GHOST/Wayland: support for cursor warp with hidden/wrapped grab enabled

As grab already uses it's own virtual coordinates, cursor warping can
be used when grab is enabled.

Currently nothing depends on this however it could be useful in future.

1 files changed, 58 insertions, 18 deletions

diff --git a/intern/ghost/intern/GHOST_SystemWayland.cpp b/intern/ghost/intern/GHOST_SystemWayland.cpp
index 78d2773c0c1..8e3ca59cc74 100644
--- a/intern/ghost/intern/GHOST_SystemWayland.cpp
+++ b/intern/ghost/intern/GHOST_SystemWayland.cpp
@@ -620,24 +620,17 @@ static const std::vector<std::string> mime_send = {
  * an event is received from the compositor.
  * \{ */
 
-static void relative_pointer_handle_relative_motion(
-    void *data,
-    struct zwp_relative_pointer_v1 * /*zwp_relative_pointer_v1*/,
-    const uint32_t /*utime_hi*/,
-    const uint32_t /*utime_lo*/,
-    const wl_fixed_t dx,
-    const wl_fixed_t dy,
-    const wl_fixed_t /*dx_unaccel*/,
-    const wl_fixed_t /*dy_unaccel*/)
+/**
+ * The caller is responsible for setting the value of `input->xy`.
+ */
+static void relative_pointer_handle_relative_motion_impl(input_t *input,
+                                                         GHOST_WindowWayland *win,
+                                                         const wl_fixed_t xy[2])
 {
-  input_t *input = static_cast<input_t *>(data);
-  GHOST_WindowWayland *win = window_from_surface(input->focus_pointer);
-  if (!win) {
-    return;
-  }
   const wl_fixed_t scale = win->scale();
-  input->xy[0] += dx / scale;
-  input->xy[1] += dy / scale;
+
+  input->xy[0] = xy[0];
+  input->xy[1] = xy[1];
 
 #ifdef USE_GNOME_CONFINE_HACK
   if (input->xy_software_confine) {
@@ -662,6 +655,29 @@ static void relative_pointer_handle_relative_motion(
                                                  GHOST_TABLET_DATA_NONE));
 }
 
+static void relative_pointer_handle_relative_motion(
+    void *data,
+    struct zwp_relative_pointer_v1 * /*zwp_relative_pointer_v1*/,
+    const uint32_t /*utime_hi*/,
+    const uint32_t /*utime_lo*/,
+    const wl_fixed_t dx,
+    const wl_fixed_t dy,
+    const wl_fixed_t /*dx_unaccel*/,
+    const wl_fixed_t /*dy_unaccel*/)
+{
+  input_t *input = static_cast<input_t *>(data);
+  GHOST_WindowWayland *win = window_from_surface(input->focus_pointer);
+  if (!win) {
+    return;
+  }
+  const wl_fixed_t scale = win->scale();
+  const wl_fixed_t xy_next[2] = {
+      input->xy[0] + dx / scale,
+      input->xy[1] + dy / scale,
+  };
+  relative_pointer_handle_relative_motion_impl(input, win, xy_next);
+}
+
 static const zwp_relative_pointer_v1_listener relative_pointer_listener = {
     relative_pointer_handle_relative_motion,
 };
@@ -2479,9 +2495,33 @@ GHOST_TSuccess GHOST_SystemWayland::getCursorPosition(int32_t &x, int32_t &y) co
   return GHOST_kSuccess;
 }
 
-GHOST_TSuccess GHOST_SystemWayland::setCursorPosition(const int32_t /*x*/, const int32_t /*y*/)
+GHOST_TSuccess GHOST_SystemWayland::setCursorPosition(const int32_t x, const int32_t y)
 {
-  return GHOST_kFailure;
+  /* NOTE: WAYLAND doesn't support warping the cursor.
+   * However when grab is enabled, we already simulate a cursor location
+   * so that can be set to a new location. */
+  if (d->inputs.empty()) {
+    return GHOST_kFailure;
+  }
+  input_t *input = d->inputs[0];
+  if (!input->relative_pointer) {
+    return GHOST_kFailure;
+  }
+
+  GHOST_WindowWayland *win = window_from_surface(input->focus_pointer);
+  if (!win) {
+    return GHOST_kFailure;
+  }
+  const wl_fixed_t scale = win->scale();
+  const wl_fixed_t xy_next[2] = {
+      wl_fixed_from_int(x) / scale,
+      wl_fixed_from_int(y) / scale,
+  };
+
+  /* As the cursor was "warped" generate an event at the new location. */
+  relative_pointer_handle_relative_motion_impl(input, win, xy_next);
+
+  return GHOST_kSuccess;
 }
 
 void GHOST_SystemWayland::getMainDisplayDimensions(uint32_t &width, uint32_t &height) const