Handle ui_noodle return states and start introducing connected nodes

include/ui.h

@@ -21,6 +21,8 @@
 typedef enum ui_elem_type ui_elem_type;
 typedef struct ui_elem ui_elem;
 typedef struct ui_ctx ui_ctx;
+typedef struct ui_elem_colours ui_elem_colours;
+typedef enum noodle_action noodle_action;
 
 enum ui_elem_type {
   UI_ELEM_NODE,
@@ -39,12 +41,17 @@ struct ui_elem {
   ui_elem_type type;
 };
 
-typedef struct ui_elem_colours ui_elem_colours;
 struct ui_elem_colours {
   colour fill;
   colour border;
 };
 
+enum noodle_action {
+  NOODLE_ACTION_NONE,
+  NOODLE_ACTION_DRAGGING,
+  NOODLE_ACTION_RELEASED,
+};
+
 struct ui_ctx {
   u64 count;
   i64 hovered;
@@ -66,7 +73,7 @@ bool ui_button(const window *wnd, ui_ctx *ctx, rect rect,
                ui_elem_colours colours);
 bool ui_node(const window *wnd, ui_ctx *ctx, rect rect,
              ui_elem_colours colours);
-bool ui_noodle(const window *wnd, ui_ctx *ctx, line ln, ui_elem_colours colours,
+noodle_action ui_noodle(const window *wnd, ui_ctx *ctx, line ln,
-               rect parent_node);
+                        ui_elem_colours colours, rect parent_node);
 
 #endif // !UI_H

src/compositor.c

@@ -171,10 +171,32 @@ i32 run_main_loop(void) {
           *ln = line_from_origin(origin, new_angle, DEFAULT_NOODLE_LENGTH);
         }
 
-        if (ui_noodle(main_window, &(comp.ctx), *ln, node_elem->colours,
+        switch (ui_noodle(main_window, &(comp.ctx), *ln, node_elem->colours,
-                      node_elem->rec)) {
+                          node_elem->rec)) {
+        case NOODLE_ACTION_DRAGGING:
           ln->p0.x += comp.ctx.rel_x;
           ln->p0.y += comp.ctx.rel_y;
+          break;
+        case NOODLE_ACTION_RELEASED:
+          for (u64 k = 0; k < comp.count; ++k) {
+            if (k == i) {
+              continue;
+            }
+
+            const node *nd = &(comp.nodes[k]);
+
+            if (aabb(nd->rec, comp.ctx.mouse_x, comp.ctx.mouse_y)) {
+              point p0 = {nd->rec.topleft.x + nd->rec.w / 2,
+                          nd->rec.topleft.y + nd->rec.h / 2};
+
+              ln->p0 = p0;
+            } else {
+              ln->p0 = ln->p1;
+            }
+          }
+          break;
+        default:
+          break;
         }
 
         if (delta_multiplier > 0) {

src/ui.c

@@ -141,10 +141,10 @@ bool ui_node(const window *wnd, ui_ctx *ctx, rect rect,
   return false;
 }
 
-bool ui_noodle(const window *wnd, ui_ctx *ctx, line ln, ui_elem_colours colours,
+noodle_action ui_noodle(const window *wnd, ui_ctx *ctx, line ln,
-               rect parent_node) {
+                        ui_elem_colours colours, rect parent_node) {
   if (ctx->count + 1 >= MAX_UI_ELEMENTS) {
-    return false;
+    return NOODLE_ACTION_NONE;
   }
 
   u64 id = get_id(ctx);
@@ -220,24 +220,25 @@ bool ui_noodle(const window *wnd, ui_ctx *ctx, line ln, ui_elem_colours colours,
   }
 
   if (wnd != ctx->wnd || (ctx->active >= 0 && ctx->active != id)) {
-    return false;
+    return NOODLE_ACTION_NONE;
   }
 
   if (ctx->mouse_up) {
     if (ctx->hovered == ctx->active && ctx->hovered == id) {
       ctx->hovered = ctx->active = -1;
+      return NOODLE_ACTION_RELEASED;
     }
 
-    return true;
+    return NOODLE_ACTION_NONE;
   }
 
   if (ctx->hovered == id && ctx->active == id) {
-    return true;
+    return NOODLE_ACTION_DRAGGING;
   }
 
   if (!aabb(bounding_box, ctx->mouse_x, ctx->mouse_y) ||
       aabb(parent_node, ctx->mouse_x, ctx->mouse_y)) {
-    return false;
+    return NOODLE_ACTION_NONE;
   }
 
   ctx->hovered = id;
@@ -246,7 +247,7 @@ bool ui_noodle(const window *wnd, ui_ctx *ctx, line ln, ui_elem_colours colours,
     ctx->active = id;
   }
 
-  return false;
+  return NOODLE_ACTION_NONE;
 }
 
 internal u64 get_id(ui_ctx *ctx) {