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Diffstat (limited to 'sys/mwcs/gen/mwc2trand.x')
-rw-r--r-- | sys/mwcs/gen/mwc2trand.x | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/sys/mwcs/gen/mwc2trand.x b/sys/mwcs/gen/mwc2trand.x new file mode 100644 index 00000000..0cb156bd --- /dev/null +++ b/sys/mwcs/gen/mwc2trand.x @@ -0,0 +1,38 @@ +# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. + +include "../mwcs.h" + +# MW_C2TRAN -- Optimized 2D coordinate transformation. + +procedure mw_c2trand (a_ct, x1,y1, x2,y2) + +pointer a_ct #I pointer to CTRAN descriptor +double x1,y1 #I coordinates in input system +double x2,y2 #O coordinates in output system + +pointer ct, ltm, ltv +double p1[2], p2[2] + +begin + # Get real or double version of descriptor. + ct = CT_D(a_ct) + + ltm = CT_LTM(ct) + ltv = CT_LTV(ct) + + if (CT_TYPE(ct) == LNR) { + # Simple linear, nonrotated transformation. + x2 = Memd[ltm ] * x1 + Memd[ltv ] + y2 = Memd[ltm+3] * y1 + Memd[ltv+1] + } else if (CT_TYPE(ct) == LRO) { + # Linear, rotated transformation. + p1[1] = x1; p1[2] = y1 + x2 = Memd[ltm ] * p1[1] + Memd[ltm+1] * p1[2] + Memd[ltv ] + y2 = Memd[ltm+2] * p1[1] + Memd[ltm+3] * p1[2] + Memd[ltv+1] + } else { + # General case involving one or more functional terms. + p1[1] = x1; p1[2] = y1 + call mw_ctrand (a_ct, p1, p2, 2) + x2 = p2[1]; y2 = p2[2] + } +end |