Files
traffic-simulator/src/infrastructure/road.zig

94 lines
3.0 KiB
Zig

const rl = @import("raylib");
const c = @import("../common/constants.zig");
const Node = @import("node.zig").Node;
pub const Road = struct {
/// Road ID, used for identification, particularly as we'll access all entities via pointers
id: usize,
/// Pointers to the nodes that encapsulated our road
nodes: [2]*Node,
/// Calculated road length
length: f32,
/// Constructor, which sets nodes for the road and calculates its length
pub fn init(new_id: usize, start: *Node, end: *Node) Road {
var road: Road = .{
.id = new_id,
.nodes = .{start, end},
.length = 0,
};
road.length = road.calculate_length();
return road;
}
/// This makes the road ptr DEAD
pub fn deinit(self: *Road, allocator: std.mem.Allocator) void {
allocator.destroy(self);
}
/// Calculates length of the road by taking its two nodes
fn calculate_length(self: *const Road) f32 {
const start = self.nodes[0];
const end = self.nodes[1];
const x_diff = end.pos.x - start.pos.x;
const y_diff = end.pos.y - start.pos.y;
const square_diff = x_diff * x_diff + y_diff * y_diff;
return @sqrt(square_diff);
}
/// Simple function which draws the node
///
/// In the future as we improve and make roads more complex with multiple lanes and such
/// it will gradually become more complex
pub fn draw(self: *const Road, highlighted: bool) void {
const colour = if (highlighted) c.ROAD_HIGHLIGHTED_COLOUR else c.ROAD_COLOUR;
rl.drawLineEx(self.nodes[0].pos, self.nodes[1].pos, c.ROAD_SIZE, colour);
}
/// Important: after this function executes, this road is no longer reachable from its bounding nodes
///
/// The function unreferences self (road) from its bounding nodes
pub fn unreferenceNodes(self: *const Road) !void {
try self.nodes[0].unreferenceRoad(self);
try self.nodes[1].unreferenceRoad(self);
}
/// Checks whether pos coordinate is on the referenced road
pub fn isHighlighted(self: *const Road, pos: rl.Vector2) bool {
return rl.checkCollisionPointLine(pos, self.nodes[0].pos, self.nodes[1].pos, c.ROAD_SIZE);
}
};
const std = @import("std");
const expect = std.testing.expect;
test "valid road nodes" {
var gpa: std.heap.DebugAllocator(.{}) = .init;
defer _ = gpa.deinit();
const allocator = gpa.allocator();
const start: Node = .init(34, .{.x = 500, .y = 500});
const start_ptr = try allocator.create(Node);
defer {
start_ptr.deinit(allocator);
allocator.destroy(start_ptr);
}
start_ptr.* = start;
const end: Node = .init(227, .{.x = 600, .y = 500});
const end_ptr = try allocator.create(Node);
defer {
end_ptr.deinit(allocator);
allocator.destroy(end_ptr);
}
end_ptr.* = end;
const road: Road = .init(11, start_ptr, end_ptr);
try expect(road.nodes[0].id == 34);
try expect(road.nodes[1].id == 227);
}