diff options
Diffstat (limited to 'vendors/jquery-file-upload/server/gae-go/resize/resize.go')
| -rw-r--r-- | vendors/jquery-file-upload/server/gae-go/resize/resize.go | 247 |
1 files changed, 0 insertions, 247 deletions
diff --git a/vendors/jquery-file-upload/server/gae-go/resize/resize.go b/vendors/jquery-file-upload/server/gae-go/resize/resize.go deleted file mode 100644 index dcb627870..000000000 --- a/vendors/jquery-file-upload/server/gae-go/resize/resize.go +++ /dev/null @@ -1,247 +0,0 @@ -// Copyright 2011 The 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 resize - -import ( - "image" - "image/color" -) - -// Resize returns a scaled copy of the image slice r of m. -// The returned image has width w and height h. -func Resize(m image.Image, r image.Rectangle, w, h int) image.Image { - if w < 0 || h < 0 { - return nil - } - if w == 0 || h == 0 || r.Dx() <= 0 || r.Dy() <= 0 { - return image.NewRGBA64(image.Rect(0, 0, w, h)) - } - switch m := m.(type) { - case *image.RGBA: - return resizeRGBA(m, r, w, h) - case *image.YCbCr: - if m, ok := resizeYCbCr(m, r, w, h); ok { - return m - } - } - ww, hh := uint64(w), uint64(h) - dx, dy := uint64(r.Dx()), uint64(r.Dy()) - // The scaling algorithm is to nearest-neighbor magnify the dx * dy source - // to a (ww*dx) * (hh*dy) intermediate image and then minify the intermediate - // image back down to a ww * hh destination with a simple box filter. - // The intermediate image is implied, we do not physically allocate a slice - // of length ww*dx*hh*dy. - // For example, consider a 4*3 source image. Label its pixels from a-l: - // abcd - // efgh - // ijkl - // To resize this to a 3*2 destination image, the intermediate is 12*6. - // Whitespace has been added to delineate the destination pixels: - // aaab bbcc cddd - // aaab bbcc cddd - // eeef ffgg ghhh - // - // eeef ffgg ghhh - // iiij jjkk klll - // iiij jjkk klll - // Thus, the 'b' source pixel contributes one third of its value to the - // (0, 0) destination pixel and two thirds to (1, 0). - // The implementation is a two-step process. First, the source pixels are - // iterated over and each source pixel's contribution to 1 or more - // destination pixels are summed. Second, the sums are divided by a scaling - // factor to yield the destination pixels. - // TODO: By interleaving the two steps, instead of doing all of - // step 1 first and all of step 2 second, we could allocate a smaller sum - // slice of length 4*w*2 instead of 4*w*h, although the resultant code - // would become more complicated. - n, sum := dx*dy, make([]uint64, 4*w*h) - for y := r.Min.Y; y < r.Max.Y; y++ { - for x := r.Min.X; x < r.Max.X; x++ { - // Get the source pixel. - r32, g32, b32, a32 := m.At(x, y).RGBA() - r64 := uint64(r32) - g64 := uint64(g32) - b64 := uint64(b32) - a64 := uint64(a32) - // Spread the source pixel over 1 or more destination rows. - py := uint64(y) * hh - for remy := hh; remy > 0; { - qy := dy - (py % dy) - if qy > remy { - qy = remy - } - // Spread the source pixel over 1 or more destination columns. - px := uint64(x) * ww - index := 4 * ((py/dy)*ww + (px / dx)) - for remx := ww; remx > 0; { - qx := dx - (px % dx) - if qx > remx { - qx = remx - } - sum[index+0] += r64 * qx * qy - sum[index+1] += g64 * qx * qy - sum[index+2] += b64 * qx * qy - sum[index+3] += a64 * qx * qy - index += 4 - px += qx - remx -= qx - } - py += qy - remy -= qy - } - } - } - return average(sum, w, h, n*0x0101) -} - -// average convert the sums to averages and returns the result. -func average(sum []uint64, w, h int, n uint64) image.Image { - ret := image.NewRGBA(image.Rect(0, 0, w, h)) - for y := 0; y < h; y++ { - for x := 0; x < w; x++ { - index := 4 * (y*w + x) - ret.SetRGBA(x, y, color.RGBA{ - uint8(sum[index+0] / n), - uint8(sum[index+1] / n), - uint8(sum[index+2] / n), - uint8(sum[index+3] / n), - }) - } - } - return ret -} - -// resizeYCbCr returns a scaled copy of the YCbCr image slice r of m. -// The returned image has width w and height h. -func resizeYCbCr(m *image.YCbCr, r image.Rectangle, w, h int) (image.Image, bool) { - var verticalRes int - switch m.SubsampleRatio { - case image.YCbCrSubsampleRatio420: - verticalRes = 2 - case image.YCbCrSubsampleRatio422: - verticalRes = 1 - default: - return nil, false - } - ww, hh := uint64(w), uint64(h) - dx, dy := uint64(r.Dx()), uint64(r.Dy()) - // See comment in Resize. - n, sum := dx*dy, make([]uint64, 4*w*h) - for y := r.Min.Y; y < r.Max.Y; y++ { - Y := m.Y[y*m.YStride:] - Cb := m.Cb[y/verticalRes*m.CStride:] - Cr := m.Cr[y/verticalRes*m.CStride:] - for x := r.Min.X; x < r.Max.X; x++ { - // Get the source pixel. - r8, g8, b8 := color.YCbCrToRGB(Y[x], Cb[x/2], Cr[x/2]) - r64 := uint64(r8) - g64 := uint64(g8) - b64 := uint64(b8) - // Spread the source pixel over 1 or more destination rows. - py := uint64(y) * hh - for remy := hh; remy > 0; { - qy := dy - (py % dy) - if qy > remy { - qy = remy - } - // Spread the source pixel over 1 or more destination columns. - px := uint64(x) * ww - index := 4 * ((py/dy)*ww + (px / dx)) - for remx := ww; remx > 0; { - qx := dx - (px % dx) - if qx > remx { - qx = remx - } - qxy := qx * qy - sum[index+0] += r64 * qxy - sum[index+1] += g64 * qxy - sum[index+2] += b64 * qxy - sum[index+3] += 0xFFFF * qxy - index += 4 - px += qx - remx -= qx - } - py += qy - remy -= qy - } - } - } - return average(sum, w, h, n), true -} - -// resizeRGBA returns a scaled copy of the RGBA image slice r of m. -// The returned image has width w and height h. -func resizeRGBA(m *image.RGBA, r image.Rectangle, w, h int) image.Image { - ww, hh := uint64(w), uint64(h) - dx, dy := uint64(r.Dx()), uint64(r.Dy()) - // See comment in Resize. - n, sum := dx*dy, make([]uint64, 4*w*h) - for y := r.Min.Y; y < r.Max.Y; y++ { - pixOffset := m.PixOffset(r.Min.X, y) - for x := r.Min.X; x < r.Max.X; x++ { - // Get the source pixel. - r64 := uint64(m.Pix[pixOffset+0]) - g64 := uint64(m.Pix[pixOffset+1]) - b64 := uint64(m.Pix[pixOffset+2]) - a64 := uint64(m.Pix[pixOffset+3]) - pixOffset += 4 - // Spread the source pixel over 1 or more destination rows. - py := uint64(y) * hh - for remy := hh; remy > 0; { - qy := dy - (py % dy) - if qy > remy { - qy = remy - } - // Spread the source pixel over 1 or more destination columns. - px := uint64(x) * ww - index := 4 * ((py/dy)*ww + (px / dx)) - for remx := ww; remx > 0; { - qx := dx - (px % dx) - if qx > remx { - qx = remx - } - qxy := qx * qy - sum[index+0] += r64 * qxy - sum[index+1] += g64 * qxy - sum[index+2] += b64 * qxy - sum[index+3] += a64 * qxy - index += 4 - px += qx - remx -= qx - } - py += qy - remy -= qy - } - } - } - return average(sum, w, h, n) -} - -// Resample returns a resampled copy of the image slice r of m. -// The returned image has width w and height h. -func Resample(m image.Image, r image.Rectangle, w, h int) image.Image { - if w < 0 || h < 0 { - return nil - } - if w == 0 || h == 0 || r.Dx() <= 0 || r.Dy() <= 0 { - return image.NewRGBA64(image.Rect(0, 0, w, h)) - } - curw, curh := r.Dx(), r.Dy() - img := image.NewRGBA(image.Rect(0, 0, w, h)) - for y := 0; y < h; y++ { - for x := 0; x < w; x++ { - // Get a source pixel. - subx := x * curw / w - suby := y * curh / h - r32, g32, b32, a32 := m.At(subx, suby).RGBA() - r := uint8(r32 >> 8) - g := uint8(g32 >> 8) - b := uint8(b32 >> 8) - a := uint8(a32 >> 8) - img.SetRGBA(x, y, color.RGBA{r, g, b, a}) - } - } - return img -} |