feat: import imgfactory files

Author: fumiama

color.go

@@ -8,6 +8,21 @@ import (
 	"unsafe"
 )
 
+var (
+	White   = color.RGBA{255, 255, 255, 255}
+	Black   = color.RGBA{0, 0, 0, 255}
+	Red     = color.RGBA{255, 0, 0, 255}
+	Green   = color.RGBA{0, 255, 0, 255}
+	Blue    = color.RGBA{0, 0, 255, 255}
+	Yellow  = color.RGBA{255, 255, 0, 255}
+	Cyan    = color.RGBA{0, 255, 255, 255}
+	Magenta = color.RGBA{255, 0, 255, 255}
+	Grey    = color.RGBA{190, 190, 190, 255}
+	Pink    = color.RGBA{255, 181, 197, 255}
+	Orange  = color.RGBA{255, 165, 0, 255}
+	Opaque  = color.RGBA{0, 0, 0, 0}
+)
+
 // takecolor 实现基于k-means算法的图像取色算法
 func takecolor(img image.Image, k int) []color.RGBA {
 	rgbaimg := imageToRGBA(img)

color_test.go

@@ -106,18 +106,16 @@ func TestDistance_SameColor(t *testing.T) {
 }
 
 func TestDistance_BlackAndWhite(t *testing.T) {
-	black := color.RGBA{0, 0, 0, 255}
-	white := color.RGBA{255, 255, 255, 255}
 	// sqrt(255^2 * 3) = 255 * sqrt(3)
 	want := 255 * math.Sqrt(3)
-	got := distance(black, white)
+	got := distance(Black, White)
 	if math.Abs(got-want) > 1e-9 {
 		t.Errorf("distance(black, white) = %v, want %v", got, want)
 	}
 }
 
 func TestDistance_SingleChannel(t *testing.T) {
-	a := color.RGBA{0, 0, 0, 255}
+	a := Black
 	b := color.RGBA{3, 4, 0, 255}
 	// sqrt(9 + 16) = 5
 	want := 5.0
@@ -263,13 +261,11 @@ func TestTakecolor_SolidColorKGreaterThan1(t *testing.T) {
 func TestTakecolor_TwoDistinctColors(t *testing.T) {
 	// k-means 的初始中心随机选取，可能两次都落到同一颜色区域导致不收敛。
 	// 多次运行，验证算法至少能在 30 次尝试中有一次正确分离两种颜色。
-	red := color.RGBA{255, 0, 0, 255}
-	blue := color.RGBA{0, 0, 255, 255}
-	img := twoColorImage(20, 20, red, blue)
+	img := twoColorImage(20, 20, Red, Blue)
 	const maxAttempts = 30
 	for attempt := 0; attempt < maxAttempts; attempt++ {
 		result := takecolor(img, 2)
-		if len(result) == 2 && colorInSlice(red, result, 5) && colorInSlice(blue, result, 5) {
+		if len(result) == 2 && colorInSlice(Red, result, 5) && colorInSlice(Blue, result, 5) {
 			return // 成功分离，测试通过
 		}
 	}

context.go

@@ -415,7 +415,7 @@ func (dc *Context) SetColor(c color.Color) {
 // 符号（#）是可选的。支持3位数和6位数的变体。8位数字
 // 也可以提供设置 alpha 值。
 func (dc *Context) SetHexColor(x string) {
-	dc.SetRGBA255(parseHexColor(x))
+	dc.SetRGBA255(ParseHexColor(x))
 }
 
 // SetRGBA255 sets the current color. r, g, b, a values should be between 0 and

context_test.go

@@ -1,7 +1,6 @@
 package gg
 
 import (
-	"image/color"
 	"math/rand"
 	"testing"
 )
@@ -288,9 +287,9 @@ func TestDrawPoint(t *testing.T) {
 func TestLinearGradient(t *testing.T) {
 	dc := NewContext(100, 100)
 	g := NewLinearGradient(0, 0, 100, 100)
-	g.AddColorStop(0, color.RGBA{0, 255, 0, 255})
-	g.AddColorStop(1, color.RGBA{0, 0, 255, 255})
-	g.AddColorStop(0.5, color.RGBA{255, 0, 0, 255})
+	g.AddColorStop(0, Green)
+	g.AddColorStop(1, Blue)
+	g.AddColorStop(0.5, Red)
 	dc.SetFillStyle(g)
 	dc.DrawRectangle(0, 0, 100, 100)
 	dc.Fill()
@@ -301,9 +300,9 @@ func TestLinearGradient(t *testing.T) {
 func TestRadialGradient(t *testing.T) {
 	dc := NewContext(100, 100)
 	g := NewRadialGradient(30, 50, 0, 70, 50, 50)
-	g.AddColorStop(0, color.RGBA{0, 255, 0, 255})
-	g.AddColorStop(1, color.RGBA{0, 0, 255, 255})
-	g.AddColorStop(0.5, color.RGBA{255, 0, 0, 255})
+	g.AddColorStop(0, Green)
+	g.AddColorStop(1, Blue)
+	g.AddColorStop(0.5, Red)
 	dc.SetFillStyle(g)
 	dc.DrawRectangle(0, 0, 100, 100)
 	dc.Fill()

examples/gradient-conic_test.go

@@ -13,16 +13,16 @@ func TestGC(t *testing.T) {
 	grad1 := gg.NewConicGradient(200, 200, 0)
 	grad1.AddColorStop(0.0, color.Black)
 	grad1.AddColorStop(0.5, color.RGBA{255, 215, 0, 255})
-	grad1.AddColorStop(1.0, color.RGBA{255, 0, 0, 255})
+	grad1.AddColorStop(1.0, gg.Red)
 
 	grad2 := gg.NewConicGradient(200, 200, 90)
-	grad2.AddColorStop(0.00, color.RGBA{255, 0, 0, 255})
-	grad2.AddColorStop(0.16, color.RGBA{255, 255, 0, 255})
-	grad2.AddColorStop(0.33, color.RGBA{0, 255, 0, 255})
-	grad2.AddColorStop(0.50, color.RGBA{0, 255, 255, 255})
-	grad2.AddColorStop(0.66, color.RGBA{0, 0, 255, 255})
-	grad2.AddColorStop(0.83, color.RGBA{255, 0, 255, 255})
-	grad2.AddColorStop(1.00, color.RGBA{255, 0, 0, 255})
+	grad2.AddColorStop(0.00, gg.Red)
+	grad2.AddColorStop(0.16, gg.Yellow)
+	grad2.AddColorStop(0.33, gg.Green)
+	grad2.AddColorStop(0.50, gg.Cyan)
+	grad2.AddColorStop(0.66, gg.Blue)
+	grad2.AddColorStop(0.83, gg.Magenta)
+	grad2.AddColorStop(1.00, gg.Red)
 
 	dc.SetStrokeStyle(grad1)
 	dc.SetLineWidth(20)

examples/gradient-linear_test.go

@@ -11,9 +11,9 @@ func TestGL(t *testing.T) {
 	dc := gg.NewContext(500, 400)
 
 	grad := gg.NewLinearGradient(20, 320, 400, 20)
-	grad.AddColorStop(0, color.RGBA{0, 255, 0, 255})
-	grad.AddColorStop(1, color.RGBA{0, 0, 255, 255})
-	grad.AddColorStop(0.5, color.RGBA{255, 0, 0, 255})
+	grad.AddColorStop(0, gg.Green)
+	grad.AddColorStop(1, gg.Blue)
+	grad.AddColorStop(0.5, gg.Red)
 
 	dc.SetColor(color.White)
 	dc.DrawRectangle(20, 20, 400-20, 300)

examples/gradient-radial_test.go

@@ -11,8 +11,8 @@ func TestGR(t *testing.T) {
 	dc := gg.NewContext(400, 200)
 
 	grad := gg.NewRadialGradient(100, 100, 10, 100, 120, 80)
-	grad.AddColorStop(0, color.RGBA{0, 255, 0, 255})
-	grad.AddColorStop(1, color.RGBA{0, 0, 255, 255})
+	grad.AddColorStop(0, gg.Green)
+	grad.AddColorStop(1, gg.Blue)
 
 	dc.SetFillStyle(grad)
 	dc.DrawRectangle(0, 0, 200, 200)

examples/gradient-text_test.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"image/color"
 	"testing"
 
 	"github.com/FloatTech/gg"
@@ -29,8 +28,8 @@ func TestGT(t *testing.T) {
 
 	// set a gradient
 	g := gg.NewLinearGradient(0, 0, W, H)
-	g.AddColorStop(0, color.RGBA{255, 0, 0, 255})
-	g.AddColorStop(1, color.RGBA{0, 0, 255, 255})
+	g.AddColorStop(0, gg.Red)
+	g.AddColorStop(1, gg.Blue)
 	dc.SetFillStyle(g)
 
 	// using the mask, fill the context with the gradient

factory/README.md

@@ -0,0 +1,3 @@
+# factory
+
+Originally from [FloatTech/imgfactory](https://github.com/FloatTech/imgfactory), operating raw image.NRGBA object.

factory/effects.go

@@ -0,0 +1,102 @@
+package factory
+
+import (
+	"image/color"
+
+	"github.com/disintegration/imaging"
+)
+
+// float64转uint8
+func floatUint8(a float64) uint8 {
+	b := int64(a + 0.5)
+	if b > 255 {
+		return 255
+	}
+	if b > 0 {
+		return uint8(b)
+	}
+	return 0
+}
+
+// AdjustBrightness 亮度(-100, 100)
+func (dst *Factory) AdjustBrightness(s float64) *Factory {
+	return &Factory{
+		im: imaging.AdjustBrightness(dst.im, s),
+	}
+}
+
+// AdjustContrast 对比度(-100, 100)
+func (dst *Factory) AdjustContrast(a float64) *Factory {
+	return &Factory{
+		im: imaging.AdjustContrast(dst.im, a),
+	}
+}
+
+// AdjustSaturation 饱和度(-100, 100)
+func (dst *Factory) AdjustSaturation(a float64) *Factory {
+	return &Factory{
+		im: imaging.AdjustSaturation(dst.im, a),
+	}
+}
+
+// Sharpen 锐化
+func (dst *Factory) Sharpen(a float64) *Factory {
+	return &Factory{
+		im: imaging.Sharpen(dst.im, a),
+	}
+}
+
+// Blur 模糊图像 正数
+func (dst *Factory) Blur(a float64) *Factory {
+	return &Factory{
+		im: imaging.Blur(dst.im, a),
+	}
+}
+
+// Grayscale 灰度
+func (dst *Factory) Grayscale() *Factory {
+	b := dst.im.Bounds()
+	for y1 := b.Min.Y; y1 <= b.Max.Y; y1++ {
+		for x1 := b.Min.X; x1 <= b.Max.X; x1++ {
+			a := dst.im.At(x1, y1)
+			c := color.NRGBAModel.Convert(a).(color.NRGBA)
+			f := 0.299*float64(c.R) + 0.587*float64(c.G) + 0.114*float64(c.B)
+			c.R = floatUint8(f)
+			c.G = floatUint8(f)
+			c.B = floatUint8(f)
+			dst.im.Set(x1, y1, c)
+		}
+	}
+	return dst
+}
+
+// Invert 反色
+func (dst *Factory) Invert() *Factory {
+	b := dst.im.Bounds()
+	for y1 := b.Min.Y; y1 <= b.Max.Y; y1++ {
+		for x1 := b.Min.X; x1 <= b.Max.X; x1++ {
+			a := dst.im.At(x1, y1)
+			c := color.NRGBAModel.Convert(a).(color.NRGBA)
+			c.R = 255 - c.R
+			c.G = 255 - c.G
+			c.B = 255 - c.B
+			dst.im.Set(x1, y1, c)
+		}
+	}
+	return dst
+}
+
+// Relief 浮雕
+func (dst *Factory) Relief() *Factory {
+	return &Factory{
+		im: imaging.Convolve3x3(
+			dst.im,
+			[9]float64{
+				-1, -1, 0,
+				-1, 1, 1,
+				0, 1, 1,
+			},
+			nil,
+		),
+	}
+}