cocoa-cb: initial implementation via opengl-cb API

this is meant to replace the old and not properly working vo_gpu/opengl
cocoa backend in the future. the problems are various shortcomings of
Apple's opengl implementation and buggy behaviour in certain
circumstances that couldn't be properly worked around. there are also
certain regressions on newer macOS versions from 10.11 onwards.

- awful opengl performance with a none layer backed context
- huge amount of dropped frames with an early context flush
- flickering of system elements like the dock or volume indicator
- double buffering not properly working with a none layer backed context
- bad performance in fullscreen because of system optimisations

all the problems were caused by using a normal opengl context, that
seems somewhat abandoned by apple, and are fixed by using a layer backed
opengl context instead. problems that couldn't be fixed could be
properly worked around.

this has all features our old backend has sans the wid embedding,
the possibility to disable the automatic GPU switching and taking
screenshots of the window content. the first was deemed unnecessary by
me for now, since i just use the libmpv API that others can use anyway.
second is technically not possible atm because we have to pre-allocate
our opengl context at a time the config isn't read yet, so we can't get
the needed property. third one is a bit tricky because of deadlocking
and it needed to be in sync, hopefully i can work around that in the
future.

this also has at least one additional feature or eye-candy. a properly
working fullscreen animation with the native fs. also since this is a
direct port of the old backend of the parts that could be used, though
with adaptions and improvements, this looks a lot cleaner and easier to
understand.

some credit goes to @pigoz for the initial swift build support which
i could improve upon.

Fixes: #5478, #5393, #5152, #5151, #4615, #4476, #3978, #3746, #3739,
#2392, #2217

1 files changed, 255 insertions, 0 deletions

diff --git a/osdep/macOS_mpv_helper.swift b/osdep/macOS_mpv_helper.swift
new file mode 100644
index 0000000000..39be9cc8c7
--- /dev/null
+++ b/osdep/macOS_mpv_helper.swift
@@ -0,0 +1,255 @@
+/*
+ * This file is part of mpv.
+ *
+ * mpv is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * mpv is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import Cocoa
+import OpenGL.GL
+import OpenGL.GL3
+
+class MPVHelper: NSObject {
+
+    var mpvHandle: OpaquePointer?
+    var mpvGLCBContext: OpaquePointer?
+    var mpvLog: OpaquePointer?
+    var inputContext: OpaquePointer?
+    var mpctx: UnsafeMutablePointer<MPContext>?
+
+    init(_ mpv: OpaquePointer) {
+        super.init()
+        mpvHandle = mpv
+        mpvLog = mp_log_new(UnsafeMutablePointer<MPContext>(mpvHandle),
+                            mp_client_get_log(mpvHandle), "cocoacb")
+        mpctx = UnsafeMutablePointer<MPContext>(mp_client_get_core(mpvHandle))
+        inputContext = mpctx!.pointee.input
+
+        mpv_observe_property(mpvHandle, 0, "ontop", MPV_FORMAT_FLAG)
+        mpv_observe_property(mpvHandle, 0, "border", MPV_FORMAT_FLAG)
+        mpv_observe_property(mpvHandle, 0, "keepaspect-window", MPV_FORMAT_FLAG)
+    }
+
+    func setGLCB() {
+        if mpvHandle == nil {
+            sendError("No mpv handle available.")
+            exit(1)
+        }
+        mpvGLCBContext = OpaquePointer(mp_get_sub_api2(mpvHandle, MPV_SUB_API_OPENGL_CB, false))
+        if mpvGLCBContext == nil {
+            sendError("libmpv does not have the opengl-cb sub-API.")
+            exit(1)
+        }
+    }
+
+    func initGLCB() {
+        if mpvGLCBContext == nil {
+            setGLCB()
+        }
+        if mpv_opengl_cb_init_gl(mpvGLCBContext, nil, getProcAddress, nil) < 0 {
+            sendError("GL init has failed.")
+            exit(1)
+        }
+    }
+
+    let getProcAddress: mpv_opengl_cb_get_proc_address_fn = {
+            (ctx: UnsafeMutableRawPointer?, name: UnsafePointer<Int8>?) -> UnsafeMutableRawPointer? in
+        let symbol: CFString = CFStringCreateWithCString(
+                                kCFAllocatorDefault, name, kCFStringEncodingASCII)
+        let indentifier = CFBundleGetBundleWithIdentifier("com.apple.opengl" as CFString)
+        let addr = CFBundleGetFunctionPointerForName(indentifier, symbol)
+
+        if symbol as String == "glFlush" {
+            return glDummyPtr()
+        }
+
+        return addr
+    }
+
+    func setGLCBUpdateCallback(_ callback: @escaping mpv_opengl_cb_update_fn, context object: AnyObject) {
+        if mpvGLCBContext == nil {
+            sendWarning("Init mpv opengl-cb first.")
+        } else {
+            mpv_opengl_cb_set_update_callback(mpvGLCBContext, callback, MPVHelper.bridge(obj: object))
+        }
+    }
+
+    func setGLCBControlCallback(_ callback: @escaping mpv_opengl_cb_control_fn, context object: AnyObject) {
+        if mpvGLCBContext == nil {
+            sendWarning("Init mpv opengl-cb first.")
+        } else {
+            mp_client_set_control_callback(mpvGLCBContext, callback, MPVHelper.bridge(obj: object))
+        }
+    }
+
+    func reportGLCBFlip() {
+        if mpvGLCBContext == nil { return }
+            mpv_opengl_cb_report_flip(mpvGLCBContext, 0)
+    }
+
+    func drawGLCB(_ surface: NSSize) {
+        if mpvGLCBContext != nil {
+            var i: GLint = 0
+            glGetIntegerv(GLenum(GL_DRAW_FRAMEBUFFER_BINDING), &i)
+
+            mpv_opengl_cb_draw(mpvGLCBContext, i, Int32(surface.width), Int32(-surface.height))
+        } else {
+            glClearColor(0, 0, 0, 1)
+            glClear(GLbitfield(GL_COLOR_BUFFER_BIT))
+        }
+    }
+
+    func setGLCBICCProfile(_ profile: NSColorSpace) {
+        if mpvGLCBContext == nil { return }
+        var iccData = profile.iccProfileData
+        iccData!.withUnsafeMutableBytes { (u8Ptr: UnsafeMutablePointer<UInt8>) in
+            let icc = bstrdup(nil, bstr(start: u8Ptr, len: iccData!.count))
+            mp_client_set_icc_profile(mpvGLCBContext, icc)
+        }
+    }
+
+    func setGLCBLux(_ lux: Int) {
+        if mpvGLCBContext == nil { return }
+        mp_client_set_ambient_lux(mpvGLCBContext, Int32(lux))
+    }
+
+    func command(_ cmd: String) {
+        if mpvHandle == nil { return }
+        mpv_command_string(mpvHandle, cmd)
+    }
+
+    func commandAsync(_ cmd: [String?], id: UInt64 = 1) {
+        if mpvHandle == nil { return }
+        var mCmd = cmd
+        mCmd.append(nil)
+        var cargs = mCmd.map { $0.flatMap { UnsafePointer<Int8>(strdup($0)) } }
+        mpv_command_async(mpvHandle, id, &cargs)
+        for ptr in cargs { free(UnsafeMutablePointer(mutating: ptr)) }
+    }
+
+    func getBoolProperty(_ name: String) -> Bool {
+        if mpvHandle == nil { return false }
+        var value = Int32()
+        mpv_get_property(mpvHandle, name, MPV_FORMAT_FLAG, &value)
+        return value > 0
+    }
+
+    func getIntProperty(_ name: String) -> Int {
+        if mpvHandle == nil { return 0 }
+        var value = Int64()
+        mpv_get_property(mpvHandle, name, MPV_FORMAT_INT64, &value)
+        return Int(value)
+    }
+
+    func getStringProperty(_ name: String) -> String? {
+        if mpvHandle == nil { return nil }
+        let value = mpv_get_property_string(mpvHandle, name)
+        let str = value == nil ? nil : String(cString: value!)
+        mpv_free(value)
+        return str
+    }
+
+    func canBeDraggedAt(_ pos: NSPoint) -> Bool {
+        if inputContext == nil { return false }
+        let canDrag = !mp_input_test_dragging(inputContext!, Int32(pos.x), Int32(pos.y))
+        return canDrag
+    }
+
+    func setMousePosition(_ pos: NSPoint) {
+        if inputContext == nil { return }
+        mp_input_set_mouse_pos(inputContext!, Int32(pos.x), Int32(pos.y))
+    }
+
+    func putAxis(_ mpkey: Int32, delta: Double) {
+        if inputContext == nil { return }
+        mp_input_put_wheel(inputContext!, mpkey, delta)
+    }
+
+    func sendVerbose(_ msg: String) {
+        send(message: msg, type: MSGL_V)
+    }
+
+    func sendInfo(_ msg: String) {
+        send(message: msg, type: MSGL_INFO)
+    }
+
+    func sendWarning(_ msg: String) {
+        send(message: msg, type: MSGL_WARN)
+    }
+
+    func sendError(_ msg: String) {
+        send(message: msg, type: MSGL_ERR)
+    }
+
+    func send(message msg: String, type t: Int) {
+        if mpvLog == nil {
+            sendFallback(message: msg, type: t)
+        } else {
+            let args: [CVarArg] = [ (msg as NSString).utf8String! ]
+            mp_msg_va(mpvLog, Int32(t), "%s\n", getVaList(args))
+        }
+    }
+
+    func sendFallback(message msg: String, type t: Int) {
+        var level = "\u{001B}"
+        switch t {
+        case MSGL_V:
+            level += "[0;30m[VERBOSE]"
+        case MSGL_INFO:
+            level += "[0;30m[INFO]"
+        case MSGL_WARN:
+            level += "[0;33m"
+        case MSGL_ERR:
+            level += "[0;31m"
+        default:
+            level += "[0;30m"
+        }
+
+        print("\(level)[osx/cocoacb] \(msg)\u{001B}[0;30m")
+    }
+
+    func deinitGLCB() {
+        mpv_opengl_cb_set_update_callback(mpvGLCBContext, nil, nil)
+        mp_client_set_control_callback(mpvGLCBContext, nil, nil)
+        mpv_opengl_cb_uninit_gl(mpvGLCBContext)
+        mpvGLCBContext = nil
+    }
+
+    func deinitMPV() {
+        mpvHandle = nil
+        mpvLog = nil
+        inputContext = nil
+        mpctx = nil
+    }
+
+    // (__bridge void*)
+    class func bridge<T: AnyObject>(obj: T) -> UnsafeMutableRawPointer {
+        return UnsafeMutableRawPointer(Unmanaged.passUnretained(obj).toOpaque())
+    }
+
+    // (__bridge T*)
+    class func bridge<T: AnyObject>(ptr: UnsafeRawPointer) -> T {
+        return Unmanaged<T>.fromOpaque(ptr).takeUnretainedValue()
+    }
+
+    // *(char **) MPV_FORMAT_STRING on mpv_event_property
+    class func mpvStringArrayToString(_ obj: UnsafeMutableRawPointer) -> String? {
+        let cstr = UnsafeMutablePointer<UnsafeMutablePointer<Int8>>(OpaquePointer(obj))
+        return String(cString: cstr[0])
+    }
+
+    // MPV_FORMAT_FLAG
+    class func mpvFlagToBool(_ obj: UnsafeMutableRawPointer) -> Bool? {
+        return UnsafePointer<Bool>(OpaquePointer(obj))?.pointee
+    }
+}