1 files changed, 41 insertions, 30 deletions

diff --git a/src/pkg/image/names.go b/src/pkg/image/names.go
index 0b621cff5..c309684ce 100644
--- a/src/pkg/image/names.go
+++ b/src/pkg/image/names.go
@@ -4,53 +4,64 @@
 
 package image
 
-// Colors from the HTML 4.01 specification: http://www.w3.org/TR/REC-html40/types.html#h-6.5
-// These names do not necessarily match those from other lists, such as the X11 color names.
 var (
-	Aqua    = ColorImage{RGBAColor{0x00, 0xff, 0xff, 0xff}}
-	Black   = ColorImage{RGBAColor{0x00, 0x00, 0x00, 0xff}}
-	Blue    = ColorImage{RGBAColor{0x00, 0x00, 0xff, 0xff}}
-	Fuchsia = ColorImage{RGBAColor{0xff, 0x00, 0xff, 0xff}}
-	Gray    = ColorImage{RGBAColor{0x80, 0x80, 0x80, 0xff}}
-	Green   = ColorImage{RGBAColor{0x00, 0x80, 0x00, 0xff}}
-	Lime    = ColorImage{RGBAColor{0x00, 0xff, 0x00, 0xff}}
-	Maroon  = ColorImage{RGBAColor{0x80, 0x00, 0x00, 0xff}}
-	Navy    = ColorImage{RGBAColor{0x00, 0x00, 0x80, 0xff}}
-	Olive   = ColorImage{RGBAColor{0x80, 0x80, 0x00, 0xff}}
-	Red     = ColorImage{RGBAColor{0xff, 0x00, 0x00, 0xff}}
-	Purple  = ColorImage{RGBAColor{0x80, 0x00, 0x80, 0xff}}
-	Silver  = ColorImage{RGBAColor{0xc0, 0xc0, 0xc0, 0xff}}
-	Teal    = ColorImage{RGBAColor{0x00, 0x80, 0x80, 0xff}}
-	White   = ColorImage{RGBAColor{0xff, 0xff, 0xff, 0xff}}
-	Yellow  = ColorImage{RGBAColor{0xff, 0xff, 0x00, 0xff}}
-
-	// These synonyms are not in HTML 4.01.
-	Cyan    = Aqua
-	Magenta = Fuchsia
+	// 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 a practically infinite-sized Image of uniform Color.
+// 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) {
+func (c *ColorImage) RGBA() (r, g, b, a uint32) {
 	return c.C.RGBA()
 }
 
-func (c ColorImage) ColorModel() ColorModel {
+func (c *ColorImage) ColorModel() ColorModel {
 	return ColorModelFunc(func(Color) Color { return c.C })
 }
 
-func (c ColorImage) Width() int { return 1e9 }
+func (c *ColorImage) Bounds() Rectangle { return Rectangle{Point{-1e9, -1e9}, Point{1e9, 1e9}} }
 
-func (c ColorImage) Height() int { return 1e9 }
-
-func (c ColorImage) At(x, y int) Color { return c.C }
+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 {
+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}
+}