From c902d6d6a8e5d933f54f8791efa88d545c829188 Mon Sep 17 00:00:00 2001
From: GlassOnTin <GlassOnTin@users.noreply.github.com>
Date: Tue, 31 Mar 2026 00:11:41 +0100
Subject: [PATCH] server: allow external renderer and allocator on Android

On Android, the standard wlr_renderer_autocreate() and
wlr_allocator_autocreate() paths fail because there is no DRM
subsystem. Android apps create EGL contexts via eglGetDisplay()
and provide GPU buffers via AHardwareBuffer.

Add hooks guarded by #ifdef __ANDROID__ that check for externally
provided renderer/allocator globals before falling back to
autocreate. This allows the JNI bridge to:

1. Create an EGL context via Android's native EGL
2. Wrap it in wlr_egl_create_with_context()
3. Create a GLES2 renderer via wlr_gles2_renderer_create()
4. Provide a custom allocator (e.g. AHardwareBuffer-based)

The globals (android_renderer, android_allocator) are declared
extern and only referenced when __ANDROID__ is defined, so there
is no impact on non-Android builds.

Ref: https://github.com/GlassOnTin/Haven/issues/47
---
 src/server.c | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/server.c b/src/server.c
index 653caf59..fe01e271 100644
--- a/src/server.c
+++ b/src/server.c
@@ -502,7 +502,17 @@ server_init(void)
 	 * The renderer is responsible for defining the various pixel formats it
 	 * supports for shared memory, this configures that for clients.
 	 */
-	server.renderer = wlr_renderer_autocreate(server.backend);
+#ifdef __ANDROID__
+	/* Android: accept externally created renderer (e.g. GLES2 via
+	 * eglGetDisplay + wlr_egl_create_with_context) */
+	extern struct wlr_renderer *android_renderer;
+	if (android_renderer) {
+		server.renderer = android_renderer;
+	} else
+#endif
+	{
+		server.renderer = wlr_renderer_autocreate(server.backend);
+	}
 	if (!server.renderer) {
 		wlr_log(WLR_ERROR, "unable to create renderer");
 		exit(EXIT_FAILURE);
@@ -541,8 +551,16 @@ server_init(void)
 	 * the renderer and the backend. It handles the buffer creation,
 	 * allowing wlroots to render onto the screen
 	 */
-	server.allocator = wlr_allocator_autocreate(
-		server.backend, server.renderer);
+#ifdef __ANDROID__
+	extern struct wlr_allocator *android_allocator;
+	if (android_allocator) {
+		server.allocator = android_allocator;
+	} else
+#endif
+	{
+		server.allocator = wlr_allocator_autocreate(
+			server.backend, server.renderer);
+	}
 	if (!server.allocator) {
 		wlr_log(WLR_ERROR, "unable to create allocator");
 		exit(EXIT_FAILURE);