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Diffstat (limited to 'Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/rgba_interpolation.go')
-rw-r--r-- | Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/rgba_interpolation.go | 150 |
1 files changed, 0 insertions, 150 deletions
diff --git a/Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/rgba_interpolation.go b/Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/rgba_interpolation.go deleted file mode 100644 index 92534e7eb..000000000 --- a/Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/rgba_interpolation.go +++ /dev/null @@ -1,150 +0,0 @@ -// Copyright 2010 The draw2d Authors. All rights reserved. -// created: 21/11/2010 by Laurent Le Goff -// see http://pippin.gimp.org/image_processing/chap_resampling.html - -package draw2d - -import ( - "image" - "image/color" - "image/draw" - "math" -) - -type ImageFilter int - -const ( - LinearFilter ImageFilter = iota - BilinearFilter - BicubicFilter -) - -//see http://pippin.gimp.org/image_processing/chap_resampling.html -func getColorLinear(img image.Image, x, y float64) color.Color { - return img.At(int(x), int(y)) -} - -func getColorBilinear(img image.Image, x, y float64) color.Color { - x0 := math.Floor(x) - y0 := math.Floor(y) - dx := x - x0 - dy := y - y0 - - rt, gt, bt, at := img.At(int(x0), int(y0)).RGBA() - r0, g0, b0, a0 := float64(rt), float64(gt), float64(bt), float64(at) - rt, gt, bt, at = img.At(int(x0+1), int(y0)).RGBA() - r1, g1, b1, a1 := float64(rt), float64(gt), float64(bt), float64(at) - rt, gt, bt, at = img.At(int(x0+1), int(y0+1)).RGBA() - r2, g2, b2, a2 := float64(rt), float64(gt), float64(bt), float64(at) - rt, gt, bt, at = img.At(int(x0), int(y0+1)).RGBA() - r3, g3, b3, a3 := float64(rt), float64(gt), float64(bt), float64(at) - - r := int(lerp(lerp(r0, r1, dx), lerp(r3, r2, dx), dy)) - g := int(lerp(lerp(g0, g1, dx), lerp(g3, g2, dx), dy)) - b := int(lerp(lerp(b0, b1, dx), lerp(b3, b2, dx), dy)) - a := int(lerp(lerp(a0, a1, dx), lerp(a3, a2, dx), dy)) - return color.RGBA{uint8(r >> 8), uint8(g >> 8), uint8(b >> 8), uint8(a >> 8)} -} - -/** --- LERP --- /lerp/, vi.,n. --- --- Quasi-acronym for Linear Interpolation, used as a verb or noun for --- the operation. "Bresenham's algorithm lerps incrementally between the --- two endpoints of the line." (From Jargon File (4.4.4, 14 Aug 2003) -*/ -func lerp(v1, v2, ratio float64) float64 { - return v1*(1-ratio) + v2*ratio -} - -func getColorCubicRow(img image.Image, x, y, offset float64) color.Color { - c0 := img.At(int(x), int(y)) - c1 := img.At(int(x+1), int(y)) - c2 := img.At(int(x+2), int(y)) - c3 := img.At(int(x+3), int(y)) - rt, gt, bt, at := c0.RGBA() - r0, g0, b0, a0 := float64(rt), float64(gt), float64(bt), float64(at) - rt, gt, bt, at = c1.RGBA() - r1, g1, b1, a1 := float64(rt), float64(gt), float64(bt), float64(at) - rt, gt, bt, at = c2.RGBA() - r2, g2, b2, a2 := float64(rt), float64(gt), float64(bt), float64(at) - rt, gt, bt, at = c3.RGBA() - r3, g3, b3, a3 := float64(rt), float64(gt), float64(bt), float64(at) - r, g, b, a := cubic(offset, r0, r1, r2, r3), cubic(offset, g0, g1, g2, g3), cubic(offset, b0, b1, b2, b3), cubic(offset, a0, a1, a2, a3) - return color.RGBA{uint8(r >> 8), uint8(g >> 8), uint8(b >> 8), uint8(a >> 8)} -} - -func getColorBicubic(img image.Image, x, y float64) color.Color { - x0 := math.Floor(x) - y0 := math.Floor(y) - dx := x - x0 - dy := y - y0 - c0 := getColorCubicRow(img, x0-1, y0-1, dx) - c1 := getColorCubicRow(img, x0-1, y0, dx) - c2 := getColorCubicRow(img, x0-1, y0+1, dx) - c3 := getColorCubicRow(img, x0-1, y0+2, dx) - rt, gt, bt, at := c0.RGBA() - r0, g0, b0, a0 := float64(rt), float64(gt), float64(bt), float64(at) - rt, gt, bt, at = c1.RGBA() - r1, g1, b1, a1 := float64(rt), float64(gt), float64(bt), float64(at) - rt, gt, bt, at = c2.RGBA() - r2, g2, b2, a2 := float64(rt), float64(gt), float64(bt), float64(at) - rt, gt, bt, at = c3.RGBA() - r3, g3, b3, a3 := float64(rt), float64(gt), float64(bt), float64(at) - r, g, b, a := cubic(dy, r0, r1, r2, r3), cubic(dy, g0, g1, g2, g3), cubic(dy, b0, b1, b2, b3), cubic(dy, a0, a1, a2, a3) - return color.RGBA{uint8(r >> 8), uint8(g >> 8), uint8(b >> 8), uint8(a >> 8)} -} - -func cubic(offset, v0, v1, v2, v3 float64) uint32 { - // offset is the offset of the sampled value between v1 and v2 - return uint32(((((-7*v0+21*v1-21*v2+7*v3)*offset+ - (15*v0-36*v1+27*v2-6*v3))*offset+ - (-9*v0+9*v2))*offset + (v0 + 16*v1 + v2)) / 18.0) -} - -func DrawImage(src image.Image, dest draw.Image, tr MatrixTransform, op draw.Op, filter ImageFilter) { - bounds := src.Bounds() - x0, y0, x1, y1 := float64(bounds.Min.X), float64(bounds.Min.Y), float64(bounds.Max.X), float64(bounds.Max.Y) - tr.TransformRectangle(&x0, &y0, &x1, &y1) - var x, y, u, v float64 - var c1, c2, cr color.Color - var r, g, b, a, ia, r1, g1, b1, a1, r2, g2, b2, a2 uint32 - var color color.RGBA - for x = x0; x < x1; x++ { - for y = y0; y < y1; y++ { - u = x - v = y - tr.InverseTransform(&u, &v) - if bounds.Min.X <= int(u) && bounds.Max.X > int(u) && bounds.Min.Y <= int(v) && bounds.Max.Y > int(v) { - c1 = dest.At(int(x), int(y)) - switch filter { - case LinearFilter: - c2 = src.At(int(u), int(v)) - case BilinearFilter: - c2 = getColorBilinear(src, u, v) - case BicubicFilter: - c2 = getColorBicubic(src, u, v) - } - switch op { - case draw.Over: - r1, g1, b1, a1 = c1.RGBA() - r2, g2, b2, a2 = c2.RGBA() - ia = M - a2 - r = ((r1 * ia) / M) + r2 - g = ((g1 * ia) / M) + g2 - b = ((b1 * ia) / M) + b2 - a = ((a1 * ia) / M) + a2 - color.R = uint8(r >> 8) - color.G = uint8(g >> 8) - color.B = uint8(b >> 8) - color.A = uint8(a >> 8) - cr = color - default: - cr = c2 - } - dest.Set(int(x), int(y), cr) - } - } - } -} |