1 files changed, 30 insertions, 24 deletions
diff --git a/tex/context/base/thrd-trg.tex b/tex/context/base/thrd-trg.tex
index 3fce672d5..dda81a8af 100644
--- a/tex/context/base/thrd-trg.tex
+++ b/tex/context/base/thrd-trg.tex
@@ -6,6 +6,12 @@
 
 \unprotect
 
+% compare: \number 0.5 \number -0.5 \number 1.5 \number -1.5
+%
+% so we need:
+
+\def\realnumber#1{\withoutpt\the\dimexpr#1\s!pt\relax} % brrr
+
 \chardef     \@iv         =     4
 \chardef     \@xc         =    90 % was \nin@ty
 \chardef     \@clxx       =   180
@@ -51,22 +57,22 @@
 %D calculations.
 
 \def\calculatesin#1%
-  {{\expandafter\ifx\csname sin \number#1\endcsname\relax
+  {{\expandafter\ifx\csname sin \realnumber{#1}\endcsname\relax
       \!!dimena#1\onepoint
       \tg@@sin
-      \expandafter\xdef\csname sin \number#1\endcsname{\withoutpt\the\!!dimena}%
+      \expandafter\xdef\csname sin \realnumber{#1}\endcsname{\withoutpt\the\!!dimena}%
     \fi}}
 
 \def\calculatecos#1%
-  {{\expandafter\ifx\csname cos \number#1\endcsname\relax
+  {{\expandafter\ifx\csname cos \realnumber{#1}\endcsname\relax
       \!!dimena\@xc\onepoint
       \advance\!!dimena-#1\onepoint
       \tg@@sin
-      \expandafter\xdef\csname cos \number#1\endcsname{\withoutpt\the\!!dimena}%
+      \expandafter\xdef\csname cos \realnumber{#1}\endcsname{\withoutpt\the\!!dimena}%
     \fi}}
 
 \def\calculatetan#1%
-  {{\expandafter\ifx\csname tan \number#1\endcsname\relax
+  {{\expandafter\ifx\csname tan \realnumber{#1}\endcsname\relax
       \calculatesin{#1}%
       \calculatecos{#1}%
       \!!dimena\calculatedcos{#1}\onepoint
@@ -74,40 +80,40 @@
       \!!dimenb\calculatedsin{#1}\onepoint
       \!!dimenb\@xvi@k\!!dimenb
       \divide\!!dimenb\!!dimena
-      \expandafter\xdef\csname tan \number#1\endcsname{\withoutpt\the\!!dimenb}%
+      \expandafter\xdef\csname tan \realnumber{#1}\endcsname{\withoutpt\the\!!dimenb}%
    \fi}}
 
 %D The results are accessed with:
 
-\def\calculatedsin#1{\csname sin \number#1\endcsname}
-\def\calculatedcos#1{\csname cos \number#1\endcsname}
-\def\calculatedtan#1{\csname tan \number#1\endcsname}
+\def\calculatedsin#1{\csname sin \realnumber{#1}\endcsname}
+\def\calculatedcos#1{\csname cos \realnumber{#1}\endcsname}
+\def\calculatedtan#1{\csname tan \realnumber{#1}\endcsname}
 
 %D A more save implementation would be:
 
-\def\calculatedsin#1{\executeifdefined{sin \number#1}\!!zerocount}
-\def\calculatedcos#1{\executeifdefined{cos \number#1}\!!plusone}
-\def\calculatedtan#1{\executeifdefined{tan \number#1}\!!zerocount}
+\def\calculatedsin#1{\executeifdefined{sin \realnumber{#1}}\!!zerocount}
+\def\calculatedcos#1{\executeifdefined{cos \realnumber{#1}}\!!plusone  }
+\def\calculatedtan#1{\executeifdefined{tan \realnumber{#1}}\!!zerocount}
 
 %D A few values are predefined, although, on todays systems there
 %D is no real reason for that. I've added the 270 ones and changed
 %D the -90 tan. Also, I prefer text (\type {\!!..} instead of
 %D counters \type {\..}.
 
-\expandafter\let\csname sin   0\endcsname\!!zerocount
-\expandafter\let\csname cos   0\endcsname\!!plusone
-\expandafter\let\csname sin  90\endcsname\!!plusone
-\expandafter\let\csname cos  90\endcsname\!!zerocount
-\expandafter\let\csname sin 180\endcsname\!!zerocount
-\expandafter\let\csname cos 180\endcsname\!!minusone
-\expandafter\let\csname sin 270\endcsname\!!minusone
-\expandafter\let\csname cos 270\endcsname\!!zerocount
+\expandafter\let\csname sin \realnumber{  0}\endcsname\!!zerocount
+\expandafter\let\csname cos \realnumber{  0}\endcsname\!!plusone
+\expandafter\let\csname sin \realnumber{ 90}\endcsname\!!plusone
+\expandafter\let\csname cos \realnumber{ 90}\endcsname\!!zerocount
+\expandafter\let\csname sin \realnumber{180}\endcsname\!!zerocount
+\expandafter\let\csname cos \realnumber{180}\endcsname\!!minusone
+\expandafter\let\csname sin \realnumber{270}\endcsname\!!minusone
+\expandafter\let\csname cos \realnumber{270}\endcsname\!!zerocount
 
-\expandafter\let\csname sin -90\endcsname\!!minusone
-\expandafter\let\csname cos -90\endcsname\!!zerocount
+\expandafter\let\csname sin \realnumber{-90}\endcsname\!!minusone
+\expandafter\let\csname cos \realnumber{-90}\endcsname\!!zerocount
 
-\expandafter\def\csname tan  90\endcsname{\writestatus\m!systems{infinite tan +90}}
-\expandafter\def\csname tan -90\endcsname{\writestatus\m!systems{infinite tan -90}}
+\expandafter\def\csname tan \realnumber{ 90}\endcsname{\writestatus\m!systems{infinite tan +90}}
+\expandafter\def\csname tan \realnumber{-90}\endcsname{\writestatus\m!systems{infinite tan -90}}
 
 %D Usage: \type {\calculatesin{10}} and \type {\calculatedsin{10}}