add a start wave button

game/commands.odin

@@ -15,6 +15,9 @@ Command :: struct {
 }
 
 gather_commands :: proc(world: ^World) -> Command {
+	ui_cmd := overlay_ui_command(world)
+	if ui_cmd.kind != .None do return ui_cmd
+
 	if world.phase == .Build && rl.IsKeyPressed(.N) {
 		return Command{kind = .Start_Wave}
 	}

game/constants.odin

@@ -26,3 +26,6 @@ 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_BUTTON_COLOR :: rl.Color{60, 120, 60, 255}
+OVERLAY_BUTTON_HOVER :: rl.Color{80, 150, 80, 255}
+

game/hud.odin

@@ -9,7 +9,6 @@ render_hud :: proc(world: ^World) {
 
 	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:

game/overlay.odin

@@ -18,5 +18,31 @@ render_overlay :: proc(world: ^World) {
 
 	hp := fmt.ctprintf("Health: %d", world.base_health)
 	rl.DrawText(hp, x, y, font_size, OVERLAY_TEXT_COLOR)
+
+	if world.phase == .Build {
+		btn := start_wave_button_rect()
+		mouse := rl.GetMousePosition()
+		hovered := rl.CheckCollisionPointRec(mouse, btn)
+		bg := hovered ? OVERLAY_BUTTON_HOVER : OVERLAY_BUTTON_COLOR
+		rl.DrawRectangleRec(btn, bg)
+		rl.DrawText("Start Wave", i32(btn.x) + 8, i32(btn.y) + 3, 16, OVERLAY_TEXT_COLOR)
+	}
+}
+
+start_wave_button_rect :: proc() -> rl.Rectangle {
+	return {x = f32(SCREEN_W - 120), y = 3, width = 110, height = 22}
+}
+
+overlay_ui_command :: proc(world: ^World) -> Command {
+	if world.phase != .Build do return Command{kind = .None}
+
+	mouse := rl.GetMousePosition()
+	btn := start_wave_button_rect()
+
+	if rl.CheckCollisionPointRec(mouse, btn) && rl.IsMouseButtonPressed(.LEFT) {
+		return Command{kind = .Start_Wave}
+	}
+
+	return Command{kind = .None}
 }