2022-12-09 16:33:00

1 files changed, 71 insertions, 63 deletions

diff --git a/metapost/context/base/mpxl/mp-lmtx.mpxl b/metapost/context/base/mpxl/mp-lmtx.mpxl
index f26af8a60..e6daff660 100644
--- a/metapost/context/base/mpxl/mp-lmtx.mpxl
+++ b/metapost/context/base/mpxl/mp-lmtx.mpxl
@@ -1024,6 +1024,7 @@ presetparameters "chart" [
     percentage      = false,
     maximum         = 0,
     distance        = 1mm,
+    threshold       = eps,
 
   % labels          = { },
     labelstyle      = "",
@@ -1084,17 +1085,18 @@ def lmt_chart_bar       = applyparameters "chart:bar"       "lmt_do_chart_bar"
 
 def lmt_do_chart_start (expr what) =
     pushparameters what ;
-    save width, height, depth, distance, linewidth, linegap, labelgap, labelfraction, value, nofsamples, nofsamplesets ;
+    save width, height, depth, distance, threshold, linewidth, linegap, labelgap, labelfraction, value, nofsamples, nofsamplesets ;
     save fillcolor, linecolor, drawcolor, labelcolor, labelstyle, labelformat, labelstrut, labelanchor, colormode ;
     string fillcolor, linecolor, drawcolor, labelcolor, labelstyle, labelformat, labelstrut, labelanchor, colormode ;
     if hasparameter "sampleset" :
         setluaparameter what "samples" (getparameter "sampleset") ;
     fi ;
+    threshold := getparameter "threshold" ;
+    linewidth := getparameter "linewidth" ;
     height := getparameter "height" ;
-    depth := max((getparameter "originsize"), (getparameter "innerradius")) ;
+    depth := max(getparameter "originsize", (getparameter "innerradius"), 8*linewidth) ;
     width := getparameter "width" ;
     distance := getparameter "distance" ;
-    linewidth := getparameter "linewidth" ;
     linegap := getparameterdefault "linegap" linewidth ;
     drawcolor := getparameter "drawcolor" ;
     colormode :=  getparameter "colormode" ;
@@ -1194,78 +1196,84 @@ vardef lmt_do_chart_circle =
             nofsamplesets := 1 ;
             save p, q, r, s, t, pl, ql, first, last, total, factor, n, percentage, initial, clockwise ;
             path p, q, r, s[], t[] ; boolean percentage, clockwise ;
+            save value, v;
             clockwise := true ;
             percentage := getparameter "percentage" ;
             initial := if not clockwise : - fi getparameter "initialangle" ; % watch sign
             total := 0 ;
             for i = 1 upto nofsamples :
-                total := total + getparameter "samples" (1) i ; % () is needed else 1i
-            endfor ;
-            factor := 100/total ;
-            first := initial ;
-            if clockwise :
-                p := (reverse fullcircle rotated first) ysized (height) ;
-                q := (reverse fullcircle rotated first) ysized (depth) ;
-            else :
-                p := fullcircle ysized (height) ;
-                q := fullcircle ysized (depth) ;
-            fi ;
-            r := origin -- (2*height,0) ;
-            pl := ((linewidth + linegap) / (arclength p)) * 360;
-            ql := ((linewidth + linegap) / (arclength q)) * 360;
-            for i = 1 upto nofsamples :
-                fillcolor := getparameter "fillcolors" i ;
-                linecolor := getparameterdefault "linecolors" i "" ;
-                if linecolor = "" :
-                    linecolor := fillcolor ;
+                value := getparameter "samples" (1) i ;
+                if value > threshold :
+                    total := total + value ;
                 fi ;
-                value := (getparameter "samples" (1) i) * factor ;
-if (value > -eps) and (value < eps) :
-    s[i] := origin ;
-    t[i] := origin ;
-else :
-%                 if (value > -eps) and (value < eps) :
-%                     value := eps ; % otherwise weird effects with zero
-%                 fi ;
-                last := first if clockwise : - else : + fi (360/100) * value ;
-                s[i] :=         ((p cutbefore (r rotated first)) cutafter (r rotated (last + pl))) ;
-                t[i] := reverse ((q cutbefore (r rotated first)) cutafter (r rotated (last + ql))) ;
-                path piece ; piece := s[i] -- t[i] -- cycle ;
-                if fillcolor <> "" :
-                    fill piece
-                        withpen pencircle scaled linewidth
-                        withcolor fillcolor
-                    ;
-                fi ;
-                if linecolor <> "" :
-                    if linewidth > 0 :
-                        interim linecap := butt ;
-                        draw piece
-                            withpen pencircle scaled linewidth
-                            withcolor if linecolor <> "" : linecolor else drawcolor : fi
-                        ;
-                    fi ;
-                fi ;
-                first := last ;
-fi ;
             endfor ;
-            if linewidth > 0 :
-                clip currentpicture to p enlarged linewidth ;
-            fi ;
-            if getparameter "showlabels" :
+            if total = 0 :
+                message("zero total in circular chart");
+            else :
+                factor := 100/total ;
                 first := initial ;
+                if clockwise :
+                    p := (reverse fullcircle rotated first) ysized (height) ;
+                    q := (reverse fullcircle rotated first) ysized (depth) ;
+                else :
+                    p := fullcircle ysized (height) ;
+                    q := fullcircle ysized (depth) ;
+                fi ;
+                r := origin -- (2*height,0) ;
+                pl := ((linewidth + linegap) / (arclength p)) * 360;
+                ql := ((linewidth + linegap) / (arclength q)) * 360;
+                v := 0 ;
                 for i = 1 upto nofsamples :
                     value := getparameter "samples" (1) i ;
-                    last := first if clockwise : - else : + fi (360/100) * value * factor ;
-if (value > -eps) and (value < eps) :
-else :
-                    draw lmt_do_chart_text (s,i,value)
-                        shifted ((labelfraction*(height/2),0) rotated ((first+last)/2)) ;
-                    first := last ;
-fi ;
+                    if value > threshold :
+                        v := v + 1 ;
+                        fillcolor := getparameter "fillcolors" i ;
+                        linecolor := getparameterdefault "linecolors" i "" ;
+                        if linecolor = "" :
+                            linecolor := fillcolor ;
+                        fi ;
+                        value := value * factor ;
+                        last := first if clockwise : - else : + fi (360/100) * value ;
+                        s[v] :=         ((p cutbefore (r rotated first)) cutafter (r rotated (last + pl))) ;
+                        t[v] := reverse ((q cutbefore (r rotated first)) cutafter (r rotated (last + ql))) ;
+                        path piece ; piece := s[v] -- t[v] -- cycle ;
+                        if fillcolor <> "" :
+                            fill piece
+                                withpen pencircle scaled linewidth
+                                withcolor fillcolor
+                            ;
+                        fi ;
+                        if linecolor <> "" :
+                            if linewidth > 0 :
+                                interim linecap := butt ;
+                                draw piece
+                                    withpen pencircle scaled linewidth
+                                    withcolor if linecolor <> "" : linecolor else drawcolor : fi
+                                ;
+                            fi ;
+                        fi ;
+                        first := last ;
+                    fi ;
                 endfor ;
+                if linewidth > 0 :
+                    clip currentpicture to p enlarged linewidth ;
+                fi ;
+                if getparameter "showlabels" :
+                    first := initial ;
+                    v := 0 ;
+                    for i = 1 upto nofsamples :
+                        value := getparameter "samples" (1) i ;
+                        if value > threshold :
+                            v := v + 1 ;
+                            last := first if clockwise : - else : + fi (360/100) * value * factor ;
+                            draw lmt_do_chart_text (s,i,value)
+                                shifted ((labelfraction*(height/2),0) rotated ((first+last)/2)) ;
+                            first := last ;
+                        fi
+                    endfor ;
+                fi ;
+                lmt_do_chart_legend ;
             fi ;
-            lmt_do_chart_legend ;
         fi ;
         lmt_do_chart_stop ;
     )