package image
func (p *Alpha) Opaque() bool
Opaque scans the entire image and reports whether it is fully opaque.
Golang image.Alpha.Opaque function usage example
package main
import (
"fmt"
"image"
"image/draw"
)
func main() {
canvas := image.NewAlpha(image.Rect(0, 0, 100, 100))
// is this canvas(image) opaque
op := canvas.Opaque()
fmt.Println("canvas is opaque ? ", op)
rgba := image.NewRGBA(image.Rect(0, 0, 100, 100))
// see http://golang.org/pkg/image/#pkg-variables for image.Opaque
draw.Draw(rgba, image.Rect(0, 0, 100, 100), image.Opaque, image.ZP, draw.Src)
op1 := rgba.Opaque()
fmt.Println("rgba is opaque ? ", op1)
}
Output :
canvas is opaque ? false
rgba is opaque ? true
Reference :
http://golang.org/pkg/image/#Alpha.Opaque
