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Diffstat (limited to 'vendor/github.com/nfnt/resize/thumbnail.go')
-rw-r--r-- | vendor/github.com/nfnt/resize/thumbnail.go | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/vendor/github.com/nfnt/resize/thumbnail.go b/vendor/github.com/nfnt/resize/thumbnail.go new file mode 100644 index 0000000000..9efc246bee --- /dev/null +++ b/vendor/github.com/nfnt/resize/thumbnail.go @@ -0,0 +1,55 @@ +/* +Copyright (c) 2012, Jan Schlicht <jan.schlicht@gmail.com> + +Permission to use, copy, modify, and/or distribute this software for any purpose +with or without fee is hereby granted, provided that the above copyright notice +and this permission notice appear in all copies. + +THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH +REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND +FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, +INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS +OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER +TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF +THIS SOFTWARE. +*/ + +package resize + +import ( + "image" +) + +// Thumbnail will downscale provided image to max width and height preserving +// original aspect ratio and using the interpolation function interp. +// It will return original image, without processing it, if original sizes +// are already smaller than provided constraints. +func Thumbnail(maxWidth, maxHeight uint, img image.Image, interp InterpolationFunction) image.Image { + origBounds := img.Bounds() + origWidth := uint(origBounds.Dx()) + origHeight := uint(origBounds.Dy()) + newWidth, newHeight := origWidth, origHeight + + // Return original image if it have same or smaller size as constraints + if maxWidth >= origWidth && maxHeight >= origHeight { + return img + } + + // Preserve aspect ratio + if origWidth > maxWidth { + newHeight = uint(origHeight * maxWidth / origWidth) + if newHeight < 1 { + newHeight = 1 + } + newWidth = maxWidth + } + + if newHeight > maxHeight { + newWidth = uint(newWidth * maxHeight / newHeight) + if newWidth < 1 { + newWidth = 1 + } + newHeight = maxHeight + } + return Resize(newWidth, newHeight, img, interp) +} |