Imported Upstream version 60upstream/60

1 files changed, 67 insertions, 0 deletions

diff --git a/src/pkg/image/names.go b/src/pkg/image/names.go
new file mode 100644
index 000000000..c309684ce
--- /dev/null
+++ b/src/pkg/image/names.go
@@ -0,0 +1,67 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package image
+
+var (
+	// Black is an opaque black ColorImage.
+	Black = NewColorImage(Gray16Color{0})
+	// White is an opaque white ColorImage.
+	White = NewColorImage(Gray16Color{0xffff})
+	// Transparent is a fully transparent ColorImage.
+	Transparent = NewColorImage(Alpha16Color{0})
+	// Opaque is a fully opaque ColorImage.
+	Opaque = NewColorImage(Alpha16Color{0xffff})
+)
+
+// A ColorImage is an infinite-sized Image of uniform Color.
+// It implements both the Color and Image interfaces.
+type ColorImage struct {
+	C Color
+}
+
+func (c *ColorImage) RGBA() (r, g, b, a uint32) {
+	return c.C.RGBA()
+}
+
+func (c *ColorImage) ColorModel() ColorModel {
+	return ColorModelFunc(func(Color) Color { return c.C })
+}
+
+func (c *ColorImage) Bounds() Rectangle { return Rectangle{Point{-1e9, -1e9}, Point{1e9, 1e9}} }
+
+func (c *ColorImage) At(x, y int) Color { return c.C }
+
+// Opaque scans the entire image and returns whether or not it is fully opaque.
+func (c *ColorImage) Opaque() bool {
+	_, _, _, a := c.C.RGBA()
+	return a == 0xffff
+}
+
+func NewColorImage(c Color) *ColorImage {
+	return &ColorImage{c}
+}
+
+// A Tiled is an infinite-sized Image that repeats another Image in both
+// directions. Tiled{i, p}.At(x, y) will equal i.At(x+p.X, y+p.Y) for all
+// points {x+p.X, y+p.Y} within i's Bounds.
+type Tiled struct {
+	I      Image
+	Offset Point
+}
+
+func (t *Tiled) ColorModel() ColorModel {
+	return t.I.ColorModel()
+}
+
+func (t *Tiled) Bounds() Rectangle { return Rectangle{Point{-1e9, -1e9}, Point{1e9, 1e9}} }
+
+func (t *Tiled) At(x, y int) Color {
+	p := Point{x, y}.Add(t.Offset).Mod(t.I.Bounds())
+	return t.I.At(p.X, p.Y)
+}
+
+func NewTiled(i Image, offset Point) *Tiled {
+	return &Tiled{i, offset}
+}