GHOST: get/set cursor position now uses client instead of screen coords

Use client (window) relative coordinates for cursor position access,
this only moves the conversion from window-manager into GHOST,
(no functional changes).

This is needed for fix a bug in GHOST/Wayland which doesn't support
accessing absolute cursor coordinates & the window is needed to properly
access the cursor coordinates.

As it happens every caller to GHOST_GetCursorPosition was already making
the values window-relative, so there is little benefit in attempting to
workaround the problem on the Wayland side.

If needed the screen-space versions of functions can be exposed again.

5 files changed, 95 insertions, 11 deletions

diff --git a/intern/ghost/GHOST_C-api.h b/intern/ghost/GHOST_C-api.h
index 0f05e501d17..4cbc0d65b11 100644
--- a/intern/ghost/GHOST_C-api.h
+++ b/intern/ghost/GHOST_C-api.h
@@ -383,27 +383,28 @@ extern bool GHOST_GetCursorVisibility(GHOST_WindowHandle windowhandle);
 extern GHOST_TSuccess GHOST_SetCursorVisibility(GHOST_WindowHandle windowhandle, bool visible);
 
 /**
- * Returns the current location of the cursor (location in screen coordinates)
+ * Returns the current location of the cursor (location in client relative coordinates)
  * \param systemhandle: The handle to the system.
  * \param x: The x-coordinate of the cursor.
  * \param y: The y-coordinate of the cursor.
  * \return Indication of success.
  */
-extern GHOST_TSuccess GHOST_GetCursorPosition(GHOST_SystemHandle systemhandle,
-                                              int32_t *x,
-                                              int32_t *y);
-
+GHOST_TSuccess GHOST_GetCursorPosition(const GHOST_SystemHandle systemhandle,
+                                       const GHOST_WindowHandle windowhandle,
+                                       int32_t *x,
+                                       int32_t *y);
 /**
- * Updates the location of the cursor (location in screen coordinates).
+ * Updates the location of the cursor (location in client relative coordinates).
  * Not all operating systems allow the cursor to be moved (without the input device being moved).
  * \param systemhandle: The handle to the system.
  * \param x: The x-coordinate of the cursor.
  * \param y: The y-coordinate of the cursor.
  * \return Indication of success.
  */
-extern GHOST_TSuccess GHOST_SetCursorPosition(GHOST_SystemHandle systemhandle,
-                                              int32_t x,
-                                              int32_t y);
+GHOST_TSuccess GHOST_SetCursorPosition(GHOST_SystemHandle systemhandle,
+                                       GHOST_WindowHandle windowhandle,
+                                       int32_t x,
+                                       int32_t y);
 
 void GHOST_GetCursorGrabState(GHOST_WindowHandle windowhandle,
                               GHOST_TGrabCursorMode *r_mode,
diff --git a/intern/ghost/GHOST_ISystem.h b/intern/ghost/GHOST_ISystem.h
index d7485975906..91cf1c4c558 100644
--- a/intern/ghost/GHOST_ISystem.h
+++ b/intern/ghost/GHOST_ISystem.h
@@ -365,6 +365,25 @@ class GHOST_ISystem {
    ***************************************************************************************/
 
   /**
+   * Returns the current location of the cursor (location in window coordinates)
+   * \param x: The x-coordinate of the cursor.
+   * \param y: The y-coordinate of the cursor.
+   * \return Indication of success.
+   */
+  virtual GHOST_TSuccess getCursorPositionClientRelative(const GHOST_IWindow *window,
+                                                         int32_t &x,
+                                                         int32_t &y) const = 0;
+  /**
+   * Updates the location of the cursor (location in window coordinates).
+   * \param x: The x-coordinate of the cursor.
+   * \param y: The y-coordinate of the cursor.
+   * \return Indication of success.
+   */
+  virtual GHOST_TSuccess setCursorPositionClientRelative(GHOST_IWindow *window,
+                                                         int32_t x,
+                                                         int32_t y) = 0;
+
+  /**
    * Returns the current location of the cursor (location in screen coordinates)
    * \param x: The x-coordinate of the cursor.
    * \param y: The y-coordinate of the cursor.
diff --git a/intern/ghost/intern/GHOST_C-api.cpp b/intern/ghost/intern/GHOST_C-api.cpp
index 8c690767810..65e7de707ec 100644
--- a/intern/ghost/intern/GHOST_C-api.cpp
+++ b/intern/ghost/intern/GHOST_C-api.cpp
@@ -348,19 +348,49 @@ GHOST_TSuccess GHOST_SetCursorVisibility(GHOST_WindowHandle windowhandle, bool v
   return window->setCursorVisibility(visible);
 }
 
-GHOST_TSuccess GHOST_GetCursorPosition(GHOST_SystemHandle systemhandle, int32_t *x, int32_t *y)
+/* Unused, can expose again if needed although WAYLAND
+ * can only properly use client relative coordinates, so leave disabled if possible. */
+#if 0
+GHOST_TSuccess GHOST_GetCursorPositionScreenCoords(GHOST_SystemHandle systemhandle,
+                                                   int32_t *x,
+                                                   int32_t *y)
 {
   GHOST_ISystem *system = (GHOST_ISystem *)systemhandle;
 
   return system->getCursorPosition(*x, *y);
 }
 
-GHOST_TSuccess GHOST_SetCursorPosition(GHOST_SystemHandle systemhandle, int32_t x, int32_t y)
+GHOST_TSuccess GHOST_SetCursorPositionScreenCoords(GHOST_SystemHandle systemhandle,
+                                                   int32_t x,
+                                                   int32_t y)
 {
   GHOST_ISystem *system = (GHOST_ISystem *)systemhandle;
 
   return system->setCursorPosition(x, y);
 }
+#endif
+
+GHOST_TSuccess GHOST_GetCursorPosition(const GHOST_SystemHandle systemhandle,
+                                       const GHOST_WindowHandle windowhandle,
+                                       int32_t *x,
+                                       int32_t *y)
+{
+  const GHOST_ISystem *system = (const GHOST_ISystem *)systemhandle;
+  const GHOST_IWindow *window = (const GHOST_IWindow *)windowhandle;
+
+  return system->getCursorPositionClientRelative(window, *x, *y);
+}
+
+GHOST_TSuccess GHOST_SetCursorPosition(GHOST_SystemHandle systemhandle,
+                                       GHOST_WindowHandle windowhandle,
+                                       int32_t x,
+                                       int32_t y)
+{
+  GHOST_ISystem *system = (GHOST_ISystem *)systemhandle;
+  GHOST_IWindow *window = (GHOST_IWindow *)windowhandle;
+
+  return system->setCursorPositionClientRelative(window, x, y);
+}
 
 GHOST_TSuccess GHOST_SetCursorGrab(GHOST_WindowHandle windowhandle,
                                    GHOST_TGrabCursorMode mode,
diff --git a/intern/ghost/intern/GHOST_System.cpp b/intern/ghost/intern/GHOST_System.cpp
index 2f4ab9ee37c..cf04287af9f 100644
--- a/intern/ghost/intern/GHOST_System.cpp
+++ b/intern/ghost/intern/GHOST_System.cpp
@@ -260,6 +260,29 @@ GHOST_TSuccess GHOST_System::pushEvent(GHOST_IEvent *event)
   return success;
 }
 
+GHOST_TSuccess GHOST_System::getCursorPositionClientRelative(const GHOST_IWindow *window,
+                                                             int32_t &x,
+                                                             int32_t &y) const
+{
+  /* Sub-classes that can implement this directly should do so. */
+  int32_t screen_x, screen_y;
+  GHOST_TSuccess success = getCursorPosition(screen_x, screen_y);
+  if (success == GHOST_kSuccess) {
+    window->screenToClient(screen_x, screen_y, x, y);
+  }
+  return success;
+}
+
+GHOST_TSuccess GHOST_System::setCursorPositionClientRelative(GHOST_IWindow *window,
+                                                             int32_t x,
+                                                             int32_t y)
+{
+  /* Sub-classes that can implement this directly should do so. */
+  int32_t screen_x, screen_y;
+  window->clientToScreen(x, y, screen_x, screen_y);
+  return setCursorPosition(screen_x, screen_y);
+}
+
 GHOST_TSuccess GHOST_System::getModifierKeyState(GHOST_TModifierKey mask, bool &isDown) const
 {
   GHOST_ModifierKeys keys;
diff --git a/intern/ghost/intern/GHOST_System.h b/intern/ghost/intern/GHOST_System.h
index e4a49551222..42f0a773dea 100644
--- a/intern/ghost/intern/GHOST_System.h
+++ b/intern/ghost/intern/GHOST_System.h
@@ -203,6 +203,17 @@ class GHOST_System : public GHOST_ISystem {
    * Cursor management functionality
    ***************************************************************************************/
 
+  /* Client relative functions use a default implementation
+   * that converts from screen-coordinates to client coordinates.
+   * Implementations may override. */
+
+  GHOST_TSuccess getCursorPositionClientRelative(const GHOST_IWindow *window,
+                                                 int32_t &x,
+                                                 int32_t &y) const override;
+  GHOST_TSuccess setCursorPositionClientRelative(GHOST_IWindow *window,
+                                                 int32_t x,
+                                                 int32_t y) override;
+
   /**
    * Inherited from GHOST_ISystem but left pure virtual
    * <pre>