diff options
Diffstat (limited to 'sys/plio/pllseg.h')
| -rw-r--r-- | sys/plio/pllseg.h | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/sys/plio/pllseg.h b/sys/plio/pllseg.h new file mode 100644 index 00000000..2f358944 --- /dev/null +++ b/sys/plio/pllseg.h @@ -0,0 +1,56 @@ +# PLLSEG.H -- Macros for sequentially reading segments of a line list. +# +# pll_init (ll, descriptor) +# npix = pll_nleft (descriptor) +# val = pll_getseg (ll, descriptor, npix, value) +# +# pll_init Initialize descriptor for sequential i/o from the linelist LL. +# pll_nleft Number of pixels left in the current line segment of constant +# value. Zero is returned at the EOL. +# pll_getseg Read NPIX pixels from the current segment, advancing to the +# next segment automatically when the the current segment is +# exhausted. +# +# The descriptor is an integer array, the contents of which are hidden from +# the application using these macros. This package uses the internal +# procedure PLL_NEXTSEG, which is included in PL package library. + +# Range list i/o descriptor. +define LEN_PLLDES 7 +define ld_nleft $1[1] +define ld_value $1[2] +define ld_x $1[3] +define ld_ip $1[4] +define ld_hi $1[5] +define ld_next_nleft $1[6] +define ld_next_value $1[7] + +# PLL_INIT -- Initialize the linelist descriptor. +define (pll_init, { # $1=ll $2=des + # ld_x($2) = 1 + ld_hi($2) = 1 + if (LL_OLDFORMAT($1)) + ld_ip($2) = OLL_FIRST + else + ld_ip($2) = LL_FIRST($1) + ld_next_nleft($2) = 0 + ld_nleft($2) = 0 + call pll_nextseg ($1, $2) +}) + +# PLL_NLEFT -- Number of pixels left in the current segment. +define pll_nleft ld_nleft($1) + +# PLL_GETSEG -- Read pixels from the current segment. +define (pll_getseg, { # $1=ll $2=des $3=npix $4=value + $4 = ld_value($2) + # ld_x($2) = ld_x($2) + $3 + ld_nleft($2) = ld_nleft($2) - $3 + if (ld_nleft($2) <= 0) + if (ld_next_nleft($2) > 0) { + ld_nleft($2) = ld_next_nleft($2) + ld_value($2) = ld_next_value($2) + ld_next_nleft($2) = 0 + } else + call pll_nextseg ($1, $2) +}) |