50 lines
1.3 KiB
Go
50 lines
1.3 KiB
Go
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// Copyright 2015 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build !go1.9
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package draw
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import (
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"image"
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"image/color"
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"image/draw"
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)
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// Drawer contains the Draw method.
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type Drawer interface {
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// Draw aligns r.Min in dst with sp in src and then replaces the
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// rectangle r in dst with the result of drawing src on dst.
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Draw(dst Image, r image.Rectangle, src image.Image, sp image.Point)
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}
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// Image is an image.Image with a Set method to change a single pixel.
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type Image interface {
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image.Image
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Set(x, y int, c color.Color)
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}
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// Op is a Porter-Duff compositing operator.
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type Op int
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const (
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// Over specifies ``(src in mask) over dst''.
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Over Op = Op(draw.Over)
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// Src specifies ``src in mask''.
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Src Op = Op(draw.Src)
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)
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// Draw implements the Drawer interface by calling the Draw function with
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// this Op.
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func (op Op) Draw(dst Image, r image.Rectangle, src image.Image, sp image.Point) {
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(draw.Op(op)).Draw(dst, r, src, sp)
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}
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// Quantizer produces a palette for an image.
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type Quantizer interface {
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// Quantize appends up to cap(p) - len(p) colors to p and returns the
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// updated palette suitable for converting m to a paletted image.
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Quantize(p color.Palette, m image.Image) color.Palette
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}
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