;;; R7RS-PNM --- Library for reading and writing PNM (Portable Any Map) files for R7RS
;;; Copyright © 2024 Masaya Tojo <masaya@tojo.tokyo>
;;;
;;; This file is part of R7RS-PNM.
;;;
;;; R7RS-PNM is free software: you can redistribute it and/or modify it
;;; under the terms of the GNU Lesser General Public License as published
;;; by the Free Software Foundation, either version 3 of the License, or
;;; (at your option) any later version.
;;;
;;; R7RS-PNM 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 Lesser General Public License for more details.
;;;
;;; You should have received a copy of the GNU Lesser General Public License
;;; along with R7RS-PNM. If not, see <https://www.gnu.org/licenses/>.

(define-library (image-format pnm image)
  (export make-pnm-image
          pnm-image?
          pnm-image-type
          pnm-image-width
          pnm-image-height
          pnm-image-maxval
          pnm-image-data
          pnm-image-pixel-getter
          pnm-image-pixel-setter
          pnm-image-ref
          pnm-image-set!)
  (import (scheme base)
          (scheme case-lambda))
  (begin
    (define-record-type <pnm-image>
      (make-pnm-image type width height maxval data pixel-getter pixel-setter)
      pnm-image?
      (type pnm-image-type)
      (width pnm-image-width)
      (height pnm-image-height)
      (maxval pnm-image-maxval)
      (data pnm-image-data)
      (pixel-getter pnm-image-pixel-getter)
      (pixel-setter pnm-image-pixel-setter))

    (define (pnm-image-ref pnm-image x y)
      ((pnm-image-pixel-getter pnm-image) x y))

    (define pnm-image-set!
      (case-lambda
        ((pnm-image x y v)
         ((pnm-image-pixel-setter pnm-image) x y v))
        ((pnm-image x y r g b)
         ((pnm-image-pixel-setter pnm-image) x y r g b))))))