56 lines
1.0 KiB
Go
56 lines
1.0 KiB
Go
|
package render
|
||
|
|
|
||
|
|
import (
|
||
|
|
"errors"
|
||
|
|
"image"
|
||
|
|
"image/gif"
|
||
|
|
"image/jpeg"
|
||
|
|
"image/png"
|
||
|
|
"os"
|
||
|
|
"path/filepath"
|
||
|
|
|
||
|
|
"golang.org/x/image/bmp"
|
||
|
|
)
|
||
|
|
|
||
|
|
// OpenImage opens an image file from disk.
|
||
|
|
//
|
||
|
|
// Supported file types are: jpeg, gif, png, bmp.
|
||
|
|
func OpenImage(filename string) (image.Image, error) {
|
||
|
|
fh, err := os.Open(filename)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
|
||
|
|
var img image.Image
|
||
|
|
|
||
|
|
switch filepath.Ext(filename) {
|
||
|
|
case ".jpg":
|
||
|
|
fallthrough
|
||
|
|
case ".jpeg":
|
||
|
|
img, err = jpeg.Decode(fh)
|
||
|
|
case ".png":
|
||
|
|
img, err = png.Decode(fh)
|
||
|
|
case ".bmp":
|
||
|
|
img, err = bmp.Decode(fh)
|
||
|
|
case ".gif":
|
||
|
|
img, err = gif.Decode(fh)
|
||
|
|
default:
|
||
|
|
return nil, errors.New("unsupported file type")
|
||
|
|
}
|
||
|
|
|
||
|
|
return img, err
|
||
|
|
}
|
||
|
|
|
||
|
|
// ImageToRGBA converts a Go image.Image into an image.RGBA.
|
||
|
|
func ImageToRGBA(input image.Image) *image.RGBA {
|
||
|
|
var bounds = input.Bounds()
|
||
|
|
var rgba = image.NewRGBA(bounds)
|
||
|
|
for x := bounds.Min.X; x < bounds.Max.X; x++ {
|
||
|
|
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
|
||
|
|
color := input.At(x, y)
|
||
|
|
rgba.Set(x, y, color)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return rgba
|
||
|
|
}
|