switch (rotation) { + case RTCVideoRotation_0: { + float values[16] = {-1.0, -1.0, cropLeft, cropBottom, + 1.0, -1.0, cropRight, cropBottom, + -1.0, 1.0, cropLeft, cropTop, + 1.0, 1.0, cropRight, cropTop}; + memcpy(buffer, &values, sizeof(values)); + } break; + case RTCVideoRotation_90: { + float values[16] = {-1.0, -1.0, cropRight, cropBottom, + 1.0, -1.0, cropRight, cropTop, + -1.0, 1.0, cropLeft, cropBottom, + 1.0, 1.0, cropLeft, cropTop}; + memcpy(buffer, &values, sizeof(values)); + } break; + case RTCVideoRotation_180: { + float values[16] = {-1.0, -1.0, cropRight, cropTop, + 1.0, -1.0, cropLeft, cropTop, + -1.0, 1.0, cropRight, cropBottom, + 1.0, 1.0, cropLeft, cropBottom}; + memcpy(buffer, &values, sizeof(values)); + } break; + case RTCVideoRotation_270: { + float values[16] = {-1.0, -1.0, cropLeft, cropTop, + 1.0, -1.0, cropLeft, cropBottom, + -1.0, 1.0, cropRight, cropTop, + 1.0, 1.0, cropRight, cropBottom}; + memcpy(buffer, &values, sizeof(values)); + } break; + } +} + +// 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 RTCMTLRenderer { + __kindof MTKView *_view; + + // Controller. + dispatch_semaphore_t _inflight_semaphore; + + // Renderer. + id<MTLDevice> _device; + id<MTLCommandQueue> _commandQueue; + id<MTLLibrary> _defaultLibrary; + id<MTLRenderPipelineState> _pipelineState; + + // Buffers. + id<MTLBuffer> _vertexBuffer; + + // Values affecting the vertex buffer. Stored for comparison to avoid unnecessary recreation. + int _oldFrameWidth; + int _oldFrameHeight; + int _oldCropWidth; + int _oldCropHeight; + int _oldCropX; + int _oldCropY; + RTCVideoRotation _oldRotation; +} + +@synthesize rotationOverride = _rotationOverride; + +- (instancetype)init { + if (self = [super init]) { + _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]) { + _view = view; + view.device = _device; + view.preferredFramesPerSecond = 30; + view.autoResizeDrawable = NO; + + [self loadAssets]; + + float vertexBufferArray[16] = {0}; + _vertexBuffer = [_device newBufferWithBytes:vertexBufferArray + length:sizeof(vertexBufferArray) + options:MTLResourceCPUCacheModeWriteCombined]; + success = YES; + } + return success; +} +#pragma mark - Inheritance + +- (id<MTLDevice>)currentMetalDevice { + return _device; +} + +- (NSString *)shaderSource { + RTC_DCHECK_NOTREACHED() << "Virtual method not implemented in subclass."; + return nil; +} + +- (void)uploadTexturesToRenderEncoder:(id<MTLRenderCommandEncoder>)renderEncoder { + RTC_DCHECK_NOTREACHED() << "Virtual method not implemented in subclass."; +} + +- (void)getWidth:(int *)width + height:(int *)height + cropWidth:(int *)cropWidth + cropHeight:(int *)cropHeight + cropX:(int *)cropX + cropY:(int *)cropY + ofFrame:(nonnull RTC_OBJC_TYPE(RTCVideoFrame) *)frame { + RTC_DCHECK_NOTREACHED() << "Virtual method not implemented in subclass."; +} + +- (BOOL)setupTexturesForFrame:(nonnull RTC_OBJC_TYPE(RTCVideoFrame) *)frame { + // Apply rotation override if set. + RTCVideoRotation rotation; + NSValue *rotationOverride = self.rotationOverride; + if (rotationOverride) { +#if defined(__IPHONE_11_0) && defined(__IPHONE_OS_VERSION_MAX_ALLOWED) && \ + (__IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_11_0) + if (@available(iOS 11, *)) { + [rotationOverride getValue:&rotation size:sizeof(rotation)]; + } else +#endif + { + [rotationOverride getValue:&rotation]; + } + } else { + rotation = frame.rotation; + } + + int frameWidth, frameHeight, cropWidth, cropHeight, cropX, cropY; + [self getWidth:&frameWidth + height:&frameHeight + cropWidth:&cropWidth + cropHeight:&cropHeight + cropX:&cropX + cropY:&cropY + ofFrame:frame]; + + // Recompute the texture cropping and recreate vertexBuffer if necessary. + if (cropX != _oldCropX || cropY != _oldCropY || cropWidth != _oldCropWidth || + cropHeight != _oldCropHeight || rotation != _oldRotation || frameWidth != _oldFrameWidth || + frameHeight != _oldFrameHeight) { + getCubeVertexData(cropX, + cropY, + cropWidth, + cropHeight, + frameWidth, + frameHeight, + rotation, + (float *)_vertexBuffer.contents); + _oldCropX = cropX; + _oldCropY = cropY; + _oldCropWidth = cropWidth; + _oldCropHeight = cropHeight; + _oldRotation = rotation; + _oldFrameWidth = frameWidth; + _oldFrameHeight = frameHeight; + } + + return YES; +} + +#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; + NSString *shaderSource = [self shaderSource]; + + 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)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)render { + 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:0 atIndex:0]; + [self uploadTexturesToRenderEncoder:renderEncoder]; + + [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:(RTC_OBJC_TYPE(RTCVideoFrame) *)frame { + @autoreleasepool { + // Wait until the inflight (curently sent to GPU) command buffer + // has completed the GPU work. + dispatch_semaphore_wait(_inflight_semaphore, DISPATCH_TIME_FOREVER); + + if ([self setupTexturesForFrame:frame]) { + [self render]; + } else { + dispatch_semaphore_signal(_inflight_semaphore); + } + } +} + +@end |