Add code to copy cursor image to opengl texture and update on event update (not used yet)

include/cursor.h

@@ -0,0 +1,28 @@
+#ifndef GSR_CURSOR_H
+#define GSR_CURSOR_H
+
+#include "egl.h"
+#include "vec2.h"
+
+#include <X11/Xlib.h>
+
+typedef struct {
+    gsr_egl *egl;
+    Display *display;
+    Window window;
+    int x_fixes_event_base;
+
+    unsigned int texture_id;
+    vec2i size;
+    vec2i hotspot;
+
+    bool cursor_image_set;
+} gsr_cursor;
+
+int gsr_cursor_init(gsr_cursor *self, gsr_egl *egl, Display *display);
+void gsr_cursor_deinit(gsr_cursor *self);
+
+int gsr_cursor_change_window_target(gsr_cursor *self, Window window);
+void gsr_cursor_update(gsr_cursor *self, XEvent *xev);
+
+#endif /* GSR_CURSOR_H */