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92 lines
2.0 KiB
Go
92 lines
2.0 KiB
Go
package render
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import (
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"image"
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"image/color"
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_ "image/gif" // register gif, jpeg, png format handlers
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_ "image/jpeg"
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"image/png"
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"math"
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"os"
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"golang.org/x/image/draw"
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)
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func ReadImage(path string) (*image.NRGBA, error) {
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reader, err := os.Open(path)
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if err != nil {
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return nil, err
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}
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img, _, err := image.Decode(reader)
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if err != nil {
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return nil, err
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}
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return imgToNRGBA(img), nil
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}
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func WriteImage(path string, img image.Image) error {
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f, err := os.Create(path)
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if err != nil {
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return err
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}
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if err := png.Encode(f, img); err != nil {
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f.Close()
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return err
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}
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return nil
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}
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func imgToNRGBA(img image.Image) *image.NRGBA {
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b := img.Bounds()
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r := image.NewNRGBA(b)
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for x := b.Min.X; x < b.Max.X; x++ {
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for y := b.Min.Y; y < b.Max.Y; y++ {
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r.Set(x, y, img.At(x, y))
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}
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}
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return r
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}
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// ImgColorFilter replaces `from` with `to` in `img`, and sets all other pixels
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// to color.Transparent
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func ImgColorFilter(img *image.NRGBA, from, to color.NRGBA) *image.NRGBA {
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b := img.Bounds()
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r := image.NewNRGBA(b)
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for x := b.Min.X; x < b.Max.X; x++ {
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for y := b.Min.Y; y < b.Max.Y; y++ {
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if img.At(x, y) == from {
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r.SetNRGBA(x, y, to)
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} else {
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r.Set(x, y, color.Transparent)
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}
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}
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}
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return r
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}
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func ScaleImage(img image.Image, factorX, factorY float64, highQuality bool) (scaled *image.NRGBA) {
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b := img.Bounds()
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newX := int(math.Ceil(factorX * float64(b.Max.X)))
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newY := int(math.Ceil(factorY * float64(b.Max.Y)))
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scaledBounds := image.Rect(0, 0, newX, newY)
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scaledImg := image.NewNRGBA(scaledBounds)
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scaler := draw.NearestNeighbor
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if highQuality {
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scaler = draw.CatmullRom
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}
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scaler.Scale(scaledImg, scaledBounds, img, b, draw.Src, nil)
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return scaledImg
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}
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func RotateImage90(img *image.NRGBA) (rotated *image.NRGBA) {
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b := img.Bounds()
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rotated = image.NewNRGBA(image.Rect(0, 0, b.Max.Y, b.Max.X))
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for x := b.Min.X; x < b.Max.X; x++ {
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for y := b.Min.Y; y < b.Max.Y; y++ {
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col := img.NRGBAAt(x, y)
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rotated.SetNRGBA(b.Max.Y-y, x, col)
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}
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}
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return
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}
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