Support drawing a node with connection that can be modified by user

src/compositor.c

@@ -148,8 +148,8 @@ i32 run_main_loop(void) {
     }
 
     for (u64 i = 0; i < comp.count; ++i) {
-      comp.nodes[i].rec = ui_node(main_window, &(comp.ctx), comp.nodes[i].rec,
-                                  comp.nodes[i].colours);
+      comp.nodes[i].node = ui_node(main_window, &(comp.ctx), comp.nodes[i].node,
+                                   comp.nodes[i].colours);
     }
 
     for (u64 i = 0; i < MAX_WINDOWS; ++i) {
@@ -175,12 +175,16 @@ void add_node(compositor *comp, node_type type, node_data data, i32 x, i32 y,
   }
 
   comp->nodes[(comp->count)++] = (node){
-      .rec =
-          (rect){
-              .topleft.x = x,
-              .topleft.y = y,
-              .w = NODE_WIDTH,
-              .h = NODE_HEIGHT,
+      .node =
+          (ui_node_elem){
+              .rec =
+                  (rect){
+                      .topleft.x = x,
+                      .topleft.y = y,
+                      .w = NODE_WIDTH,
+                      .h = NODE_HEIGHT,
+                  },
+              .noodle = (line){0},
           },
       .colours = colours,
       .type = type,