imagefn - empty.go

     1  package imagefn // import "vimagination.zapto.org/imagefn"
     2  
     3  import (
     4  	"image"
     5  	"image/color"
     6  )
     7  
     8  type empty struct {
     9  	color.Model
    10  	Min image.Point
    11  }
    12  
    13  func newEmpty(i image.Image) image.Image {
    14  	e := empty{
    15  		Model: i.ColorModel(),
    16  		Min:   i.Bounds().Min,
    17  	}
    18  
    19  	if _, ok := i.(setter); ok {
    20  		return &emptySet{
    21  			empty: e,
    22  		}
    23  	}
    24  	return &e
    25  }
    26  
    27  func (e empty) ColorModel() color.Model {
    28  	return e.Model
    29  }
    30  
    31  func (e empty) Bounds() image.Rectangle {
    32  	return image.Rectangle{e.Min, e.Min}
    33  }
    34  
    35  func (e empty) At(x, y int) color.Color {
    36  	return e.Model.Convert(color.Alpha{})
    37  }
    38  
    39  type emptySet struct {
    40  	empty
    41  }
    42  
    43  func (emptySet) Set(_, _ int, _ color.Color) {}
    44