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
|
# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <imhdr.h>
include <mach.h>
include <gset.h>
include "wdes.h"
include "crtpict.h"
# CRT_DRAW_GREYSCALE -- Draw steps representing greyscale increments on output.
procedure crt_draw_greyscale (gp, cl)
pointer gp
pointer cl
short grey[NSTEPS]
char label[SZ_LABEL]
int ndev_rows, i, dummy
real ndc_xs, ndc_xe, ndc_ys, ndc_ye, yres, del_y
real delta_grey, delta_x, x_start, x, dz1, dz2
bool ggetb()
int ggeti(), itoc()
real ggetr()
errchk ggetb, ggeti, ggetr, gpcell, ggetr, gtext
begin
if (ggetb (gp, "z1") && ggetb (gp, "z2")) {
dz1 = ggetr (gp, "z1")
dz2 = ggetr (gp, "z2")
} else {
dz1 = 0.
dz2 = 255.
}
ndev_rows = ggeti (gp, "yr")
yres = (CRT_YE - CRT_YS) * ndev_rows
# The (NDC) device coordinates of the greyscale_window are calculated.
ndc_xs = CRT_XS
ndc_xe = CRT_XE
ndc_ys = CRT_YS + ((GRAPHICS_FRACTION(cl) + IMAGE_FRACTION(cl) + SPACE)*
yres) / ndev_rows
ndc_ye = ndc_ys + ((yres * GREYSCALE_FRACTION(cl)) / ndev_rows)
ndc_ye = min (ndc_ye, CRT_YE)
del_y = ndc_ye - ndc_ys
# Calculate and output grey levels
call gseti (gp, G_WCS, 0)
delta_grey = (dz2 - dz1) / real(NSTEPS - 1)
delta_x = (ndc_xe - ndc_xs) / NSTEPS
x_start = ndc_xs + (delta_x / 2.0)
do i = 1, NSTEPS {
grey[i] = short (dz1 + (i-1) * delta_grey + 0.5)
dummy = itoc (int(grey[i]), label, SZ_LABEL)
x = x_start + (i - 1) * delta_x
call gtext (gp, x, ndc_ys, label, "h=c;s=0.25;v=t")
}
call gpcell (gp, grey, NSTEPS, 1, ndc_xs, ndc_ys + (0.05 * del_y),
ndc_xe, ndc_ye)
end
|
