1 files changed, 58 insertions(+), 9 deletions(-)

M main.go

@@ 622,18 622,13 @@ func run(w *app.Window) error {
 			ready = nil
 			audioInit = true
 			for idx, f := range freqs {
-				hue := float64(idx) / float64(IdxMax) * 360
-				col := colorful.Hcl(hue, 1, 1).Clamped()
-				r, g, b, a := col.RGBA()
+				pos := float64(idx) / float64(IdxMax)
+				col := gradient.GetInterpolatedColorFor(pos)
+				nrgba := color.NRGBAModel.Convert(col).(color.NRGBA)
 				players[idx] = Pipe{
 					player: c.NewPlayer(NewSineWave(f)),
 					freq:   f,
-					col: color.NRGBA{
-						R: uint8(r),
-						G: uint8(g),
-						B: uint8(b),
-						A: uint8(a),
-					},
+					col:    nrgba,
 				}
 			}
 			log.Println("organ initialized")


@@ 653,3 648,57 @@ func main() {
 	}()
 	app.Main()
 }
+
+/* Start copied from go-colorful example, this part is MIT licensed */
+// https://github.com/lucasb-eyer/go-colorful/blob/master/doc/gradientgen/gradientgen.go
+
+// This table contains the "keypoints" of the colorgradient you want to generate.
+// The position of each keypoint has to live in the range [0,1]
+type GradientTable []struct {
+	Col colorful.Color
+	Pos float64
+}
+
+// This is the meat of the gradient computation. It returns a HCL-blend between
+// the two colors around `t`.
+// Note: It relies heavily on the fact that the gradient keypoints are sorted.
+func (gt GradientTable) GetInterpolatedColorFor(t float64) colorful.Color {
+	for i := 0; i < len(gt)-1; i++ {
+		c1 := gt[i]
+		c2 := gt[i+1]
+		if c1.Pos <= t && t <= c2.Pos {
+			// We are in between c1 and c2. Go blend them!
+			t := (t - c1.Pos) / (c2.Pos - c1.Pos)
+			return c1.Col.BlendHcl(c2.Col, t).Clamped()
+		}
+	}
+
+	// Nothing found? Means we're at (or past) the last gradient keypoint.
+	return gt[len(gt)-1].Col
+}
+
+// This is a very nice thing Golang forces you to do!
+// It is necessary so that we can write out the literal of the colortable below.
+func MustParseHex(s string) colorful.Color {
+	c, err := colorful.Hex(s)
+	if err != nil {
+		panic("MustParseHex: " + err.Error())
+	}
+	return c
+}
+
+var gradient = GradientTable{
+	{MustParseHex("#9e0142"), 0.0},
+	{MustParseHex("#d53e4f"), 0.1},
+	{MustParseHex("#f46d43"), 0.2},
+	{MustParseHex("#fdae61"), 0.3},
+	{MustParseHex("#fee090"), 0.4},
+	{MustParseHex("#ffffbf"), 0.5},
+	{MustParseHex("#e6f598"), 0.6},
+	{MustParseHex("#abdda4"), 0.7},
+	{MustParseHex("#66c2a5"), 0.8},
+	{MustParseHex("#3288bd"), 0.9},
+	{MustParseHex("#5e4fa2"), 1.0},
+}
+
+/* end copied from go-colorful */