Nuke GLFW from Orbit

This deletes the GLFW apprt from the Ghostty codebase.

The GLFW apprt was the original apprt used by Ghostty (well, before
Ghostty even had the concept of an "apprt" -- it was all just a single
application then). It let me iterate on the core terminal features,
rendering, etc. without bothering about the UI. It was a good way to get
started. But it has long since outlived its usefulness.

We've had a stable GTK apprt for Linux (and Windows via WSL) and a
native macOS app via libghostty for awhile now. The GLFW apprt only
remained within the tree for a few reasons:

  1. Primarily, it provided a faster feedback loop on macOS because
     building the macOS app historically required us to hop out of the
     zig build system and into Xcode, which is slow and cumbersome.

  2. It was a convenient way to narrow whether a bug was in the
     core Ghostty codebase or in the apprt itself. If a bug was in both
     the glfw and macOS app then it was likely in the core.

  3. It provided us a way on macOS to test OpenGL.

All of these reasons are no longer valid. Respectively:

  1. Our Zig build scripts now execute the `xcodebuild` CLI directly and
     can open the resulting app, stream logs, etc. This is the same
     experience we have on Linux. (Xcode has always been a dependency of
     building on macOS in general, so this is not cumbersome.)

  2. We have a healthy group of maintainers, many of which have access
     to both macOS and Linux, so we can quickly narrow down bugs
     regardless of the apprt.

  3. Our OpenGL renderer hasn't been compatible with macOS for some time
     now, so this is no longer a useful feature.

At this point, the GLFW apprt is just a burden. It adds complexity
across the board, and some people try to run Ghostty with it in the real
world and get confused when it doesn't work (it's always been lacking in
features and buggy compared to the other apprts).

So, it's time to say goodbye. Its bittersweet because it is a big part
of Ghostty's history, but we've grown up now and it's time to move on.
Thank you, goodbye.

(NOTE: If you are a user of the GLFW apprt, then please fork the project
prior to this commit or start a new project based on it. We've warned
against using it for a very, very long time now.)

1 files changed, 2 insertions, 43 deletions

diff --git a/src/renderer/OpenGL.zig b/src/renderer/OpenGL.zig
index cf195361e..00df8e273 100644
--- a/src/renderer/OpenGL.zig
+++ b/src/renderer/OpenGL.zig
@@ -5,7 +5,6 @@ const std = @import("std");
 const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
 const builtin = @import("builtin");
-const glfw = @import("glfw");
 const gl = @import("opengl");
 const shadertoy = @import("shadertoy.zig");
 const apprt = @import("../apprt.zig");
@@ -60,18 +59,6 @@ pub fn deinit(self: *OpenGL) void {
     self.* = undefined;
 }
 
-/// Returns the hints that we want for this
-pub fn glfwWindowHints(config: *const configpkg.Config) glfw.Window.Hints {
-    _ = config;
-    return .{
-        .context_version_major = MIN_VERSION_MAJOR,
-        .context_version_minor = MIN_VERSION_MINOR,
-        .opengl_profile = .opengl_core_profile,
-        .opengl_forward_compat = true,
-        .transparent_framebuffer = true,
-    };
-}
-
 /// 32-bit windows cross-compilation breaks with `.c` for some reason, so...
 const gl_debug_proc_callconv =
     @typeInfo(
@@ -172,8 +159,7 @@ fn prepareContext(getProcAddress: anytype) !void {
 
 /// This is called early right after surface creation.
 pub fn surfaceInit(surface: *apprt.Surface) !void {
-    // Treat this like a thread entry
-    const self: OpenGL = undefined;
+    _ = surface;
 
     switch (apprt.runtime) {
         else => @compileError("unsupported app runtime for OpenGL"),
@@ -181,8 +167,6 @@ pub fn surfaceInit(surface: *apprt.Surface) !void {
         // GTK uses global OpenGL context so we load from null.
         apprt.gtk => try prepareContext(null),
 
-        apprt.glfw => try self.threadEnter(surface),
-
         apprt.embedded => {
             // TODO(mitchellh): this does nothing today to allow libghostty
             // to compile for OpenGL targets but libghostty is strictly
@@ -205,17 +189,12 @@ pub fn surfaceInit(surface: *apprt.Surface) !void {
 pub fn finalizeSurfaceInit(self: *const OpenGL, surface: *apprt.Surface) !void {
     _ = self;
     _ = surface;
-
-    // For GLFW, we grabbed the OpenGL context in surfaceInit and
-    // we need to release it before we start the renderer thread.
-    if (apprt.runtime == apprt.glfw) {
-        glfw.makeContextCurrent(null);
-    }
 }
 
 /// Callback called by renderer.Thread when it begins.
 pub fn threadEnter(self: *const OpenGL, surface: *apprt.Surface) !void {
     _ = self;
+    _ = surface;
 
     switch (apprt.runtime) {
         else => @compileError("unsupported app runtime for OpenGL"),
@@ -227,21 +206,6 @@ pub fn threadEnter(self: *const OpenGL, surface: *apprt.Surface) !void {
             // on the main thread. As such, we don't do anything here.
         },
 
-        apprt.glfw => {
-            // We need to make the OpenGL context current. OpenGL requires
-            // that a single thread own the a single OpenGL context (if any).
-            // This ensures that the context switches over to our thread.
-            // Important: the prior thread MUST have detached the context
-            // prior to calling this entrypoint.
-            glfw.makeContextCurrent(surface.window);
-            errdefer glfw.makeContextCurrent(null);
-            glfw.swapInterval(1);
-
-            // Load OpenGL bindings. This API is context-aware so this sets
-            // a threadlocal context for these pointers.
-            try prepareContext(&glfw.getProcAddress);
-        },
-
         apprt.embedded => {
             // TODO(mitchellh): this does nothing today to allow libghostty
             // to compile for OpenGL targets but libghostty is strictly
@@ -262,11 +226,6 @@ pub fn threadExit(self: *const OpenGL) void {
             // be sharing the global bindings with other windows.
         },
 
-        apprt.glfw => {
-            gl.glad.unload();
-            glfw.makeContextCurrent(null);
-        },
-
         apprt.embedded => {
             // TODO: see threadEnter
         },