1 files changed, 348 insertions, 0 deletions
diff --git a/third_party/rust/khronos-egl/examples/wayland-dynamic.rs b/third_party/rust/khronos-egl/examples/wayland-dynamic.rs
new file mode 100644
index 0000000000..cb9748cb68
--- /dev/null
+++ b/third_party/rust/khronos-egl/examples/wayland-dynamic.rs
@@ -0,0 +1,348 @@
+extern crate gl;
+extern crate khronos_egl as egl;
+extern crate wayland_client;
+extern crate wayland_egl;
+extern crate wayland_protocols;
+extern crate libloading;
+
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::ptr;
+use std::ffi::CStr;
+use gl::types::{GLint, GLuint, GLchar, GLenum, GLboolean, GLvoid};
+
+use wayland_client::{
+	protocol::{wl_compositor::WlCompositor, wl_surface::WlSurface},
+	DispatchData, Display, EventQueue, Main
+};
+
+use wayland_protocols::xdg_shell::client::{
+	xdg_surface::{self, XdgSurface},
+	xdg_wm_base::{self, XdgWmBase},
+};
+
+fn process_xdg_event(xdg: Main<XdgWmBase>, event: xdg_wm_base::Event, _dd: DispatchData) {
+	use xdg_wm_base::Event::*;
+
+	match event {
+		Ping { serial } => xdg.pong(serial),
+		_ => (),
+	}
+}
+
+struct DisplayConnection {
+	display: Display,
+	event_queue: EventQueue,
+	compositor: Main<WlCompositor>,
+	xdg: Main<XdgWmBase>,
+}
+
+fn setup_wayland() -> DisplayConnection {
+	let display =
+		wayland_client::Display::connect_to_env().expect("unable to connect to the wayland server");
+	let mut event_queue = display.create_event_queue();
+	let attached_display = display.clone().attach(event_queue.token());
+
+	let globals = wayland_client::GlobalManager::new(&attached_display);
+
+	// Roundtrip to retrieve the globals list
+	event_queue
+		.sync_roundtrip(&mut (), |_, _, _| unreachable!())
+		.unwrap();
+
+	// Get the compositor.
+	let compositor: Main<WlCompositor> = globals.instantiate_exact(1).unwrap();
+
+	// Xdg protocol.
+	let xdg: Main<XdgWmBase> = globals.instantiate_exact(1).unwrap();
+	xdg.quick_assign(process_xdg_event);
+
+	DisplayConnection {
+		display,
+		event_queue,
+		compositor,
+		xdg,
+	}
+}
+
+fn setup_egl(egl: &egl::DynamicInstance, display: &Display) -> egl::Display {
+	let egl_display = egl.get_display(display.get_display_ptr() as *mut std::ffi::c_void).unwrap();
+	egl.initialize(egl_display).unwrap();
+
+	egl_display
+}
+
+fn create_context(egl: &egl::DynamicInstance, display: egl::Display) -> (egl::Context, egl::Config) {
+	let attributes = [
+		egl::RED_SIZE,
+		8,
+		egl::GREEN_SIZE,
+		8,
+		egl::BLUE_SIZE,
+		8,
+		egl::NONE,
+	];
+
+	let config = egl.choose_first_config(display, &attributes)
+		.expect("unable to choose an EGL configuration")
+		.expect("no EGL configuration found");
+
+	let context_attributes = [
+		egl::CONTEXT_MAJOR_VERSION,
+		4,
+		egl::CONTEXT_MINOR_VERSION,
+		0,
+		egl::CONTEXT_OPENGL_PROFILE_MASK,
+		egl::CONTEXT_OPENGL_CORE_PROFILE_BIT,
+		egl::NONE,
+	];
+
+	let context = egl.create_context(display, config, None, &context_attributes)
+		.expect("unable to create an EGL context");
+
+	(context, config)
+}
+
+struct Surface {
+	handle: Main<WlSurface>,
+	initialized: AtomicBool
+}
+
+fn create_surface(
+	egl: &Arc<egl::DynamicInstance>,
+	ctx: &DisplayConnection,
+	egl_display: egl::Display,
+	egl_context: egl::Context,
+	egl_config: egl::Config,
+	width: i32,
+	height: i32,
+) -> Arc<Surface> {
+	let wl_surface = ctx.compositor.create_surface();
+	let xdg_surface = ctx.xdg.get_xdg_surface(&wl_surface);
+
+	let xdg_toplevel = xdg_surface.get_toplevel();
+	xdg_toplevel.set_app_id("khronos-egl-test".to_string());
+	xdg_toplevel.set_title("Test".to_string());
+
+	wl_surface.commit();
+	ctx.display.flush().unwrap();
+
+	let surface = Arc::new(Surface {
+		handle: wl_surface,
+		initialized: AtomicBool::new(false)
+	});
+
+	let weak_surface = Arc::downgrade(&surface);
+
+	let egl = egl.clone();
+	xdg_surface.quick_assign(move |xdg_surface: Main<XdgSurface>, event: xdg_surface::Event, _dd: DispatchData| {
+		use xdg_surface::Event::*;
+
+		match event {
+			Configure { serial } => {
+				if let Some(surface) = weak_surface.upgrade() {
+					if !surface.initialized.swap(true, Ordering::Relaxed) {
+						let wl_egl_surface = wayland_egl::WlEglSurface::new(&surface.handle, width, height);
+
+						let egl_surface = unsafe {
+							egl.create_window_surface(
+								egl_display,
+								egl_config,
+								wl_egl_surface.ptr() as egl::NativeWindowType,
+								None,
+							)
+							.expect("unable to create an EGL surface")
+						};
+
+						egl.make_current(egl_display, Some(egl_surface), Some(egl_surface), Some(egl_context))
+							.expect("unable to bind the context");
+
+						render();
+
+						egl.swap_buffers(egl_display, egl_surface)
+							.expect("unable to post the surface content");
+
+						xdg_surface.ack_configure(serial);
+					}
+				}
+			},
+			_ => (),
+		}
+	});
+
+	surface
+}
+
+fn main() {
+	let egl = unsafe { Arc::new(egl::DynamicInstance::<egl::EGL1_5>::load_required().expect("unable to load libEGL.so.1")) };
+
+	// Setup Open GL.
+	egl.bind_api(egl::OPENGL_API)
+		.expect("unable to select OpenGL API");
+	gl::load_with(|name| egl.get_proc_address(name).unwrap() as *const std::ffi::c_void);
+
+	// Setup the Wayland client.
+	let mut ctx = setup_wayland();
+
+	// Setup EGL.
+	let egl_display = setup_egl(&egl, &ctx.display);
+	let (egl_context, egl_config) = create_context(&egl, egl_display);
+
+	// Create a surface.
+	// Note that it must be kept alive to the end of execution.
+	let _surface = create_surface(&egl, &ctx, egl_display, egl_context, egl_config, 800, 600);
+
+	loop {
+		ctx.event_queue
+			.dispatch(&mut (), |_, _, _| { /* we ignore unfiltered messages */ })
+			.unwrap();
+	}
+}
+
+const VERTEX: &'static [GLint; 8] = &[
+	-1, -1,
+	1, -1,
+	1, 1,
+	-1, 1
+];
+
+const INDEXES: &'static [GLuint; 4] = &[
+	0, 1, 2, 3
+];
+
+const VERTEX_SHADER: &[u8] = b"#version 400
+in vec2 position;
+
+void main() {
+	gl_Position = vec4(position, 0.0f, 1.0f);
+}
+\0";
+
+const FRAGMENT_SHADER: &[u8] = b"#version 400
+out vec4 color;
+
+void main() {
+	color = vec4(1.0f, 0.0f, 0.0f, 1.0f);
+}
+\0";
+
+fn render() {
+	unsafe {
+		let vertex_shader = gl::CreateShader(gl::VERTEX_SHADER);
+		check_gl_errors();
+		let src = CStr::from_bytes_with_nul_unchecked(VERTEX_SHADER).as_ptr();
+		gl::ShaderSource(vertex_shader, 1, (&[src]).as_ptr(), ptr::null());
+		check_gl_errors();
+		gl::CompileShader(vertex_shader);
+		check_shader_status(vertex_shader);
+
+		let fragment_shader = gl::CreateShader(gl::FRAGMENT_SHADER);
+		check_gl_errors();
+		let src = CStr::from_bytes_with_nul_unchecked(FRAGMENT_SHADER).as_ptr();
+		gl::ShaderSource(fragment_shader, 1, (&[src]).as_ptr(), ptr::null());
+		check_gl_errors();
+		gl::CompileShader(fragment_shader);
+		check_shader_status(fragment_shader);
+
+		let program = gl::CreateProgram();
+		check_gl_errors();
+		gl::AttachShader(program, vertex_shader);
+		check_gl_errors();
+		gl::AttachShader(program, fragment_shader);
+		check_gl_errors();
+		gl::LinkProgram(program);
+		check_gl_errors();
+		gl::UseProgram(program);
+		check_gl_errors();
+
+		let mut buffer = 0;
+		gl::GenBuffers(1, &mut buffer);
+		check_gl_errors();
+		gl::BindBuffer(gl::ARRAY_BUFFER, buffer);
+		check_gl_errors();
+		gl::BufferData(
+			gl::ARRAY_BUFFER,
+			8 * 4,
+			VERTEX.as_ptr() as *const std::ffi::c_void,
+			gl::STATIC_DRAW
+		);
+		check_gl_errors();
+
+		let mut vertex_input = 0;
+		gl::GenVertexArrays(1, &mut vertex_input);
+		check_gl_errors();
+		gl::BindVertexArray(vertex_input);
+		check_gl_errors();
+		gl::EnableVertexAttribArray(0);
+		check_gl_errors();
+		gl::VertexAttribPointer(
+			0, 2, gl::INT, gl::FALSE as GLboolean, 0, 0 as *const GLvoid
+		);
+		check_gl_errors();
+
+		let mut indexes = 0;
+		gl::GenBuffers(1, &mut indexes);
+		check_gl_errors();
+		gl::BindBuffer(gl::ELEMENT_ARRAY_BUFFER, indexes);
+		check_gl_errors();
+		gl::BufferData(
+			gl::ELEMENT_ARRAY_BUFFER,
+			4 * 4,
+			INDEXES.as_ptr() as *const std::ffi::c_void,
+			gl::STATIC_DRAW
+		);
+		check_gl_errors();
+
+		gl::DrawElements(gl::TRIANGLE_FAN, 4, gl::UNSIGNED_INT, std::ptr::null());
+		check_gl_errors();
+	}
+}
+
+fn format_error(e: GLenum) -> &'static str {
+	 match e {
+		  gl::NO_ERROR => "No error",
+		  gl::INVALID_ENUM => "Invalid enum",
+		  gl::INVALID_VALUE => "Invalid value",
+		  gl::INVALID_OPERATION => "Invalid operation",
+		  gl::INVALID_FRAMEBUFFER_OPERATION => "Invalid framebuffer operation",
+		  gl::OUT_OF_MEMORY => "Out of memory",
+		  gl::STACK_UNDERFLOW => "Stack underflow",
+		  gl::STACK_OVERFLOW => "Stack overflow",
+		  _ => "Unknown error"
+	 }
+}
+
+pub fn check_gl_errors() {
+	 unsafe {
+		  match gl::GetError() {
+				gl::NO_ERROR => (),
+				e => {
+					panic!("OpenGL error: {}", format_error(e))
+				}
+		  }
+	 }
+}
+
+unsafe fn check_shader_status(shader: GLuint) {
+	let mut status = gl::FALSE as GLint;
+	gl::GetShaderiv(shader, gl::COMPILE_STATUS, &mut status);
+	if status != (gl::TRUE as GLint) {
+		let mut len = 0;
+		gl::GetProgramiv(shader, gl::INFO_LOG_LENGTH, &mut len);
+		if len > 0 {
+			let mut buf = Vec::with_capacity(len as usize);
+			buf.set_len((len as usize) - 1); // subtract 1 to skip the trailing null character
+			gl::GetProgramInfoLog(
+				shader,
+				len,
+				ptr::null_mut(),
+				buf.as_mut_ptr() as *mut GLchar,
+			);
+
+			let log = String::from_utf8(buf).unwrap();
+			eprintln!("shader compilation log:\n{}", log);
+		}
+
+		panic!("shader compilation failed");
+	}
+}