feat(wayland-egl): 补上客户端做 GPU 渲染的唯一入口

mcpp.toml

@@ -86,6 +86,7 @@ members = [
     "tests/examples/libffi",
     "tests/examples/expat",
     "tests/examples/wayland",
+    "tests/examples/wayland-egl",
     "tests/examples/egl",
     "tests/examples/gl",
     "tests/examples/libevdev",

pkgs/f/freedesktop.wayland-egl.lua

@@ -0,0 +1,51 @@
+-- freedesktop.wayland-egl — libwayland-egl, and the reason a Wayland client
+-- could not use the GPU until now.
+--
+-- A Wayland client that draws with EGL needs three things: a `wl_surface` from
+-- libwayland-client, an `EGLDisplay` from libEGL, and something to join them.
+-- That something is `wl_egl_window_create(surface, w, h)` — the only way to get
+-- an `EGLNativeWindowType` on Wayland, and it lives in this library and nowhere
+-- else. Without it the sequence
+--
+--     wl_surface -> wl_egl_window -> eglCreateWindowSurface -> draw
+--
+-- has no second step.
+--
+-- WHY IT WAS MISSING, since the gap is instructive: the fork built the four
+-- members a COMPOSITOR needs — client, server, util, scanner — and a compositor
+-- renders into GBM buffers, so it never asks for this. The index therefore
+-- looked complete from the server side and was unusable from the client side.
+-- Upstream ships the source in the same tarball (`upstream/egl/`, 118 lines);
+-- this was a member nobody had written, not a decision anyone had made.
+--
+-- ─────────────────────────────────────────────────────────────────────────
+-- FIFTH MEMBER OF THE SAME TARBALL
+--
+-- `freedesktop.wayland`, `-server`, `-util`, `-scanner` and this one are five
+-- index entries backed by ONE archive, each naming a different workspace
+-- member. Adding this one changed the archive, so all five carry the new
+-- sha256 in the same commit — see the note in that commit on why the tag was
+-- left alone and a release ASSET was published instead.
+package = {
+    spec        = "1",
+    namespace   = "freedesktop",
+    name        = "wayland-egl",
+    description = "libwayland-egl 1.26.0 — wl_egl_window, the bridge from a wl_surface to an EGL window surface",
+    licenses    = {"MIT"},
+    repo        = "https://github.com/mcpplibs/wayland",
+    type        = "package",
+
+    xpm = {
+        linux = {
+            ["1.26.0"] = {
+                url = {
+                    GLOBAL = "https://github.com/mcpplibs/wayland/releases/download/v1.26.0/wayland-1.26.0-mcpp2.tar.gz",
+                    CN     = "https://gitcode.com/mcpp-res/wayland/releases/download/1.26.0/wayland-1.26.0-mcpp2.tar.gz",
+                },
+                sha256 = "bcf388cc1dd6617fdce5cb595defbe2aa1fae8db292ca5d7fd84afda2811be32",
+            },
+        },
+    },
+
+    mcpp = "*/mcpp/egl/mcpp.toml",
+}

pkgs/f/freedesktop.wayland-scanner.lua

@@ -33,10 +33,10 @@ package = {
         linux = {
             ["1.26.0"] = {
                 url = {
-                    GLOBAL = "https://github.com/mcpplibs/wayland/archive/refs/tags/v1.26.0.tar.gz",
-                    CN     = "https://gitcode.com/mcpp-res/wayland/releases/download/1.26.0/wayland-1.26.0.tar.gz",
+                    GLOBAL = "https://github.com/mcpplibs/wayland/releases/download/v1.26.0/wayland-1.26.0-mcpp2.tar.gz",
+                    CN     = "https://gitcode.com/mcpp-res/wayland/releases/download/1.26.0/wayland-1.26.0-mcpp2.tar.gz",
                 },
-                sha256 = "961a900dafe76e713c2e46d9a064ff3a6375622f4057013472a04c44d8bcb6e8",
+                sha256 = "bcf388cc1dd6617fdce5cb595defbe2aa1fae8db292ca5d7fd84afda2811be32",
             },
         },
     },

pkgs/f/freedesktop.wayland-server.lua

@@ -33,10 +33,10 @@ package = {
         linux = {
             ["1.26.0"] = {
                 url = {
-                    GLOBAL = "https://github.com/mcpplibs/wayland/archive/refs/tags/v1.26.0.tar.gz",
-                    CN     = "https://gitcode.com/mcpp-res/wayland/releases/download/1.26.0/wayland-1.26.0.tar.gz",
+                    GLOBAL = "https://github.com/mcpplibs/wayland/releases/download/v1.26.0/wayland-1.26.0-mcpp2.tar.gz",
+                    CN     = "https://gitcode.com/mcpp-res/wayland/releases/download/1.26.0/wayland-1.26.0-mcpp2.tar.gz",
                 },
-                sha256 = "961a900dafe76e713c2e46d9a064ff3a6375622f4057013472a04c44d8bcb6e8",
+                sha256 = "bcf388cc1dd6617fdce5cb595defbe2aa1fae8db292ca5d7fd84afda2811be32",
             },
         },
     },

pkgs/f/freedesktop.wayland-util.lua

@@ -33,10 +33,10 @@ package = {
         linux = {
             ["1.26.0"] = {
                 url = {
-                    GLOBAL = "https://github.com/mcpplibs/wayland/archive/refs/tags/v1.26.0.tar.gz",
-                    CN     = "https://gitcode.com/mcpp-res/wayland/releases/download/1.26.0/wayland-1.26.0.tar.gz",
+                    GLOBAL = "https://github.com/mcpplibs/wayland/releases/download/v1.26.0/wayland-1.26.0-mcpp2.tar.gz",
+                    CN     = "https://gitcode.com/mcpp-res/wayland/releases/download/1.26.0/wayland-1.26.0-mcpp2.tar.gz",
                 },
-                sha256 = "961a900dafe76e713c2e46d9a064ff3a6375622f4057013472a04c44d8bcb6e8",
+                sha256 = "bcf388cc1dd6617fdce5cb595defbe2aa1fae8db292ca5d7fd84afda2811be32",
             },
         },
     },

pkgs/f/freedesktop.wayland.lua

@@ -33,10 +33,10 @@ package = {
         linux = {
             ["1.26.0"] = {
                 url = {
-                    GLOBAL = "https://github.com/mcpplibs/wayland/archive/refs/tags/v1.26.0.tar.gz",
-                    CN     = "https://gitcode.com/mcpp-res/wayland/releases/download/1.26.0/wayland-1.26.0.tar.gz",
+                    GLOBAL = "https://github.com/mcpplibs/wayland/releases/download/v1.26.0/wayland-1.26.0-mcpp2.tar.gz",
+                    CN     = "https://gitcode.com/mcpp-res/wayland/releases/download/1.26.0/wayland-1.26.0-mcpp2.tar.gz",
                 },
-                sha256 = "961a900dafe76e713c2e46d9a064ff3a6375622f4057013472a04c44d8bcb6e8",
+                sha256 = "bcf388cc1dd6617fdce5cb595defbe2aa1fae8db292ca5d7fd84afda2811be32",
             },
         },
     },

tests/examples/wayland-egl/mcpp.toml

@@ -0,0 +1,31 @@
+# wayland-egl test member — the client-side GPU path.
+#
+# Its own `[indices]`, for the reason the sibling wayland member documents: the
+# workspace root maps `compat` to this checkout and lookup is BY NAMESPACE, so
+# `freedesktop.*` would otherwise resolve against the published index instead of
+# the packages under test.
+[indices]
+freedesktop = { path = "../../.." }
+
+[package]
+name     = "wayland-egl-tests"
+version  = "0.1.0"
+standard = "c++23"
+
+# ONE package named, and libwayland-client arrives with it.
+#
+# `freedesktop.wayland-egl`'s own manifest declares `freedesktop.wayland` as a
+# PATH dependency — the two are workspace members of the same fork — and naming
+# it here as a version dependency as well is rejected outright:
+#
+#     error: dependency 'freedesktop.wayland' is requested as both a version
+#            dep (by 'wayland-egl-tests') and a path dep (by
+#            'freedesktop.wayland-egl@1.26.0'). Pick one.
+#
+# That is the right diagnostic: two spellings of one dependency could resolve
+# to two different trees. So the client comes in transitively, which is also
+# what a real consumer gets — `wl_egl_window_create` takes a `wl_surface *`
+# that only libwayland-client can produce, so the edge exists whether or not
+# the consumer names it.
+[target.'cfg(linux)'.dependencies.freedesktop]
+wayland-egl = "1.26.0"

tests/examples/wayland-egl/tests/wayland-egl.cpp

@@ -0,0 +1,126 @@
+// freedesktop.wayland-egl — the step that used to be missing.
+//
+// WHAT THIS CAN AND CANNOT ASSERT, decided by what the library actually is.
+//
+// libwayland-egl is 118 lines and holds no connection: `wl_egl_window_create`
+// allocates a struct, stores the `wl_surface *` it was handed, and records a
+// size. It calls no client function and talks to no compositor — an EGL
+// implementation later reads and writes the struct through
+// `wayland-egl-backend.h`.
+//
+// So a CI runner with no compositor can exercise the whole library honestly.
+// What it cannot do is `eglCreateWindowSurface`, which needs a real
+// `wl_display` from a real compositor — asserting that here would only assert
+// that the runner has a desktop session.
+//
+// THE BACKEND HEADER IS INCLUDED ON PURPOSE. `wayland-egl-core.h` exposes four
+// functions and an opaque type, so through it alone the only observable is
+// "create returned non-null". `wayland-egl-backend.h` is the contract this
+// library has with an EGL implementation — Mesa includes it — and reading the
+// struct through it is what lets the test check that create and resize wrote
+// what they claim.
+//
+// The `wl_surface *` is a null pointer ON PURPOSE: upstream stores it without
+// dereferencing (wayland-egl.c:93), so this exercises the real path, and the
+// test can then assert the pointer round-tripped.
+
+#ifdef __linux__
+
+#include <wayland-client.h>
+#include <wayland-egl.h>
+#include <wayland-egl-backend.h>
+
+#include <cstdio>
+#include <cstring>
+
+import freedesktop.wayland.egl;
+
+namespace {
+
+int failures = 0;
+
+void check(bool ok, const char *what)
+{
+    std::printf("%-58s %s\n", what, ok ? "ok" : "FAILED");
+    if (!ok) {
+        ++failures;
+    }
+}
+
+} // namespace
+
+int main()
+{
+    // ── 1. The module carries the API ────────────────────────────────────
+    // Taking the address of each is what makes this a check rather than a
+    // comment: a name that vanished from the module is a compile error here,
+    // which is the guarantee genmod.py gives the client and server wrappers
+    // and that this hand-written module needs by other means.
+    check(&wl_egl_window_create != nullptr,            "module exports wl_egl_window_create");
+    check(&wl_egl_window_destroy != nullptr,           "module exports wl_egl_window_destroy");
+    check(&wl_egl_window_resize != nullptr,            "module exports wl_egl_window_resize");
+    check(&wl_egl_window_get_attached_size != nullptr, "module exports wl_egl_window_get_attached_size");
+
+    // ── 2. The bridge itself ─────────────────────────────────────────────
+    // This is the call that did not exist in this ecosystem before: the only
+    // way to turn a wl_surface into something EGL can render into.
+    wl_egl_window *w = wl_egl_window_create(nullptr, 640, 480);
+    check(w != nullptr, "wl_egl_window_create(surface, 640, 480)");
+    if (w == nullptr) {
+        std::printf("\n%d check(s) failed\n", failures);
+        return 1;
+    }
+
+    // ── 3. It wrote what it was given ────────────────────────────────────
+    // Read back through the backend header, which is how Mesa reads it.
+    // `version` matters most of the three: an EGL implementation switches on
+    // it, and it is the field upstream casts away constness to set.
+    std::printf("   version=%ld  size=%d x %d\n",
+                (long)w->version, w->width, w->height);
+    check(w->version == WL_EGL_WINDOW_VERSION, "…and stamped WL_EGL_WINDOW_VERSION");
+    check(w->width == 640 && w->height == 480, "…and recorded 640 x 480");
+    check(w->surface == nullptr,               "…and round-tripped the wl_surface pointer");
+
+    // ── 4. attached size is 0 BEFORE any EGL implementation attaches ─────
+    // Not an oversight and not the creation size: `attached_width/height` are
+    // written by the EGL side when it attaches a buffer, and `create` calloc's
+    // them to zero. The first version of this test asserted 640 x 480 here and
+    // was wrong — the check now encodes the real contract, which is that a
+    // window nothing has rendered into reports nothing attached.
+    int aw = -1, ah = -1;
+    wl_egl_window_get_attached_size(w, &aw, &ah);
+    std::printf("   attached size before any EGL attach: %d x %d\n", aw, ah);
+    check(aw == 0 && ah == 0, "get_attached_size reports 0 x 0 until EGL attaches");
+
+    // ── 5. Resize is what a client calls on every configure event ────────
+    wl_egl_window_resize(w, 800, 600, 0, 0);
+    check(w->width == 800 && w->height == 600, "wl_egl_window_resize updated the geometry");
+
+    // A rejected resize, which is a real branch: upstream returns early on a
+    // non-positive dimension rather than storing it, so the previous size must
+    // survive. Same guard `create` uses.
+    wl_egl_window_resize(w, 0, 600, 0, 0);
+    check(w->width == 800 && w->height == 600, "…and a width of 0 is refused, not stored");
+
+    wl_egl_window_destroy(w);
+    check(true, "wl_egl_window_destroy");
+
+    // ── 6. create rejects a degenerate size ──────────────────────────────
+    check(wl_egl_window_create(nullptr, 0, 480) == nullptr,
+          "wl_egl_window_create refuses a width of 0");
+
+    // ── 7. The two halves agree on the linkage they share ────────────────
+    // `wl_display_connect` comes from libwayland-client and is NOT in
+    // libwayland-egl — the fork's CI asserts that separation on the library,
+    // and this asserts the consumer side: both are reachable from one program,
+    // which is the arrangement a real client is in.
+    check(&wl_display_connect != nullptr,
+          "libwayland-client is in the same program (wl_display_connect)");
+
+    std::printf("\n%d check(s) failed\n", failures);
+    return failures == 0 ? 0 : 1;
+}
+
+#else
+int main() { return 0; }
+#endif