r10508: add close-up function

[cl-photo.git] / fov.lisp

diff --git a/fov.lisp b/fov.lisp
index 2b01e8293c35d223b8e4cfbd8836551277e65024..211820af13e616d9d5b83818b908f84e47eb8a15 100644 (file)
--- a/fov.lisp
+++ b/fov.lisp
@@ -50,26 +50,30 @@ Default is infinity (magnification 0)"
    (aov-one-dim focal-length (diagonal frame-width frame-height)
                 :projection projection :magnification magnification)))
 
-(defun gaussian-lens (&key object-distance image-distance focal-length)
+(defun gaussian-lens (&key object-distance image-distance focal-length (units :mm))
+  "object-distance is in units. image-distance and focal-length are in mm."
   (cond
    ((and object-distance image-distance (not focal-length))
-    (float (/ 1 (+ (/ 1 object-distance) (/ 1 image-distance)))))
+    ;; Return focal length
+    (float (/ 1 (+ (/ 1 (length->mm object-distance units)) (/ 1 image-distance)))))
    ((and object-distance focal-length (not image-distance))
+    ;; Return image distance
     (cond
-     ((= focal-length object-distance)
+     ((= focal-length (length->mm object-distance units))
         most-positive-double-float)
-     ((> focal-length object-distance)
+     ((> focal-length (length->mm object-distance units))
       :error)
      (t
-      (float (/ 1 (- (/ 1 focal-length) (/ 1 object-distance)))))))
+      (float (/ 1 (- (/ 1 focal-length) (/ 1 (length->mm object-distance units))))))))
    ((and image-distance focal-length (not object-distance))
+    ;; Return object distance
     (cond
      ((= focal-length image-distance)
         most-positive-double-float)
      ((> focal-length image-distance)
       :error)
      (t
-      (float (/ 1 (- (/ 1 focal-length) (/ 1 image-distance)))))))
+      (mm->length (float (/ 1 (- (/ 1 focal-length) (/ 1 image-distance)))) units))))
    (t
     (error "Must specify two, and only two, of the parameters: focal-length, image-distance, object-distance"))))
 
@@ -104,12 +108,13 @@ and image distance (mm) for a given image (mm) and object distance (mm)."
    ((and object-distance (not image-distance) (not magnification))
     (setq image-distance (gaussian-lens
                           :focal-length focal-length
-                          :object-distance (length->mm object-distance units))))
+                          :object-distance object-distance
+                         :units units)))
    ((and (not object-distance) image-distance (not magnification))
-    (setq object-distance (mm->length (gaussian-lens
-                                       :focal-length focal-length
-                                       :image-distance image-distance)
-                                      units)))
+    (setq object-distance (gaussian-lens
+                          :focal-length focal-length
+                          :image-distance image-distance
+                          :units units)))
    ((and (not object-distance) (not image-distance) magnification)
     (setf image-distance (image-distance-magnification focal-length magnification)
           object-distance (when (numberp image-distance)
@@ -154,6 +159,51 @@ focal-length and image-distance are in mm, object-distance is in units"
    (t
     (error "Must set two, and only two, of the parameters: image-distance, object-distance, and focal-length."))))
 
+(defun close-up (&key focal-length object-distance image-distance magnification (units :feet) &aux bellows-factor)
+  "Computes the parameters for focusing closer than infinity.
+Requires two, and only two, of the input parameters.
+Returns: focal-length object-distance image-distance magnification bellows-factor."
+  (cond
+    ((and focal-length object-distance (not image-distance) (not magnification))
+     (setq magnification (magnification :focal-length focal-length
+                                       :object-distance object-distance
+                                       :units units))
+     (setq image-distance (gaussian-lens :focal-length focal-length
+                                        :object-distance object-distance
+                                        :units units)))
+    ((and focal-length (not object-distance) image-distance (not magnification))
+     (setq magnification (magnification :focal-length focal-length
+                                       :image-distance image-distance
+                                       :units units))
+     (setq object-distance (gaussian-lens :focal-length focal-length
+                                        :image-distance image-distance
+                                        :units units)))
+    ((and (not focal-length) object-distance image-distance (not magnification))
+     (setq magnification (magnification :object-distance object-distance
+                                       :image-distance image-distance
+                                       :units units))
+     (setq focal-length (gaussian-lens :object-distance object-distance
+                                      :image-distance image-distance
+                                      :units units)))
+    ((and focal-length (not object-distance) (not image-distance) magnification)
+     (setq image-distance (image-distance-magnification focal-length magnification))
+     (setq object-distance (gaussian-lens :focal-length focal-length
+                                         :image-distance image-distance
+                                         :units units)))
+    ((and (not focal-length) object-distance (not image-distance) magnification)
+     (setq image-distance (* magnification (length->mm object-distance units)))
+     (setq focal-length (gaussian-lens :image-distance image-distance
+                                      :object-distance object-distance
+                                      :units units)))
+    ((and (not focal-length) (not object-distance) image-distance magnification)
+     (setq object-distance (mm->length (float (/ image-distance magnification)) units))
+     (setq focal-length (gaussian-lens :image-distance image-distance
+                                      :object-distance object-distance
+                                      :units units)))
+    (t
+     (error "Must set two, and only two input parameters: focal-length, image-distance, object-distance, magnifcation.")))
+  (values focal-length object-distance image-distance magnification (1+ magnification)))
+
 (defun bellows-factor (focal-length object-distance)
   "Returns the bellows factor, the ratio of effective aperature to actual aperture."
   (1+ (magnification :focal-length focal-length :object-distance object-distance)))