1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
|
# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <mach.h>
include <pkg/gtools.h>
include "icfit.h"
# ICG_NEAREST -- Find the nearest point to the cursor and return the index.
# The nearest point to the cursor in NDC coordinates is determined.
# The cursor is moved to the nearest point selected.
int procedure icg_nearest$t (ic, gp, gt, cv, x, y, npts, wx, wy)
pointer ic # ICFIT pointer
pointer gp # GIO pointer
pointer gt # GTOOLS pointer
pointer cv # CURFIT pointer
PIXEL x[npts], y[npts] # Data points
int npts # Number of points
real wx, wy # Cursor position
int pt
pointer sp, xout, yout
int icg_n$t(), gt_geti()
begin
call smark (sp)
call salloc (xout, npts, TY_PIXEL)
call salloc (yout, npts, TY_PIXEL)
call icg_axes$t (ic, gt, cv, 1, x, y, Mem$t[xout], npts)
call icg_axes$t (ic, gt, cv, 2, x, y, Mem$t[yout], npts)
if (gt_geti (gt, GTTRANSPOSE) == NO)
pt = icg_n$t (gp, Mem$t[xout], Mem$t[yout], npts, wx, wy)
else
pt = icg_n$t (gp, Mem$t[yout], Mem$t[xout], npts, wy, wx)
call sfree (sp)
return (pt)
end
int procedure icg_n$t (gp, x, y, npts, wx, wy)
pointer gp # GIO pointer
PIXEL x[npts], y[npts] # Data points
int npts # Number of points
real wx, wy # Cursor position
int i, j
real x0, y0, r2, r2min
begin
# Transform world cursor coordinates to NDC.
call gctran (gp, wx, wy, wx, wy, 1, 0)
# Search for nearest point.
r2min = MAX_REAL
do i = 1, npts {
call gctran (gp, real (x[i]), real (y[i]), x0, y0, 1, 0)
r2 = (x0 - wx) ** 2 + (y0 - wy) ** 2
if (r2 < r2min) {
r2min = r2
j = i
}
}
# Move the cursor to the selected point and return the index.
if (j != 0)
call gscur (gp, real (x[j]), real (y[j]))
return (j)
end
|
