diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/nfnt/resize/filters.go')
| -rw-r--r-- | Godeps/_workspace/src/github.com/nfnt/resize/filters.go | 143 |
1 files changed, 0 insertions, 143 deletions
diff --git a/Godeps/_workspace/src/github.com/nfnt/resize/filters.go b/Godeps/_workspace/src/github.com/nfnt/resize/filters.go deleted file mode 100644 index 4ce04e389..000000000 --- a/Godeps/_workspace/src/github.com/nfnt/resize/filters.go +++ /dev/null @@ -1,143 +0,0 @@ -/* -Copyright (c) 2012, Jan Schlicht <jan.schlicht@gmail.com> - -Permission to use, copy, modify, and/or distribute this software for any purpose -with or without fee is hereby granted, provided that the above copyright notice -and this permission notice appear in all copies. - -THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH -REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND -FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, -INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS -OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER -TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF -THIS SOFTWARE. -*/ - -package resize - -import ( - "math" -) - -func nearest(in float64) float64 { - if in >= -0.5 && in < 0.5 { - return 1 - } - return 0 -} - -func linear(in float64) float64 { - in = math.Abs(in) - if in <= 1 { - return 1 - in - } - return 0 -} - -func cubic(in float64) float64 { - in = math.Abs(in) - if in <= 1 { - return in*in*(1.5*in-2.5) + 1.0 - } - if in <= 2 { - return in*(in*(2.5-0.5*in)-4.0) + 2.0 - } - return 0 -} - -func mitchellnetravali(in float64) float64 { - in = math.Abs(in) - if in <= 1 { - return (7.0*in*in*in - 12.0*in*in + 5.33333333333) * 0.16666666666 - } - if in <= 2 { - return (-2.33333333333*in*in*in + 12.0*in*in - 20.0*in + 10.6666666667) * 0.16666666666 - } - return 0 -} - -func sinc(x float64) float64 { - x = math.Abs(x) * math.Pi - if x >= 1.220703e-4 { - return math.Sin(x) / x - } - return 1 -} - -func lanczos2(in float64) float64 { - if in > -2 && in < 2 { - return sinc(in) * sinc(in*0.5) - } - return 0 -} - -func lanczos3(in float64) float64 { - if in > -3 && in < 3 { - return sinc(in) * sinc(in*0.3333333333333333) - } - return 0 -} - -// range [-256,256] -func createWeights8(dy, filterLength int, blur, scale float64, kernel func(float64) float64) ([]int16, []int, int) { - filterLength = filterLength * int(math.Max(math.Ceil(blur*scale), 1)) - filterFactor := math.Min(1./(blur*scale), 1) - - coeffs := make([]int16, dy*filterLength) - start := make([]int, dy) - for y := 0; y < dy; y++ { - interpX := scale*(float64(y)+0.5) - 0.5 - start[y] = int(interpX) - filterLength/2 + 1 - interpX -= float64(start[y]) - for i := 0; i < filterLength; i++ { - in := (interpX - float64(i)) * filterFactor - coeffs[y*filterLength+i] = int16(kernel(in) * 256) - } - } - - return coeffs, start, filterLength -} - -// range [-65536,65536] -func createWeights16(dy, filterLength int, blur, scale float64, kernel func(float64) float64) ([]int32, []int, int) { - filterLength = filterLength * int(math.Max(math.Ceil(blur*scale), 1)) - filterFactor := math.Min(1./(blur*scale), 1) - - coeffs := make([]int32, dy*filterLength) - start := make([]int, dy) - for y := 0; y < dy; y++ { - interpX := scale*(float64(y)+0.5) - 0.5 - start[y] = int(interpX) - filterLength/2 + 1 - interpX -= float64(start[y]) - for i := 0; i < filterLength; i++ { - in := (interpX - float64(i)) * filterFactor - coeffs[y*filterLength+i] = int32(kernel(in) * 65536) - } - } - - return coeffs, start, filterLength -} - -func createWeightsNearest(dy, filterLength int, blur, scale float64) ([]bool, []int, int) { - filterLength = filterLength * int(math.Max(math.Ceil(blur*scale), 1)) - filterFactor := math.Min(1./(blur*scale), 1) - - coeffs := make([]bool, dy*filterLength) - start := make([]int, dy) - for y := 0; y < dy; y++ { - interpX := scale*(float64(y)+0.5) - 0.5 - start[y] = int(interpX) - filterLength/2 + 1 - interpX -= float64(start[y]) - for i := 0; i < filterLength; i++ { - in := (interpX - float64(i)) * filterFactor - if in >= -0.5 && in < 0.5 { - coeffs[y*filterLength+i] = true - } else { - coeffs[y*filterLength+i] = false - } - } - } - - return coeffs, start, filterLength -} |