DOCS/client_api_examples: add opengl-cb-based cocoa example.

Contains a basic toggle button that pauses the video.

1 files changed, 310 insertions, 0 deletions

diff --git a/DOCS/client_api_examples/cocoa-openglcb/cocoa-openglcb.m b/DOCS/client_api_examples/cocoa-openglcb/cocoa-openglcb.m
new file mode 100644
index 0000000000..f65c6a3664
--- /dev/null
+++ b/DOCS/client_api_examples/cocoa-openglcb/cocoa-openglcb.m
@@ -0,0 +1,310 @@
+// Plays a video from the command line in an opengl view in its own window.
+
+// Build with: clang -o cocoa-openglcb cocoa-openglcb.m `pkg-config --libs --cflags mpv` -framework Cocoa -framework OpenGL
+
+#import <mpv/client.h>
+#import <mpv/opengl_cb.h>
+
+#import <stdio.h>
+#import <stdlib.h>
+#import <OpenGL/gl.h>
+
+#import <Cocoa/Cocoa.h>
+
+
+static inline void check_error(int status)
+{
+    if (status < 0) {
+        printf("mpv API error: %s\n", mpv_error_string(status));
+        exit(1);
+    }
+}
+
+static void *get_proc_address(void *ctx, const char *name)
+{
+    CFStringRef symbolName = CFStringCreateWithCString(kCFAllocatorDefault, name, kCFStringEncodingASCII);
+    void *addr = CFBundleGetFunctionPointerForName(CFBundleGetBundleWithIdentifier(CFSTR("com.apple.opengl")), symbolName);
+    CFRelease(symbolName);
+    return addr;
+}
+
+static void glupdate(void *ctx);
+
+@interface MpvClientOGLView : NSOpenGLView
+@property mpv_opengl_cb_context *mpvGL;
+- (instancetype)initWithFrame:(NSRect)frame;
+- (void)drawRect;
+- (void)flushBlack;
+@end
+
+@implementation MpvClientOGLView
+- (instancetype)initWithFrame:(NSRect)frame
+{
+    // make sure the pixel format is double buffered so we can use
+    // [[self openGLContext] flushBuffer].
+    NSOpenGLPixelFormatAttribute attributes[] = {
+        NSOpenGLPFADoubleBuffer,
+        0
+    };
+    self = [super initWithFrame:frame
+                    pixelFormat:[[NSOpenGLPixelFormat alloc] initWithAttributes:attributes]];
+
+    if (self) {
+        [self setAutoresizingMask:NSViewWidthSizable|NSViewHeightSizable];
+        // swap on vsyncs
+        GLint swapInt = 1;
+        [[self openGLContext] setValues:&swapInt forParameter:NSOpenGLCPSwapInterval];
+        [[self openGLContext] makeCurrentContext];
+    }
+    return self;
+}
+
+- (void)flushBlack
+{
+    glClearColor(0, 0, 0, 0);
+    glClear(GL_COLOR_BUFFER_BIT);
+    [[self openGLContext] flushBuffer];
+    [[self openGLContext] flushBuffer];
+}
+
+- (void)prepareOpenGL
+{
+    [super prepareOpenGL];
+    [self flushBlack];
+    self.mpvGL = nil;
+}
+
+- (void)drawRect
+{
+    if (self.mpvGL)
+        mpv_opengl_cb_draw(self.mpvGL, 0, self.bounds.size.width, -self.bounds.size.height);
+    [[self openGLContext] flushBuffer];
+}
+
+- (void)drawRect:(NSRect)dirtyRect
+{
+    [self drawRect];
+}
+@end
+
+@interface CocoaWindow : NSWindow
+@property(retain, readonly) MpvClientOGLView *glView;
+@property(retain, readonly) NSButton *pauseButton;
+@end
+
+@implementation CocoaWindow
+- (BOOL)canBecomeMainWindow { return YES; }
+- (BOOL)canBecomeKeyWindow { return YES; }
+- (void)initOGLView {
+    NSRect bounds = [[self contentView] bounds];
+    // window coordinate origin is bottom left
+    NSRect glFrame = NSMakeRect(bounds.origin.x, bounds.origin.y + 30, bounds.size.width, bounds.size.height - 30);
+    _glView = [[MpvClientOGLView alloc] initWithFrame:glFrame];
+    [self.contentView addSubview:_glView];
+
+    NSRect buttonFrame = NSMakeRect(bounds.origin.x, bounds.origin.y, 60, 30);
+    _pauseButton = [[NSButton alloc] initWithFrame:buttonFrame];
+    _pauseButton.buttonType = NSToggleButton;
+    // button target has to be the delegate (it holds the mpv context
+    // pointer), so that's set later.
+    _pauseButton.action = @selector(togglePause:);
+    _pauseButton.title = @"Pause";
+    _pauseButton.alternateTitle = @"Play";
+    [self.contentView addSubview:_pauseButton];
+}
+@end
+
+@interface AppDelegate : NSObject <NSApplicationDelegate>
+{
+    mpv_handle *mpv;
+    dispatch_queue_t queue;
+    CocoaWindow *window;
+}
+@end
+
+static void wakeup(void *);
+
+@implementation AppDelegate
+
+- (void)createWindow {
+
+    int mask = NSTitledWindowMask|NSClosableWindowMask|
+               NSMiniaturizableWindowMask|NSResizableWindowMask;
+
+    window = [[CocoaWindow alloc]
+        initWithContentRect:NSMakeRect(0, 0, 1280, 720)
+                  styleMask:mask
+                    backing:NSBackingStoreBuffered
+                      defer:NO];
+
+    // force a minimum size to stop opengl from exploding.
+    [window setMinSize:NSMakeSize(200, 200)];
+    [window initOGLView];
+    [window setTitle:@"cocoa-openglcb example"];
+    [window makeMainWindow];
+    [window makeKeyAndOrderFront:nil];
+
+    NSMenu *m = [[NSMenu alloc] initWithTitle:@"AMainMenu"];
+    NSMenuItem *item = [m addItemWithTitle:@"Apple" action:nil keyEquivalent:@""];
+    NSMenu *sm = [[NSMenu alloc] initWithTitle:@"Apple"];
+    [m setSubmenu:sm forItem:item];
+    [sm addItemWithTitle: @"quit" action:@selector(terminate:) keyEquivalent:@"q"];
+    [NSApp setMenu:m];
+    [NSApp activateIgnoringOtherApps:YES];
+}
+
+- (void) applicationDidFinishLaunching:(NSNotification *)notification {
+    [NSApp setActivationPolicy:NSApplicationActivationPolicyRegular];
+    atexit_b(^{
+        // Because activation policy has just been set to behave like a real
+        // application, that policy must be reset on exit to prevent, among
+        // other things, the menubar created here from remaining on screen.
+        [NSApp setActivationPolicy:NSApplicationActivationPolicyProhibited];
+    });
+
+    // Read filename
+    NSArray *args = [NSProcessInfo processInfo].arguments;
+    if (args.count < 2) {
+        NSLog(@"Expected filename on command line");
+        exit(1);
+    }
+    NSString *filename = args[1];
+
+    [self createWindow];
+    window.pauseButton.target = self;
+
+    mpv = mpv_create();
+    if (!mpv) {
+        printf("failed creating context\n");
+        exit(1);
+    }
+
+    check_error(mpv_set_option_string(mpv, "input-media-keys", "yes"));
+    // request important errors
+    check_error(mpv_request_log_messages(mpv, "warn"));
+
+    check_error(mpv_initialize(mpv));
+    check_error(mpv_set_option_string(mpv, "vo", "opengl-cb"));
+    mpv_opengl_cb_context *mpvGL = mpv_get_sub_api(mpv, MPV_SUB_API_OPENGL_CB);
+    if (!mpvGL) {
+        puts("libmpv does not have the opengl-cb sub-API.");
+        exit(1);
+    }
+    // pass the mpvGL context to our view
+    window.glView.mpvGL = mpvGL;
+    int r = mpv_opengl_cb_init_gl(mpvGL, NULL, get_proc_address, NULL);
+    if (r < 0) {
+        puts("gl init has failed.");
+        exit(1);
+    }
+    mpv_opengl_cb_set_update_callback(mpvGL, glupdate, (__bridge void *)window.glView);
+
+    // Deal with MPV in the background.
+    queue = dispatch_queue_create("mpv", DISPATCH_QUEUE_SERIAL);
+    dispatch_async(queue, ^{
+        // Register to be woken up whenever mpv generates new events.
+        mpv_set_wakeup_callback(mpv, wakeup, (__bridge void *)self);
+        // Load the indicated file
+        const char *cmd[] = {"loadfile", filename.UTF8String, NULL};
+        check_error(mpv_command(mpv, cmd));
+    });
+}
+
+static void glupdate(void *ctx)
+{
+    MpvClientOGLView *glView = (__bridge MpvClientOGLView *)ctx;
+    // I'm still not sure what the best way to handle this is, but this
+    // works.
+    dispatch_async(dispatch_get_main_queue(), ^{
+        [glView drawRect];
+    });
+}
+
+- (void) handleEvent:(mpv_event *)event
+{
+    switch (event->event_id) {
+    case MPV_EVENT_SHUTDOWN: {
+        mpv_detach_destroy(mpv);
+        mpv_opengl_cb_uninit_gl(window.glView.mpvGL);
+        mpv = NULL;
+        printf("event: shutdown\n");
+        break;
+    }
+
+    case MPV_EVENT_LOG_MESSAGE: {
+        struct mpv_event_log_message *msg = (struct mpv_event_log_message *)event->data;
+        printf("[%s] %s: %s", msg->prefix, msg->level, msg->text);
+    }
+
+    default:
+        printf("event: %s\n", mpv_event_name(event->event_id));
+    }
+}
+
+- (void)togglePause:(NSButton *)button
+{
+    if (mpv) {
+        switch (button.state) {
+            case NSOffState:
+                {
+                    int pause = 0;
+                    mpv_set_property(mpv, "pause", MPV_FORMAT_FLAG, &pause);
+                }
+                break;
+            case NSOnState:
+                {
+                    int pause = 1;
+                    mpv_set_property(mpv, "pause", MPV_FORMAT_FLAG, &pause);
+                }
+                break;
+            default:
+                NSLog(@"This should never happen.");
+        }
+    }
+}
+
+- (void) readEvents
+{
+    dispatch_async(queue, ^{
+        while (mpv) {
+            mpv_event *event = mpv_wait_event(mpv, 0);
+            if (event->event_id == MPV_EVENT_NONE)
+                break;
+            [self handleEvent:event];
+        }
+    });
+}
+
+static void wakeup(void *context)
+{
+    AppDelegate *a = (__bridge AppDelegate *) context;
+    [a readEvents];
+}
+
+// quit when the window is closed.
+- (BOOL)applicationShouldTerminateAfterLastWindowClosed:(NSApplication *)app
+{
+    return YES;
+}
+
+- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender
+{
+    NSLog(@"Terminating.");
+    const char *args[] = {"quit", NULL};
+    mpv_command(mpv, args);
+    [window.glView clearGLContext];
+    return NSTerminateNow;
+}
+
+@end
+
+// Delete this if you already have a main.m.
+int main(int argc, const char * argv[]) {
+    @autoreleasepool {
+        NSApplication *app = [NSApplication sharedApplication];
+        AppDelegate *delegate = [AppDelegate new];
+        app.delegate = delegate;
+        [app run];
+    }
+    return 0;
+}