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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <plset.h>
include <plio.h>
include "../plrseg.h"
# PL_RANGEROP -- Rasterop operation between source and destination range lists.
# The indicated rasterop operation is performed upon the source and destination
# range lists, writing the result to RL_OUT, which is a copy of RL_DST except
# for the region affected by the rasterop operation (note that the destination
# range list cannot be edited in place since it may change size).
procedure pl_rangeropi (rl_src, xs, src_maxval,
rl_dst, ds, dst_maxval, rl_out, npix, rop)
int rl_src[3,ARB] #I source range list
int xs #I starting pixel index in src range list
int src_maxval #I max pixel value in src mask
int rl_dst[3,ARB] #I destination range list
int ds #I starting pixel index in dst range list
int dst_maxval #I max pixel value in dst mask
int rl_out[3,ARB] #O output list (edited version of rl_dst)
int npix #I number of pixels to convert
int rop #I rasterop
bool need_src, need_dst, rop_enable
int data, src_value, v_src, v_dst, pv
int segsize, opcode, x, i, np, rn_o, p
int d_src[LEN_PLRDES], d_dst[LEN_PLRDES]
begin
need_src = R_NEED_SRC(rop)
need_dst = R_NEED_DST(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 = dst_maxval
}
# Advance to the desired position in the source list, discarding
# the unused ranges. The point XS may lie within a range or in a
# zero area of the input line.
if (need_src) {
x = 1
plr_init (rl_src, d_src)
do i = 1, ARB {
np = min (plr_nleft(d_src), xs - x)
plr_getseg (rl_src, d_src, np, v_src)
x = x + np
if (x >= xs || np == 0)
break
}
}
# Advance through both the source and destination lists, extracting
# line segments which have a constant value in each input list; the
# values for the two lists may differ. Apply the given rasterop to
# the source and destination pixel values and write each line segment
# as a range to the output list. If the ranges in the two input lists
# differ (randomly overlap) then the output list will generally be
# more fragmented, i.e., have more ranges of constant value. As each
# output range is generated compare it with the previous range to see
# if they can be joined, as applying a rasterop may cause two different
# ranges to have the same value.
x = 1
rn_o = RL_FIRST
segsize = ds - 1
rop_enable = false
plr_init (rl_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 properly performed
# 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, plr_nleft(d_dst))
if (need_src && rop_enable && plr_nleft(d_src) > 0)
np = min (np, plr_nleft(d_src))
if (np <= 0)
break
# Get the segment value and advance the line pointers. We must
# read the DST list whether or not we will use the data, since
# the list pointer must be advanced NPIX pixels so that we may
# copy the remainder of the list after the loop.
plr_getseg (rl_dst, d_dst, np, v_dst)
if (rop_enable) {
# Get v_src.
if (need_src) {
v_src = 0
if (plr_nleft (d_src) > 0)
plr_getseg (rl_src, d_src, np, v_src)
if (R_NOTSRC(rop)) {
v_src = not (v_src)
if (src_maxval != 0)
v_src = and (int(v_src), src_maxval)
}
if (v_src != 0 && src_maxval == 1)
v_src = src_value
}
# Get v_dst.
if (need_dst) {
if (R_NOTDST(rop)) {
v_dst = not (v_dst)
if (dst_maxval != 0)
v_dst = and (int(v_dst), dst_maxval)
}
}
# Apply the rasterop.
switch (opcode) {
case PIX_CLR:
pv = 0
case PIX_SET:
pv = data
case PIX_SRC, PIX_NOTSRC:
pv = v_src
case PIX_DST, PIX_NOTDST:
pv = v_dst
case PIX_SRC_AND_DST, PIX_SRC_AND_NOTDST, PIX_NOTSRC_AND_DST:
pv = and (v_src, v_dst)
case PIX_SRC_OR_DST, PIX_SRC_OR_NOTDST, PIX_NOTSRC_OR_DST:
pv = or (v_src, v_dst)
case PIX_SRC_XOR_DST:
pv = xor (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, or map int
# to bool for the case of a boolean output mask.
if (dst_maxval == 1 && pv != 0)
pv = 1
else if (dst_maxval > 1)
pv = and (int(pv), dst_maxval)
} else
pv = v_dst
# Output a nonzero range.
if (pv > 0) {
p = rn_o - 1
if (p >= RL_FIRST &&
pv == rl_out[3,p] && x == rl_out[1,p] + rl_out[2,p]) {
# Merge new range with previous one.
rl_out[2,p] = rl_out[2,p] + np
} else {
rl_out[1,rn_o] = x
rl_out[2,rn_o] = np
rl_out[3,rn_o] = pv
rn_o = rn_o + 1
}
}
x = x + np
segsize = segsize - np
}
# Update the range list header.
call amovi (rl_dst, rl_out, (RL_FIRST - 1) * 3)
RL_LEN(rl_out) = rn_o - 1
end
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