add GoColor()

mazznoer · Aug 2, 2024 · 1c00e98 · 1c00e98
1 parent 2b2df15
commit 1c00e98
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Showing 3 changed files with 56 additions and 7 deletions.
diff --git a/builder_test.go b/builder_test.go
@@ -1,6 +1,7 @@
 package colorgrad
 
 import (
+	"image/color"
 	"testing"
 )
 
@@ -61,24 +62,44 @@ func Test_Builder(t *testing.T) {
 	test(t, grad.At(90).HexString(), "#0000ff")
 
 	// Multiple colors, custom domain
-	grad, err = NewGradient().
-		HtmlColors("#00f", "#00ffff").
-		Colors(Rgb8(255, 255, 0, 255), Hwb(0, 0, 0, 1)).
-		HtmlColors("gold").
+	gb := NewGradient()
+	grad, err = gb.HtmlColors("#00f", "#00ffff").
+		Colors(
+			Rgb8(255, 255, 0, 255),
+			Hwb(320, 0.1, 0.3, 1),
+			GoColor(color.RGBA{R: 127, G: 0, B: 0, A: 127}),
+			GoColor(color.Gray{185}),
+		).
+		HtmlColors("gold", "hwb(320, 10%, 30%)").
 		Domain(10, 50).
+		Mode(BlendRgb).
+		Interpolation(InterpolationLinear).
 		Build()
 	test(t, err, nil)
 	test(t, domain(grad.Domain()), [2]float64{10, 50})
-	testSlice(t, colors2hex(grad.Colors(5)), []string{
+	testSlice(t, colors2hex(grad.Colors(8)), []string{
 		"#0000ff",
 		"#00ffff",
 		"#ffff00",
-		"#ff0000",
+		"#b31980", // xxx
+		"#ff00007f",
+		"#b9b9b9",
+		"#ffd700",
+		"#b31a80",
+	})
+	testSlice(t, colors2hex(*gb.GetColors()), []string{
+		"#0000ff",
+		"#00ffff",
+		"#ffff00",
+		"#b31a80",
+		"#ff00007f",
+		"#b9b9b9",
 		"#ffd700",
+		"#b31a80",
 	})
 
 	// Filter stops
-	gb := NewGradient()
+	gb = NewGradient()
 	gb.HtmlColors("gold", "red", "blue", "yellow", "black", "white", "plum")
 	gb.Domain(0, 0, 0.5, 0.5, 0.5, 1, 1)
 	_, err = gb.Build()

diff --git a/gradient.go b/gradient.go
@@ -1,6 +1,7 @@
 package colorgrad
 
 import (
+	"image/color"
 	"math"
 
 	"github.com/mazznoer/csscolorparser"
@@ -63,6 +64,20 @@ func Rgb8(r, g, b, a uint8) Color {
 	return Color{R: float64(r) / 255, G: float64(g) / 255, B: float64(b) / 255, A: float64(a) / 255}
 }
 
+func GoColor(col color.Color) Color {
+	r, g, b, a := col.RGBA()
+	if a == 0 {
+		return csscolorparser.Color{}
+	}
+	r *= 0xffff
+	r /= a
+	g *= 0xffff
+	g /= a
+	b *= 0xffff
+	b /= a
+	return csscolorparser.Color{R: float64(r) / 65535.0, G: float64(g) / 65535.0, B: float64(b) / 65535.0, A: float64(a) / 65535.0}
+}
+
 type gradientBase interface {
 	// Get color at certain position
 	At(float64) Color

diff --git a/gradient_test.go b/gradient_test.go
@@ -2,6 +2,7 @@ package colorgrad
 
 import (
 	"fmt"
+	"image/color"
 	"testing"
 )
 
@@ -10,6 +11,18 @@ func Test_Basic(t *testing.T) {
 	test(t, Rgb8(46, 139, 87, 255).HexString(), "#2e8b57")
 	test(t, Hwb(330, 0.4118, 0, 1).HexString(), "#ff69b4")
 
+	// Go color
+	test(t, GoColor(color.RGBA{R: 255, G: 0, B: 0, A: 255}).HexString(), "#ff0000")
+	test(t, GoColor(color.RGBA{R: 127, G: 0, B: 0, A: 127}).HexString(), "#ff00007f")
+	test(t, GoColor(color.RGBA{R: 0, G: 0, B: 0, A: 0}).HexString(), "#00000000")
+
+	test(t, GoColor(color.NRGBA{R: 0, G: 255, B: 0, A: 255}).HexString(), "#00ff00")
+	test(t, GoColor(color.NRGBA{R: 0, G: 255, B: 0, A: 127}).HexString(), "#00ff007f")
+
+	test(t, GoColor(color.Gray{0}).HexString(), "#000000")
+	test(t, GoColor(color.Gray{127}).HexString(), "#7f7f7f")
+
+	// Enums
 	test(t, BlendRgb.String(), "BlendRgb")
 	test(t, fmt.Sprintf("%s", BlendLinearRgb), "BlendLinearRgb")
 	test(t, fmt.Sprintf("%v", BlendOklab), "BlendOklab")