Revision: 1.1 - (view) (download)
1 : | ktanaka | 1.1 | ;; ------------------------------------------- ;; |
2 : | ;; dist.l (distance between point, line, ... ) ;; | ||
3 : | ;; ------------------------------------------- ;; | ||
4 : | |||
5 : | (defun distance-points (a b) | ||
6 : | (lets ((x0 (first a)) (y0 (second a)) | ||
7 : | (x1 (first b)) (y1 (second b)) | ||
8 : | (dx (difference x1 x0)) (dy (difference y1 y0))) | ||
9 : | (fix (plus (times dx dx) (times dy dy))))) | ||
10 : | |||
11 : | (defun distance-point-line (p l) | ||
12 : | (lets ((A (first l)) | ||
13 : | (B (second l)) | ||
14 : | (PA (sqrt (float (distance-points p A)))) | ||
15 : | (PB (sqrt (float (distance-points p B)))) | ||
16 : | (AB (sqrt (float (distance-points A B)))) | ||
17 : | (d (fix (difference (plus PA PB) AB)))) | ||
18 : | (* d d))) | ||
19 : | |||
20 : | (comment ;; old version | ||
21 : | ;; -------------------------------- ;; | ||
22 : | ;; distance overflow integer range! ;; | ||
23 : | ;; -------------------------------- ;; | ||
24 : | ;; ------------------------------------------------- ;; | ||
25 : | ;; (discance-pointe-line (10 20) ((30 40) (50 60))) ;; | ||
26 : | ;; line: dy*(x-x0) = dx*(y-y0) ;; | ||
27 : | ;; i.e. dy*x - dx*y + (-dy*x0 + dx*y0) = 0 ;; | ||
28 : | ;; ax + by + c = 0 ;; | ||
29 : | ;; ------------------------------------------------- ;; | ||
30 : | (defun distance-point-line (p l) | ||
31 : | (lets ((x (float (car p))) (y (float (cadr p))) | ||
32 : | (x0 (float (caar l))) (y0 (float (cadar l))) | ||
33 : | (x1 (float (caadr l))) (y1 (float (cadadr l))) | ||
34 : | (dx (-$ x1 x0)) (dy (-$ y1 y0)) | ||
35 : | (a dy) | ||
36 : | (b (minus dx)) | ||
37 : | (c (+$ (*$ (minus dy) x0) (*$ dx y0))) | ||
38 : | (ax+by+c (+$ (*$ a x) (*$ b y) c)) | ||
39 : | (a^2+b^2 (+$ (*$ a a) (*$ b b))) | ||
40 : | (distance (//$ (*$ ax+by+c ax+by+c) a^2+b^2))) | ||
41 : | (fix distance))) | ||
42 : | |||
43 : | (setq *rad->deg* (//$ 90.0 (arccos 0.0))) | ||
44 : | (defun radian->degree (rad) | ||
45 : | (fix (*$ *rad->deg* rad)))) | ||
46 : | |||
47 : | (defun cos-see-angle-point-line (p l) | ||
48 : | (lets ((x (float (first p))) (y (float (second p))) | ||
49 : | (px (-$ (float (caar l)) x)) | ||
50 : | (py (-$ (float (cadar l)) y)) | ||
51 : | (qx (-$ (float (caadr l)) x)) | ||
52 : | (qy (-$ (float (cadadr l)) y)) | ||
53 : | (plen (sqrt (+$ (*$ px px) (*$ py py)))) | ||
54 : | (qlen (sqrt (+$ (*$ qx qx) (*$ qy qy)))) | ||
55 : | (inner (+$ (*$ px qx) (*$ py qy))) | ||
56 : | (cos-theta (//$ inner (*$ plen qlen)))) | ||
57 : | cos-theta)) | ||
58 : | |||
59 : | (defun nth-of-nearest-point (org points) | ||
60 : | (let ((kouho-distance (distance-points org (car points))) | ||
61 : | (kouho-point 0)) | ||
62 : | (do ((rest (cdr points) (cdr rest)) | ||
63 : | (i 1 (1+ i))) | ||
64 : | ((null rest) kouho-point) | ||
65 : | (lets ((now (car rest)) | ||
66 : | (now-distance (distance-points org now))) | ||
67 : | (cond ((< now-distance kouho-distance) | ||
68 : | (setq kouho-distance now-distance | ||
69 : | kouho-point i))))))) | ||
70 : | |||
71 : | (defun nth-of-nearest-line (org lines) | ||
72 : | (let ((kouho-distance (distance-point-line org (car lines))) | ||
73 : | (kouho-line 0)) | ||
74 : | (do ((rest (cdr lines) (cdr rest)) | ||
75 : | (i 1 (1+ i))) | ||
76 : | ((null rest) kouho-line) | ||
77 : | (lets ((now (car rest)) | ||
78 : | (now-distance (distance-point-line org now))) | ||
79 : | (cond ((< now-distance kouho-distance) | ||
80 : | (setq kouho-distance now-distance | ||
81 : | kouho-line i))))))) | ||
82 : | |||
83 : | ;; ------------------------------------------------- ;; | ||
84 : | ;; (setq org '(0 0) | ||
85 : | ;; points '((10 10) (20 20) (4 3) (2 10) (1 1)) | ||
86 : | ;; lines '(((11 10) (20 20)) | ||
87 : | ;; (( 4 3) ( 2 10)) | ||
88 : | ;; (( 2 1) ( 2 0)) | ||
89 : | ;; (( 1 0) ( 0 1)))) | ||
90 : | ;; | ||
91 : | ;; (print (nth-of-nearest-point org points)) | ||
92 : | ;; (print (nth-of-nearest-line org lines)) | ||
93 : | ;; ------------------------------------------------- ;; |
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