Update go.mod

.gitignore

@@ -0,0 +1,4 @@
+child_porn
+imageutils.test
+cpu.out
+profile.out

README

@@ -0,0 +1,3 @@
+(with a dummy as fuck image rescaling)
+utilities work in theory, but doing everything very slow.
+i really love Go's image.Image interface type, but its really hard to do something with it well.

concat.go

@@ -21,9 +21,9 @@ type pair struct {
 }
 
 // Takes color.Model of the first Image.
-func (p pair) ColorModel() color.Model { return p.first.ColorModel() }
+func (p *pair) ColorModel() color.Model { return p.first.ColorModel() }
 
-func (p pair) Bounds() image.Rectangle {
+func (p *pair) Bounds() image.Rectangle {
 	var (
 		b1 = p.first.Bounds()
 		b2 = p.second.Bounds()
@@ -52,7 +52,7 @@ func (p pair) Bounds() image.Rectangle {
 	}
 }
 
-func (p pair) At(x, y int) color.Color {
+func (p *pair) At(x, y int) color.Color {
 	img := image.NewRGBA(p.Bounds())
 
 	point := image.Point{}
@@ -86,7 +86,7 @@ func (p pair) At(x, y int) color.Color {
 	return img.At(x, y)
 }
 
-func render(p pair) image.Image {
+func render(p *pair) image.Image {
 	img := image.NewRGBA(p.Bounds())
 
 	point := image.Point{}
@@ -122,5 +122,5 @@ func render(p pair) image.Image {
 
 // Concat concatenates second image on a given side.
 func Concat(i1, i2 image.Image, s Side) image.Image {
-	return render(pair{i1, i2, s})
+	return render(&pair{i1, i2, s})
 }

concat_test.go

@@ -0,0 +1,24 @@
+package imageutils
+
+import (
+	"image"
+	"image/png"
+	"io"
+	"testing"
+)
+
+func BenchmarkConcat(b *testing.B) {
+	var instance image.Image = image.NewRGBA(image.Rect(0, 0, 0, 0))
+	pixel := SinglePixel{}
+
+	for i := 0; i < b.N; i++ {
+		instance = Concat(instance, pixel, Right)
+	}
+	err := png.Encode(
+		io.Discard,
+		instance,
+	)
+	if err != nil {
+		panic(err)
+	}
+}

genprof

@@ -0,0 +1,2 @@
+go test -cpuprofile=profile.out -bench=$1 &&
+go tool pprof -text profile.out

go.mod

@@ -1,3 +1,5 @@
-module github.com/potassium5703/imageutils
+module git.niplace.ru/XoxJlopeZi4BB/imageutils
 
-go 1.21.4
+go 1.22.6
+
+require github.com/potassium5703/texture v0.0.0-20240820054037-fce43fc4b0f0 // indirect

go.sum

@@ -0,0 +1,2 @@
+github.com/potassium5703/texture v0.0.0-20240820054037-fce43fc4b0f0 h1:sowjIIVme5ovcdB0kjP3w+4xbVNrlOPdx7Up4LIGJz8=
+github.com/potassium5703/texture v0.0.0-20240820054037-fce43fc4b0f0/go.mod h1:KwM7hMpZhr3XySWuK/SZ7s1BXVQe8p1IyZftYg9KtWY=

scale_test.go

@@ -0,0 +1,45 @@
+package imageutils
+
+import (
+	"image"
+	"image/color"
+	"image/draw"
+	"image/png"
+	"io"
+	"testing"
+
+	"github.com/potassium5703/texture"
+)
+
+func Render(img image.Image, rect image.Rectangle) image.Image {
+	newimg := image.NewRGBA(rect)
+	draw.Draw(newimg, rect, image.White, image.ZP, draw.Src)
+	draw.Draw(newimg, rect, img, image.ZP, draw.Over)
+	return newimg
+}
+
+func BenchmarkScale(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		err := png.Encode(io.Discard,
+			Scale(Render(
+				texture.New(color.White,
+					color.Black, 2),
+				image.Rect(0, 0, 64, 64),
+			), 64),
+		)
+		if err != nil {
+			panic(err)
+		}
+	}
+}
+
+func BenchmarkSinglePixel(b *testing.B) {
+	instance := SinglePixel{}
+	err := png.Encode(io.Discard,
+		Scale(instance, b.N),
+	)
+	if err != nil {
+		panic(err)
+	}
+
+}

util.go

@@ -0,0 +1,20 @@
+package imageutils
+
+import (
+	"image"
+	"image/color"
+)
+
+type SinglePixel struct{}
+
+func (s SinglePixel) At(x, y int) color.Color {
+	return color.White
+}
+
+func (s SinglePixel) ColorModel() color.Model {
+	return color.RGBAModel
+}
+
+func (s SinglePixel) Bounds() image.Rectangle {
+	return image.Rect(0, 0, 1, 1)
+}