branch: elpa/telephone-line
commit 9c36180ba2852bf605fff220e9a8ca76797ea7b0
Author: Daniel Bordak <[email protected]>
Commit: Daniel Bordak <[email protected]>
Enhanced axis documentation and new trig function
---
telephone-line-utils.el | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/telephone-line-utils.el b/telephone-line-utils.el
index fac12947c9..ab6a951435 100644
--- a/telephone-line-utils.el
+++ b/telephone-line-utils.el
@@ -50,12 +50,30 @@
(ceiling (separator-height) 2))
(defun create-axis (length)
- "Create an axis of length LENGTH."
+ "Create an axis of length LENGTH.
+For odd lengths, this is a sequence from -floor(LENGTH/2) to
++floor(LENGTH/2), so for instance a LENGTH of 9 produces:
+
+ -4 -3 -2 -1 0 +1 +2 +3 +4
+
+For even lengths, the 0 is duplicated to preserve symmetry.
+For instance, a LENGTH of 10 produces:
+
+ -4 -3 -2 -1 0 0 +1 +2 +3 +4"
(let ((middle (1- (ceiling length 2))))
(append (number-sequence (- middle) 0)
(number-sequence (if (cl-oddp length) 1 0) middle))))
-(defun normalize-axis (seq)
+(defun create-trig-axis (length)
+ "Create a trig axis with LENGTH steps, ranging from -pi to +pi.
+As with create-axis, on even LENGTHs, the 0 is repeated to
+preserve symmetry."
+ (let* ((integer-axis (create-axis length))
+ (integer-max (seq-max integer-axis)))
+ (mapcar (lambda (x)
+ (/ (* float-pi x) integer-max)))))
+
+(defun -normalize-axis (seq)
"Apply an offset to all values of SEQ such that its range begins at 0."
(let ((minimum (seq-min seq)))
(if (not (eq minimum 0))
@@ -122,7 +140,7 @@ color1 and color2."
(defun create-body (width height axis-func pattern-func)
"Create a bytestring of a PBM image body of dimensions WIDTH and HEIGHT, and
shape created from AXIS-FUNC and PATTERN-FUNC."
- (let* ((normalized-axis (normalize-axis (mapcar axis-func (create-axis
height))))
+ (let* ((normalized-axis (-normalize-axis (mapcar axis-func (create-axis
height))))
(range (1+ (seq-max normalized-axis)))
(scaling-factor (/ width (float range))))
(mapcar (lambda (x)
