more braille styles (ideas from drawille)

added 'braille-peak' and 'braille-snake'.  'braille-peak'
renders only the top point, and 'braille-snake' fills some in.

I should have stressed earlier that I only got the braille drawing ideas
after coming across drawille ( https://github.com/asciimoo/drawille ).

i3pystatus/core/util.py

@@ -371,7 +371,7 @@ def make_graph(values, upper_limit=100.0, style="blocks"):
 
     :param values: An array of values to graph.
     :param upper_limit: Maximum value for the y axis.
-    :param style: Drawing style (currently 'blocks' or 'braille').
+    :param style: Drawing style ('blocks', 'braille-fill', 'braille-peak', or 'braille-snake').
     :returns: Bar as a string
     """
     values = [float(n) for n in values]
@@ -384,18 +384,39 @@ def make_graph(values, upper_limit=100.0, style="blocks"):
             graph = '_' * len(values)
         else:
             graph = ''.join(bar[int((n - mn) / extent * bar_count)] for n in values)
-    elif style == 'braille':
+    elif style in ['braille-fill', 'braille-peak', 'braille-snake']:
         # idea from https://github.com/asciimoo/drawille
         # unicode values from http://en.wikipedia.org/wiki/Braille
-        v2 = values if len(values) % 2 == 0 else values + [mn]
+
-        l = len(v2) // 2
+        vpad = values if len(values) % 2 == 0 else values + [mn]
-        if extent == 0:
+        vscale = [round(4 * (vp - mn) / extent) for vp in vpad]
-            graph = chr(0x2800) * l  # should be visually equiv to ' '
+        l = len(vscale) // 2
+
+        # do the 2-character collapse separately for clarity
+        if 'fill' in style:
+            vbits = [[0, 0x40, 0x44, 0x46, 0x47][vs] for vs in vscale]
+        elif 'peak' in style:
+            vbits = [[0, 0x40, 0x04, 0x02, 0x01][vs] for vs in vscale]
         else:
+            assert('snake' in style)
+            # there are a few choices for what to put last in vb2.
+            # arguable vscale[-1] from the _previous_ call is best.
+            vb2 = [vscale[0]] + vscale + [0]
+            vbits = []
+            for i in range(1, l + 1):
+                c = 0
+                for j in range(min(vb2[i - 1], vb2[i], vb2[i + 1]), vb2[i] + 1):
+                    c |= [0, 0x40, 0x04, 0x02, 0x01][j]
+                vbits.append(c)
+
+        # 2-character collapse
         graph = ''
         for i in range(0, l, 2):
-                b1 = [0, 0x40, 0x44, 0x46, 0x47][round(4 * (v2[i] - mn) / extent)]
+            b1 = vbits[i]
-                b2 = [0, 0x80, 0xa0, 0xb0, 0xb8][round(4 * (v2[i + 1] - mn) / extent)]
+            b2 = vbits[i + 1]
+            if b2 & 0x40:
+                b2 = b2 - 0x30
+            b2 = b2 << 3
             graph += chr(0x2800 + b1 + b2)
     else:
         raise NotImplementedError("Graph drawing style '%s' unimplemented." % style)

i3pystatus/cpu_usage_graph.py

@@ -26,7 +26,7 @@ class CpuUsageGraph(CpuUsage, ColorRangeModule):
         ("start_color", "Hex or English name for start of color range, eg '#00FF00' or 'green'"),
         ("end_color", "Hex or English name for end of color range, eg '#FF0000' or 'red'"),
         ("graph_width", "Width of the cpu usage graph"),
-        ("graph_style", "Graph style, currently 'blocks' or 'braille'"),
+        ("graph_style", "Graph style ('blocks', 'braille-fill', 'braille-peak', or 'braille-snake')"),
     )
 
     graph_width = 15

i3pystatus/network.py

@@ -254,7 +254,7 @@ class Network(IntervalModule, ColorRangeModule):
         ("start_color", "Hex or English name for start of color range, eg '#00FF00' or 'green'"),
         ("end_color", "Hex or English name for end of color range, eg '#FF0000' or 'red'"),
         ("graph_width", "Width of the network traffic graph"),
-        ("graph_style", "Graph style, currently 'blocks' or 'braille'"),
+        ("graph_style", "Graph style ('blocks', 'braille-fill', 'braille-peak', or 'braille-snake')"),
         ("upper_limit",
          "Expected max kb/s. This value controls how the network traffic graph is drawn and in what color"),
         ("graph_type", "Whether to draw the network traffic graph for input or output. "