;; Copyright (c) Camden Dixie O'Brien
;; SPDX-License-Identifier: AGPL-3.0-only

(in-package :ham)

(defclass simulation ()
  ((update :initarg :update)
   (render :initarg :render)
   (state :initarg :start-state)
   (width :initarg :width :initform 800)
   (height :initarg :height :initform 600)
   (running :initform nil)
   simulation-thread))

(defmethod run ((sim simulation))
  (sdl2:make-this-thread-main
   (lambda ()
	 (with-slots (width height running) sim
	   (with-graphics-context (ctx :width width :height height)
		 (loop while running do
		   (run-update sim (/ 1.0 60.0)) ; assume 60 Hz
		   (run-render sim ctx)))))))

(defmethod start ((sim simulation))
  (with-slots (running simulation-thread) sim
	(setf running t)
	(setf simulation-thread
		  (sb-thread:make-thread (lambda () (run sim))
								 :name "ham-simulation-thread"))))

(defmethod stop ((sim simulation))
  (with-slots (running simulation-thread) sim
	(setf running nil)
	(sb-thread:join-thread simulation-thread)))

(defmethod run-update ((sim simulation) dt)
  (with-slots (update state) sim
	(setf state (funcall update state dt))))

(defmethod run-render ((sim simulation) ctx)
  (with-slots (render state) sim
	(let ((frame (apply render state)))
	  (display-frame ctx frame))))