87013da148
Change-Id: I70a5e3703dea436354e9591fce7b704ec749c2d1 Reviewed-on: https://go-review.googlesource.com/7541 Reviewed-by: Rob Pike <r@golang.org>
65 lines
1.3 KiB
Go
65 lines
1.3 KiB
Go
// 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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package draw_test
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import (
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"fmt"
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"image"
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"image/png"
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"log"
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"os"
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"golang.org/x/image/draw"
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"golang.org/x/image/math/f64"
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)
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func ExampleDraw() {
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fSrc, err := os.Open("../testdata/blue-purple-pink.png")
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if err != nil {
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log.Fatal(err)
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}
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defer fSrc.Close()
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src, err := png.Decode(fSrc)
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if err != nil {
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log.Fatal(err)
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}
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sr := src.Bounds()
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dst := image.NewRGBA(image.Rect(0, 0, 400, 300))
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qs := []draw.Interpolator{
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draw.NearestNeighbor,
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draw.ApproxBiLinear,
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draw.CatmullRom,
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}
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const cos60, sin60 = 0.5, 0.866025404
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t := &f64.Aff3{
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+2 * cos60, -2 * sin60, 100,
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+2 * sin60, +2 * cos60, 100,
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}
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draw.Copy(dst, image.Point{20, 30}, src, sr, nil)
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for i, q := range qs {
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q.Scale(dst, image.Rect(200+10*i, 100*i, 600+10*i, 150+100*i), src, sr, nil)
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}
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draw.NearestNeighbor.Transform(dst, t, src, sr, nil)
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// Change false to true to write the resultant image to disk.
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if false {
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fDst, err := os.Create("out.png")
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if err != nil {
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log.Fatal(err)
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}
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defer fDst.Close()
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err = png.Encode(fDst, dst)
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if err != nil {
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log.Fatal(err)
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}
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}
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fmt.Printf("dst has bounds %v.\n", dst.Bounds())
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// Output:
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// dst has bounds (0,0)-(400,300).
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}
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