positioner rootston cleanup and bugfix

rootston/xdg_shell_v6.c

@@ -97,19 +97,16 @@ static void popup_constraint_offset(struct roots_xdg_popup_v6 *popup,
 
 	*offset_x = *offset_y = 0;
 
-	double popup_ox = popup_lx - output_box->x;
-	double popup_oy = popup_ly - output_box->y;
-
 	if (popup_lx < output_box->x) {
 		*offset_x = output_box->x - popup_lx;
 	} else if (popup_lx + popup_width > output_box->x + output_box->width) {
-		*offset_x = popup_width - (output_box->width - popup_ox);
+		*offset_x = output_box->x + output_box->width - (popup_lx + popup_width);
 	}
 
 	if (popup_ly < output_box->y) {
 		*offset_y = output_box->y - popup_ly;
 	} else if (popup_ly + popup_height > output_box->y + output_box->height) {
-		*offset_y = popup_height - (output_box->height - popup_oy);
+		*offset_y = output_box->y + output_box->height - (popup_ly + popup_height);
 	}
 }
 
@@ -163,6 +160,7 @@ static bool popup_unconstrain_slide(struct roots_xdg_popup_v6 *popup) {
 	if (offset_x) {
 		popup->wlr_popup->geometry.x += offset_x;
 	}
+
 	if (offset_y) {
 		popup->wlr_popup->geometry.y += offset_y;
 	}