Source file src/image/names.go

Documentation: image

     1  // Copyright 2010 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package image
     6  
     7  import (
     8  	"image/color"
     9  )
    10  
    11  var (
    12  	// Black is an opaque black uniform image.
    13  	Black = NewUniform(color.Black)
    14  	// White is an opaque white uniform image.
    15  	White = NewUniform(color.White)
    16  	// Transparent is a fully transparent uniform image.
    17  	Transparent = NewUniform(color.Transparent)
    18  	// Opaque is a fully opaque uniform image.
    19  	Opaque = NewUniform(color.Opaque)
    20  )
    21  
    22  // Uniform is an infinite-sized Image of uniform color.
    23  // It implements the color.Color, color.Model, and Image interfaces.
    24  type Uniform struct {
    25  	C color.Color
    26  }
    27  
    28  func (c *Uniform) RGBA() (r, g, b, a uint32) {
    29  	return c.C.RGBA()
    30  }
    31  
    32  func (c *Uniform) ColorModel() color.Model {
    33  	return c
    34  }
    35  
    36  func (c *Uniform) Convert(color.Color) color.Color {
    37  	return c.C
    38  }
    39  
    40  func (c *Uniform) Bounds() Rectangle { return Rectangle{Point{-1e9, -1e9}, Point{1e9, 1e9}} }
    41  
    42  func (c *Uniform) At(x, y int) color.Color { return c.C }
    43  
    44  // Opaque scans the entire image and reports whether it is fully opaque.
    45  func (c *Uniform) Opaque() bool {
    46  	_, _, _, a := c.C.RGBA()
    47  	return a == 0xffff
    48  }
    49  
    50  func NewUniform(c color.Color) *Uniform {
    51  	return &Uniform{c}
    52  }
    53  

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