blob: 7fcba49a312c0ec436d1d5a6cba18b7e7ca547f6 [file] [log] [blame]
/*
* 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 "WebRTC/RTCLogging.h"
#import "WebRTC/RTCVideoFrame.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";
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(RTCVideoRotation rotation) {
switch (rotation) {
case RTCVideoRotation_0:
return 0;
case RTCVideoRotation_90:
return 16;
case RTCVideoRotation_180:
return 32;
case RTCVideoRotation_270:
return 48;
}
return 0;
}
// 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;
// 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];
success = YES;
}
return success;
}
#pragma mark - Inheritance
- (id<MTLDevice>)currentMetalDevice {
return _device;
}
- (NSString *)shaderSource {
RTC_NOTREACHED() << "Virtual method not implemented in subclass.";
return nil;
}
- (void)uploadTexturesToRenderEncoder:(id<MTLRenderCommandEncoder>)renderEncoder {
RTC_NOTREACHED() << "Virtual method not implemented in subclass.";
}
- (BOOL)setupTexturesForFrame:(nonnull RTCVideoFrame *)frame {
_offset = offsetForRotation(frame.rotation);
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;
id<MTLLibrary> sourceLibrary =
[_device newLibraryWithSource:[self 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)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];
[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:(RTCVideoFrame *)frame {
@autoreleasepool {
if ([self setupTexturesForFrame:frame]) {
[self render];
}
}
}
@end