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Diffstat (limited to 'Godeps/_workspace/src/code.google.com/p/graphics-go/graphics/thumbnail.go')
-rw-r--r-- | Godeps/_workspace/src/code.google.com/p/graphics-go/graphics/thumbnail.go | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/code.google.com/p/graphics-go/graphics/thumbnail.go b/Godeps/_workspace/src/code.google.com/p/graphics-go/graphics/thumbnail.go new file mode 100644 index 000000000..d3ad7e8f7 --- /dev/null +++ b/Godeps/_workspace/src/code.google.com/p/graphics-go/graphics/thumbnail.go @@ -0,0 +1,41 @@ +// Copyright 2011 The Graphics-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 graphics + +import ( + "image" + "image/draw" +) + +// Thumbnail scales and crops src so it fits in dst. +func Thumbnail(dst draw.Image, src image.Image) error { + // Scale down src in the dimension that is closer to dst. + sb := src.Bounds() + db := dst.Bounds() + rx := float64(sb.Dx()) / float64(db.Dx()) + ry := float64(sb.Dy()) / float64(db.Dy()) + var b image.Rectangle + if rx < ry { + b = image.Rect(0, 0, db.Dx(), int(float64(sb.Dy())/rx)) + } else { + b = image.Rect(0, 0, int(float64(sb.Dx())/ry), db.Dy()) + } + + buf := image.NewRGBA(b) + if err := Scale(buf, src); err != nil { + return err + } + + // Crop. + // TODO(crawshaw): improve on center-alignment. + var pt image.Point + if rx < ry { + pt.Y = (b.Dy() - db.Dy()) / 2 + } else { + pt.X = (b.Dx() - db.Dx()) / 2 + } + draw.Draw(dst, db, buf, pt, draw.Src) + return nil +} |