enmetric()ize total time output in demo summary

src/demo/demo.c

@@ -411,15 +411,16 @@ int main(int argc, char** argv){
   bool failed = false;
   printf("\n");
   printf("        total│frames│output(B)│ rendering│%%r│%6s│\n", "FPS");
-  printf("══╤═╤═══════╪══════╪═════════╪══════════╪══╪══════╡\n");
+  printf("══╤═╤════════╪══════╪═════════╪══════════╪══╪══════╡\n");
   for(size_t i = 0 ; i < strlen(demos) ; ++i){
     char totalbuf[BPREFIXSTRLEN + 1];
+    char timebuf[PREFIXSTRLEN + 1];
+    qprefix(results[i].timens, GIG, timebuf, 0);
     bprefix(results[i].stats.render_bytes, 1, totalbuf, 0);
     double avg = results[i].stats.render_ns / (double)results[i].stats.renders;
-    printf("%2zu│%c│%2lu.%03lus│%6lu│%*s│%8juµs│%2ld│%6.1f│%s\n", i,
+    printf("%2zu│%c│%*ss│%6lu│%*s│%8juµs│%2ld│%6.1f│%s\n", i,
            results[i].selector,
-           results[i].timens / GIG,
-           (results[i].timens % GIG) / 1000000,
+           PREFIXSTRLEN, timebuf,
            results[i].stats.renders,
            BPREFIXSTRLEN, totalbuf,
            results[i].stats.render_ns / 1000,

src/lib/enmetric.c

@@ -23,7 +23,7 @@ const char *enmetric(uintmax_t val, unsigned decimal, char *buf, int omitdec,
 
   pthread_once(&ponce, convinit);
   if(decisep == NULL){
-
+    return NULL;
   }
   if(decimal == 0 || mult == 0){
     return NULL;
@@ -68,10 +68,13 @@ const char *enmetric(uintmax_t val, unsigned decimal, char *buf, int omitdec,
       buf[sprintfed + 1] = '\0';
     }
   }else{ // unscaled output, consumed == 0, dv == mult
+    // val / decimal < dv (or we ran out of prefixes)
     if(omitdec && val % decimal == 0){
       sprintf(buf, "%ju", val / decimal);
     }else{
-      sprintf(buf, "%ju%s%02ju", val / decimal, decisep, val % decimal);
+      uintmax_t divider = (decimal > mult ? decimal / mult : 1) * 10;
+      uintmax_t remain = (val % decimal) / divider;
+      sprintf(buf, "%ju%s%02ju", val / decimal, decisep, remain);
     }
   }
   return buf;

tests/enmetric.cpp

@@ -321,4 +321,17 @@ TEST_CASE("Enmetric") {
     CHECK(sizeof(suffixes) * 10 > i);
   }
 
+  // Output ought be scaled down for output while maintaining precision during
+  // computation of that output. For instance, we might feed a number of
+  // nanoseconds, but want output in seconds.
+  // This requires 'decimal' = 1000000000.
+  SUBCASE("ScaledGig") {
+    char gold[PREFIXSTRLEN + 1] = "9.02";
+    char buf[PREFIXSTRLEN + 1];
+    uintmax_t val = 9027854993;
+    uintmax_t decimal = 1000000000;
+    REQUIRE(qprefix(val, decimal, buf, 0));
+    CHECK(!strcmp(buf, gold));
+  }
+
 }

tests/render.cpp

@@ -74,7 +74,6 @@ TEST_CASE("RenderTest") {
     free(egc);
     egc = notcurses_at_yx(nc_, 0, 2, &c);
     REQUIRE(egc);
-fprintf(stderr, "HAVE [%s] WANT \xe5\xbd\xa2\n", egc);
     CHECK(!strcmp("\xe5\xbd\xa2", egc));
     CHECK(cell_double_wide_p(&c));
     free(egc);