Don't forget to transform coordinates for the grab surface.
diff --git a/wayland-system-compositor.c b/wayland-system-compositor.c
index 9ba4ea3..90d61bf 100644
--- a/wayland-system-compositor.c
+++ b/wayland-system-compositor.c
@@ -849,14 +849,26 @@
compositor_commit
};
+static void
+wlsc_surface_transform(struct wlsc_surface *surface,
+ int32_t x, int32_t y, int32_t *sx, int32_t *sy)
+{
+ /* Transform to surface coordinates. */
+ *sx = (x - surface->map.x) * surface->width / surface->map.width;
+ *sy = (y - surface->map.y) * surface->height / surface->map.height;
+}
+
static struct wlsc_surface *
pick_surface(struct wlsc_input_device *device, int32_t *sx, int32_t *sy)
{
struct wlsc_compositor *ec = device->ec;
struct wlsc_surface *es;
- if (device->grab > 0)
+ if (device->grab > 0) {
+ wlsc_surface_transform(device->grab_surface,
+ device->x, device->y, sx, sy);
return device->grab_surface;
+ }
es = container_of(ec->surface_list.prev,
struct wlsc_surface, link);
@@ -865,10 +877,7 @@
device->x < es->map.x + es->map.width &&
es->map.y <= device->y &&
device->y < es->map.y + es->map.height) {
- /* Transform to surface coordinates. */
- *sx = (device->x - es->map.x) * es->width / es->map.width;
- *sy = (device->y - es->map.y) * es->height / es->map.height;
-
+ wlsc_surface_transform(es, device->x, device->y, sx, sy);
return es;
}