Implemented Entity tagged union for highlighted entity (similar to abstract class in some ways)

src/common/constants.zig

@@ -23,3 +23,6 @@ pub const ROAD_SIZE = 20;
 pub const ROAD_COLOUR = clr.black;
 /// Colour of the road that is highlighted
 pub const ROAD_HIGHLIGHTED_COLOUR = clr.green;
+
+pub const TEXT_SIZE = 50;
+pub const TEXT_COLOUR = clr.black;

src/common/structures.zig

@@ -0,0 +1,7 @@
+const Road = @import("../infrastructure/road.zig").Road;
+const Node = @import("../infrastructure/node.zig").Node;
+
+pub const Entity = union(enum) {
+    node: *Node,
+    road: *Road,
+};

src/infrastructure/node.zig

@@ -1,7 +1,7 @@
 const std = @import("std");
 const rl = @import("raylib");
 
-const c = @import("../constants.zig");
+const c = @import("../common/constants.zig");
 const e = @import("../errors.zig");
 const Road = @import("road.zig").Road;
 
@@ -39,11 +39,16 @@ pub const Node = struct {
         rl.drawCircleV(self.pos, c.NODE_RADIUS, colour);
     }
 
-    /// Identifies whether the pos (location) is within the snapping radius of the node
+    /// Determines whether the pos (location) is within the snapping radius of the node
-    pub fn posWithinRadius(self: *const Node, pos: rl.Vector2) bool {
+    pub fn withinSnapRadius(self: *const Node, pos: rl.Vector2) bool {
         return rl.checkCollisionPointCircle(pos, self.pos, c.NODE_SNAP_RADIUS);
     }
 
+    /// Determines whether the pos (location) is within the strict (visual representation) radius of the node
+    pub fn withinRadius(self: *const Node, pos: rl.Vector2) bool {
+        return rl.checkCollisionPointCircle(pos, self.pos, c.NODE_RADIUS);
+    }
+
     /// Tries to reference the passed road to self
     ///
     /// Returns an error if the passed road cannot be appended to the list or if said road is already in the list

src/infrastructure/node_manager.zig

@@ -1,7 +1,7 @@
 const std = @import("std");
 const Vector2 = @import("raylib").Vector2;
 
-const c = @import("../constants.zig");
+const c = @import("../common/constants.zig");
 const e = @import("../errors.zig");
 const Node = @import("node.zig").Node;
 const Road = @import("road.zig").Road;
@@ -53,7 +53,7 @@ pub const NodeManager = struct {
     /// otherwise creates a new node and returns its pointer
     pub fn getSelectedNode(self: *NodeManager, allocator: std.mem.Allocator, pos: Vector2) !*Node {
         for (self.nodes.items) |node| {
-            if (node.posWithinRadius(pos)) return node;
+            if (node.withinSnapRadius(pos)) return node;
         }
 
         // No node is within that position, so we must create a new one
@@ -98,6 +98,14 @@ pub const NodeManager = struct {
 
         return e.Entity.NotFound;
     }
+
+    pub fn getHighlightedNode(self: *const NodeManager, pos: Vector2) ?*Node {
+        for (self.nodes.items) |node| {
+            if (node.withinRadius(pos)) return node;
+        }
+
+        return null;
+    }
 };
 
 const expect = std.testing.expect;

src/infrastructure/road.zig

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

src/infrastructure/road_manager.zig

@@ -7,13 +7,11 @@ const Node = @import("node.zig").Node;
 pub const RoadManager = struct {
     next_id: usize,
     roads: std.ArrayList(*Road),
-    highlighted_road: ?*Road,
 
     pub fn init() RoadManager {
         return .{
             .next_id = 0,
             .roads = .empty,
-            .highlighted_road = null,
         };
     }
 
@@ -26,9 +24,9 @@ pub const RoadManager = struct {
     }
 
     /// Draws all the roads in the list, sends the information ahead whether the road drawn should be highlighted
-    pub fn draw(self: *const RoadManager, delete_mode: bool) void {
+    pub fn draw(self: *const RoadManager, highlighted_road: ?*Road) void {
         for (self.roads.items) |road| {
-            const is_highlighted = delete_mode and self.highlighted_road != null and self.highlighted_road.? == road;
+            const is_highlighted = if (highlighted_road) |h_road| road == h_road else false;
             road.draw(is_highlighted);
         }
     }
@@ -85,16 +83,13 @@ pub const RoadManager = struct {
         return e.Entity.NotFound;
     }
 
-    /// Sets the pointer to the road that is intersection with pos coordinate
+    /// Returns if pos is pointing at a road, or null if it isn't at any
-    pub fn update_highlighted_road(self: *RoadManager, pos: Vector2) void {
+    pub fn getHighlightedRoad(self: *const RoadManager, pos: Vector2) ?*Road {
         for (self.roads.items) |road| {
-            if (!road.isHighlighted(pos)) continue;
+            if (road.isHighlighted(pos)) return road;
-
-            self.highlighted_road = road;
-            return;
         }
 
-        self.highlighted_road = null;
+        return null;
     }
 };
 

src/main.zig

@@ -1,7 +1,7 @@
 const std = @import("std");
 const rl = @import("raylib");
 
-const c = @import("constants.zig");
+const c = @import("common/constants.zig");
 const Simulator = @import("simulator.zig").Simulator;
 
 pub fn main(init: std.process.Init) !void {

src/simulator.zig

@@ -1,7 +1,9 @@
 const std = @import("std");
 const rl = @import("raylib");
 
-const c = @import("constants.zig");
+const c = @import("common/constants.zig");
+const st = @import("common/structures.zig");
+const Road = @import("infrastructure/road.zig").Road;
 const NodeManager = @import("infrastructure/node_manager.zig").NodeManager;
 const RoadManager = @import("infrastructure/road_manager.zig").RoadManager;
 
@@ -18,6 +20,12 @@ pub const Simulator = struct {
     /// Tracks whether the system will delete the road cursor is pointed at
     /// (in such case, the road-to-be-deleted will also be highlighted)
     delete_mode: bool,
+    /// Tracks whether highlighting all entities that are connected to hovered entity is enabled
+    ///
+    /// 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)
+    show_connections: bool,
+    highlighted_entity: ?st.Entity,
 
     /// Constructor for convenience
     pub fn init(new_allocator: std.mem.Allocator) Simulator {
@@ -27,6 +35,8 @@ pub const Simulator = struct {
             .road_man = .init(),
             .auto_continue = false,
             .delete_mode = false,
+            .show_connections = false,
+            .highlighted_entity = null,
         };
     }
 
@@ -40,13 +50,21 @@ pub const Simulator = struct {
     pub fn draw(self: *const Simulator, pos: rl.Vector2) void {
         rl.clearBackground(c.BACKGROUND_COLOR);
 
-        self.road_man.draw(self.delete_mode);
+        var highlighted_road: ?*Road = null;
+
+        if (self.delete_mode) {
+            if (self.highlighted_entity) |entity| {
+                if (entity == .road) highlighted_road = entity.road;
+            }
+        }
+
+        self.road_man.draw(highlighted_road);
         self.node_man.draw(pos);
     }
 
     /// Update tick
     pub fn update(self: *Simulator, pos: rl.Vector2) void {
-        self.road_man.update_highlighted_road(pos);
+        self.updateHighlightedEntity(pos);
     }
 
     /// Exposed input handling function exposed to raylib
@@ -59,6 +77,7 @@ 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);
 
         if (rl.isKeyReleased(.c)) self.clear() catch |err| {
             std.debug.panic("Failed to clear the entities: {}\n", .{err});
@@ -72,7 +91,7 @@ pub const Simulator = struct {
 
     /// Function that handles functionality that executes upon left click
     fn leftClickEvent(self: *Simulator, pos: rl.Vector2) void {
-        if (self.delete_mode) {
+        if (self.delete_mode and self.highlighted_entity != null and self.highlighted_entity.? == .road) {
             self.delete_road() catch |err| {
                 std.debug.panic("Failed to delete the road: {}\n", .{err});
             };
@@ -104,8 +123,9 @@ pub const Simulator = struct {
 
     /// User initiated road destroying functionality
     fn delete_road(self: *Simulator) !void {
-        if (self.road_man.highlighted_road == null) return;
+        // We can trust this because this only gets called if valid and if type is road
-        const h_road = self.road_man.highlighted_road.?;
+        std.debug.assert(self.highlighted_entity != null and self.highlighted_entity.? == .road);
+        const h_road = self.highlighted_entity.?.road;
 
         const start_node = h_road.nodes[0];
         const end_node = h_road.nodes[1];
@@ -113,7 +133,6 @@ pub const Simulator = struct {
         self.road_man.deleteRoad(self.allocator, h_road) catch |err| {
             std.debug.panic("Road deletion failed: {}\n", .{err});
         };
-        self.road_man.highlighted_road = null;
 
         if (start_node.roads.items.len == 0)
             try self.node_man.deleteNode(self.allocator, start_node);
@@ -127,4 +146,19 @@ pub const Simulator = struct {
         self.road_man.clear(self.allocator);
         try self.node_man.clear(self.allocator);
     }
+
+    /// Updates the variable that tracks the highlighted entity
+    fn updateHighlightedEntity(self: *Simulator, pos: rl.Vector2) void {
+        if (self.node_man.getHighlightedNode(pos)) |node| {
+            self.highlighted_entity = .{ .node = node };
+            return;
+        }
+
+        if (self.road_man.getHighlightedRoad(pos)) |road| {
+            self.highlighted_entity = .{ .road = road };
+            return;
+        }
+
+        self.highlighted_entity = null;
+    }
 };