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
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
|
# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <plset.h>
include "pllseg.h"
include <plio.h>
# PL_LINESTENCIL -- Rasterop operation between source and destination line
# lists, reading the source and applying the rasterop only in the regions
# specified by the stencil line list. The stencil list is aligned with the
# source list.
procedure pl_linestencil (ll_src,xs,src_maxval, ll_dst,ds,dst_maxval,
ll_stn,ss, ll_out, npix, rop)
short ll_src[ARB] #I source line list
int xs #I starting pixel index in src line list
int src_maxval #I maximum pixel value, source mask
short ll_dst[ARB] #I destination line list
int ds #I starting pixel index in dst line list
int dst_maxval #I maximum pixel value, destination mask
short ll_stn[ARB] #I stencil line list
int ss #I starting pixel index in stn line list
short ll_out[ARB] #O output list (edited version of ll_dst)
int npix #I number of pixels to convert
int rop #I rasterop
bool need_src, rop_enable
int o_op, o_iz, o_pv, o_np, o_hi
int segsize, v_src, v_dst, v_stn, pv, src_value
int opcode, data, x1, hi, dv, v, iz, nz, np, op, n, i
int d_src[LEN_PLLDES], d_dst[LEN_PLLDES], d_stn[LEN_PLLDES]
define copyout_ 91
define done_ 92
begin
need_src = R_NEED_SRC(rop)
opcode = R_OPCODE(rop)
data = R_DATA(rop)
# Pixel value to be used if input mask is boolean.
if (src_maxval == 1)
src_value = data
if (src_value <= 0)
src_value = src_maxval
# Advance to the indicated position in the source list, discarding
# the instructions once read. The point XS may lie within the range
# of an instruction.
if (need_src) {
x1 = 1
pll_init (ll_src, d_src)
do i = 1, ARB {
np = min (pll_nleft(d_src), xs - x1)
pll_getseg (ll_src, d_src, np, v_src)
x1 = x1 + np
if (x1 >= xs || np == 0)
break
}
}
# Advance to the indicated position in the stencil list. This causes
# the point SS in the stencil to be aligned with the point XS in the
# source.
if (need_src) {
x1 = 1
pll_init (ll_stn, d_stn)
do i = 1, ARB {
np = min (pll_nleft(d_stn), xs - x1)
pll_getseg (ll_stn, d_stn, np, v_stn)
x1 = x1 + np
if (x1 >= xs || np == 0)
break
}
}
# Copy DST to OUT, applying the rasterop in the region of NPIX pixels
# beginning at DS. To simplify things (avoid pathological complexity
# in this case) we suffer some unnecessary unpacking and repacking
# of encoded line list instructions in the regions of the DST list
# which are simply copied. This avoids the need for special treatment
# at the edges of the region to which the ROP applies. ROP_ENABLE is
# false initially, true in the ROP region, and false again to the
# right. The number of pixels in each region is given by SEGSIZE.
o_pv = -1
op = LL_CURHDRLEN + 1
segsize = ds - 1
rop_enable = false
x1 = 1; iz = 1; hi = 1
pll_init (ll_dst, d_dst)
do i = 1, ARB {
# Set up for the next segment (before, in, and after the region to
# which the ROP applies), when the current segment is exhausted.
if (segsize <= 0)
if (!rop_enable) {
# Begin processing central region.
segsize = npix
rop_enable = true
if (segsize <= 0)
next
} else {
# Begin processing final region.
segsize = ARB
rop_enable = false
}
# Determine the length of the next output segment. This is the
# largest segment of constant value formed by the intersection of
# the two lists. If bounds checking has been performed properly
# then it should not be possible to see nleft=zero on either input
# list. Note that zeroed regions are valid data here.
np = min (segsize, pll_nleft(d_dst))
if (need_src && rop_enable && pll_nleft(d_src) > 0) {
np = min (np, pll_nleft(d_src))
if (pll_nleft (d_stn) > 0)
np = min (np, pll_nleft(d_stn))
}
if (np <= 0)
break
# Get the segment value and advance the line pointers. We always
# have to read the DST list to copy it to the output. We read the
# SRC list and apply the rasterop only in the region to which the
# ROP applies.
pll_getseg (ll_dst, d_dst, np, v_dst)
if (rop_enable) {
if (need_src) {
v_src = 0
if (pll_nleft (d_src) > 0)
pll_getseg (ll_src, d_src, np, v_src)
if (v_src != 0 && src_maxval == 1)
v_src = src_value
pll_getseg (ll_stn, d_stn, np, v_stn)
if (v_stn == 0)
goto copyout_
}
# Compute the pixel value for the new output segment, given the
# source and destination pixel values and the rasterop supplied.
switch (opcode) {
case PIX_CLR:
pv = 0
case PIX_SET:
pv = data
case PIX_SRC:
pv = v_src
case PIX_DST:
pv = v_dst
case PIX_NOTSRC:
pv = not (v_src)
case PIX_NOTDST:
pv = not (v_dst)
case PIX_SRC_AND_DST:
pv = and (v_src, v_dst)
case PIX_SRC_OR_DST:
pv = or (v_src, v_dst)
case PIX_SRC_XOR_DST:
pv = xor (v_src, v_dst)
case PIX_SRC_AND_NOTDST:
pv = and (v_src, not(v_dst))
case PIX_SRC_OR_NOTDST:
pv = or (v_src, not(v_dst))
case PIX_NOTSRC_AND_DST:
pv = and (not(v_src), v_dst)
case PIX_NOTSRC_OR_DST:
pv = or (not(v_src), v_dst)
case PIX_NOT_SRC_AND_DST:
pv = not (and (v_src, v_dst))
case PIX_NOT_SRC_OR_DST:
pv = not (or (v_src, v_dst))
case PIX_NOT_SRC_XOR_DST:
pv = not (xor (v_src, v_dst))
}
# Mask the high bits to prevent negative values, handle the
# case of a boolean output mask.
if (dst_maxval == 1 && pv != 0)
pv = 1
else if (dst_maxval > 1)
pv = and (dst_maxval, pv)
} else
copyout_ pv = v_dst
if (pv == 0) {
if (pll_nleft (d_dst) <= 0) {
# Output zeros at end of list.
x1 = x1 + np
} else {
# Keep going until we get a nonzero range.
o_pv = 0
x1 = x1 + np
segsize = segsize - np
next
}
} else if (pv == o_pv) {
# Combine with previous range.
iz = o_iz
hi = o_hi
op = o_op
x1 = x1 - o_np
segsize = segsize + o_np
np = np + o_np
o_np = np
} else {
# Save current range parameters.
o_op = op
o_np = np
o_iz = iz
o_hi = hi
o_pv = pv
}
# Encode an instruction to regenerate the current range of NP data
# values of nonzero level PV, starting at X1. In the most complex
# case we must update the high value and output a range of zeros,
# followed by a range of NP high values. If NP is 1, we can
# probably use a PN or [ID]S instruction to save space.
nz = x1 - iz
# Change the high value?
if (pv > 0) {
dv = pv - hi
if (dv != 0) {
# Output IH or DH instruction?
hi = pv
if (abs(dv) > I_DATAMAX) {
ll_out[op] = M_SH + and (pv, I_DATAMAX)
op = op + 1
ll_out[op] = pv / I_SHIFT
op = op + 1
} else {
if (dv < 0)
ll_out[op] = M_DH + (-dv)
else
ll_out[op] = M_IH + dv
op = op + 1
# Convert to IS or DS if range is a single pixel.
if (np == 1 && nz == 0) {
v = ll_out[op-1]
ll_out[op-1] = or (v, M_MOVE)
goto done_
}
}
}
}
# Output range of zeros to catch up to current range?
if (nz > 0) {
# Output the ZN instruction.
for (n=nz; n > 0; n = n - I_DATAMAX) {
ll_out[op] = M_ZN + min(I_DATAMAX,n)
op = op + 1
}
# Convert to PN if range is a single pixel.
if (np == 1 && pv > 0) {
ll_out[op-1] = ll_out[op-1] + M_PN + 1
goto done_
}
# At end of list.
if (pv == 0)
goto done_
}
# The only thing left is the HN instruction if we get here.
for (n=np; n > 0; n = n - I_DATAMAX) {
ll_out[op] = M_HN + min(I_DATAMAX,n)
op = op + 1
}
done_
segsize = segsize - np
x1 = x1 + np
iz = x1
}
# Update the line list header.
call amovs (ll_dst, ll_out, LL_CURHDRLEN)
LL_SETLEN(ll_out, op - 1)
end
|
