diff options
Diffstat (limited to 'vendor/github.com/disintegration/imaging/transform.go')
| -rw-r--r-- | vendor/github.com/disintegration/imaging/transform.go | 196 |
1 files changed, 163 insertions, 33 deletions
diff --git a/vendor/github.com/disintegration/imaging/transform.go b/vendor/github.com/disintegration/imaging/transform.go index a11601bba..30410c278 100644 --- a/vendor/github.com/disintegration/imaging/transform.go +++ b/vendor/github.com/disintegration/imaging/transform.go @@ -2,23 +2,25 @@ package imaging import ( "image" + "image/color" + "math" ) -// Rotate90 rotates the image 90 degrees counterclockwise and returns the transformed image. -func Rotate90(img image.Image) *image.NRGBA { +// FlipH flips the image horizontally (from left to right) and returns the transformed image. +func FlipH(img image.Image) *image.NRGBA { src := toNRGBA(img) srcW := src.Bounds().Max.X srcH := src.Bounds().Max.Y - dstW := srcH - dstH := srcW + dstW := srcW + dstH := srcH dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH)) parallel(dstH, func(partStart, partEnd int) { for dstY := partStart; dstY < partEnd; dstY++ { for dstX := 0; dstX < dstW; dstX++ { - srcX := dstH - dstY - 1 - srcY := dstX + srcX := dstW - dstX - 1 + srcY := dstY srcOff := srcY*src.Stride + srcX*4 dstOff := dstY*dst.Stride + dstX*4 @@ -32,8 +34,8 @@ func Rotate90(img image.Image) *image.NRGBA { return dst } -// Rotate180 rotates the image 180 degrees counterclockwise and returns the transformed image. -func Rotate180(img image.Image) *image.NRGBA { +// FlipV flips the image vertically (from top to bottom) and returns the transformed image. +func FlipV(img image.Image) *image.NRGBA { src := toNRGBA(img) srcW := src.Bounds().Max.X srcH := src.Bounds().Max.Y @@ -45,7 +47,7 @@ func Rotate180(img image.Image) *image.NRGBA { for dstY := partStart; dstY < partEnd; dstY++ { for dstX := 0; dstX < dstW; dstX++ { - srcX := dstW - dstX - 1 + srcX := dstX srcY := dstH - dstY - 1 srcOff := srcY*src.Stride + srcX*4 @@ -60,8 +62,8 @@ func Rotate180(img image.Image) *image.NRGBA { return dst } -// Rotate270 rotates the image 270 degrees counterclockwise and returns the transformed image. -func Rotate270(img image.Image) *image.NRGBA { +// Transpose flips the image horizontally and rotates 90 degrees counter-clockwise. +func Transpose(img image.Image) *image.NRGBA { src := toNRGBA(img) srcW := src.Bounds().Max.X srcH := src.Bounds().Max.Y @@ -74,7 +76,7 @@ func Rotate270(img image.Image) *image.NRGBA { for dstY := partStart; dstY < partEnd; dstY++ { for dstX := 0; dstX < dstW; dstX++ { srcX := dstY - srcY := dstW - dstX - 1 + srcY := dstX srcOff := srcY*src.Stride + srcX*4 dstOff := dstY*dst.Stride + dstX*4 @@ -88,21 +90,21 @@ func Rotate270(img image.Image) *image.NRGBA { return dst } -// FlipH flips the image horizontally (from left to right) and returns the transformed image. -func FlipH(img image.Image) *image.NRGBA { +// Transverse flips the image vertically and rotates 90 degrees counter-clockwise. +func Transverse(img image.Image) *image.NRGBA { src := toNRGBA(img) srcW := src.Bounds().Max.X srcH := src.Bounds().Max.Y - dstW := srcW - dstH := srcH + dstW := srcH + dstH := srcW dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH)) parallel(dstH, func(partStart, partEnd int) { for dstY := partStart; dstY < partEnd; dstY++ { for dstX := 0; dstX < dstW; dstX++ { - srcX := dstW - dstX - 1 - srcY := dstY + srcX := dstH - dstY - 1 + srcY := dstW - dstX - 1 srcOff := srcY*src.Stride + srcX*4 dstOff := dstY*dst.Stride + dstX*4 @@ -116,21 +118,21 @@ func FlipH(img image.Image) *image.NRGBA { return dst } -// FlipV flips the image vertically (from top to bottom) and returns the transformed image. -func FlipV(img image.Image) *image.NRGBA { +// Rotate90 rotates the image 90 degrees counterclockwise and returns the transformed image. +func Rotate90(img image.Image) *image.NRGBA { src := toNRGBA(img) srcW := src.Bounds().Max.X srcH := src.Bounds().Max.Y - dstW := srcW - dstH := srcH + dstW := srcH + dstH := srcW dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH)) parallel(dstH, func(partStart, partEnd int) { for dstY := partStart; dstY < partEnd; dstY++ { for dstX := 0; dstX < dstW; dstX++ { - srcX := dstX - srcY := dstH - dstY - 1 + srcX := dstH - dstY - 1 + srcY := dstX srcOff := srcY*src.Stride + srcX*4 dstOff := dstY*dst.Stride + dstX*4 @@ -144,21 +146,21 @@ func FlipV(img image.Image) *image.NRGBA { return dst } -// Transpose flips the image horizontally and rotates 90 degrees counter-clockwise. -func Transpose(img image.Image) *image.NRGBA { +// Rotate180 rotates the image 180 degrees counterclockwise and returns the transformed image. +func Rotate180(img image.Image) *image.NRGBA { src := toNRGBA(img) srcW := src.Bounds().Max.X srcH := src.Bounds().Max.Y - dstW := srcH - dstH := srcW + dstW := srcW + dstH := srcH dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH)) parallel(dstH, func(partStart, partEnd int) { for dstY := partStart; dstY < partEnd; dstY++ { for dstX := 0; dstX < dstW; dstX++ { - srcX := dstY - srcY := dstX + srcX := dstW - dstX - 1 + srcY := dstH - dstY - 1 srcOff := srcY*src.Stride + srcX*4 dstOff := dstY*dst.Stride + dstX*4 @@ -172,8 +174,8 @@ func Transpose(img image.Image) *image.NRGBA { return dst } -// Transverse flips the image vertically and rotates 90 degrees counter-clockwise. -func Transverse(img image.Image) *image.NRGBA { +// Rotate270 rotates the image 270 degrees counterclockwise and returns the transformed image. +func Rotate270(img image.Image) *image.NRGBA { src := toNRGBA(img) srcW := src.Bounds().Max.X srcH := src.Bounds().Max.Y @@ -185,7 +187,7 @@ func Transverse(img image.Image) *image.NRGBA { for dstY := partStart; dstY < partEnd; dstY++ { for dstX := 0; dstX < dstW; dstX++ { - srcX := dstH - dstY - 1 + srcX := dstY srcY := dstW - dstX - 1 srcOff := srcY*src.Stride + srcX*4 @@ -199,3 +201,131 @@ func Transverse(img image.Image) *image.NRGBA { return dst } + +// Rotate rotates an image by the given angle counter-clockwise . +// The angle parameter is the rotation angle in degrees. +// The bgColor parameter specifies the color of the uncovered zone after the rotation. +func Rotate(img image.Image, angle float64, bgColor color.Color) *image.NRGBA { + src := toNRGBA(img) + srcW := src.Bounds().Max.X + srcH := src.Bounds().Max.Y + dstW, dstH := rotatedSize(srcW, srcH, angle) + dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH)) + + if dstW <= 0 || dstH <= 0 { + return dst + } + + srcXOff := float64(srcW)/2 - 0.5 + srcYOff := float64(srcH)/2 - 0.5 + dstXOff := float64(dstW)/2 - 0.5 + dstYOff := float64(dstH)/2 - 0.5 + + bgColorNRGBA := color.NRGBAModel.Convert(bgColor).(color.NRGBA) + sin, cos := math.Sincos(math.Pi * float64(angle) / 180) + + parallel(dstH, func(partStart, partEnd int) { + for dstY := partStart; dstY < partEnd; dstY++ { + for dstX := 0; dstX < dstW; dstX++ { + xf, yf := rotatePoint(float64(dstX)-dstXOff, float64(dstY)-dstYOff, sin, cos) + xf, yf = xf+srcXOff, yf+srcYOff + interpolatePoint(dst, dstX, dstY, src, xf, yf, bgColorNRGBA) + } + } + }) + + return dst +} + +func rotatePoint(x, y, sin, cos float64) (float64, float64) { + return x*cos - y*sin, x*sin + y*cos +} + +func rotatedSize(w, h int, angle float64) (int, int) { + if w <= 0 || h <= 0 { + return 0, 0 + } + + sin, cos := math.Sincos(math.Pi * float64(angle) / 180) + x1, y1 := rotatePoint(float64(w-1), 0, sin, cos) + x2, y2 := rotatePoint(float64(w-1), float64(h-1), sin, cos) + x3, y3 := rotatePoint(0, float64(h-1), sin, cos) + + minx := math.Min(x1, math.Min(x2, math.Min(x3, 0))) + maxx := math.Max(x1, math.Max(x2, math.Max(x3, 0))) + miny := math.Min(y1, math.Min(y2, math.Min(y3, 0))) + maxy := math.Max(y1, math.Max(y2, math.Max(y3, 0))) + + neww := maxx - minx + 1 + if neww-math.Floor(neww) > 0.1 { + neww++ + } + newh := maxy - miny + 1 + if newh-math.Floor(newh) > 0.1 { + newh++ + } + + return int(neww), int(newh) +} + +func interpolatePoint(dst *image.NRGBA, dstX, dstY int, src *image.NRGBA, xf, yf float64, bgColor color.NRGBA) { + dstIndex := dstY*dst.Stride + dstX*4 + + x0 := int(math.Floor(xf)) + y0 := int(math.Floor(yf)) + bounds := src.Bounds() + if !image.Pt(x0, y0).In(image.Rect(bounds.Min.X-1, bounds.Min.Y-1, bounds.Max.X, bounds.Max.Y)) { + dst.Pix[dstIndex+0] = bgColor.R + dst.Pix[dstIndex+1] = bgColor.G + dst.Pix[dstIndex+2] = bgColor.B + dst.Pix[dstIndex+3] = bgColor.A + return + } + + xq := xf - float64(x0) + yq := yf - float64(y0) + + var pxs [4]color.NRGBA + var cfs [4]float64 + + for i := 0; i < 2; i++ { + for j := 0; j < 2; j++ { + k := i*2 + j + pt := image.Pt(x0+j, y0+i) + if pt.In(bounds) { + l := pt.Y*src.Stride + pt.X*4 + pxs[k].R = src.Pix[l+0] + pxs[k].G = src.Pix[l+1] + pxs[k].B = src.Pix[l+2] + pxs[k].A = src.Pix[l+3] + } else { + pxs[k] = bgColor + } + } + } + + cfs[0] = (1 - xq) * (1 - yq) + cfs[1] = xq * (1 - yq) + cfs[2] = (1 - xq) * yq + cfs[3] = xq * yq + + var r, g, b, a float64 + for i := range pxs { + wa := float64(pxs[i].A) * cfs[i] + r += float64(pxs[i].R) * wa + g += float64(pxs[i].G) * wa + b += float64(pxs[i].B) * wa + a += wa + } + + if a != 0 { + r /= a + g /= a + b /= a + } + + dst.Pix[dstIndex+0] = clamp(r) + dst.Pix[dstIndex+1] = clamp(g) + dst.Pix[dstIndex+2] = clamp(b) + dst.Pix[dstIndex+3] = clamp(a) +} |