;;; bad-grid --- sdl2 renderer -*- lexical-binding: t -*-
;;; Commentary:
;;; Code:

(require 'cl-lib)
(cl-pushnew "." load-path :test #'string=)
(require 'luki-lisp)

(-> 'bad-ecs)

;; +----------------+
;; | dynamic module |
;; +----------------+

(let ((dm (@f "bad-sdl%s" module-file-suffix)))
  (load dm nil t)
  (declare-function sdl_draw_init        dm)
  (declare-function sdl_draw_quit        dm)
  (declare-function sdl_draw_frame       dm)
  (declare-function sdl_draw_grid_init   dm)
  (declare-function sdl_draw_grid_toggle dm))

;; +------+
;; | grid |
;; +------+

(defvar ecs-grid   nil)
(defvar ecs-grid-h nil)
(defvar ecs-grid-w nil)

(defun ecs-grid-init ()
  (setf ecs-grid-w 109)
  (setf ecs-grid-h  31)
  (setf ecs-grid (make-vector ecs-grid-h nil))
  (cl-loop
    for i from 0 to ecs-grid-h
    for line-str = (format "line %04d " i)
    for len      = (- ecs-grid-w (--- line-str))
    for fin      = " 0101"
    for len-fin  = (--- fin)
    for str      = (concat line-str (make-string (- len len-fin 1) ?-) fin)
    for row across-ref ecs-grid do (setf row str)))

(cl-defmethod ecs-grid-set ((row integer) (col integer) (val integer))
  (aset (aref ecs-grid row) col val))

(defun bad-grid-string ()
  (mapconcat #'concat ecs-grid "\n"))

(cl-defmethod ecs-grid-clear (&optional (chr 32))
  (cl-loop for row being the elements of     ecs-grid using (index i) do
  (cl-loop for _   being the elements of-ref row      using (index j) do
  (aset (aref ecs-grid i) j chr))))

(defun bad-fps ()
  (sdl_draw_init)
  (ecs-grid-init)
  (sdl_draw_grid_toggle)
  (cl-loop
   with hz     = (bad-hz)
   with fps    = 60
   with delta  = (// hz fps)
   with frames = 8092
   with slp    = 0
   with ahead  = 0
   with done   = 0
   with beg    = (bad-ticks)
   with stops  = (number-sequence (+ beg delta) (+ beg (* frames delta)) delta)
   with prestr = (make-string 20 32)
   for ft from 0
   for draw    = (z (m ft 4))
   for next in stops
   for ver-msg        = (@f "%sGNU Emacs %s | debian %s | SDL 3.3.7 | OpenGL 4.6" prestr emacs-version system-type)
   for set-to-msg     = (@f "%sfps (set to) %d"                                   prestr fps)
   for frames-msg     = (@f "%sframe %d of %d (%d%%)"                             prestr done frames (* 100 (// done frames)))
   for actual-fps-msg = (@f "%sfps (actual) %.1f"                                 prestr (// (* done hz) (- (bad-ticks) beg)))
   for ahead-msg      = (@f "%stotal sleep: %.1f s -> %.5f s/frame"               prestr ahead (// ahead done)) do
     (when draw
       (mapc (L (i) (aset ecs-grid i " ")) '(15 17 18 19)))
     (mapc (L (i) (aset ecs-grid i " ")) '(20 16 14 13 12))
     (aset ecs-grid 13 ver-msg)
     (when draw
       (aset ecs-grid 15 frames-msg)
       (aset ecs-grid 17 set-to-msg)
       (aset ecs-grid 18 actual-fps-msg)
       (aset ecs-grid 19 ahead-msg))
     (sdl_draw_frame) (++ done)
     (setf slp (// (- next (bad-ticks)) hz))
     (++ ahead slp)
     (sleep-for slp)
   finally (sdl_draw_quit)))

(<- 'bad-grid)
;;; bad-grid.el ends here