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hide rng from globalvars

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Signed-off-by: s3rj1k <evasive.gyron@gmail.com>
This commit is contained in:
s3rj1k 2019-05-10 14:34:10 +03:00
parent 0cd14acc40
commit 69064ee416
1 changed files with 30 additions and 23 deletions
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53
captcha.go
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@ -22,9 +22,7 @@ import (
const charPreset = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
// nolint: gochecknoglobals
var (
rng = rand.New(rand.NewSource(time.Now().UnixNano()))
ttfFont *truetype.Font
)
@ -58,6 +56,8 @@ type Options struct {
width int
height int
rng *rand.Rand
}
func newDefaultOption(width, height int) *Options {
@ -70,8 +70,15 @@ func newDefaultOption(width, height int) *Options {
FontScale: 1.0,
Noise: 1.0,
Palette: []color.Color{},
width: width,
height: height,
width: width,
height: height,
rng: rand.New(
rand.NewSource(
time.Now().UnixNano(),
),
),
}
}
@ -157,7 +164,7 @@ func NewMathExpr(width int, height int, option ...SetOption) (*Data, error) {
setOption(options)
}
text, equation := randomEquation()
text, equation := randomEquation(options.rng)
img := image.NewNRGBA(image.Rect(0, 0, width, height))
draw.Draw(img, img.Bounds(), &image.Uniform{options.BackgroundColor}, image.ZP, draw.Src)
drawNoise(img, options)
@ -173,7 +180,7 @@ func NewMathExpr(width int, height int, option ...SetOption) (*Data, error) {
func randomText(opts *Options) (text string) {
n := len(opts.CharPreset)
for i := 0; i < opts.TextLength; i++ {
text += string(opts.CharPreset[rng.Intn(n)])
text += string(opts.CharPreset[opts.rng.Intn(n)])
}
return text
@ -182,13 +189,13 @@ func randomText(opts *Options) (text string) {
func drawNoise(img *image.NRGBA, opts *Options) {
noiseCount := (opts.width * opts.height) / int(28.0/opts.Noise)
for i := 0; i < noiseCount; i++ {
x := rng.Intn(opts.width)
y := rng.Intn(opts.height)
img.Set(x, y, randomColor())
x := opts.rng.Intn(opts.width)
y := opts.rng.Intn(opts.height)
img.Set(x, y, randomColor(opts.rng))
}
}
func randomColor() color.RGBA {
func randomColor(rng *rand.Rand) color.RGBA {
red := rng.Intn(256)
green := rng.Intn(256)
blue := rng.Intn(256)
@ -209,14 +216,14 @@ func drawSineCurve(img *image.NRGBA, opts *Options) {
if opts.width <= 40 {
xStart, xEnd = 1, opts.width-1
} else {
xStart = rng.Intn(opts.width/10) + 1
xEnd = opts.width - rng.Intn(opts.width/10) - 1
xStart = opts.rng.Intn(opts.width/10) + 1
xEnd = opts.width - opts.rng.Intn(opts.width/10) - 1
}
curveHeight := float64(rng.Intn(opts.height/6) + opts.height/6)
yStart := rng.Intn(opts.height*2/3) + opts.height/6
angle := 1.0 + rng.Float64()
curveHeight := float64(opts.rng.Intn(opts.height/6) + opts.height/6)
yStart := opts.rng.Intn(opts.height*2/3) + opts.height/6
angle := 1.0 + opts.rng.Float64()
yFlip := 1.0
if rng.Intn(2) == 0 {
if opts.rng.Intn(2) == 0 {
yFlip = -1.0
}
curveColor := randomColorFromOptions(opts)
@ -236,15 +243,15 @@ func drawText(text string, img *image.NRGBA, opts *Options) error { // nolint: i
ctx.SetFont(ttfFont)
fontSpacing := opts.width / len(text)
fontOffset := rng.Intn(fontSpacing / 2)
fontOffset := opts.rng.Intn(fontSpacing / 2)
for idx, char := range text {
fontScale := 0.8 + rng.Float64()*0.4
fontScale := 0.8 + opts.rng.Float64()*0.4
fontSize := float64(opts.height) / fontScale * opts.FontScale
ctx.SetFontSize(fontSize)
ctx.SetSrc(image.NewUniform(randomColorFromOptions(opts)))
x := fontSpacing*idx + fontOffset
y := opts.height/6 + rng.Intn(opts.height/3) + int(fontSize/2)
y := opts.height/6 + opts.rng.Intn(opts.height/3) + int(fontSize/2)
pt := freetype.Pt(x, y)
if _, err := ctx.DrawString(string(char), pt); err != nil {
return err
@ -257,13 +264,13 @@ func drawText(text string, img *image.NRGBA, opts *Options) error { // nolint: i
func randomColorFromOptions(opts *Options) color.Color {
length := len(opts.Palette)
if length == 0 {
return randomInvertColor(opts.BackgroundColor)
return randomInvertColor(opts.rng, opts.BackgroundColor)
}
return opts.Palette[rng.Intn(length)]
return opts.Palette[opts.rng.Intn(length)]
}
func randomInvertColor(base color.Color) color.Color {
func randomInvertColor(rng *rand.Rand, base color.Color) color.Color {
baseLightness := getLightness(base)
var value float64
if baseLightness >= 0.5 {
@ -314,7 +321,7 @@ func minColor(numList ...uint32) (min uint32) {
return min
}
func randomEquation() (text string, equation string) {
func randomEquation(rng *rand.Rand) (text string, equation string) {
left := 1 + rng.Intn(9)
right := 1 + rng.Intn(9)
text = strconv.Itoa(left + right)