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author | Nigel Tao <nigeltao@golang.org> | 2011-06-02 18:51:41 +1000 |
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committer | Nigel Tao <nigeltao@golang.org> | 2011-06-02 18:51:41 +1000 |
commit | 422abf3b8e9fd94c31bb064af4aab8d27d4dbf10 (patch) | |
tree | f21408446a29006512a3ad8acac85468615155e3 | |
parent | b873701dbde3a9ea562d5297c5d06956a00feccd (diff) | |
download | go-422abf3b8e9fd94c31bb064af4aab8d27d4dbf10.tar.gz go-422abf3b8e9fd94c31bb064af4aab8d27d4dbf10.zip |
image: add a SubImage method.
R=r
CC=golang-dev
https://golang.org/cl/4515179
-rw-r--r-- | src/pkg/image/image.go | 91 | ||||
-rw-r--r-- | src/pkg/image/ycbcr/ycbcr.go | 9 |
2 files changed, 100 insertions, 0 deletions
diff --git a/src/pkg/image/image.go b/src/pkg/image/image.go index 4350acc820..1bdac36f5e 100644 --- a/src/pkg/image/image.go +++ b/src/pkg/image/image.go @@ -58,6 +58,16 @@ func (p *RGBA) SetRGBA(x, y int, c RGBAColor) { p.Pix[y*p.Stride+x] = c } +// SubImage returns an image representing the portion of the image p visible +// through r. The returned value shares pixels with the original image. +func (p *RGBA) SubImage(r Rectangle) Image { + return &RGBA{ + Pix: p.Pix, + Stride: p.Stride, + Rect: p.Rect.Intersect(r), + } +} + // Opaque scans the entire image and returns whether or not it is fully opaque. func (p *RGBA) Opaque() bool { if p.Rect.Empty() { @@ -117,6 +127,16 @@ func (p *RGBA64) SetRGBA64(x, y int, c RGBA64Color) { p.Pix[y*p.Stride+x] = c } +// SubImage returns an image representing the portion of the image p visible +// through r. The returned value shares pixels with the original image. +func (p *RGBA64) SubImage(r Rectangle) Image { + return &RGBA64{ + Pix: p.Pix, + Stride: p.Stride, + Rect: p.Rect.Intersect(r), + } +} + // Opaque scans the entire image and returns whether or not it is fully opaque. func (p *RGBA64) Opaque() bool { if p.Rect.Empty() { @@ -176,6 +196,16 @@ func (p *NRGBA) SetNRGBA(x, y int, c NRGBAColor) { p.Pix[y*p.Stride+x] = c } +// SubImage returns an image representing the portion of the image p visible +// through r. The returned value shares pixels with the original image. +func (p *NRGBA) SubImage(r Rectangle) Image { + return &NRGBA{ + Pix: p.Pix, + Stride: p.Stride, + Rect: p.Rect.Intersect(r), + } +} + // Opaque scans the entire image and returns whether or not it is fully opaque. func (p *NRGBA) Opaque() bool { if p.Rect.Empty() { @@ -235,6 +265,16 @@ func (p *NRGBA64) SetNRGBA64(x, y int, c NRGBA64Color) { p.Pix[y*p.Stride+x] = c } +// SubImage returns an image representing the portion of the image p visible +// through r. The returned value shares pixels with the original image. +func (p *NRGBA64) SubImage(r Rectangle) Image { + return &NRGBA64{ + Pix: p.Pix, + Stride: p.Stride, + Rect: p.Rect.Intersect(r), + } +} + // Opaque scans the entire image and returns whether or not it is fully opaque. func (p *NRGBA64) Opaque() bool { if p.Rect.Empty() { @@ -294,6 +334,16 @@ func (p *Alpha) SetAlpha(x, y int, c AlphaColor) { p.Pix[y*p.Stride+x] = c } +// SubImage returns an image representing the portion of the image p visible +// through r. The returned value shares pixels with the original image. +func (p *Alpha) SubImage(r Rectangle) Image { + return &Alpha{ + Pix: p.Pix, + Stride: p.Stride, + Rect: p.Rect.Intersect(r), + } +} + // Opaque scans the entire image and returns whether or not it is fully opaque. func (p *Alpha) Opaque() bool { if p.Rect.Empty() { @@ -353,6 +403,16 @@ func (p *Alpha16) SetAlpha16(x, y int, c Alpha16Color) { p.Pix[y*p.Stride+x] = c } +// SubImage returns an image representing the portion of the image p visible +// through r. The returned value shares pixels with the original image. +func (p *Alpha16) SubImage(r Rectangle) Image { + return &Alpha16{ + Pix: p.Pix, + Stride: p.Stride, + Rect: p.Rect.Intersect(r), + } +} + // Opaque scans the entire image and returns whether or not it is fully opaque. func (p *Alpha16) Opaque() bool { if p.Rect.Empty() { @@ -412,6 +472,16 @@ func (p *Gray) SetGray(x, y int, c GrayColor) { p.Pix[y*p.Stride+x] = c } +// SubImage returns an image representing the portion of the image p visible +// through r. The returned value shares pixels with the original image. +func (p *Gray) SubImage(r Rectangle) Image { + return &Gray{ + Pix: p.Pix, + Stride: p.Stride, + Rect: p.Rect.Intersect(r), + } +} + // Opaque scans the entire image and returns whether or not it is fully opaque. func (p *Gray) Opaque() bool { return true @@ -457,6 +527,16 @@ func (p *Gray16) SetGray16(x, y int, c Gray16Color) { p.Pix[y*p.Stride+x] = c } +// SubImage returns an image representing the portion of the image p visible +// through r. The returned value shares pixels with the original image. +func (p *Gray16) SubImage(r Rectangle) Image { + return &Gray16{ + Pix: p.Pix, + Stride: p.Stride, + Rect: p.Rect.Intersect(r), + } +} + // Opaque scans the entire image and returns whether or not it is fully opaque. func (p *Gray16) Opaque() bool { return true @@ -544,6 +624,17 @@ func (p *Paletted) SetColorIndex(x, y int, index uint8) { p.Pix[y*p.Stride+x] = index } +// SubImage returns an image representing the portion of the image p visible +// through r. The returned value shares pixels with the original image. +func (p *Paletted) SubImage(r Rectangle) Image { + return &Paletted{ + Pix: p.Pix, + Stride: p.Stride, + Rect: p.Rect.Intersect(r), + Palette: p.Palette, + } +} + // Opaque scans the entire image and returns whether or not it is fully opaque. func (p *Paletted) Opaque() bool { for _, c := range p.Palette { diff --git a/src/pkg/image/ycbcr/ycbcr.go b/src/pkg/image/ycbcr/ycbcr.go index cda45996df..c1c58b708b 100644 --- a/src/pkg/image/ycbcr/ycbcr.go +++ b/src/pkg/image/ycbcr/ycbcr.go @@ -169,6 +169,15 @@ func (p *YCbCr) At(x, y int) image.Color { } } +// SubImage returns an image representing the portion of the image p visible +// through r. The returned value shares pixels with the original image. +func (p *YCbCr) SubImage(r image.Rectangle) image.Image { + q := new(YCbCr) + *q = *p + q.Rect = q.Rect.Intersect(r) + return q +} + func (p *YCbCr) Opaque() bool { return true } |