feat: add the disks and cache cards

disks draws a ring per filesystem from the df sample, with the NFS
server address read from the device field and a labelled-bar fallback
when the rings would be too small to read. cache shows the ~/.cache
total and its four largest children from the du sample.

card.ring now resets the cairo path first: a preceding card.text()
leaves a current point, and cairo_arc() joins to it with a straight
line, so the disks rings were drawn with stray chords. The ring
primitive had no caller until now, which is why it went unnoticed.

1 files changed, 4 insertions, 0 deletions

diff --git a/lib/card.lua b/lib/card.lua
index 8e04e0b..48a7f2e 100644
--- a/lib/card.lua
+++ b/lib/card.lua
@@ -184,6 +184,10 @@ function M.ring(cr, cx, cy, r, frac, colour, colors, width)
   if frac < 0 then frac = 0 elseif frac > 1 then frac = 1 end
   width = width or math.max(3, r * 0.18)
 
+  -- Start a fresh path. A preceding card.text() leaves a current point behind,
+  -- and cairo_arc() joins to it with a straight line, so without this every
+  -- ring after a label is drawn with a stray chord to the text baseline.
+  cairo_new_path(cr)
   cairo_set_line_width(cr, width)
   cairo_set_line_cap(cr, CAIRO_LINE_CAP_ROUND)