Implemented relations displaying mode

src/common/constants.zig

@@ -16,10 +16,11 @@ pub const NODE_COLOUR = clr.brown;
 pub const NODE_TEMP_COLOUR = clr.orange;
 /// The colour of the node being at the cursor
 pub const NODE_CURSOR_COLOUR = clr.blue;
+pub const NODE_RELATED_COLOUR = clr.purple;
 
 /// Road (line) size
 pub const ROAD_SIZE = 20;
 /// Regular road colour
 pub const ROAD_COLOUR = clr.black;
 /// Colour of the road that is highlighted
-pub const ROAD_HIGHLIGHTED_COLOUR = clr.green;
+pub const ROAD_HIGHLIGHTED_COLOUR = clr.green;

src/infrastructure/node.zig

@@ -3,6 +3,7 @@ const rl = @import("raylib");
 
 const c = @import("../common/constants.zig");
 const e = @import("../errors.zig");
+const st = @import("../common/structures.zig");
 const Road = @import("road.zig").Road;
 
 pub const Node = struct {

src/infrastructure/node_manager.zig

@@ -26,6 +26,7 @@ pub const NodeManager = struct {
     /// Deinitialises every node (pointer) within the list and then deinits the list containing the nodes itself
     pub fn deinit(self: *NodeManager, allocator: std.mem.Allocator) !void {
         for (self.nodes.items) |node| {
+            node.roads.clearRetainingCapacity();
             try node.deinit(allocator);
         }
         self.nodes.deinit(allocator);

src/infrastructure/road.zig

@@ -1,6 +1,7 @@
 const rl = @import("raylib");
 
 const c = @import("../common/constants.zig");
+const st = @import("../common/structures.zig");
 const Node = @import("node.zig").Node;
 
 pub const Road = struct {

src/simulator.zig

@@ -24,6 +24,8 @@ pub const Simulator = struct {
     ///
     /// For example, if I hover over a node it will highlight all roads that are connected to it;
     /// Same goes for hovering over a road or in the future, a car (might show destination and path to it)
+    ///
+    /// Note: It only works outside of the delete mode
     show_connections: bool,
     highlighted_entity: ?st.Entity,
 
@@ -51,7 +53,6 @@ pub const Simulator = struct {
         rl.clearBackground(c.BACKGROUND_COLOR);
 
         var highlighted_road: ?*Road = null;
-
         if (self.delete_mode) {
             if (self.highlighted_entity) |entity| {
                 if (entity == .road) highlighted_road = entity.road;
@@ -60,6 +61,33 @@ pub const Simulator = struct {
 
         self.road_man.draw(highlighted_road);
         self.node_man.draw(pos);
+
+        self.drawRelatedSelectedEntities();
+    }
+
+    fn drawRelatedSelectedEntities(self: *const Simulator) void {
+        if (!self.show_connections or self.highlighted_entity == null) return;
+        const h_entity = self.highlighted_entity.?;
+
+        switch (h_entity) {
+            .node => {
+                const node = h_entity.node;
+
+                for (node.roads.items) |road| {
+                    road.draw(true);
+                }
+
+                node.draw(c.NODE_RELATED_COLOUR);
+            },
+            .road => {
+                const road = h_entity.road;
+
+                road.draw(true);
+
+                road.nodes[0].draw(c.NODE_RELATED_COLOUR);
+                road.nodes[1].draw(c.NODE_RELATED_COLOUR);
+            },
+        }
     }
 
     /// Update tick
@@ -77,7 +105,7 @@ pub const Simulator = struct {
     fn handleKeyboardInput(self: *Simulator) void {
         self.auto_continue = rl.isKeyDown(.left_control);
         self.delete_mode = rl.isKeyDown(.left_shift);
-        self.show_connections = rl.isKeyDown(.left_alt);
+        self.show_connections = rl.isKeyDown(.left_alt) and !self.delete_mode;
 
         if (rl.isKeyReleased(.c)) self.clear() catch |err| {
             std.debug.panic("Failed to clear the entities: {}\n", .{err});
@@ -102,6 +130,7 @@ pub const Simulator = struct {
 
     /// User initiated road building functionality
     fn new_road(self: *Simulator, pos: rl.Vector2) void {
+        if (self.show_connections) return;
         const cur_node = self.node_man.getSelectedNode(self.allocator, pos) catch |err| {
             std.debug.panic("Failed to append the newly created node at pos ({d}, {d}) to node list: {}\n", .{
                 pos.x, pos.y, err
@@ -143,6 +172,7 @@ pub const Simulator = struct {
 
     /// Clearing node and road lists without deinitialising them (only the children)
     fn clear(self: *Simulator) !void {
+        self.highlighted_entity = null;
         self.road_man.clear(self.allocator);
         try self.node_man.clear(self.allocator);
     }