;;;; -*- Mode: LISP; Syntax: ANSI-Common-Lisp; Base: 10; Package: photo -*-
;;;; *************************************************************************
;;;; FILE IDENTIFICATION
;;;;
;;;; Name:          convert.lisp
;;;; Purpose:       Conversions functions for cl-photo
;;;; Programmer:    Kevin M. Rosenberg
;;;; Date Started:  April 2005
;;;;
;;;; $Id$
;;;;
;;;; This file, part of cl-photo, is Copyright (c) 2005 by Kevin M. Rosenberg
;;;;
;;;; cl-photo users are granted the rights to distribute and use this software
;;;; as governed by the terms of the GNU General Public License v2
;;;; (http://www.gnu.org/licenses/gpl.html)
;;;;
;;;; *************************************************************************

(in-package #:photo)

(defconstant +radian->degrees+ (/ 360d0 pi 2))
(defconstant +inches->mm+ 25.4d0)

(declaim (inline diagonal))
(defun diagonal (x y)
  (sqrt (+ (* x x) (* y y))))

(declaim (inline radians->degrees))
(defun radians->degrees (r)
  (* +radian->degrees+ r))

(declaim (inline degrees->radians))
(defun degrees->radians (r)
  (/ r +radian->degrees+))

(declaim (inline mm->feet))
(defun mm->feet (d)
  (/ d +inches->mm+ 12))

(declaim (inline feet->mm))
(defun feet->mm (d)
  (* d 12 +inches->mm+))

(declaim (inline inches->mm))
(defun inches->mm (d)
  (* d +inches->mm+))

(declaim (inline mm->inches))
(defun mm->inches (d)
  (/ d +inches->mm+))

(defun length->mm (d units)
  "Convert a length in units to mm."
  (ecase units
    (:mm d)
    (:inches (inches->mm d))
    (:feet (* 12 (inches->mm d)))
    (:yards (* 36 (inches->mm d)))
    (:meters (* 1000 d))))

(defun mm->length (d units)
  "Convert a number of mm to units."
  (ecase units
    (:mm d)
    (:inches (mm->inches d))
    (:feet (/ (mm->inches d) 12))
    (:yards (/ (mm->inches d) 36))
    (:meters (/ d 1000))))

(defun format-dimensions (format)
  "Returns format dimensions in mm."
  (ecase format
    (:aps-c (cons 22.7 15.1))
    ((:aps :dx) (cons 24 16))
    ((:35 :35mm) (cons 36 24))
    ((:645 :6x4.5cm) (cons 60 45))
    ((:6x6 :6x6cm) (cons 60 60))
    ((:6x7 :6x7cm) (cons 60 70))
    ((:6x9 :6x9cm) (cons 60 90))
    ((:4x5 :4x5in) (cons (* 4 +inches->mm+) (* 5 +inches->mm+)))
    ((:5x7 :5x7in) (cons (* 5 +inches->mm+) (* 7 +inches->mm+)))
    ((:8x10 :8x10in) (cons (* 8 +inches->mm+) (* 10 +inches->mm+))) 
    (:11x13.75in (cons (* 11 +inches->mm+) (* 13.75 +inches->mm+)))
    (:11x16.5in (cons (* 11 +inches->mm+) (* 16.5 +inches->mm+)))
    (:13x19in (cons (* 13 +inches->mm+) (* 19 +inches->mm+)))
    (:16x20in (cons (* 13 +inches->mm+) (* 19 +inches->mm+)))
    (:16x24in (cons (* 13 +inches->mm+) (* 19 +inches->mm+)))
    (:18x22.5in (cons (* 13 +inches->mm+) (* 19 +inches->mm+)))
    (:18x24in (cons (* 13 +inches->mm+) (* 19 +inches->mm+)))
    (:24x30in (cons (* 13 +inches->mm+) (* 19 +inches->mm+)))
    (:24x36in (cons (* 13 +inches->mm+) (* 19 +inches->mm+)))
    ))