From c2359d0321e03606ca7e2b69b69170fca4c4009a Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Tue, 29 Jun 2021 13:32:07 +0200
Subject: [PATCH] surface: implement wl_surface.offset

References: https://gitlab.freedesktop.org/wayland/wayland/-/merge_requests/123
---
 types/wlr_compositor.c | 33 +++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/types/wlr_compositor.c b/types/wlr_compositor.c
index f76e920a..331d932d 100644
--- a/types/wlr_compositor.c
+++ b/types/wlr_compositor.c
@@ -15,7 +15,7 @@
 #include "util/signal.h"
 #include "util/time.h"
 
-#define COMPOSITOR_VERSION 4
+#define COMPOSITOR_VERSION 5
 #define CALLBACK_VERSION 1
 
 static int min(int fst, int snd) {
@@ -44,6 +44,14 @@ static void surface_handle_attach(struct wl_client *client,
 		struct wl_resource *buffer_resource, int32_t dx, int32_t dy) {
 	struct wlr_surface *surface = wlr_surface_from_resource(resource);
 
+	if (wl_resource_get_version(resource) >= WL_SURFACE_OFFSET_SINCE_VERSION &&
+			(dx != 0 || dy != 0)) {
+		wl_resource_post_error(resource, WL_SURFACE_ERROR_INVALID_OFFSET,
+			"Offset must be zero on wl_surface.attach version >= %"PRIu32,
+			WL_SURFACE_OFFSET_SINCE_VERSION);
+		return;
+	}
+
 	struct wlr_buffer *buffer = NULL;
 	if (buffer_resource != NULL) {
 		buffer = wlr_buffer_from_resource(buffer_resource);
@@ -53,13 +61,16 @@ static void surface_handle_attach(struct wl_client *client,
 		}
 	}
 
-	surface->pending.committed |=
-		WLR_SURFACE_STATE_BUFFER | WLR_SURFACE_STATE_OFFSET;
-	surface->pending.dx = dx;
-	surface->pending.dy = dy;
+	surface->pending.committed |= WLR_SURFACE_STATE_BUFFER;
 
 	wlr_buffer_unlock(surface->pending.buffer);
 	surface->pending.buffer = buffer;
+
+	if (wl_resource_get_version(resource) < WL_SURFACE_OFFSET_SINCE_VERSION) {
+		surface->pending.committed |= WLR_SURFACE_STATE_OFFSET;
+		surface->pending.dx = dx;
+		surface->pending.dy = dy;
+	}
 }
 
 static void surface_handle_damage(struct wl_client *client,
@@ -578,6 +589,15 @@ static void surface_handle_damage_buffer(struct wl_client *client,
 		x, y, width, height);
 }
 
+static void surface_handle_offset(struct wl_client *client,
+		struct wl_resource *resource, int32_t x, int32_t y) {
+	struct wlr_surface *surface = wlr_surface_from_resource(resource);
+
+	surface->pending.committed |= WLR_SURFACE_STATE_OFFSET;
+	surface->pending.dx = x;
+	surface->pending.dy = y;
+}
+
 static const struct wl_surface_interface surface_implementation = {
 	.destroy = surface_handle_destroy,
 	.attach = surface_handle_attach,
@@ -588,7 +608,8 @@ static const struct wl_surface_interface surface_implementation = {
 	.commit = surface_handle_commit,
 	.set_buffer_transform = surface_handle_set_buffer_transform,
 	.set_buffer_scale = surface_handle_set_buffer_scale,
-	.damage_buffer = surface_handle_damage_buffer
+	.damage_buffer = surface_handle_damage_buffer,
+	.offset = surface_handle_offset,
 };
 
 struct wlr_surface *wlr_surface_from_resource(struct wl_resource *resource) {