[Wayland] Add mouse grab/lock functionality. (#15103)

* [Wayland] Add mouse grab functionality.

Co-authored-by: Colin Kinloch <colin@kinlo.ch>

input/common/wayland_common.c

@@ -421,6 +421,34 @@ static void wl_touch_handle_motion(void *data,
    }
 }
 
+static void handle_relative_motion(void *data,
+   struct zwp_relative_pointer_v1 *zwp_relative_pointer_v1,
+   uint32_t utime_hi, uint32_t utime_lo,
+   wl_fixed_t dx, wl_fixed_t dy,
+   wl_fixed_t dx_unaccel, wl_fixed_t dy_unaccel)
+{
+   gfx_ctx_wayland_data_t *wl = (gfx_ctx_wayland_data_t*)data;
+
+   wl->input.mouse.delta_x = wl_fixed_to_int(dx);
+   wl->input.mouse.delta_y = wl_fixed_to_int(dy);
+
+   if (wl->locked_pointer)
+   {
+      wl->input.mouse.x += wl->input.mouse.delta_x;
+      wl->input.mouse.y += wl->input.mouse.delta_y;
+   }
+}
+
+static void 
+locked_pointer_locked(void *data, struct zwp_locked_pointer_v1 *locked_pointer)
+{
+}
+
+static void 
+locked_pointer_unlocked(void *data, struct zwp_locked_pointer_v1 *locked_pointer)
+{
+}
+
 static void wl_touch_handle_frame(void *data, struct wl_touch *wl_touch) { }
 
 static void wl_touch_handle_cancel(void *data, struct wl_touch *wl_touch)
@@ -460,6 +488,11 @@ static void wl_seat_handle_capabilities(void *data,
    {
       wl->wl_pointer = wl_seat_get_pointer(seat);
       wl_pointer_add_listener(wl->wl_pointer, &pointer_listener, wl);
+      wl->wl_relative_pointer =
+         zwp_relative_pointer_manager_v1_get_relative_pointer(
+	    wl->relative_pointer_manager, wl->wl_pointer);
+      zwp_relative_pointer_v1_add_listener(wl->wl_relative_pointer,
+         &relative_pointer_listener, wl);
    }
    else if (!(caps & WL_SEAT_CAPABILITY_POINTER) && wl->wl_pointer)
    {
@@ -626,6 +659,17 @@ static void wl_registry_handle_global(void *data, struct wl_registry *reg,
             interface, zxdg_decoration_manager_v1_interface.name))
       wl->deco_manager = (struct zxdg_decoration_manager_v1*)wl_registry_bind(
             reg, id, &zxdg_decoration_manager_v1_interface, MIN(version, 1));
+   else if (string_is_equal(interface, zwp_pointer_constraints_v1_interface.name))
+   {
+      wl->pointer_constraints = (struct zwp_pointer_constraints_v1*)
+         wl_registry_bind(
+            reg, id, &zwp_pointer_constraints_v1_interface, MIN(version, 1));
+      wl->locked_pointer = NULL;
+   }
+   else if (string_is_equal(interface, zwp_relative_pointer_manager_v1_interface.name))
+      wl->relative_pointer_manager = (struct zwp_relative_pointer_manager_v1*)
+         wl_registry_bind(
+            reg, id, &zwp_relative_pointer_manager_v1_interface, MIN(version, 1));
 }
 
 static void wl_registry_handle_global_remove(void *data,
@@ -951,6 +995,15 @@ const struct wl_data_offer_listener data_offer_listener = {
    wl_data_offer_handle_action
 };
 
+const struct zwp_relative_pointer_v1_listener relative_pointer_listener = {
+   .relative_motion = handle_relative_motion,
+};
+
+const struct zwp_locked_pointer_v1_listener locked_pointer_listener = {
+   .locked = locked_pointer_locked,
+   .unlocked = locked_pointer_unlocked,
+};
+
 void flush_wayland_fd(void *data)
 {
    struct pollfd fd             = {0};

input/common/wayland_common.h

@@ -41,6 +41,12 @@
 /* Generated from xdg-decoration-unstable-v1.h */
 #include "../../gfx/common/wayland/xdg-decoration-unstable-v1.h"
 
+/* Generated from pointer-constraints-unstable-v1.h */
+#include "../../gfx/common/wayland/pointer-constraints-unstable-v1.h"
+
+/* Generated from relative-pointer-unstable-v1.h */
+#include "../../gfx/common/wayland/relative-pointer-unstable-v1.h"
+
 #define UDEV_KEY_MAX			     0x2ff
 #define UDEV_MAX_KEYS           (UDEV_KEY_MAX + 7) / 8
 
@@ -138,6 +144,8 @@ typedef struct gfx_ctx_wayland_data
    struct xdg_toplevel *xdg_toplevel;
    struct wl_keyboard *wl_keyboard;
    struct wl_pointer  *wl_pointer;
+   struct zwp_relative_pointer_v1 *wl_relative_pointer;
+   struct zwp_locked_pointer_v1 *locked_pointer;
    struct wl_touch *wl_touch;
    struct wl_seat *seat;
    struct wl_shm *shm;
@@ -157,6 +165,8 @@ typedef struct gfx_ctx_wayland_data
    struct zxdg_toplevel_decoration_v1 *deco;
    struct zwp_idle_inhibit_manager_v1 *idle_inhibit_manager;
    struct zwp_idle_inhibitor_v1 *idle_inhibitor;
+   struct zwp_pointer_constraints_v1 *pointer_constraints;
+   struct zwp_relative_pointer_manager_v1 *relative_pointer_manager;
    output_info_t *current_output;
 #ifdef HAVE_VULKAN
    gfx_ctx_vulkan_data_t vk;
@@ -211,6 +221,10 @@ extern const struct wl_keyboard_listener keyboard_listener;
 
 extern const struct wl_pointer_listener pointer_listener;
 
+extern const struct zwp_relative_pointer_v1_listener relative_pointer_listener;
+
+extern const struct zwp_locked_pointer_v1_listener locked_pointer_listener;
+
 extern const struct wl_touch_listener touch_listener;
 
 extern const struct wl_seat_listener seat_listener;

input/drivers/wayland_input.c

@@ -73,8 +73,6 @@ static void input_wl_poll(void *data)
 
    flush_wayland_fd(wl);
 
-   wl->mouse.delta_x            = wl->mouse.x - wl->mouse.last_x;
-   wl->mouse.delta_y            = wl->mouse.y - wl->mouse.last_y;
    wl->mouse.last_x             = wl->mouse.x;
    wl->mouse.last_y             = wl->mouse.y;
 
@@ -84,6 +82,27 @@ static void input_wl_poll(void *data)
       wl->mouse.delta_y         = 0;
    }
 
+   if (wl->gfx->locked_pointer)
+   {
+      /* Get effective 'absolute' pointer location
+       * (last position + delta, bounded by current
+       * application window dimensions) */
+      wl->mouse.x         += wl->mouse.delta_x;
+      wl->mouse.y         += wl->mouse.delta_y;
+
+      /* Clamp X */
+      if (wl->mouse.x < 0)
+         wl->mouse.x = 0;
+      if (wl->mouse.x >= wl->gfx->buffer_width)
+         wl->mouse.x = (wl->gfx->buffer_width - 1);
+
+      /* Clamp Y */
+      if (wl->mouse.y < 0)
+         wl->mouse.y = 0;
+      if (wl->mouse.y >= wl->gfx->buffer_height)
+         wl->mouse.y = (wl->gfx->buffer_height - 1);
+   }
+
    for (id = 0; id < MAX_TOUCHES; id++)
    {
       if (wayland_context_gettouchpos(wl->gfx, id, &touch_x, &touch_y))
@@ -154,6 +173,7 @@ static int16_t input_wl_state(
       unsigned id)
 {
    input_ctx_wayland_data_t *wl = (input_ctx_wayland_data_t*)data;
+   int x, y = 0;
 
    switch (device)
    {
@@ -267,10 +287,14 @@ static int16_t input_wl_state(
                   wl->mouse.wd = false;
                   return state;
                case RETRO_DEVICE_ID_MOUSE_X:
-                  return screen ? wl->mouse.x : wl->mouse.delta_x;
+		  x = screen ? wl->mouse.x : wl->mouse.delta_x;
-               case RETRO_DEVICE_ID_MOUSE_Y:
+                  wl->mouse.delta_x = 0;
-                  return screen ? wl->mouse.y : wl->mouse.delta_y;
+                  return x;
-               case RETRO_DEVICE_ID_MOUSE_LEFT:
+	       case RETRO_DEVICE_ID_MOUSE_Y:
+		  y = screen ? wl->mouse.y : wl->mouse.delta_y;
+                  wl->mouse.delta_y = 0;
+                  return y;
+	       case RETRO_DEVICE_ID_MOUSE_LEFT:
                   return wl->mouse.left;
                case RETRO_DEVICE_ID_MOUSE_RIGHT:
                   return wl->mouse.right;
@@ -406,10 +430,25 @@ static uint64_t input_wl_get_capabilities(void *data)
 
 static void input_wl_grab_mouse(void *data, bool state)
 {
-   /* This function does nothing but registering it is necessary for allowing
+  input_ctx_wayland_data_t *wl = (input_ctx_wayland_data_t*)data;
-    * mouse-grab toggling. */
+
-   (void)data;
+  gfx_ctx_wayland_data_t *gfx = (gfx_ctx_wayland_data_t*)wl->gfx;
-   (void)state;
+
+   if (gfx->pointer_constraints)
+   {
+      if (state)
+      {
+         gfx->locked_pointer = zwp_pointer_constraints_v1_lock_pointer(gfx->pointer_constraints,
+            gfx->surface, gfx->wl_pointer, NULL, ZWP_POINTER_CONSTRAINTS_V1_LIFETIME_PERSISTENT);
+	 zwp_locked_pointer_v1_add_listener(gfx->locked_pointer,
+	    &locked_pointer_listener, gfx);
+      }
+      else if (gfx->locked_pointer)
+      {
+         zwp_locked_pointer_v1_destroy(gfx->locked_pointer);
+         gfx->locked_pointer = NULL;
+      }
+   }
 }
 
 input_driver_t input_wayland = {