refactor gold rewards and tower cost; fix wave test leak

README.md

@@ -0,0 +1,14 @@
+## Game
+
+This is a very simple game. 
+
+## Objective
+
+- Explore Nystrom's Game Programming patterns when appropriate.
+- Learn Odin
+- Enjoy the love of hand writing code (cuz I love it)
+
+## Goals
+- Build a playable single player game
+- Build a multiplayer aspect
+- Keep things as simple as possible

game/app.odin

@@ -3,27 +3,31 @@ package game
 import rl "vendor:raylib"
 
 run :: proc() {
-	rl.InitWindow(SCREEN_W, SCREEN_H, "Tower Defense")
-	defer rl.CloseWindow()
-	rl.SetTargetFPS(60)
+	init_display()
+	defer {
+		shutdown_display()
+		rl.CloseWindow()
+	}
 
 	world := init_world()
+	defer {
+		delete(world.path)
+		delete(world.towers)
+		delete(world.events)
+		delete(world.spawner.recipe)
+	}
 
 	for !rl.WindowShouldClose() {
 		dt := rl.GetFrameTime()
 
+		update_display()
 		update_world(&world, dt)
 
-		rl.BeginDrawing()
-		rl.ClearBackground(rl.Color{34, 139, 34, 255})
-
+		begin_game_draw()
 		render_world(&world)
-		rl.EndDrawing()
+		render_overlay(&world)
+		render_controls(&world)
+		end_game_draw()
 	}
-
-	delete(world.path)
-	delete(world.towers)
-	delete(world.events)
-
 }
 

game/commands.odin

@@ -6,6 +6,7 @@ Command_Kind :: enum {
 	None,
 	Place_Tower,
 	Start_Wave,
+	Upgrade_Tower,
 }
 
 Command :: struct {
@@ -15,18 +16,24 @@ Command :: struct {
 }
 
 gather_commands :: proc(world: ^World) -> Command {
+	ui_cmd := poll_controls_command(world)
+	if ui_cmd.kind != .None do return ui_cmd
+
+	if rl.IsKeyPressed(.ONE) do world.selected_tower = .Archer
+	if rl.IsKeyPressed(.TWO) do world.selected_tower = .Cannon
+	if rl.IsKeyPressed(.THREE) do world.selected_tower = .Ice
 	if world.phase == .Build && rl.IsKeyPressed(.N) {
 		return Command{kind = .Start_Wave}
 	}
 
-	if world.phase == .Build && rl.IsMouseButtonPressed(.LEFT) {
-		mouse := rl.GetMousePosition()
+	if rl.IsMouseButtonPressed(.RIGHT) {
+		mouse := game_mouse()
 		gx, gy := screen_to_grid(mouse.x, mouse.y)
-		return Command{kind = .Place_Tower, gx = gx, gy = gy}
+		return Command{kind = .Upgrade_Tower, gx = gx, gy = gy}
 	}
 
-	if rl.IsMouseButtonPressed(.LEFT) {
-		mouse := rl.GetMousePosition()
+	if world.phase == .Build && rl.IsMouseButtonPressed(.LEFT) {
+		mouse := game_mouse()
 		gx, gy := screen_to_grid(mouse.x, mouse.y)
 		return Command{kind = .Place_Tower, gx = gx, gy = gy}
 	}
@@ -38,9 +45,11 @@ execute_command :: proc(world: ^World, cmd: Command) {
 	switch cmd.kind {
 	case .None:
 	case .Place_Tower:
-		try_place_tower(world, cmd.gx, cmd.gy, .Archer)
+		try_place_tower(world, cmd.gx, cmd.gy, world.selected_tower)
 	case .Start_Wave:
 		start_wave(world)
+	case .Upgrade_Tower:
+		try_upgrade_tower(world, cmd.gx, cmd.gy)
 	}
 }
 

game/constants.odin

@@ -1,5 +1,7 @@
 package game
 
+import rl "vendor:raylib"
+
 MAP_W :: 30 // map width in tiles
 MAP_H :: 20 // map height in tiles
 TILE_SIZE :: 32 // size of tiles in pixels
@@ -7,13 +9,63 @@ TILE_SIZE :: 32 // size of tiles in pixels
 SCREEN_W :: MAP_W * TILE_SIZE
 SCREEN_H :: MAP_H * TILE_SIZE
 
+DEFAULT_WINDOW_W :: 1280
+DEFAULT_WINDOW_H :: 720
+
 MAX_ENEMIES :: 64
 MAX_WAVES :: 5
 MAX_TOWERS :: 32
 
-TOWER_COST :: 50
-
 MAX_PROJECTILES :: 64
 PROJECTILE_SPEED :: 280 // pixels per second
 PROJECTILE_HIT_RADIUS :: 10
+CANNON_PROJECTILES_SPEED :: 320.0
+
+OVERLAY_BAR_H :: 28
+OVERLAY_PADDING :: 6
+OVERLAY_BAR_COLOR :: rl.Color{20, 24, 20, 200}
+OVERLAY_GOLD_COLOR :: rl.Color{255, 215, 80, 255}
+OVERLAY_TEXT_COLOR :: rl.Color{240, 240, 230, 255}
+OVERLAY_FONT_SIZE :: 18
+
+CONTROL_BAR_H :: 40
+CONTROL_BAR_BG :: rl.Color{30, 55, 30, 220}
+CONTROL_BUTTON_COLOR :: rl.Color{60, 120, 60, 255}
+CONTROL_BUTTON_HOVER :: rl.Color{60, 150, 60, 255}
+
+CONTROLS_SHOP_IDLE :: rl.Color{45, 75, 45, 255}
+CONTROL_SHOP_SELECTED :: rl.Color{70, 110, 70, 255}
+CONTROLS_SHOP_HOVER :: rl.Color{90, 130, 90, 255}
+
+ICE_SLOW_DURATION :: 2.5
+ICE_SLOW_FACTOR :: 0.5
+
+ENEMY_LABEL_COLOR :: rl.Color{255, 200, 200, 255}
+
+// starting values for the game
+STARTING_BASE_HEALTH :: 20
+STARTING_GOLD :: 100
+
+//controls constants
+BOTTOM_BAR_Y :: SCREEN_H - CONTROL_BAR_H
+ARCHER_BUTTON_W :: 120
+START_WAVE_BUTTON_W :: 110
+CONTROLS_BUTTON_GAP :: 12
+CONTROLS_BUTTON_H :: 24
+CONTROLS_BUTTON_Y :: BOTTOM_BAR_Y + 8
+CONTROLS_BUTTON_X :: (SCREEN_W - (ARCHER_BUTTON_W + CONTROLS_BUTTON_GAP + START_WAVE_BUTTON_W)) / 2
+
+ARCHER_BUTTON_RECT :: rl.Rectangle {
+	f32(CONTROLS_BUTTON_X),
+	f32(CONTROLS_BUTTON_Y),
+	ARCHER_BUTTON_W,
+	CONTROLS_BUTTON_H,
+}
+
+START_WAVE_BUTTON_RECT :: rl.Rectangle {
+	f32(CONTROLS_BUTTON_X + ARCHER_BUTTON_W + CONTROLS_BUTTON_GAP),
+	f32(CONTROLS_BUTTON_Y),
+	START_WAVE_BUTTON_W,
+	CONTROLS_BUTTON_H,
+}
 

game/controls.odin

@@ -0,0 +1,76 @@
+package game
+
+import "core:fmt"
+import rl "vendor:raylib"
+
+
+poll_controls_command :: proc(world: ^World) -> Command {
+	if world.phase != .Build do return Command{kind = .None}
+
+	mouse := game_mouse()
+	if rl.IsMouseButtonPressed(.LEFT) {
+		if rl.CheckCollisionPointRec(mouse, ARCHER_BUTTON_RECT) {
+			world.selected_tower = .Archer
+		}
+		if rl.CheckCollisionPointRec(mouse, START_WAVE_BUTTON_RECT) {
+			return Command{kind = .Start_Wave}
+		}
+	}
+
+	return Command{kind = .None}
+}
+
+draw_archer_button :: proc(world: ^World, archer: rl.Rectangle) {
+	arch := TOWER_ARCHETYPES[.Archer]
+	mouse := rl.GetMousePosition()
+
+	arch_bg := CONTROLS_SHOP_IDLE
+	if world.selected_tower == .Archer do arch_bg = CONTROL_SHOP_SELECTED
+	if rl.CheckCollisionPointRec(mouse, archer) do arch_bg = CONTROLS_SHOP_HOVER
+
+	label := fmt.ctprintf("Archer - %dg", arch.cost)
+	draw_button(archer, label, arch_bg, 14, OVERLAY_TEXT_COLOR)
+}
+
+draw_start_wave_button :: proc(start_wave_rect: rl.Rectangle, mouse: rl.Vector2) {
+	bg := CONTROL_BUTTON_COLOR
+	if rl.CheckCollisionPointRec(mouse, start_wave_rect) do bg = CONTROL_BUTTON_HOVER
+
+	draw_button(start_wave_rect, "Start Wave", bg, 16, OVERLAY_TEXT_COLOR)
+}
+
+draw_build_controls :: proc(world: ^World) {
+	if world.phase != .Build do return
+	mouse := game_mouse()
+
+	rl.DrawRectangle(0, BOTTOM_BAR_Y, SCREEN_W, CONTROL_BAR_H, CONTROL_BAR_BG)
+
+	draw_archer_button(world, ARCHER_BUTTON_RECT)
+	draw_start_wave_button(START_WAVE_BUTTON_RECT, mouse)
+}
+
+render_controls :: proc(world: ^World) {
+	switch world.phase {
+	case .Build:
+		draw_build_controls(world)
+	case .Combat:
+		draw_combat_banner()
+	case .Game_Over, .Victory:
+	}
+}
+
+draw_combat_banner :: proc() {
+	rl.DrawRectangle(0, BOTTOM_BAR_Y, SCREEN_W, CONTROL_BAR_H, rl.Color{120, 40, 40, 200})
+
+	text: cstring = "Combat!"
+	font: i32 = 16
+	tw := rl.MeasureText(text, font)
+	rl.DrawText(
+		text,
+		(SCREEN_W - tw) / 2,
+		BOTTOM_BAR_Y + (CONTROL_BAR_H - font) / 2,
+		font,
+		rl.Color{255, 220, 220, 255},
+	)
+}
+

game/display.odin

@@ -0,0 +1,62 @@
+package game
+
+import rl "vendor:raylib"
+
+game_target: rl.RenderTexture2D
+
+init_display :: proc() {
+	rl.InitWindow(DEFAULT_WINDOW_W, DEFAULT_WINDOW_H, "Tower Defense")
+	rl.SetWindowState({.WINDOW_RESIZABLE})
+	rl.SetTargetFPS(60)
+	game_target = rl.LoadRenderTexture(i32(SCREEN_W), i32(SCREEN_H))
+}
+
+shutdown_display :: proc() {
+	rl.UnloadRenderTexture(game_target)
+}
+
+update_display :: proc() {
+	if rl.IsKeyPressed(.F11) {
+		rl.ToggleFullscreen()
+	}
+}
+
+game_viewport_dest :: proc() -> rl.Rectangle {
+	sw := f32(rl.GetRenderWidth())
+	sh := f32(rl.GetRenderHeight())
+	scale := min(sw / f32(SCREEN_W), sh / f32(SCREEN_H))
+	dw := f32(SCREEN_W) * scale
+	dh := f32(SCREEN_H) * scale
+	return {x = (sw - dw) * 0.5, y = (sh - dh) * 0.5, width = dw, height = dh}
+}
+
+game_mouse :: proc() -> rl.Vector2 {
+	m := rl.GetMousePosition()
+	dest := game_viewport_dest()
+	if dest.width <= 0 || dest.height <= 0 {
+		return m
+	}
+	return {
+		(m.x - dest.x) / dest.width * f32(SCREEN_W),
+		(m.y - dest.y) / dest.height * f32(SCREEN_H),
+	}
+}
+
+begin_game_draw :: proc() {
+	rl.BeginTextureMode(game_target)
+	rl.ClearBackground(rl.Color{34, 139, 34, 255})
+}
+
+end_game_draw :: proc() {
+	rl.EndTextureMode()
+
+	rl.BeginDrawing()
+	rl.ClearBackground(rl.BLACK)
+
+	dest := game_viewport_dest()
+	source := rl.Rectangle{0, 0, f32(SCREEN_W), -f32(SCREEN_H)}
+	rl.DrawTexturePro(game_target.texture, source, dest, {}, 0, rl.WHITE)
+
+	rl.EndDrawing()
+}
+

game/endscreen.odin

@@ -0,0 +1,29 @@
+package game
+
+import "core:fmt"
+import rl "vendor:raylib"
+
+draw_end_screen :: proc(world: ^World) {
+	title: cstring = "GAME OVER"
+	title_color := rl.RED
+	sub: cstring = "Press close to quit"
+	sub_color := OVERLAY_TEXT_COLOR
+
+	if world.phase == .Victory {
+		title = "VICTORY!"
+		title_color = rl.GREEN
+		sub = fmt.ctprintf("You survived %d waves!", MAX_WAVES)
+	}
+
+
+	rl.DrawRectangle(0, 0, SCREEN_W, SCREEN_H, rl.Color{0, 0, 0, 140})
+
+	title_font: i32 = 40
+	tw := rl.MeasureText(title, title_font)
+	rl.DrawText(title, (SCREEN_W - tw) / 2, SCREEN_H / 2 - 50, title_font, title_color)
+
+	sub_font: i32 = 18
+	sw := rl.MeasureText(sub, sub_font)
+	rl.DrawText(sub, (SCREEN_W - sw) / 2, SCREEN_H / 2 + 10, sub_font, sub_color)
+}
+

game/enemy.odin

@@ -1,6 +1,7 @@
 package game
 
 import "core:fmt"
+import "core:sys/posix"
 import rl "vendor:raylib"
 
 Enemy :: struct {
@@ -9,7 +10,55 @@ Enemy :: struct {
 	max_health: int,
 	active:     bool,
 	path_index: int,
-	speed:      f32,
+	base_speed: f32,
+	slow_timer: f32,
+	kind:       Enemy_Kind,
+}
+
+Enemy_Kind :: enum {
+	Grunt,
+	Runner,
+	Tank,
+}
+
+Enemy_Def :: struct {
+	base_health:     int,
+	health_per_wave: int,
+	base_speed:      f32,
+	speed_per_wave:  f32,
+	color:           rl.Color,
+	draw_radius:     f32,
+	gold_reward:     int,
+}
+
+ENEMY_DEF: [Enemy_Kind]Enemy_Def = {
+	.Grunt = {
+		base_health = 15,
+		health_per_wave = 5,
+		base_speed = 55,
+		speed_per_wave = 5,
+		color = rl.MAROON,
+		draw_radius = 11,
+		gold_reward = 5,
+	},
+	.Runner = {
+		base_health = 10,
+		health_per_wave = 2,
+		base_speed = 95,
+		speed_per_wave = 3,
+		color = rl.ORANGE,
+		draw_radius = 11,
+		gold_reward = 5,
+	},
+	.Tank = {
+		base_health = 50,
+		health_per_wave = 12,
+		base_speed = 35,
+		speed_per_wave = 2,
+		color = rl.DARKGREEN,
+		draw_radius = 14,
+		gold_reward = 10,
+	},
 }
 
 acquire_enemy :: proc(world: ^World) -> ^Enemy {
@@ -23,35 +72,34 @@ acquire_enemy :: proc(world: ^World) -> ^Enemy {
 	return nil
 }
 
-spawn_enemy :: proc(world: ^World, health: int, speed: f32) {
+spawn_enemy :: proc(world: ^World, kind: Enemy_Kind) {
 	if len(world.path) == 0 do return // don't spawn enemies if no paths exist
 
 	e := acquire_enemy(world) // grab a free slot
 	if e == nil do return // if there are no slots, skil spawning
 
+	def := ENEMY_DEF[kind]
+	health := def.base_health + world.wave * def.health_per_wave
+	speed := def.base_speed + f32(world.wave) * def.speed_per_wave
 	e^ = Enemy {
 		position   = world.path[0],
 		health     = health,
 		max_health = health,
-		speed      = speed,
+		base_speed = speed,
+		slow_timer = 0,
 		path_index = 1,
+		kind       = kind,
 		active     = true,
 	}
 }
 
-spawn_group :: proc(world: ^World, count: int) {
-	for _ in 0 ..< count {
-		spawn_enemy(world, 20, 60)
-	}
-}
-
 update_enemies :: proc(world: ^World, dt: f32) {
+	if len(world.path) < 2 do return
+
 	for i in 0 ..< MAX_ENEMIES {
 		e := &world.enemies[i]
 		if !e.active do continue
 
-		if len(world.path) == 2 do return
-
 		if e.path_index >= len(world.path) {
 			world.base_health -= 1
 			e.active = false
@@ -59,7 +107,12 @@ update_enemies :: proc(world: ^World, dt: f32) {
 		}
 
 		target := world.path[e.path_index]
-		move_toward(&e.position, target, e.speed, dt)
+		move_speed := e.base_speed
+		if e.slow_timer > 0 {
+			move_speed *= ICE_SLOW_FACTOR
+			e.slow_timer -= dt
+		}
+		move_toward(&e.position, target, move_speed, dt)
 
 		dx := target.x - e.position.x
 		dy := target.y - e.position.y
@@ -82,7 +135,12 @@ render_enemies :: proc(world: ^World) {
 	for i in 0 ..< MAX_ENEMIES {
 		e := world.enemies[i]
 		if !e.active do continue
-		rl.DrawCircle(i32(e.position.x), i32(e.position.y), 11, rl.MAROON)
+		def := ENEMY_DEF[e.kind]
+
+		rl.DrawCircle(i32(e.position.x), i32(e.position.y), def.draw_radius, def.color)
+		if e.slow_timer > 0 {
+			rl.DrawCircleLines(i32(e.position.x), i32(e.position.y), 14, rl.SKYBLUE)
+		}
 		rl.DrawText(
 			fmt.ctprintf("%d", e.health),
 			i32(e.position.x) - 4,

game/hud.odin

@@ -1,23 +0,0 @@
-package game
-
-import "core:fmt"
-import rl "vendor:raylib"
-
-render_hud :: proc(world: ^World) {
-	rl.DrawText(fmt.ctprintf("Gold: %d", world.gold), 10, 10, 22, rl.BLACK) // Gold HUD
-	rl.DrawText(fmt.ctprintf("Base HP: %d", world.base_health), 10, 32, 22, rl.BLACK) // HP HUD
-	rl.DrawText(fmt.ctprintf("Enemies: %d", active_enemy_count(world)), 10, 54, 22, rl.BLACK)
-	rl.DrawText(fmt.ctprintf("Wave: %d / %d", world.wave, MAX_WAVES), 10, 76, 22, rl.BLACK)
-
-	switch world.phase {
-	case .Build:
-		rl.DrawText("Build - click towers, N = start wave", 10, 98, 22, rl.BLACK)
-	case .Combat:
-		rl.DrawText("Combat!", 10, 98, 22, rl.MAROON)
-	case .Game_Over:
-		rl.DrawText("GAME_OVER", 260, 280, 40, rl.RED)
-	case .Victory:
-		rl.DrawText("Victory!", 260, 280, 40, rl.GREEN)
-	}
-}
-

game/map.odin

@@ -11,17 +11,10 @@ Map :: struct {
 	tiles: [MAP_H][MAP_W]Tile_Kind,
 }
 
-tile_color :: proc(kind: Tile_Kind) -> rl.Color {
-	switch kind {
-	case .Blocked:
-		return {35, 95, 35, 255}
-	case .Path:
-		return {130, 85, 45, 255}
-	case .Build:
-		return {50, 130, 50, 255}
-	}
-
-	return rl.MAGENTA
+TILE_COLORS: [Tile_Kind]rl.Color = {
+	.Blocked = {35, 95, 35, 255},
+	.Path    = {130, 85, 45, 255},
+	.Build   = {50, 130, 50, 255},
 }
 
 init_map :: proc(world_map: ^Map) {
@@ -57,7 +50,7 @@ can_build_at :: proc(world_map: ^Map, gx, gy: int) -> bool {
 render_map :: proc(world: ^World) {
 	for y in 0 ..< MAP_H {
 		for x in 0 ..< MAP_W {
-			c := tile_color(world.world_map.tiles[y][x])
+			c := TILE_COLORS[world.world_map.tiles[y][x]]
 			rl.DrawRectangle(i32(x * TILE_SIZE), i32(y * TILE_SIZE), TILE_SIZE, TILE_SIZE, c)
 		}
 	}

game/math2d.odin

@@ -17,7 +17,7 @@ screen_to_grid :: proc(px, py: f32) -> (int, int) {
 distance :: proc(a, b: Vec2) -> f32 {
 	dx := b.x - a.x
 	dy := b.y - a.y
-	return math.sqrt(dx * dx + dy + dy)
+	return math.sqrt(dx * dx + dy * dy)
 }
 
 move_toward :: proc(pos: ^Vec2, target: Vec2, speed, dt: f32) {

game/math2d_test.odin

@@ -0,0 +1,62 @@
+package game
+
+import "core:math"
+import "core:testing"
+
+@(test)
+test_distance :: proc(t: ^testing.T) {
+	a := Vec2 {
+		x = 3,
+		y = 2,
+	}
+	b := Vec2 {
+		x = 1,
+		y = 2,
+	}
+
+	d := distance(a, b)
+
+	testing.expect(t, math.abs(d - 2.0) < 0.0001)
+}
+
+@(test)
+test_move_toward_already_close :: proc(t: ^testing.T) {
+	pos := Vec2{0.5, 0}
+	target := Vec2{0, 0}
+
+	move_toward(&pos, target, 10, 1.0)
+
+	testing.expect(t, math.abs(pos.x - 0.5) < 0.0001)
+	testing.expect(t, math.abs(pos.y - 0.0) < 0.0001)
+}
+
+@(test)
+test_move_toward_reaches_target :: proc(t: ^testing.T) {
+	pos := Vec2{0, 0}
+	target := Vec2{3, 4}
+
+	move_toward(&pos, target, 100, 1.0)
+
+	testing.expect(t, math.abs(pos.x - 3) < 0.0001)
+	testing.expect(t, math.abs(pos.y - 4) < 0.0001)
+}
+
+@(test)
+test_move_toward_partial :: proc(t: ^testing.T) {
+	pos := Vec2{0, 0}
+	target := Vec2{10, 0}
+
+	move_toward(&pos, target, 2, 1.0)
+
+	testing.expect(t, math.abs(pos.x - 2) < 0.0001)
+	testing.expect(t, math.abs(pos.y) < 0.0001)
+}
+
+@(test)
+test_move_toward_diagonal :: proc(t: ^testing.T) {
+	pos := Vec2{0, 0}
+	target := Vec2{3, 4}
+
+	move_toward(&pos, target, 5, 0.5)
+}
+

game/overlay.odin

@@ -0,0 +1,33 @@
+package game
+
+import "core:fmt"
+import rl "vendor:raylib"
+
+render_overlay :: proc(world: ^World) {
+	rl.DrawRectangle(0, 0, SCREEN_W, OVERLAY_BAR_H, OVERLAY_BAR_COLOR)
+
+	y: i32 = (OVERLAY_BAR_H - OVERLAY_FONT_SIZE) / 2
+	x: i32 = OVERLAY_PADDING
+	gap: i32 : 16
+
+
+	gold := fmt.ctprintf("Gold: %d", world.gold)
+	rl.DrawText(gold, OVERLAY_PADDING, OVERLAY_PADDING, 18, OVERLAY_GOLD_COLOR)
+	x += rl.MeasureText(gold, OVERLAY_FONT_SIZE) + gap
+
+	hp := fmt.ctprintf("Health: %d", world.base_health)
+	rl.DrawText(hp, x, y, OVERLAY_FONT_SIZE, OVERLAY_TEXT_COLOR)
+	x += rl.MeasureText(hp, OVERLAY_FONT_SIZE) + gap
+
+	enemies := fmt.ctprintf("Enemies: %d", active_enemy_count(world))
+	rl.DrawText(enemies, x, y, OVERLAY_FONT_SIZE, ENEMY_LABEL_COLOR)
+	x += rl.MeasureText(enemies, OVERLAY_FONT_SIZE) + gap
+
+	waves := fmt.ctprintf("Waves: %d / %d", world.wave, MAX_WAVES)
+	rl.DrawText(waves, x, y, OVERLAY_FONT_SIZE, OVERLAY_TEXT_COLOR)
+
+	if world.phase == .Game_Over || world.phase == .Victory {
+		draw_end_screen(world)
+	}
+}
+

game/projectile.odin

@@ -3,11 +3,19 @@ package game
 import rl "vendor:raylib"
 
 Projectile :: struct {
-	active:      bool,
-	position:    Vec2,
-	target_slot: int,
-	damage:      int,
-	speed:       f32,
+	active:        bool,
+	position:      Vec2,
+	target_slot:   int,
+	damage:        int,
+	speed:         f32,
+	mode:          Projectile_Mode,
+	direction:     Vec2,
+	splash_radius: f32,
+}
+
+Projectile_Mode :: enum {
+	Homing, // chases target
+	Ballistic, // flies in a fixed direction
 }
 
 acquire_projectile :: proc(world: ^World) -> ^Projectile {
@@ -33,37 +41,87 @@ spawn_projectile :: proc(world: ^World, from: Vec2, target_slot: int, damage: in
 	p := acquire_projectile(world)
 	if p == nil do return
 
+	p.mode = .Homing
 	p^ = Projectile {
-		active      = true,
-		position    = from,
-		target_slot = target_slot,
-		damage      = damage,
-		speed       = PROJECTILE_SPEED,
+		active        = true,
+		position      = from,
+		target_slot   = target_slot,
+		damage        = damage,
+		speed         = PROJECTILE_SPEED,
+		splash_radius = 0,
 	}
 }
 
+spawn_ballistic :: proc(world: ^World, from, dir: Vec2, damage: int, splash: f32) {
+	p := acquire_projectile(world)
+	if p == nil do return
+	p^ = Projectile {
+		active        = true,
+		position      = from,
+		direction     = dir,
+		mode          = .Ballistic,
+		damage        = damage,
+		speed         = CANNON_PROJECTILES_SPEED,
+		splash_radius = splash,
+	}
+}
+
+hit_enemy_at :: proc(world: ^World, pos: Vec2, damage: int) -> bool {
+	for i in 0 ..< MAX_ENEMIES {
+		e := &world.enemies[i]
+		if !e.active do continue
+		if distance(pos, e.position) <= PROJECTILE_HIT_RADIUS {
+			apply_tower_hit(world, e, damage)
+			return true
+		}
+	}
+	return false
+}
+
 update_projectiles :: proc(world: ^World, dt: f32) {
 	for i in 0 ..< MAX_PROJECTILES {
 		p := &world.projectiles[i]
 		if !p.active do continue
 
-		target, ok := enemy_still_on_map(world, p.target_slot)
-		if !ok {
-			p.active = false
-			continue
+		switch p.mode {
+		case .Homing:
+			update_homing_projectile(world, p, dt)
+		case .Ballistic:
+			update_ballistic_projectile(world, p, dt)
 		}
+	}
+}
 
-		move_toward(&p.position, target.position, p.speed, dt)
+update_homing_projectile :: proc(world: ^World, p: ^Projectile, dt: f32) {
+	target, ok := enemy_still_on_map(world, p.target_slot)
+	if !ok {
+		p.active = false
+		return
+	}
 
-		if distance(p.position, target.position) <= PROJECTILE_HIT_RADIUS {
-			target.health -= p.damage
-			p.active = false
+	move_toward(&p.position, target.position, p.speed, dt)
 
-			if target.health <= 0 {
-				target.active = false
-				push_event(world, .Enemy_Killed, gold_reward = 5)
-			}
-		}
+	if distance(p.position, target.position) <= PROJECTILE_HIT_RADIUS {
+		p.active = false
+		apply_tower_hit(world, target, p.damage)
+	}
+}
+
+update_ballistic_projectile :: proc(world: ^World, p: ^Projectile, dt: f32) {
+	step := p.speed * dt
+	p.position.x += p.direction.x * step
+	p.position.y += p.direction.y * step
+
+	if apply_splash_damage(world, p.position, p.damage, p.splash_radius) {
+		p.active = false
+		return
+	}
+
+	if p.position.x < 0 ||
+	   p.position.y < 0 ||
+	   p.position.x > MAP_W * TILE_SIZE ||
+	   p.position.y > MAP_H * TILE_SIZE {
+		p.active = false
 	}
 }
 
@@ -71,7 +129,29 @@ render_projectiles :: proc(world: ^World) {
 	for i in 0 ..< MAX_PROJECTILES {
 		p := world.projectiles[i]
 		if !p.active do continue
-		rl.DrawCircle(i32(p.position.x), i32(p.position.y), 4, rl.GOLD)
+		color := rl.GOLD
+		radius: f32 = 4
+		if p.mode == .Ballistic {
+			color = rl.GRAY
+			radius = 6
+		}
+		rl.DrawCircle(i32(p.position.x), i32(p.position.y), radius, color)
 	}
 }
 
+apply_splash_damage :: proc(world: ^World, center: Vec2, damage: int, radius: f32) -> bool {
+	if radius <= 0 do return hit_enemy_at(world, center, damage)
+
+	hit_any := false
+	for i in 0 ..< MAX_ENEMIES {
+		e := &world.enemies[i]
+		if !e.active do continue
+		if distance(center, e.position) <= radius {
+			apply_tower_hit(world, e, damage)
+			hit_any = true
+		}
+	}
+
+	return hit_any
+}
+

game/render.odin

@@ -4,7 +4,7 @@ render_world :: proc(world: ^World) {
 	render_map(world)
 	render_enemies(world)
 	render_towers(world)
+	render_placement_preview(world)
 	render_projectiles(world)
-	render_hud(world)
 }
 

game/tower.odin

@@ -1,125 +1,91 @@
 package game
 
+import "core:fmt"
 import rl "vendor:raylib"
 
 Tower :: struct {
-	position:  Vec2,
-	kind:      Tower_Kind,
-	cooldown:  f32,
-	anchor_gx: int,
-	anchor_gy: int,
+	upgrade_level: int,
+	position:      Vec2,
+	kind:          Tower_Kind,
+	cooldown:      f32,
+	anchor_gx:     int,
+	anchor_gy:     int,
 }
 
 Tower_Kind :: enum {
 	Archer,
+	Cannon,
+	Ice,
 }
 
 Tower_Archetype :: struct {
-	kind:        Tower_Kind,
-	range:       f32,
-	damage:      int,
-	fire_rate:   f32,
-	cost:        int,
-	footprint_w: int, // 1 column wide
-	footprint_h: int, // two rows tall
+	range:            f32,
+	damage:           int,
+	fire_rate:        f32,
+	cost:             int,
+	footprint_w:      int, // 1 column wide
+	footprint_h:      int, // two rows tall
+	max_upgrade:      int,
+	upgrade_cost:     int,
+	damage_per_level: int,
+	range_per_level:  f32,
+	splash_radius:    f32,
+	color:            rl.Color,
 }
 
 TOWER_ARCHETYPES: [Tower_Kind]Tower_Archetype = {
 	.Archer = {
-		kind = .Archer,
-		range = 50,
+		range = 100,
 		damage = 12,
 		fire_rate = 0.45,
-		cost = TOWER_COST,
+		cost = 50,
 		footprint_w = 1,
 		footprint_h = 2,
+		max_upgrade = 1,
+		upgrade_cost = 40,
+		damage_per_level = 3,
+		range_per_level = 8,
+		splash_radius = 0,
+		color = rl.YELLOW,
+	},
+	.Cannon = {
+		range = 110,
+		damage = 35,
+		fire_rate = 1.2,
+		cost = 80,
+		footprint_w = 2,
+		footprint_h = 2,
+		max_upgrade = 1,
+		upgrade_cost = 40,
+		damage_per_level = 3,
+		range_per_level = 8,
+		splash_radius = 60,
+		color = rl.DARKGRAY,
+	},
+	.Ice = {
+		range = 85,
+		damage = 6,
+		fire_rate = 0.55,
+		cost = 65,
+		footprint_w = 1,
+		footprint_h = 1,
+		max_upgrade = 1,
+		upgrade_cost = 40,
+		damage_per_level = 3,
+		range_per_level = 8,
+		splash_radius = 0,
+		color = rl.DARKBLUE,
 	},
 }
 
-rects_overlap :: proc(
-	left_a, top_a, width_a, height_a: int,
-	left_b, top_b, width_b, height_b: int,
-) -> bool {
-	return(
-		left_a < left_b + width_b &&
-		left_a + width_a > left_b &&
-		top_a < top_b + height_b &&
-		top_a + height_a > top_b \
-	)
-}
-
-footprint_center :: proc(gx, gy, footprint_w, footprint_h: int) -> Vec2 {
-	return Vec2 {
-		f32(gx * TILE_SIZE + (footprint_w * TILE_SIZE) / 2),
-		f32(gy * TILE_SIZE + (footprint_h * TILE_SIZE) / 2),
-	}
-}
-
-footprint_fits_map :: proc(world_map: ^Map, gx, gy, footprint_w, footprint_h: int) -> bool {
-	if gx < 0 || gy < 0 do return false
-	if gx + footprint_w > MAP_W do return false
-	if gy + footprint_h > MAP_H do return false
-
-	for row in gy ..< gy + footprint_h {
-		for column in gx ..< gx + footprint_w {
-			if !can_build_at(world_map, column, row) do return false
-		}
-	}
-
-	return true
-}
-
-footprint_blocked :: proc(world: ^World, gx, gy, footprint_w, footprint_h: int) -> bool {
-	for placed_tower in world.towers {
-		archetype := get_archetype(placed_tower.kind)
-		if rects_overlap(
-			gx,
-			gy,
-			footprint_w,
-			footprint_h,
-			placed_tower.anchor_gx,
-			placed_tower.anchor_gy,
-			archetype.footprint_w,
-			archetype.footprint_h,
-		) {
-			return true
-		}
-	}
-
-	return false
-}
-
-get_archetype :: proc(kind: Tower_Kind) -> Tower_Archetype {
-	return TOWER_ARCHETYPES[kind]
-}
-
-try_place_tower :: proc(world: ^World, gx, gy: int, kind: Tower_Kind) -> bool {
-	if world.phase != .Build do return false
-
-	arch := get_archetype(kind)
-	footprint_w := arch.footprint_w
-	footprint_h := arch.footprint_h
-
-	if !footprint_fits_map(&world.world_map, gx, gy, footprint_w, footprint_h) do return false
-	if footprint_blocked(world, gx, gy, footprint_w, footprint_h) do return false
-	if world.gold < arch.cost do return false
-
-	world.gold -= arch.cost
-	append(
-		&world.towers,
-		Tower {
-			position = footprint_center(gx, gy, footprint_w, footprint_h),
-			anchor_gx = gx,
-			anchor_gy = gy,
-			kind = kind,
-			cooldown = 0,
-		},
-	)
-	return true
+tower_stats_at_level :: proc(tower: Tower) -> (damage: int, range: f32) {
+	arch := TOWER_ARCHETYPES[tower.kind]
+	damage = arch.damage + tower.upgrade_level * arch.damage_per_level
+	range = arch.range + f32(tower.upgrade_level) * arch.range_per_level
+	return
 }
 
 find_target_slot :: proc(tower: Tower, world: ^World) -> int {
-	arch := get_archetype(tower.kind)
 	best_slot: int = -1
 	best_dist: f32 = 999999
 
@@ -129,7 +95,8 @@ find_target_slot :: proc(tower: Tower, world: ^World) -> int {
 		if e.path_index >= len(world.path) do continue
 
 		d := distance(tower.position, e.position)
-		if d <= arch.range && d < best_dist {
+		_, range := tower_stats_at_level(tower)
+		if d <= range && d < best_dist {
 			best_slot = i
 			best_dist = d
 		}
@@ -147,28 +114,70 @@ update_towers :: proc(world: ^World, dt: f32) {
 		slot := find_target_slot(t^, world)
 		if slot < 0 do continue
 
-		arch := get_archetype(t.kind)
+		arch := TOWER_ARCHETYPES[t.kind]
 
+		damage, _ := tower_stats_at_level(t^)
 		switch t.kind {
 		case .Archer:
-			spawn_projectile(world, t.position, slot, arch.damage)
-			t.cooldown = arch.fire_rate
+			spawn_projectile(world, t.position, slot, damage)
+		case .Cannon:
+			if target := enemy_at_slot(world, slot); target != nil {
+				len := distance(t.position, target.position)
+				if (len > 0.001) {
+					dir := Vec2 {
+						(target.position.x - t.position.x) / len,
+						(target.position.y - t.position.y) / len,
+					}
+					spawn_ballistic(world, t.position, dir, damage, arch.splash_radius)
+				}
+			}
+		case .Ice:
+			if target := enemy_at_slot(world, slot); target != nil {
+				apply_ice_hit(world, target, damage)
+			}
 		}
+		t.cooldown = arch.fire_rate
 	}
 }
 
+apply_tower_hit :: proc(world: ^World, target: ^Enemy, damage: int) {
+	target.health -= damage
+	if target.health <= 0 {
+		target.active = false
+		push_event(world, .Enemy_Killed, gold_reward = ENEMY_DEF[target.kind].gold_reward)
+	}
+}
+
+apply_ice_hit :: proc(world: ^World, target: ^Enemy, damage: int) {
+	apply_tower_hit(world, target, damage)
+	if target.active do target.slow_timer = ICE_SLOW_DURATION
+}
+
+enemy_at_slot :: proc(world: ^World, slot: int) -> ^Enemy {
+	if slot < 0 || slot >= MAX_ENEMIES do return nil
+
+	e := &world.enemies[slot]
+	if !e.active do return nil
+	return e
+}
+
 render_towers :: proc(world: ^World) {
 	for t in world.towers {
-		archetype := get_archetype(t.kind)
+		archetype := TOWER_ARCHETYPES[t.kind]
 		pixel_width := f32(archetype.footprint_w * TILE_SIZE)
 		pixel_height := f32(archetype.footprint_h * TILE_SIZE)
+		color := archetype.color
 		rl.DrawRectangle(
 			i32(t.position.x - pixel_width * 0.5),
 			i32(t.position.y - pixel_height * 0.5),
 			i32(pixel_width),
 			i32(pixel_height),
-			rl.Color{255, 203, 0, 255},
+			color,
 		)
+		if t.upgrade_level > 0 {
+			label := fmt.ctprintf("Lv%d", t.upgrade_level + 1) // or just t.upgrade_level
+			rl.DrawText(label, i32(t.position.x), i32(t.position.y), 14, rl.WHITE)
+		}
 	}
 }
 

game/tower_placement.odin

@@ -0,0 +1,139 @@
+package game
+
+import rl "vendor:raylib"
+
+can_place_tower :: proc(world: ^World, gx, gy: int, kind: Tower_Kind) -> bool {
+	if world.phase != .Build do return false
+	arch := TOWER_ARCHETYPES[kind]
+	if world.gold < arch.cost do return false
+	if !footprint_fits_map(&world.world_map, gx, gy, arch.footprint_w, arch.footprint_h) do return false
+	if footprint_blocked(world, gx, gy, arch.footprint_w, arch.footprint_h) do return false
+	return true
+}
+
+rects_overlap :: proc(
+	left_a, top_a, width_a, height_a: int,
+	left_b, top_b, width_b, height_b: int,
+) -> bool {
+	return(
+		left_a < left_b + width_b &&
+		left_a + width_a > left_b &&
+		top_a < top_b + height_b &&
+		top_a + height_a > top_b \
+	)
+}
+
+footprint_center :: proc(gx, gy, footprint_w, footprint_h: int) -> Vec2 {
+	return Vec2 {
+		f32(gx * TILE_SIZE + (footprint_w * TILE_SIZE) / 2),
+		f32(gy * TILE_SIZE + (footprint_h * TILE_SIZE) / 2),
+	}
+}
+
+footprint_fits_map :: proc(world_map: ^Map, gx, gy, footprint_w, footprint_h: int) -> bool {
+	if gx < 0 || gy < 0 do return false
+	if gx + footprint_w > MAP_W do return false
+	if gy + footprint_h > MAP_H do return false
+
+	for column in 0 ..< footprint_h {
+		for row in 0 ..< footprint_w {
+			cell_column := gx + column
+			cell_row := gy + row
+			if !can_build_at(world_map, cell_column, cell_row) do return false
+		}
+	}
+
+	return true
+}
+
+footprint_blocked :: proc(world: ^World, gx, gy, footprint_w, footprint_h: int) -> bool {
+	for placed_tower in world.towers {
+		archetype := TOWER_ARCHETYPES[placed_tower.kind]
+		if rects_overlap(
+			gx,
+			gy,
+			footprint_w,
+			footprint_h,
+			placed_tower.anchor_gx,
+			placed_tower.anchor_gy,
+			archetype.footprint_w,
+			archetype.footprint_h,
+		) {
+			return true
+		}
+	}
+
+	return false
+}
+
+try_place_tower :: proc(world: ^World, gx, gy: int, kind: Tower_Kind) -> bool {
+	if !can_place_tower(world, gx, gy, kind) do return false
+
+	arch := TOWER_ARCHETYPES[kind]
+	world.gold -= arch.cost
+	append(
+		&world.towers,
+		Tower {
+			position = footprint_center(gx, gy, arch.footprint_w, arch.footprint_h),
+			anchor_gx = gx,
+			anchor_gy = gy,
+			kind = kind,
+			cooldown = 0,
+		},
+	)
+	return true
+}
+
+tower_at_grid :: proc(world: ^World, gx, gy: int) -> ^Tower {
+	for i in 0 ..< len(world.towers) {
+		t := &world.towers[i]
+		arch := TOWER_ARCHETYPES[t.kind]
+		if gx >= t.anchor_gx &&
+		   gx < t.anchor_gx + arch.footprint_w &&
+		   gy >= t.anchor_gy &&
+		   gy < t.anchor_gy + arch.footprint_h {
+			return t
+		}
+	}
+	return nil
+}
+
+try_upgrade_tower :: proc(world: ^World, gx, gy: int) -> bool {
+	if world.phase != .Build do return false
+	t := tower_at_grid(world, gx, gy)
+	if t == nil do return false
+
+	arch := TOWER_ARCHETYPES[t.kind]
+	if t.upgrade_level >= arch.max_upgrade do return false
+
+	cost := arch.upgrade_cost + t.upgrade_level * 25
+	if world.gold < cost do return false
+
+	world.gold -= cost
+	t.upgrade_level += 1
+	return true
+}
+
+render_placement_preview :: proc(world: ^World) {
+	if world.phase != .Build do return
+
+	mouse := game_mouse()
+	gx, gy := screen_to_grid(mouse.x, mouse.y)
+	arch := TOWER_ARCHETYPES[world.selected_tower]
+	ok := can_place_tower(world, gx, gy, world.selected_tower)
+
+	center := footprint_center(gx, gy, arch.footprint_w, arch.footprint_h)
+	rl.DrawCircleLines(i32(center.x), i32(center.y), arch.range, rl.Fade(rl.SKYBLUE, 0.4))
+
+	tint := rl.Fade(rl.GREEN, 0.3)
+	if !ok do tint = rl.Fade(rl.RED, 0.35)
+
+	for row in 0 ..< arch.footprint_h {
+		for col in 0 ..< arch.footprint_w {
+			px := (gx + col) * TILE_SIZE
+			py := (gy + row) * TILE_SIZE
+			rl.DrawRectangle(i32(px), i32(py), TILE_SIZE, TILE_SIZE, tint)
+		}
+	}
+}
+

game/utils.odin

@@ -0,0 +1,27 @@
+package game
+
+import rl "vendor:raylib"
+
+draw_text_centered_in_rect :: proc(
+	text: cstring,
+	rect: rl.Rectangle,
+	font_size: i32,
+	color: rl.Color,
+) {
+	text_w := rl.MeasureText(text, font_size)
+	x := i32(rect.x) + (i32(rect.width) - text_w) / 2
+	y := i32(rect.y) + (i32(rect.height) - font_size) / 2
+	rl.DrawText(text, x, y, font_size, color)
+}
+
+draw_button :: proc(
+	rect: rl.Rectangle,
+	label: cstring,
+	bg: rl.Color,
+	font_size: i32,
+	text_color: rl.Color,
+) {
+	rl.DrawRectangleRec(rect, bg)
+	draw_text_centered_in_rect(label, rect, font_size, text_color)
+}
+

game/wave.odin

@@ -8,44 +8,93 @@ Game_Phase :: enum {
 }
 
 Wave_Spawner :: struct {
-	enemies_to_spawn: int,
-	spawn_timer:      f32,
-	spawn_interval:   f32,
+	spawn_timer:     f32,
+	spawn_interval:  f32,
+	recipe:          [dynamic]Wave_Entry,
+	recipe_index:    int,
+	entry_remaining: int,
 }
 
 start_wave :: proc(world: ^World) {
 	if world.phase != .Build do return
 	world.wave += 1
 	world.phase = .Combat
+	delete(world.spawner.recipe)
 	world.spawner = Wave_Spawner {
-		enemies_to_spawn = 5 + world.wave * 2,
-		spawn_timer      = 0,
-		spawn_interval   = 0.55,
+		spawn_timer     = 0,
+		spawn_interval  = 0.55,
+		recipe          = build_wave_recipe(world.wave),
+		recipe_index    = 0,
+		entry_remaining = 0,
 	}
+	load_next_recipe_entry(world)
+}
+
+Wave_Entry :: struct {
+	kind:  Enemy_Kind,
+	count: int,
+}
+
+build_wave_recipe :: proc(wave: int) -> [dynamic]Wave_Entry {
+	recipe: [dynamic]Wave_Entry
+	switch wave {
+	case 1:
+		append(&recipe, Wave_Entry{.Grunt, 6})
+	case 2:
+		append(&recipe, Wave_Entry{.Grunt, 4})
+		append(&recipe, Wave_Entry{.Runner, 2})
+	case:
+		grunt := 3 + wave
+		runners := wave / 2
+		tanks := wave / 3
+		append(&recipe, Wave_Entry{.Grunt, grunt})
+		if runners > 0 do append(&recipe, Wave_Entry{.Runner, runners})
+		if tanks > 0 do append(&recipe, Wave_Entry{.Tank, tanks})
+	}
+
+	return recipe
+}
+
+load_next_recipe_entry :: proc(world: ^World) {
+	s := &world.spawner
+	if s.recipe_index >= len(s.recipe) {
+		s.entry_remaining = 0
+		return
+	}
+	entry := s.recipe[s.recipe_index]
+	s.entry_remaining = entry.count
+}
+
+clear_wave :: proc(world: ^World) -> bool {
+	s := world.spawner
+	if s.recipe_index < len(s.recipe) do return false
+	if s.entry_remaining > 0 do return false
+	return active_enemy_count(world) == 0
 }
 
 update_wave :: proc(world: ^World, dt: f32) {
 	if world.phase != .Combat do return
-	if world.spawner.enemies_to_spawn <= 0 do return
-	if len(world.path) < 2 do return
+	s := &world.spawner
+	if s.entry_remaining <= 0 && s.recipe_index >= len(s.recipe) do return
 
-	world.spawner.spawn_timer -= dt
-	if world.spawner.spawn_timer <= 0 {
-		health := 15 + world.wave * 5
-		speed := 55 + f32(world.wave) * 5
-		spawn_enemy(world, health, speed)
-		world.spawner.enemies_to_spawn -= 1
-		world.spawner.spawn_timer = world.spawner.spawn_interval
+	s.spawn_timer -= dt
+	if s.spawn_timer > 0 do return
+
+	if s.entry_remaining <= 0 {
+		s.recipe_index += 1
+		load_next_recipe_entry(world)
+		if s.entry_remaining <= 0 do return
 	}
-}
 
-wave_clear :: proc(world: ^World) -> bool {
-	if world.spawner.enemies_to_spawn > 0 do return false
-	return active_enemy_count(world) == 0
+	kind := s.recipe[s.recipe_index].kind
+	spawn_enemy(world, kind)
+	s.entry_remaining -= 1
+	s.spawn_timer = s.spawn_interval
+
 }
 
 update_phase :: proc(world: ^World) {
-	if world.phase == .Combat && wave_clear(world) {
+	if world.phase == .Combat && clear_wave(world) {
 		world.phase = .Build
 		push_event(world, .Wave_Survived, gold_reward = 25)
 	}
@@ -56,7 +105,7 @@ check_end :: proc(world: ^World) {
 		world.phase = .Game_Over
 	}
 
-	if world.wave >= MAX_WAVES && world.phase == .Build && wave_clear(world) {
+	if world.wave >= MAX_WAVES && world.phase == .Build && clear_wave(world) {
 		world.phase = .Victory
 	}
 }

game/wave_test.odin

@@ -0,0 +1,145 @@
+package game
+
+import "core:testing"
+
+@(test)
+test_start_wave_enters_combat :: proc(t: ^testing.T) {
+	world := World {
+		phase = .Combat,
+	}
+	world.wave = 0
+
+	start_wave(&world)
+
+	testing.expect(t, world.phase == .Combat)
+	testing.expect(t, world.wave == 0)
+}
+
+@(test)
+test_start_wave_from_build :: proc(t: ^testing.T) {
+	world := World {
+		phase = .Build,
+	}
+	world.wave = 0
+
+	start_wave(&world)
+	defer delete(world.spawner.recipe)
+
+	testing.expect(t, world.phase == .Combat)
+	testing.expect(t, world.wave == 1)
+	testing.expect(t, world.spawner.spawn_timer == 0)
+	testing.expect(t, world.spawner.spawn_interval == 0.55)
+	testing.expect(t, world.spawner.recipe_index == 0)
+}
+
+@(test)
+test_clear_wave_not_cleared :: proc(t: ^testing.T) {
+	world := World{}
+	world.spawner.recipe = make([dynamic]Wave_Entry, context.allocator)
+	append(&world.spawner.recipe, Wave_Entry{})
+	defer delete(world.spawner.recipe)
+	world.spawner.recipe_index = 0
+	world.spawner.entry_remaining = 0
+
+	result := clear_wave(&world)
+
+	testing.expect(t, result == false)
+}
+
+@(test)
+test_clear_wave_cleared :: proc(t: ^testing.T) {
+	world := World{}
+	world.spawner.recipe = make([dynamic]Wave_Entry, context.allocator)
+	append(&world.spawner.recipe, Wave_Entry{})
+	defer delete(world.spawner.recipe)
+	world.spawner.recipe_index = 1
+	world.spawner.entry_remaining = 0
+
+	result := clear_wave(&world)
+
+	testing.expect(t, result == true)
+}
+
+@(test)
+test_update_wave_ignores_build_phase :: proc(t: ^testing.T) {
+	world := init_world()
+	defer delete(world.path)
+	world.phase = .Build
+	world.spawner.spawn_timer = 0
+	world.spawner.entry_remaining = 5
+
+	update_wave(&world, 1.0)
+
+	testing.expect(t, active_enemy_count(&world) == 0)
+}
+
+@(test)
+test_update_wave_waits_for_spawn_timer :: proc(t: ^testing.T) {
+	world := init_world()
+	defer delete(world.path)
+	world.phase = .Combat
+	world.spawner.recipe = make([dynamic]Wave_Entry, context.allocator)
+	append(&world.spawner.recipe, Wave_Entry{.Grunt, 1})
+	defer delete(world.spawner.recipe)
+	world.spawner.recipe_index = 0
+	world.spawner.entry_remaining = 1
+	world.spawner.spawn_timer = 0.5
+
+	update_wave(&world, 0.1)
+
+	testing.expect(t, active_enemy_count(&world) == 0)
+	testing.expect(t, world.spawner.spawn_timer == 0.4)
+}
+
+@(test)
+test_update_wave_spawns_and_resets_timer :: proc(t: ^testing.T) {
+	world := init_world()
+	defer delete(world.path)
+	world.phase = .Combat
+	world.wave = 1
+	world.spawner.recipe = make([dynamic]Wave_Entry, context.allocator)
+	append(&world.spawner.recipe, Wave_Entry{.Grunt, 2})
+	defer delete(world.spawner.recipe)
+	world.spawner.recipe_index = 0
+	world.spawner.entry_remaining = 2
+	world.spawner.spawn_timer = 0
+	world.spawner.spawn_interval = 0.55
+
+	update_wave(&world, 0.55)
+
+	testing.expect(t, active_enemy_count(&world) == 1)
+	testing.expect(t, world.spawner.entry_remaining == 1)
+	testing.expect(t, world.spawner.spawn_timer == 0.55)
+
+	found_grunt := false
+	for i in 0 ..< MAX_ENEMIES {
+		if world.enemies[i].active {
+			testing.expect(t, world.enemies[i].kind == .Grunt)
+			found_grunt = true
+		}
+	}
+	testing.expect(t, found_grunt)
+}
+
+@(test)
+test_update_phase_from_build_phase :: proc(t: ^testing.T) {
+	world := World{}
+	defer delete(world.events)
+
+	world.phase = .Build
+	update_phase(&world)
+
+	testing.expect(t, world.phase == .Build)
+}
+
+@(test)
+test_update_phase_from_combat_phase :: proc(t: ^testing.T) {
+	world := World{}
+	defer delete(world.events)
+	world.phase = .Combat
+
+	update_phase(&world)
+
+	testing.expect(t, world.phase == .Build)
+}
+

game/world.odin

@@ -1,24 +1,26 @@
 package game
 
 World :: struct {
-	gold:        int,
-	base_health: int,
-	world_map:   Map,
-	path:        [dynamic]Vec2,
-	enemies:     [MAX_ENEMIES]Enemy,
-	towers:      [dynamic]Tower,
-	events:      [dynamic]Event,
-	phase:       Game_Phase,
-	wave:        int,
-	spawner:     Wave_Spawner,
-	projectiles: [MAX_PROJECTILES]Projectile,
+	gold:           int,
+	base_health:    int,
+	world_map:      Map,
+	path:           [dynamic]Vec2,
+	enemies:        [MAX_ENEMIES]Enemy,
+	towers:         [dynamic]Tower,
+	events:         [dynamic]Event,
+	phase:          Game_Phase,
+	wave:           int,
+	spawner:        Wave_Spawner,
+	projectiles:    [MAX_PROJECTILES]Projectile,
+	selected_tower: Tower_Kind,
 }
 
 init_world :: proc() -> World {
 	world := World {
-		gold        = 100,
-		base_health = 20,
-		phase       = .Build,
+		gold           = STARTING_GOLD,
+		base_health    = STARTING_BASE_HEALTH,
+		phase          = .Build,
+		selected_tower = .Archer,
 	}
 	init_map(&world.world_map)
 	build_path(&world.world_map, &world.path)