macos support

Cargo.toml

@@ -16,6 +16,11 @@ winapi = { version = "0.3.8", features = ["libloaderapi", "minwindef", "windef",
 [target.'cfg(target_os="linux")'.dependencies]
 x11 = { version = "2.3", features = ["xlib", "glx"] }
 
+[target.'cfg(target_os="macos")'.dependencies]
+cocoa = "0.24.0"
+objc = "0.2.7"
+core-foundation = "0.9.1"
+
 [dev-dependencies]
 gl = "0.14.0"
 winit = "0.22.2"

src/macos.rs

@@ -1,9 +1,103 @@
-use raw_window_handle::HasRawWindowHandle;
+use std::ffi::c_void;
+use std::str::FromStr;
 
-pub struct GlContext {}
+use raw_window_handle::{HasRawWindowHandle, RawWindowHandle};
+
+use cocoa::appkit::{
+    NSOpenGLContext, NSOpenGLPFAAccelerated, NSOpenGLPFAAlphaSize, NSOpenGLPFAColorSize,
+    NSOpenGLPFADoubleBuffer, NSOpenGLPFAOpenGLProfile, NSOpenGLPixelFormat,
+    NSOpenGLProfileVersion3_2Core, NSOpenGLView, NSView,
+};
+use cocoa::base::{id, nil, YES};
+use cocoa::foundation::NSAutoreleasePool;
+
+use core_foundation::base::TCFType;
+use core_foundation::bundle::{CFBundleGetBundleWithIdentifier, CFBundleGetFunctionPointerForName};
+use core_foundation::string::CFString;
+
+use objc::{msg_send, sel, sel_impl};
+
+pub struct GlContext {
+    view: id,
+    context: id,
+}
 
 impl GlContext {
-    pub fn create(parent: &impl HasRawWindowHandle) -> GlContext {
-        GlContext {}
+    pub fn create(parent: &impl HasRawWindowHandle) -> Result<GlContext, ()> {
+        let handle = if let RawWindowHandle::MacOS(handle) = parent.raw_window_handle() {
+            handle
+        } else {
+            return Err(());
+        };
+
+        if handle.ns_view.is_null() {
+            return Err(());
+        }
+
+        let parent_view = handle.ns_view as id;
+
+        unsafe {
+            #[rustfmt::skip]
+            let pixel_format = NSOpenGLPixelFormat::alloc(nil).initWithAttributes_(&[
+                NSOpenGLPFAOpenGLProfile as u32, NSOpenGLProfileVersion3_2Core as u32,
+                NSOpenGLPFAColorSize as u32, 24u32,
+                NSOpenGLPFAAlphaSize as u32, 8u32,
+                NSOpenGLPFADoubleBuffer as u32, NSOpenGLPFAAccelerated as u32,
+                0u32,
+            ]);
+
+            let view = NSOpenGLView::alloc(nil)
+                .initWithFrame_pixelFormat_(parent_view.frame(), pixel_format);
+
+            let () = msg_send![view, retain];
+            NSOpenGLView::display_(view);
+            parent_view.addSubview_(view);
+
+            let context: id = msg_send![view, openGLContext];
+            let () = msg_send![context, retain];
+
+            let () = msg_send![pixel_format, release];
+
+            Ok(GlContext { view, context })
+        }
+    }
+
+    pub fn make_current(&self) {
+        unsafe {
+            self.context.makeCurrentContext();
+        }
+    }
+
+    pub fn make_not_current(&self) {
+        unsafe {
+            NSOpenGLContext::clearCurrentContext(self.context);
+        }
+    }
+
+    pub fn get_proc_address(&self, symbol: &str) -> *const c_void {
+        let symbol_name = CFString::from_str(symbol).unwrap();
+        let framework_name = CFString::from_str("com.apple.opengl").unwrap();
+        let framework =
+            unsafe { CFBundleGetBundleWithIdentifier(framework_name.as_concrete_TypeRef()) };
+        let addr = unsafe {
+            CFBundleGetFunctionPointerForName(framework, symbol_name.as_concrete_TypeRef())
+        };
+        addr as *const c_void
+    }
+
+    pub fn swap_buffers(&self) {
+        unsafe {
+            self.context.flushBuffer();
+            let () = msg_send![self.view, setNeedsDisplay: YES];
+        }
+    }
+}
+
+impl Drop for GlContext {
+    fn drop(&mut self) {
+        unsafe {
+            let () = msg_send![self.context, release];
+            let () = msg_send![self.view, release];
+        }
     }
 }