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