X-Git-Url: http://git.kpe.io/?p=cl-photo.git;a=blobdiff_plain;f=fov.lisp;h=fba5ce9d91109b423173720ab17f099105406917;hp=43d000fa4006e5d80a928d398af975c78e40a21a;hb=b95675fd79eb1c5a791267cdc4fc0584c4f14b3b;hpb=4860883d5bf05e9e7c83d4f16a001e4edd1d1cb2

diff --git a/fov.lisp b/fov.lisp
index 43d000f..fba5ce9 100644
--- 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"))))
 
@@ -94,12 +98,7 @@ and image distance (mm) for a given image (mm) and object distance (mm)."
       (let* ((d-width (* 2 object-distance (tan (degrees->radians (/ aov-width 2)))))
              (d-height (* 2 object-distance (tan (degrees->radians (/ aov-height 2)))))
              (d-diagonal (* 2 object-distance (tan (degrees->radians (/ aov-diagonal 2))))))
-        (values (mm->length d-width units)
-                (mm->length d-height units)
-                (mm->length d-diagonal units)
-                mag
-                object-distance
-                image-distance)))))
+        (values d-width d-height d-diagonal mag object-distance image-distance)))))
 
 (defun fov (focal-length frame-width frame-height
                          &key object-distance image-distance magnification
@@ -109,12 +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)
@@ -159,7 +159,77 @@ 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)))
 
+(defun extension-tube (focal-length &key original-object-distance original-image-distance original-magnification
+		       new-object-distance new-image-distance new-magnification extension-length (units :feet))
+  "Computes the parameters for using extension tubes.
+Requires: 1. original-object-distance, original-image-distance, or original-magnification
+          2. new-object-distance, new-image-distance, new-magnification, or extension-length
+Returns: original-object-distance, original-image-distance, original-magnification, original-bellows-factor
+         new-object-distance, new-image-distance, new-magnification, extension-length."
+  
+  (multiple-value-bind (focal-length o-od o-id o-m o-bf)
+      (close-up :focal-length focal-length :object-distance original-object-distance
+		:image-distance original-image-distance :magnification original-magnification :units units)
+    
+    (cond
+     (extension-length
+      (multiple-value-bind (focal-length n-od n-id n-m n-bf)
+	  (close-up :focal-length focal-length :image-distance (+ o-id extension-length) :units units)
+	(values o-od o-id o-m o-bf n-od n-id n-m n-bf extension-length)))
+     ((not extension-length)
+      (multiple-value-bind (focal-length n-od n-id n-m n-bf)
+	  (close-up :focal-length focal-length :object-distance new-object-distance
+		    :image-distance new-image-distance :magnification new-magnification :units units)
+	(values o-od o-id o-m o-bf n-od n-id n-m n-bf (- n-id o-id)))))))
+
+
+