1 files changed, 23 insertions, 0 deletions
diff --git a/pkg/draw/heatmap.go b/pkg/draw/heatmap.go
new file mode 100644
index 0000000..7f913fd
--- /dev/null
+++ b/pkg/draw/heatmap.go
@@ -0,0 +1,23 @@
+package draw
+
+type Heatmap struct{ *Buffer }
+
+func (b *Heatmap) Size() Box { return b.Box }
+
+var shades = []rune(" ·░▒▒▒▒▓▓▓▓█")
+var nonZeroShade = 1.0 / float64(len(shades)-1)
+
+func (b *Heatmap) Set(y, x int, fill float64) {
+	if fill < 0.0 {
+		fill = 0.0
+	}
+	if fill > 0.0 && fill < nonZeroShade {
+		fill = nonZeroShade
+	}
+	if fill > 1.0 {
+		fill = 1.0
+	}
+	b.Buffer.Set(y, x, shades[int(fill*float64(len(shades)-1))])
+}
+
+func (b *Heatmap) Clear() { b.Fill(shades[0]) }