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/*
* Copyright 2015 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 "RTCNSGLVideoView.h"
#import <CoreVideo/CVDisplayLink.h>
#import <OpenGL/gl3.h>
#import "RTCVideoFrame.h"
#import "RTCOpenGLVideoRenderer.h"
@interface RTCNSGLVideoView ()
// |videoFrame| is set when we receive a frame from a worker thread and is read
// from the display link callback so atomicity is required.
@property(atomic, strong) RTCVideoFrame *videoFrame;
@property(atomic, strong) RTCOpenGLVideoRenderer *glRenderer;
- (void)drawFrame;
@end
static CVReturn OnDisplayLinkFired(CVDisplayLinkRef displayLink,
const CVTimeStamp *now,
const CVTimeStamp *outputTime,
CVOptionFlags flagsIn,
CVOptionFlags *flagsOut,
void *displayLinkContext) {
RTCNSGLVideoView *view = (__bridge RTCNSGLVideoView *)displayLinkContext;
[view drawFrame];
return kCVReturnSuccess;
}
@implementation RTCNSGLVideoView {
CVDisplayLinkRef _displayLink;
}
@synthesize delegate = _delegate;
@synthesize videoFrame = _videoFrame;
@synthesize glRenderer = _glRenderer;
- (void)dealloc {
[self teardownDisplayLink];
}
- (void)drawRect:(NSRect)rect {
[self drawFrame];
}
- (void)reshape {
[super reshape];
NSRect frame = [self frame];
CGLLockContext([[self openGLContext] CGLContextObj]);
glViewport(0, 0, frame.size.width, frame.size.height);
CGLUnlockContext([[self openGLContext] CGLContextObj]);
}
- (void)lockFocus {
NSOpenGLContext *context = [self openGLContext];
[super lockFocus];
if ([context view] != self) {
[context setView:self];
}
[context makeCurrentContext];
}
- (void)prepareOpenGL {
[super prepareOpenGL];
if (!self.glRenderer) {
self.glRenderer =
[[RTCOpenGLVideoRenderer alloc] initWithContext:[self openGLContext]];
}
[self.glRenderer setupGL];
[self setupDisplayLink];
}
- (void)clearGLContext {
[self.glRenderer teardownGL];
self.glRenderer = nil;
[super clearGLContext];
}
#pragma mark - RTCVideoRenderer
// These methods may be called on non-main thread.
- (void)setSize:(CGSize)size {
dispatch_async(dispatch_get_main_queue(), ^{
[self.delegate videoView:self didChangeVideoSize:size];
});
}
- (void)renderFrame:(RTCVideoFrame *)frame {
self.videoFrame = frame;
}
#pragma mark - Private
- (void)drawFrame {
RTCVideoFrame *videoFrame = self.videoFrame;
if (self.glRenderer.lastDrawnFrame != videoFrame) {
// This method may be called from CVDisplayLink callback which isn't on the
// main thread so we have to lock the GL context before drawing.
CGLLockContext([[self openGLContext] CGLContextObj]);
[self.glRenderer drawFrame:videoFrame];
CGLUnlockContext([[self openGLContext] CGLContextObj]);
}
}
- (void)setupDisplayLink {
if (_displayLink) {
return;
}
// Synchronize buffer swaps with vertical refresh rate.
GLint swapInt = 1;
[[self openGLContext] setValues:&swapInt forParameter:NSOpenGLCPSwapInterval];
// Create display link.
CVDisplayLinkCreateWithActiveCGDisplays(&_displayLink);
CVDisplayLinkSetOutputCallback(_displayLink,
&OnDisplayLinkFired,
(__bridge void *)self);
// Set the display link for the current renderer.
CGLContextObj cglContext = [[self openGLContext] CGLContextObj];
CGLPixelFormatObj cglPixelFormat = [[self pixelFormat] CGLPixelFormatObj];
CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext(
_displayLink, cglContext, cglPixelFormat);
CVDisplayLinkStart(_displayLink);
}
- (void)teardownDisplayLink {
if (!_displayLink) {
return;
}
CVDisplayLinkRelease(_displayLink);
_displayLink = NULL;
}
@end
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