| // Copyright 2015 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. |
| |
| // +build !go1.9,!go1.8.typealias |
| |
| package draw |
| |
| import ( |
| "image" |
| "image/color" |
| "image/draw" |
| ) |
| |
| // Drawer contains the Draw method. |
| type Drawer interface { |
| // Draw aligns r.Min in dst with sp in src and then replaces the |
| // rectangle r in dst with the result of drawing src on dst. |
| Draw(dst Image, r image.Rectangle, src image.Image, sp image.Point) |
| } |
| |
| // Image is an image.Image with a Set method to change a single pixel. |
| type Image interface { |
| image.Image |
| Set(x, y int, c color.Color) |
| } |
| |
| // Op is a Porter-Duff compositing operator. |
| type Op int |
| |
| const ( |
| // Over specifies ``(src in mask) over dst''. |
| Over Op = Op(draw.Over) |
| // Src specifies ``src in mask''. |
| Src Op = Op(draw.Src) |
| ) |
| |
| // Draw implements the Drawer interface by calling the Draw function with |
| // this Op. |
| func (op Op) Draw(dst Image, r image.Rectangle, src image.Image, sp image.Point) { |
| (draw.Op(op)).Draw(dst, r, src, sp) |
| } |
| |
| // Quantizer produces a palette for an image. |
| type Quantizer interface { |
| // Quantize appends up to cap(p) - len(p) colors to p and returns the |
| // updated palette suitable for converting m to a paletted image. |
| Quantize(p color.Palette, m image.Image) color.Palette |
| } |