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
5package image
6
7import (
8	"image/color"
9)
10
11var (
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.
24type Uniform struct {
25	C color.Color
26}
27
28func (c *Uniform) RGBA() (r, g, b, a uint32) {
29	return c.C.RGBA()
30}
31
32func (c *Uniform) ColorModel() color.Model {
33	return c
34}
35
36func (c *Uniform) Convert(color.Color) color.Color {
37	return c.C
38}
39
40func (c *Uniform) Bounds() Rectangle { return Rectangle{Point{-1e9, -1e9}, Point{1e9, 1e9}} }
41
42func (c *Uniform) At(x, y int) color.Color { return c.C }
43
44func (c *Uniform) RGBA64At(x, y int) color.RGBA64 {
45	r, g, b, a := c.C.RGBA()
46	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
47}
48
49// Opaque scans the entire image and reports whether it is fully opaque.
50func (c *Uniform) Opaque() bool {
51	_, _, _, a := c.C.RGBA()
52	return a == 0xffff
53}
54
55// NewUniform returns a new Uniform image of the given color.
56func NewUniform(c color.Color) *Uniform {
57	return &Uniform{c}
58}
59