Add testing for horizontal charts.

Bar and area charts have slightly different drawing logic when
horizontal. Other charts should fine just by transforming the mapping
from metric-space -> pixel-space.

Author: bakpakin

spork/charts.janet

@@ -30,7 +30,7 @@
 ### [x] - stippled grid lines
 ### [x] - bar chart
 ### [x] - area chart
-### [ ] - horizontal bar charts
+### [x] - horizontal bar charts
 ### [ ] - multi-bar charts
 ### [ ] - flame graph
 ### [ ] - packing chart
@@ -41,6 +41,7 @@
 ### [x] - handle nils in y-columns for sparse data
 ### [x] - easier custom chart annotations in the metric space (horizontal lines, vertical lines, etc.)
 ### [ ] - captions and sub-titles
+### [ ] - labeling data points
 
 (import spork/gfx2d :as g)
 

test/gold/horizontal_area_chart.png

@@ -484,4 +484,25 @@
 
 (test-super-minimal-chart)
 
+(defn test-horizontal-chart
+  [line-style]
+  (def c
+    (charts/line-chart
+      :title (string "H " line-style " Chart (sine waves)")
+      :data {:x (range 101)
+             :y (seq [x :range [0 100]] (math/cos (* x 0.2)))
+             :z (seq [x :range [0 100]] (math/sin (* x 0.2)))}
+      :line-style line-style
+      :color-map {:y blue :z red}
+      :super-sample 4
+      :transpose true
+      :bar-padding 2
+      :width 500
+      :height 500))
+  (check-image c (string "horizontal_" line-style "_chart.png")))
+
+(test-horizontal-chart :area)
+(test-horizontal-chart :bar)
+(test-horizontal-chart :stroke)
+
 (end-suite)