commit 07b8f0ecb146ceb7dbb2cebb9bc8cc9375296888
Author: Marto <marto@marto.si>
Date:   Sun Apr 26 15:51:04 2026 +0200

    Initial commit: base-road-network copy

diff --git a/src/common/constants.odin b/src/common/constants.odin
new file mode 100644
index 0000000..865ffa5
--- /dev/null
+++ b/src/common/constants.odin
@@ -0,0 +1,34 @@
+package common
+
+import rl "vendor:raylib"
+
+// Screen Width
+WIDTH   :: 1366
+// Screen Height
+HEIGHT  :: 768
+// Default Monitor
+MONITOR :: 0
+
+// Thickness of the road being drawn
+ROAD_SIZE		 :: 20
+// Radius of the node
+NODE_RADIUS		 :: 20
+// Size of designated radius that determines when position is within node's 'sphere'
+NODE_SNAP_RADIUS :: 3
+// Default text size
+TEXT_SIZE		 :: 50
+
+// Default road colour
+ROAD_COLOUR		      :: rl.BLACK
+// Highlighted road colour
+ROAD_HIGHLIGHT_COLOUR :: rl.GREEN
+// Node colour once it's fully built
+NODE_DONE_COLOUR      :: rl.BROWN
+// Node colour while node is being built
+NODE_BUILD_COLOUR     :: rl.ORANGE
+// Node colour while being able to start building but not doing that yet
+NODE_CURSOR_COLOUR    :: rl.BLUE
+// The colour of the overlay displaying the snap radius
+NODE_SNAP_COLOUR      :: rl.PINK
+// The default colour of the text displayed
+TEXT_COLOUR		      :: rl.BLACK
\ No newline at end of file
diff --git a/src/common/structures.odin b/src/common/structures.odin
new file mode 100644
index 0000000..977c072
--- /dev/null
+++ b/src/common/structures.odin
@@ -0,0 +1,17 @@
+package common
+
+import rl "vendor:raylib"
+
+// Stores data about intersections
+Intersection_Data :: struct {
+	// Index of the road that is intersected
+	road: u32,
+	// The exact point of intersection
+	point: rl.Vector2,
+}
+
+// Tracks the entity type
+Entity :: enum {
+	Node,
+	Road,
+}
\ No newline at end of file
diff --git a/src/draw.odin b/src/draw.odin
new file mode 100644
index 0000000..add8018
--- /dev/null
+++ b/src/draw.odin
@@ -0,0 +1,49 @@
+package main
+
+import "core:fmt"
+import rl "vendor:raylib"
+
+import "common"
+
+// Main drawing function
+draw :: proc(self: ^Simulator, pos: rl.Vector2) {
+	rl.ClearBackground(rl.LIGHTGRAY)
+	
+	// draw roads
+	for &road, index in self.roads {
+		start := road.nodes[0]
+		end := road.nodes[1]
+		
+		road_colour: rl.Color
+		if road, ok := self.highlighted_road.?; ok && road == u32(index) && self.delete_mode {
+			road_colour = common.ROAD_HIGHLIGHT_COLOUR
+		} else do road_colour = common.ROAD_COLOUR
+		
+		rl.DrawLineEx(self.nodes[start].pos, self.nodes[end].pos, common.ROAD_SIZE, road_colour)
+	}
+	
+	// draw nodes
+	for &node in self.nodes {
+		// draws the snapping radius if key is held down
+		if self.show_details do rl.DrawCircleV(node.pos, common.NODE_SNAP_RADIUS * common.NODE_RADIUS, common.NODE_SNAP_COLOUR)
+		// draws the node
+		rl.DrawCircleV(node.pos, common.NODE_RADIUS, common.NODE_DONE_COLOUR)
+	}
+	
+	// draw temp road if exists
+	if val, ok := self.temp_node.?; ok {
+		rl.DrawLineEx(self.nodes[val].pos, pos, common.ROAD_SIZE, common.ROAD_COLOUR)
+		
+		rl.DrawCircleV(self.nodes[val].pos, common.NODE_RADIUS, common.NODE_BUILD_COLOUR)
+		rl.DrawCircleV(pos, common.NODE_RADIUS, common.NODE_CURSOR_COLOUR)
+	}
+	
+	draw_ui(self)
+}
+
+// Drawing UI text, mostly for debugging purposes
+@(private="file")
+draw_ui :: proc(self: ^Simulator) {
+	entity_count := fmt.ctprintf("Nodes: %d\nRoads: %d", len(self.nodes), len(self.roads))
+	rl.DrawText(entity_count, i32(common.WIDTH - 13 * len(entity_count)), common.HEIGHT - 2 * common.TEXT_SIZE, common.TEXT_SIZE, common.TEXT_COLOUR)
+}
\ No newline at end of file
diff --git a/src/entity_management.odin b/src/entity_management.odin
new file mode 100644
index 0000000..d2143af
--- /dev/null
+++ b/src/entity_management.odin
@@ -0,0 +1,90 @@
+package main
+
+import rl "vendor:raylib"
+
+import "common"
+import inf "infrastructure"
+
+// This function only returns the index to the node or if it doesn't exist bool in the tuple is false
+@private
+get_node_index_if_exists :: proc(self: ^Simulator, pos: rl.Vector2) -> (u32, bool) {
+	for &node, index in self.nodes {
+		if inf.node_within_snapping_radius(&node, pos) do return u32(index), true
+	}
+	
+	return 0, false
+}
+
+// Given position, the function will attempt the return the pointer to the node in near vicinity, 
+// or if unsuccesful manually creating the node based on the position in the list and then returning the pointer to it
+@private
+get_node_or_new :: proc(self: ^Simulator, pos: rl.Vector2) -> u32 {
+	if node, ok := get_node_index_if_exists(self, pos); ok do return node
+	
+	node := inf.node_init(pos)
+	append(&self.nodes, node)
+	
+	return u32(len(self.nodes) - 1)
+}
+
+// Attempts to update node reference to the road;
+// Returns false if the old reference doesn't exist
+@private
+update_node_reference :: proc(self: ^Simulator, road_to_update: u32, old_ref: u32, new_ref: u32) -> bool {
+	road := &self.roads[road_to_update]
+	
+	for i in 0..<len(road.nodes) {
+		if road.nodes[i] != old_ref do continue
+		
+		road.nodes[i] = new_ref
+		inf.node_unreference_road(&self.nodes[old_ref], road_to_update)
+		append(&self.nodes[new_ref].roads, road_to_update)
+		
+		return true
+	}
+	
+	return false
+}
+
+// Function that allows deleting of any entity within the entity list (nodes, roads, etc.) while ensuring valid references
+// Returns swapped entities if they exist
+@private
+delete_entity :: proc(self: ^Simulator, entity_index: u32, type: common.Entity) -> ([2]u32, bool) {
+	mlen: u32
+	// Stores data about old and new index in case the deleted index is not last, meaning the swap occurs
+	index_change: [2]u32
+	// Tracks whether the removal of node/road will cause a swap in the (dynamic) array 
+	// and thus forcing the pre-swapped reference to be updated
+	swap_made: bool
+	
+	switch type {
+	case .Node:
+		mlen = u32(len(self.nodes))
+	case .Road:
+		mlen = u32(len(self.roads))
+	}
+	
+	last := mlen - 1
+	if entity_index != last {
+		index_change = {last, entity_index}
+		swap_made = true
+	}
+	
+	switch type {
+	case .Node:
+		unordered_remove(&self.nodes, entity_index)
+		if !swap_made do return {}, false
+		
+		for &road in self.roads do inf.road_update_node_reference(&road, index_change[0], index_change[1])
+		return index_change, true
+		
+	case .Road:
+		unordered_remove(&self.roads, entity_index)
+		if !swap_made do return {}, false
+		
+		for &node in self.nodes do inf.node_update_road_reference(&node, index_change[0], index_change[1])
+		return index_change, true
+	}
+	
+	return {}, false
+}
\ No newline at end of file
diff --git a/src/infrastructure/node.odin b/src/infrastructure/node.odin
new file mode 100644
index 0000000..15b3f97
--- /dev/null
+++ b/src/infrastructure/node.odin
@@ -0,0 +1,61 @@
+package infrastructure
+
+import "../common"
+import rl "vendor:raylib"
+
+Node :: struct {
+	// Whether the node is reachable
+	enabled: bool,
+	// This node's position
+	pos: rl.Vector2,
+	// All of the roads that are connected to the node itself;
+	// Stores the index of the Road object that is stored within Simulator struct in roads dynamic array
+	roads: [dynamic]u32,
+}
+
+// Constructor
+node_init :: proc(new_pos: rl.Vector2) -> Node {
+	return {
+		enabled = true,
+		pos = new_pos,
+		roads = nil,
+	}
+}
+
+// Destructor
+node_deinit :: proc(self: ^Node) {
+	delete(self.roads)
+}
+
+// Returns whether passed pos(ition) is within this node's snapping radius
+node_within_snapping_radius :: proc(self: ^Node, pos: rl.Vector2) -> bool {
+	return rl.CheckCollisionPointCircle(
+		pos,
+		self.pos,
+		common.NODE_SNAP_RADIUS * common.NODE_RADIUS,
+	)
+}
+
+// Tries to remove the road reference from the node; returns false if failed
+node_unreference_road :: proc(self: ^Node, road_to_unref: u32) -> bool {
+	for i in 0..<len(self.roads) {
+		if self.roads[i] != road_to_unref do continue
+		
+		unordered_remove(&self.roads, i)
+		return true
+	}
+	
+	return false
+}
+
+// Attempts to update the existing road references with new one; returns false if it can't find the old reference
+node_update_road_reference :: proc(self: ^Node, old_ref: u32, new_ref: u32) -> bool {
+	for &road in self.roads {
+		if road != old_ref do continue
+		
+		road = new_ref
+		return true
+	}
+	
+	return false
+}
\ No newline at end of file
diff --git a/src/infrastructure/road.odin b/src/infrastructure/road.odin
new file mode 100644
index 0000000..0ab758d
--- /dev/null
+++ b/src/infrastructure/road.odin
@@ -0,0 +1,25 @@
+package infrastructure
+
+Road :: struct {
+	// Index to nodes that limit the road
+	nodes: [2]u32,
+}
+
+// Road Initialisation
+road_init :: proc(start: u32, end: u32) -> Road {
+	return {
+		nodes = {start, end}
+	}
+}
+
+// Updates existing node reference to a new one; returns false if old ref was not found
+road_update_node_reference :: proc(self: ^Road, old_ref: u32, new_ref: u32) -> bool {
+	for &node in self.nodes {
+		if node != old_ref do continue
+		
+		node = new_ref
+		return true
+	}
+	
+	return false
+}
\ No newline at end of file
diff --git a/src/input.odin b/src/input.odin
new file mode 100644
index 0000000..ffd37b6
--- /dev/null
+++ b/src/input.odin
@@ -0,0 +1,62 @@
+package main
+
+import rl "vendor:raylib"
+
+import inf "infrastructure"
+
+// Public input function that gets called in graphics library loop
+handle_input :: proc(self: ^Simulator, pos: rl.Vector2) {
+	handle_keyboard_input(self)
+	handle_mouse_input(self, pos)
+}
+
+// General keyboard input event handler
+@(private="file")
+handle_keyboard_input :: proc(self: ^Simulator) {
+	self.show_details = rl.IsKeyDown(.LEFT_ALT)
+	self.auto_continue = rl.IsKeyDown(.LEFT_CONTROL)
+	self.delete_mode = rl.IsKeyDown(.LEFT_SHIFT)
+	
+	if (rl.IsKeyReleased(.C)) {
+		self.temp_node = nil
+		clear(&self.roads)
+		clear(&self.nodes)
+	}
+}
+
+// Generally mouse event handler
+@(private="file")
+handle_mouse_input :: proc(self: ^Simulator, pos: rl.Vector2) {
+	if (rl.IsMouseButtonReleased(.LEFT)) {
+		left_click_event(self, pos)
+	} else if (rl.IsMouseButtonReleased(.RIGHT)) {
+		right_click_event(self)
+	}
+}
+
+// Handles left click functionality
+@(private="file")
+left_click_event :: proc(self: ^Simulator, pos: rl.Vector2) {
+	if self.delete_mode {
+		if road, ok := self.highlighted_road.?; ok do delete_road(self, road)
+		return
+	}
+	
+	create_road(self, pos)
+}
+
+// Handles right click functionality
+@(private="file")
+right_click_event :: proc(self: ^Simulator) {
+	if self.temp_node == nil do return
+	index := self.temp_node.?
+	
+	temp_node := &self.nodes[index]
+	self.temp_node = nil
+	if len(temp_node.roads) > 0 do return	
+	
+	inf.node_deinit(temp_node)
+	// We can safely call the remove here as the only way it will get deleted is if it's the only node aka it was created during our creation process
+	// Consequently this means that it will always be on last place and never swapped with anything
+	unordered_remove(&self.nodes, index)
+}
\ No newline at end of file
diff --git a/src/main.odin b/src/main.odin
new file mode 100644
index 0000000..a7a6283
--- /dev/null
+++ b/src/main.odin
@@ -0,0 +1,29 @@
+package main
+
+import rl "vendor:raylib"
+
+import "common"
+
+main :: proc() {
+	rl.SetConfigFlags({.MSAA_4X_HINT, .WINDOW_HIGHDPI})
+	rl.InitWindow(common.WIDTH, common.HEIGHT, "Base Road Network")
+	defer rl.CloseWindow()
+	
+	rl.SetWindowMonitor(common.MONITOR)
+	rl.SetTargetFPS(rl.GetMonitorRefreshRate(common.MONITOR))
+	
+	sim: Simulator
+	defer deinit(&sim)
+	
+	for !rl.WindowShouldClose() {
+		rl.BeginDrawing()
+		defer rl.EndDrawing()
+		
+		pos := rl.GetMousePosition()
+		
+		handle_input(&sim, pos)
+		update(&sim, pos)
+		
+		draw(&sim, pos)
+	}
+}
\ No newline at end of file
diff --git a/src/simulator.odin b/src/simulator.odin
new file mode 100644
index 0000000..38cd873
--- /dev/null
+++ b/src/simulator.odin
@@ -0,0 +1,192 @@
+package main
+
+import rl "vendor:raylib"
+
+import "common"
+import "core:fmt"
+import inf "infrastructure"
+
+Simulator :: struct {
+	// Stores all nodes
+	nodes: [dynamic]inf.Node,
+	// Stores all roads
+	roads: [dynamic]inf.Road,
+	// Tracks the temporary node location
+	temp_node: Maybe(u32),
+	// Tracks the selected road
+	highlighted_road: Maybe(u32),
+	// Tracks whether the user wishes to see node's snapping radius
+	show_details: bool,
+	// Tracks whether after placing a road new one will start being placed
+	auto_continue: bool,
+	// Tracks whether the delete mode is activated
+	delete_mode: bool,
+}
+
+// Destructor
+deinit :: proc(self: ^Simulator) {
+	self.temp_node = nil
+	self.highlighted_road = nil
+	
+	delete(self.roads)
+	
+	for &node in self.nodes {
+		inf.node_deinit(&node)
+	}
+	delete(self.nodes)
+}
+
+// Functionality that runs every tick regardless of input
+update :: proc(self: ^Simulator, pos: rl.Vector2) {
+	update_highlighted_road(self, pos)
+}
+
+// Implementation of road building after a click has been registered
+@private
+create_road :: proc(self: ^Simulator, pos: rl.Vector2) {
+	// BUILD
+	cur_node_index := get_node_or_new(self, pos)
+	
+	if temp, ok := self.temp_node.?; ok {
+		// If both values are identical this means the user has to create a new road using the same nodes
+		if cur_node_index == temp do return
+		data := get_intersecting_roads(self, temp, cur_node_index)
+		split_roads_by_points(self, data, temp, cur_node_index)
+		
+		self.temp_node = self.auto_continue ? cur_node_index : nil
+		return
+	}
+	
+	self.temp_node = cur_node_index
+}
+
+// Returns data about roads that intersect the given 2 nodes (points)
+@(private="file")
+get_intersecting_roads :: proc(self: ^Simulator, start: u32, end: u32) -> []common.Intersection_Data {
+	intersections: [dynamic]common.Intersection_Data
+	collision_point: rl.Vector2
+	
+	outer: for road, index in self.roads {
+		road_start_node := road.nodes[0]
+		road_end_node := road.nodes[1]
+		
+		if !rl.CheckCollisionLines(self.nodes[start].pos, self.nodes[end].pos, self.nodes[road_start_node].pos, self.nodes[road_end_node].pos, &collision_point) do continue
+		
+		// Save the collision info
+		data := common.Intersection_Data {
+			road = u32(index),
+			point = collision_point
+		}
+		
+		node := inf.node_init(data.point)
+		// Here we check if the intersection points that were recorded before, are already within snapping radius of our current intersected point
+		for collision in intersections {
+			if (inf.node_within_snapping_radius(&node, collision.point)) do continue outer
+		}
+		
+		// Here we check if our new intersected point node is too close to already established nodes
+		if _, ok := get_node_index_if_exists(self, data.point); ok do continue
+		
+		append(&intersections, data)
+	}
+	
+	return intersections[:]
+}
+
+// Given intersection data, the function splits all existing roads and adds new nodes on intersections
+@(private="file")
+split_roads_by_points :: proc(self: ^Simulator, intersections: []common.Intersection_Data, start: u32, end: u32) {
+	if len(intersections) == 0 {
+		add_road(self, start, end)
+		return
+	}
+	
+	first_intersection_node := get_node_or_new(self, intersections[0].point)
+	add_road(self, start, first_intersection_node)
+	
+	for i in 0..<len(intersections) {
+		intersection := intersections[i]
+		// The node created at the point of intersection
+		new_node := get_node_or_new(self, intersection.point)
+		
+		// Pointer to the node that borders the road that was intersected
+		// This node and the new node will become nodes for the new road being created
+		road_old_node := self.roads[intersection.road].nodes[1]
+		
+		// The old road that was intersected now borders the new node
+		// and the old node is removed from the road's end node reference,
+		// as is the end node's road reference
+		ok := update_node_reference(self, intersection.road, road_old_node, new_node)
+		if !ok do fmt.panicf("Failed to update the node reference to the Road ID=%d, because I couldn't find old reference ID=%d\n", 
+			intersection.road, road_old_node)
+		
+		// This adds the road (to the road manager) and also references the road at both nodes (pointers)
+		add_road(self, new_node, road_old_node)
+		
+		if (i == len(intersections) - 1) do continue
+		
+		node_start := get_node_or_new(self, intersection.point)
+		node_end := get_node_or_new(self, intersections[i + 1].point)
+		
+		add_road(self, node_start, node_end)
+	}
+	
+	last_intersection_road := intersections[len(intersections) - 1]
+	last_intersection_node := get_node_or_new(self, last_intersection_road.point)
+	add_road(self, last_intersection_node, end)
+}
+
+// Adds a new road into roads array, start and end are indexes of existing nodes
+@(private="file")
+add_road :: proc(self: ^Simulator, start: u32, end: u32) {
+	road := inf.road_init(start, end)
+	append(&self.roads, road)
+	
+	road_index := u32(len(self.roads) - 1)
+	append(&self.nodes[start].roads, road_index)
+	append(&self.nodes[end].roads, road_index)
+}
+
+// Deletes the road which index was sent in, alongside deleting references of said road and removal of nodes if that road was their only connection
+@private
+delete_road :: proc(self: ^Simulator, road_to_delete: u32) {
+	// First we need to unreference this road from surrounding nodes and then delete those nodes IF this was the last road connection
+	road := self.roads[road_to_delete]
+	// Pointers to the nodes bordering the road we wish to delete
+	start_node := &self.nodes[road.nodes[0]]
+	end_node := &self.nodes[road.nodes[1]]
+	
+	// We unreference the road from the nodes bordering the road
+	start_unref := inf.node_unreference_road(start_node, road_to_delete)
+	end_unref := inf.node_unreference_road(end_node, road_to_delete)
+	if !start_unref || !end_unref do fmt.panicf("Failed to unreference one (or both) of the nodes of the Road ID=%d\n", road_to_delete)
+	
+	// Now we delete the road
+	delete_entity(self, road_to_delete, .Road)
+	
+	// After the remove we have to replace references
+	if len(start_node.roads) == 0 {
+		// If the id of the next node gets swapped we must update it accordingly
+		if result, ok := delete_entity(self, road.nodes[0], .Node); ok && result[0] == road.nodes[1] {
+			road.nodes[1] = result[1]
+		}
+	}
+	
+	if len(end_node.roads) == 0 do delete_entity(self, road.nodes[1], .Node)
+}
+
+// Keeps track of the selected/highlighted road
+@(private="file")
+update_highlighted_road :: proc(self: ^Simulator, pos: rl.Vector2) {
+	for road, index in self.roads {
+		start_node := self.nodes[road.nodes[0]]
+		end_node := self.nodes[road.nodes[1]]
+		
+		if !rl.CheckCollisionPointLine(pos, start_node.pos, end_node.pos, common.ROAD_SIZE) do continue
+		
+		self.highlighted_road = u32(index)
+		return
+	}
+	
+	self.highlighted_road = nil
+}
\ No newline at end of file