From 38ee83e45b4de7edf89bf9f0ef629eb4c6ad0fa8 Mon Sep 17 00:00:00 2001
From: Christopher Speller <crspeller@gmail.com>
Date: Thu, 12 May 2016 23:56:07 -0400
Subject: Moving to glide

---
 .../mattermost/rsc/qr/web/resize/resize.go         | 152 +++++++++++++++++++++
 1 file changed, 152 insertions(+)
 create mode 100644 vendor/github.com/mattermost/rsc/qr/web/resize/resize.go

(limited to 'vendor/github.com/mattermost/rsc/qr/web/resize')

diff --git a/vendor/github.com/mattermost/rsc/qr/web/resize/resize.go b/vendor/github.com/mattermost/rsc/qr/web/resize/resize.go
new file mode 100644
index 000000000..02c8b0040
--- /dev/null
+++ b/vendor/github.com/mattermost/rsc/qr/web/resize/resize.go
@@ -0,0 +1,152 @@
+// 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"
+)
+
+// average convert the sums to averages and returns the result.
+func average(sum []uint64, w, h int, n uint64) *image.RGBA {
+	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)
+			pix := ret.Pix[y*ret.Stride+x*4:]
+			pix[0] = uint8(sum[index+0] / n)
+			pix[1] = uint8(sum[index+1] / n)
+			pix[2] = uint8(sum[index+2] / n)
+			pix[3] = uint8(sum[index+3] / n)
+		}
+	}
+	return ret
+}
+
+// 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.RGBA {
+	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++ {
+		pix := m.Pix[(y-r.Min.Y)*m.Stride:]
+		for x := r.Min.X; x < r.Max.X; x++ {
+			// Get the source pixel.
+			p := pix[(x-r.Min.X)*4:]
+			r64 := uint64(p[0])
+			g64 := uint64(p[1])
+			b64 := uint64(p[2])
+			a64 := uint64(p[3])
+			// 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)
+}
+
+// ResizeNRGBA returns a scaled copy of the RGBA image slice r of m.
+// The returned image has width w and height h.
+func ResizeNRGBA(m *image.NRGBA, r image.Rectangle, w, h int) *image.RGBA {
+	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++ {
+		pix := m.Pix[(y-r.Min.Y)*m.Stride:]
+		for x := r.Min.X; x < r.Max.X; x++ {
+			// Get the source pixel.
+			p := pix[(x-r.Min.X)*4:]
+			r64 := uint64(p[0])
+			g64 := uint64(p[1])
+			b64 := uint64(p[2])
+			a64 := uint64(p[3])
+			r64 = (r64 * a64) / 255
+			g64 = (g64 * a64) / 255
+			b64 = (b64 * a64) / 255
+			// 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.RGBA {
+	if w < 0 || h < 0 {
+		return nil
+	}
+	if w == 0 || h == 0 || r.Dx() <= 0 || r.Dy() <= 0 {
+		return image.NewRGBA(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
+}
-- 
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