;;; Chickadee Game Toolkit
;;; Copyright © 2016 David Thompson <davet@gnu.org>
;;;
;;; Chickadee is free software: you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published
;;; by the Free Software Foundation, either version 3 of the License,
;;; or (at your option) any later version.
;;;
;;; Chickadee is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;;; General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with this program.  If not, see
;;; <http://www.gnu.org/licenses/>.

(define-module (chickadee window)
  #:use-module (ice-9 match)
  #:use-module (srfi srfi-9)
  #:use-module ((sdl2) #:prefix sdl2:)
  #:use-module ((sdl2 events) #:prefix sdl2:)
  #:use-module ((sdl2 video) #:prefix sdl2:)
  #:export (open-window
            close-window
            window?
            window-title
            window-width
            window-height
            window-fullscreen?
            with-window
            swap-buffers))

(define-record-type <window>
  (make-window sdl-window gl-context)
  window?
  (sdl-window unwrap-window)
  (gl-context window-gl-context))

(define* (open-window #:key
                      (title "Chickadee")
                      (width 640)
                      (height 480)
                      fullscreen?)
  (sdl2:set-gl-attribute! 'context-major-version 3)
  (sdl2:set-gl-attribute! 'context-minor-version 3)
  (sdl2:set-gl-attribute! 'double-buffer 1)
  (sdl2:set-gl-attribute! 'depth-size 24)
  (sdl2:set-gl-attribute! 'red-size 8)
  (sdl2:set-gl-attribute! 'green-size 8)
  (sdl2:set-gl-attribute! 'blue-size 8)
  (sdl2:set-gl-attribute! 'alpha-size 8)
  (sdl2:set-gl-attribute! 'stencil-size 8)
  (sdl2:set-gl-attribute! 'retained-backing 0)
  (sdl2:set-gl-attribute! 'framebuffer-srgb-capable 1)
  (let* ((sdl-window (sdl2:make-window #:opengl? #t
                                       #:title title
                                       #:size (list width height)
                                       #:fullscreen? fullscreen?))
         (gl-context (sdl2:make-gl-context sdl-window))
         (window (make-window sdl-window gl-context)))
    (sdl2:set-gl-swap-interval! 'vsync)
    window))

(define (close-window! window)
  "Close WINDOW."
  (sdl2:delete-gl-context! (window-gl-context window))
  (sdl2:close-window! (unwrap-window window)))

(define (window-title window)
  "Return the title of WINDOW."
  (sdl2:window-title (unwrap-window window)))

(define (set-window-title! window title)
  "Set TITLE for WINDOW."
  (sdl2:set-window-title! (unwrap-window window) title))

(define (set-window-size! window width height)
  (sdl2:set-window-size! (unwrap-window window) (list width height)))

(define-syntax-rule (with-window window body ...)
  (dynamic-wind
    (const #t)
    (lambda () body ...)
    (lambda ()
      (close-window! window))))

(define (swap-buffers window)
  (sdl2:swap-gl-window (unwrap-window window)))