Another try at pointer frame support on Wayland

This time I think I got the wheel handling correct. At least works with
my wheel mouse.

glfw/wl_platform.h

@@ -146,6 +146,13 @@ enum WaylandWindowPendingState {
     PENDING_STATE_DECORATION = 2
 };
 
+enum _GLFWWaylandAxisEvent {
+    AXIS_EVENT_UNKNOWN = 0,
+    AXIS_EVENT_CONTINUOUS = 1,
+    AXIS_EVENT_DISCRETE = 2,
+    AXIS_EVENT_VALUE120 = 3
+};
+
 // Wayland-specific per-window data
 //
 typedef struct _GLFWwindowWayland
@@ -178,6 +185,20 @@ typedef struct _GLFWwindowWayland
         struct zwlr_layer_surface_v1* zwlr_layer_surface_v1;
     } layer_shell;
 
+    /* information about axis events on current frame */
+    struct
+    {
+        struct {
+            enum _GLFWWaylandAxisEvent x_axis_type;
+            float x;
+            enum _GLFWWaylandAxisEvent y_axis_type;
+            float y;
+        } discrete, continuous;
+
+        /* Event timestamp in nanoseconds */
+        monotonic_t timestamp_ns;
+    } pointer_curr_axis_info;
+
     _GLFWcursor*                currentCursor;
     double                      cursorPosX, cursorPosY, allCursorPosX, allCursorPosY;
 
@@ -255,12 +276,6 @@ typedef struct _GLFWwindowWayland
 
 
     bool maximize_on_first_show;
-    // counters for ignoring axis events following axis_discrete events in the
-    // same frame along the same axis
-    struct {
-        unsigned int x, y;
-    } axis_discrete_count;
-
     uint32_t pending_state;
     struct {
         int width, height;