Initial implementation of proper HiDPI cursor support on Wayland.

glfw/wl_cursors.h

@@ -0,0 +1,31 @@
+// Declarations for a HiDPI-aware cursor theme manager.
+
+#include <wayland-cursor.h>
+
+typedef struct _wlCursorThemeManager _wlCursorThemeManager;
+
+/** Returns a pointer to a wlCursorThemeManagerInstance.
+ * Repeatedly calling this function will return the same instance.
+ * 
+ * The retrieved instance must be destroyed with _wlCursorThemeManagerDestroy.
+ */
+_wlCursorThemeManager* _wlCursorThemeManagerDefault(void);
+
+/** Set a wl_cursor_theme pointer variable to a pointer to a managed cursor theme.
+ * Pass the desired px as the third argument.
+ * Returns a pointer to a managed theme, or NULL if the desired px is 0 or an error occurs.
+ * 
+ * The passed theme pointer must either be NULL or a pointer to a theme managed by the passed manager.
+ * The provided pointer may be invalidated if it's non-NULL. 
+ */
+struct wl_cursor_theme*
+_wlCursorThemeManage(_wlCursorThemeManager*, struct wl_cursor_theme*, int);
+
+/** Helper method to determine the appropriate size in pixels for a given scale.
+ * 
+ * Reads XCURSOR_SIZE if it's set and is valid, else defaults to 32*scale.
+ */
+
+void _wlCursorThemeManagerDestroy(_wlCursorThemeManager*);
+ 
+int _wlCursorPxFromScale(int);