minor changes to code style and docs

LICENSE

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2014 Grigory Dryapak
+Copyright (c) 2014-2018 Grigory Dryapak
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -18,4 +18,4 @@ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
+SOFTWARE.

README.md

@@ -3,6 +3,8 @@
 [![GoDoc](https://godoc.org/github.com/disintegration/gift?status.svg)](https://godoc.org/github.com/disintegration/gift)
 [![Build Status](https://travis-ci.org/disintegration/gift.svg?branch=master)](https://travis-ci.org/disintegration/gift)
 [![Coverage Status](https://coveralls.io/repos/github/disintegration/gift/badge.svg?branch=master)](https://coveralls.io/github/disintegration/gift?branch=master)
+[![Go Report Card](https://goreportcard.com/badge/github.com/disintegration/gift)](https://goreportcard.com/report/github.com/disintegration/gift)
+
 
 *Package gift provides a set of useful image processing filters.*
 
@@ -22,19 +24,19 @@ http://godoc.org/github.com/disintegration/gift
 ### QUICK START
 
 ```go
-// 1. Create a new GIFT filter list and add some filters:
+// 1. Create a new filter list and add some filters.
 g := gift.New(
 	gift.Resize(800, 0, gift.LanczosResampling),
 	gift.UnsharpMask(1, 1, 0),
 )
 
 // 2. Create a new image of the corresponding size.
-// dst is a new target image, src is the original image
+// dst is a new target image, src is the original image.
 dst := image.NewRGBA(g.Bounds(src.Bounds()))
 
-// 3. Use Draw func to apply the filters to src and store the result in dst:
+// 3. Use the Draw func to apply the filters to src and store the result in dst.
 g.Draw(dst, src)
-``` 
+```
 
 ### USAGE
 
@@ -47,10 +49,10 @@ g := gift.New(
 ```
 Filters also can be added using the `Add` method:
 ```go
-g.Add(GaussianBlur(2)) 
+g.Add(GaussianBlur(2))
 ```
 
-The `Bounds` method takes the bounds of the source image and returns appropriate bounds for the destination image to fit the result (for example, after using `Resize` or `Rotate` filters). 
+The `Bounds` method takes the bounds of the source image and returns appropriate bounds for the destination image to fit the result (for example, after using `Resize` or `Rotate` filters).
 
 ```go
 dst := image.NewRGBA(g.Bounds(src.Bounds()))
@@ -100,7 +102,7 @@ gift.New().DrawAt(dstImage, fgImage, image.Pt(100, 100), gift.OverOperator)
     - Rotate90()
     - Transpose()
     - Transverse()
-    
+
 + Adjustments & effects
 
     - Brightness(percentage float32)
@@ -133,7 +135,7 @@ gift.New().DrawAt(dstImage, fgImage, image.Pt(100, 100), gift.OverOperator)
 
 The original image:
 
-![](testdata/src.png) 
+![](testdata/src.png)
 
 Resulting images after applying some of the filters:
 
@@ -205,7 +207,7 @@ func main() {
 				g = g0 + 0.1 // shift the green channel by 0.1
 				b = 0        // set the blue channel to 0
 				a = a0       // preserve the alpha channel
-				return
+				return r, g, b, a
 			},
 		),
 		"convolution_emboss": gift.Convolution(

colors.go

@@ -292,7 +292,7 @@ func convertHSLToRGB(h, s, l float32) (float32, float32, float32) {
 		return l, l, l
 	}
 
-	_v := func(p, q, t float32) float32 {
+	hueToRGB := func(p, q, t float32) float32 {
 		if t < 0 {
 			t++
 		}
@@ -319,9 +319,9 @@ func convertHSLToRGB(h, s, l float32) (float32, float32, float32) {
 	}
 	p = 2*l - q
 
-	r := _v(p, q, h+1/3.0)
-	g := _v(p, q, h)
-	b := _v(p, q, h-1/3.0)
+	r := hueToRGB(p, q, h+1/3.0)
+	g := hueToRGB(p, q, h)
+	b := hueToRGB(p, q, h-1/3.0)
 
 	return r, g, b
 }
@@ -494,7 +494,7 @@ func Threshold(percentage float32) Filter {
 //				g = g0 + 0.1 // shift the green channel by 0.1
 //				b = 0        // set the blue channel to 0
 //				a = a0       // preserve the alpha channel
-//				return
+//				return r, g, b, a
 //			},
 //		),
 //	)

convolution.go

@@ -106,7 +106,7 @@ func (p *convolutionFilter) Draw(dst draw.Image, src image.Image, options *Optio
 	pixSetter := newPixelSetter(dst)
 
 	parallelize(options.Parallelization, srcb.Min.Y, srcb.Max.Y, func(start, stop int) {
-		// init temp rows
+		// Init temporary rows.
 		starty := start
 		rows := make([][]pixel, ksize)
 		for i := 0; i < ksize; i++ {
@@ -122,7 +122,7 @@ func (p *convolutionFilter) Draw(dst draw.Image, src image.Image, options *Optio
 		}
 
 		for y := start; y < stop; y++ {
-			// calculate dst row
+			// Calculate dst row.
 			for x := srcb.Min.X; x < srcb.Max.X; x++ {
 				var r, g, b, a float32
 				for _, w := range weights {
@@ -165,7 +165,7 @@ func (p *convolutionFilter) Draw(dst draw.Image, src image.Image, options *Optio
 				pixSetter.setPixel(dstb.Min.X+x-srcb.Min.X, dstb.Min.Y+y-srcb.Min.Y, pixel{r, g, b, a})
 			}
 
-			// rotate temp rows
+			// Rotate temporary rows.
 			if y < stop-1 {
 				tmprow := rows[0]
 				for i := 0; i < ksize-1; i++ {
@@ -216,7 +216,8 @@ func Convolution(kernel []float32, normalize, alpha, abs bool, delta float32) Fi
 	}
 }
 
-// prepare pixel weights using convolution kernel. weights equal to 0 are excluded
+// prepareConvolutionWeights1d prepares pixel weights using a convolution kernel.
+// Weights equal to 0 are excluded.
 func prepareConvolutionWeights1d(kernel []float32) (int, []uweight) {
 	size := len(kernel)
 	if size%2 == 0 {
@@ -239,7 +240,7 @@ func prepareConvolutionWeights1d(kernel []float32) (int, []uweight) {
 	return size, weights
 }
 
-// calculate pixels for one line according to weights
+// convolveLine convolves a single line of pixels according to the given weights.
 func convolveLine(dstBuf []pixel, srcBuf []pixel, weights []uweight) {
 	max := len(srcBuf) - 1
 	if max < 0 {
@@ -270,7 +271,7 @@ func convolveLine(dstBuf []pixel, srcBuf []pixel, weights []uweight) {
 	}
 }
 
-// fast vertical 1d convolution
+// convolve1dv performs a fast vertical 1d convolution.
 func convolve1dv(dst draw.Image, src image.Image, kernel []float32, options *Options) {
 	srcb := src.Bounds()
 	dstb := dst.Bounds()
@@ -295,7 +296,7 @@ func convolve1dv(dst draw.Image, src image.Image, kernel []float32, options *Opt
 	})
 }
 
-// fast horizontal 1d convolution
+// convolve1dh performs afast horizontal 1d convolution.
 func convolve1dh(dst draw.Image, src image.Image, kernel []float32, options *Options) {
 	srcb := src.Bounds()
 	dstb := dst.Bounds()

convolution_test.go

@@ -6,7 +6,6 @@ import (
 )
 
 func TestConvolution(t *testing.T) {
-
 	testData := []struct {
 		desc                  string
 		kernel                []float32
@@ -229,7 +228,6 @@ func TestConvolution(t *testing.T) {
 }
 
 func TestGaussianBlur(t *testing.T) {
-
 	testData := []struct {
 		desc           string
 		sigma          float32
@@ -320,7 +318,6 @@ func TestGaussianBlur(t *testing.T) {
 }
 
 func TestUnsharpMask(t *testing.T) {
-
 	testData := []struct {
 		desc                     string
 		sigma, amount, threshold float32
@@ -411,7 +408,6 @@ func TestUnsharpMask(t *testing.T) {
 }
 
 func TestMean(t *testing.T) {
-
 	testData := []struct {
 		desc           string
 		ksize          int

effects.go

@@ -43,12 +43,12 @@ func (p *pixelateFilter) Draw(dst draw.Image, src image.Image, options *Options)
 	parallelize(options.Parallelization, 0, numBlocksY, func(start, stop int) {
 		for by := start; by < stop; by++ {
 			for bx := 0; bx < numBlocksX; bx++ {
-				// calculate the block bounds
+				// Calculate the block bounds.
 				bb := image.Rect(bx*blockSize, by*blockSize, (bx+1)*blockSize, (by+1)*blockSize)
 				bbSrc := bb.Add(srcb.Min).Intersect(srcb)
 				bbDst := bbSrc.Sub(srcb.Min).Add(dstb.Min).Intersect(dstb)
 
-				// calculate average color of the block
+				// Calculate the average color of the block.
 				var r, g, b, a float32
 				var cnt float32
 				for y := bbSrc.Min.Y; y < bbSrc.Max.Y; y++ {
@@ -68,7 +68,7 @@ func (p *pixelateFilter) Draw(dst draw.Image, src image.Image, options *Options)
 					a /= cnt
 				}
 
-				// set the calculated color for all pixels in the block
+				// Set the calculated color for all pixels in the block.
 				for y := bbDst.Min.Y; y < bbDst.Max.Y; y++ {
 					for x := bbDst.Min.X; x < bbDst.Max.X; x++ {
 						pixSetter.setPixel(x, y, pixel{r, g, b, a})

gift.go

@@ -1,23 +1,19 @@
 /*
-
 Package gift provides a set of useful image processing filters.
 
 Basic usage:
 
-	// 1. Create a new GIFT and add some filters:
-
+	// 1. Create a new filter list and add some filters.
 	g := gift.New(
 	    gift.Resize(800, 0, gift.LanczosResampling),
 	    gift.UnsharpMask(1, 1, 0),
 	)
 
 	// 2. Create a new image of the corresponding size.
-	// dst is a new target image, src is the original image
-
+	// dst is a new target image, src is the original image.
 	dst := image.NewRGBA(g.Bounds(src.Bounds()))
 
-	// 3. Use Draw func to apply the filters to src and store the result in dst:
-
+	// 3. Use the Draw func to apply the filters to src and store the result in dst.
 	g.Draw(dst, src)
 
 */
@@ -45,21 +41,21 @@ var defaultOptions = Options{
 	Parallelization: true,
 }
 
-// GIFT implements a list of filters that can be applied to an image at once.
+// GIFT is a list of image processing filters.
 type GIFT struct {
 	Filters []Filter
 	Options Options
 }
 
-// New creates a new instance of the filter toolkit and initializes it with the given list of filters.
+// New creates a new filter list and initializes it with the given slice of filters.
 func New(filters ...Filter) *GIFT {
 	return &GIFT{
 		Filters: filters,
 		Options: defaultOptions,
 	}
 }
 
-// SetParallelization enables or disables faster image processing using parallel goroutines.
+// SetParallelization enables or disables the image processing parallelization.
 // Parallelization is enabled by default.
 func (g *GIFT) SetParallelization(isEnabled bool) {
 	g.Options.Parallelization = isEnabled

gift_test.go

@@ -571,7 +571,7 @@ func TestGolden(t *testing.T) {
 				g = g0 + 0.1
 				b = 0
 				a = a0
-				return
+				return r, g, b, a
 			},
 		),
 		"convolution_emboss": Convolution(
@@ -644,7 +644,7 @@ func BenchmarkFilter(b *testing.B) {
 				g = g0 + 0.1
 				b = 0
 				a = a0
-				return
+				return r, g, b, a
 			},
 		)},
 		{"ColorspaceSRGBToLinear", ColorspaceSRGBToLinear()},

rank.go

@@ -71,7 +71,7 @@ func (p *rankFilter) Draw(dst draw.Image, src image.Image, options *Options) {
 		}
 
 		for y := start; y < stop; y++ {
-			// init buffer
+			// Init buffer.
 			pxbuf = pxbuf[:0]
 			for i := srcb.Min.X - kradius; i <= srcb.Min.X+kradius; i++ {
 				for j := y - kradius; j <= y+kradius; j++ {
@@ -163,7 +163,7 @@ func (p *rankFilter) Draw(dst draw.Image, src image.Image, options *Options) {
 
 				pixSetter.setPixel(dstb.Min.X+x-srcb.Min.X, dstb.Min.Y+y-srcb.Min.Y, pixel{r, g, b, a})
 
-				// rotate buffer columns
+				// Rotate buffer columns.
 				if x < srcb.Max.X-1 {
 					copy(pxbuf[0:], pxbuf[ksize:])
 					pxbuf = pxbuf[0 : ksize*(ksize-1)]

resize_test.go

@@ -1,6 +1,7 @@
 package gift
 
 import (
+	"bytes"
 	"image"
 	"testing"
 )
@@ -64,7 +65,7 @@ func TestResize(t *testing.T) {
 	if img1.Bounds().Size() != img1Exp.Bounds().Size() {
 		t.Errorf("expected %v got %v", img1Exp.Bounds().Size(), img1.Bounds().Size())
 	}
-	if !comparePix(img1Exp.Pix, img1.Pix) {
+	if !bytes.Equal(img1Exp.Pix, img1.Pix) {
 		t.Errorf("expected %v got %v", img1Exp.Pix, img1.Pix)
 	}
 
@@ -84,7 +85,7 @@ func TestResize(t *testing.T) {
 	if img1.Bounds().Size() != img1Exp.Bounds().Size() {
 		t.Errorf("expected %v got %v", img1Exp.Bounds().Size(), img1.Bounds().Size())
 	}
-	if !comparePix(img1Exp.Pix, img1.Pix) {
+	if !bytes.Equal(img1Exp.Pix, img1.Pix) {
 		t.Errorf("expected %v got %v", img1Exp.Pix, img1.Pix)
 	}