custom shakes

sgreben · Oct 17, 2018 · 237c80b · 237c80b
1 parent 7fffe92
commit 237c80b
Showing 1 changed file with 28 additions and 12 deletions.
diff --git a/cmd/gif/shake.go b/cmd/gif/shake.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"github.com/sgreben/yeetgif/pkg/piecewiselinear"
 	"image"
 	"math"
 	"math/rand"
@@ -13,37 +14,52 @@ import (
 func CommandShake(cmd *cli.Cmd) {
 	cmd.Spec = "[OPTIONS]"
 	var (
-		random = gifcmd.Float{Value: 0.5}
-		f      = gifcmd.Float{Value: 1.0}
-		a      = gifcmd.Float{Value: 8.0}
+		random = gifcmd.Float{Value: 0.75}
+		f      = gifcmd.FloatsCSV{Values: []float64{1}}
+		a      = gifcmd.FloatsCSV{Values: []float64{7}}
 	)
 	cmd.VarOpt("f frequency", &f, "")
 	cmd.VarOpt("a amplitude", &a, "")
 	cmd.VarOpt("r random", &random, "🌀")
 	cmd.Action = func() {
-		Shake(images, random.Value, f.Value, a.Value)
+		amplitudeF := piecewiselinear.Function{}
+		k := float64(len(a.Values) - 1)
+		for i := 0; i < len(a.Values); i++ {
+			amplitudeF.X = append(amplitudeF.X, float64(i)/k)
+			amplitudeF.Y = append(amplitudeF.Y, float64((a.Values)[i]))
+		}
+		frequencyF := piecewiselinear.Function{}
+		k = float64(len(f.Values) - 1)
+		for i := 0; i < len(f.Values); i++ {
+			frequencyF.X = append(frequencyF.X, float64(i)/k)
+			frequencyF.Y = append(frequencyF.Y, float64((f.Values)[i]))
+		}
+		Shake(images, random.Value, frequencyF.At, amplitudeF.At)
 	}
 }
 
 // Shake `images`
-func Shake(images []image.Image, random, frequency, amplitude float64) {
-	n := len(images)
+func Shake(images []image.Image, random float64, frequency , amplitude func(float64)float64) {
+	n := float64(len(images))
 	phaseY := math.Pi / 2
 	move := func(i int) {
 		rX, rY := rand.Float64(), rand.Float64()
+		t := float64(i)/n
+		a := amplitude(t)
+		f := frequency(t)
 		offset := image.Point{
-			X: int(amplitude * math.Sin(2*math.Pi*frequency*float64(i)/float64(n)+(rX*2*math.Pi))),
-			Y: int(amplitude * math.Sin(2*math.Pi*frequency*float64(i)/float64(n)+phaseY+(rY*2*math.Pi))),
+			X: int(a * math.Sin(2*math.Pi*f*t+(rX*2*math.Pi))),
+			Y: int(a * math.Sin(2*math.Pi*f*t+phaseY+(rY*2*math.Pi))),
 		}
 		if !config.Pad {
 			images[i] = imaging.Paste(image.NewNRGBA(images[i].Bounds()), images[i], offset)
 			return
 		}
 		bounds := images[i].Bounds()
-		bounds.Min.X -= int(amplitude)
-		bounds.Max.X += int(amplitude)
-		bounds.Min.Y -= int(amplitude)
-		bounds.Max.Y += int(amplitude)
+		bounds.Min.X -= int(a)
+		bounds.Max.X += int(a)
+		bounds.Min.Y -= int(a)
+		bounds.Max.Y += int(a)
 		images[i] = imaging.Paste(image.NewNRGBA(bounds), images[i], offset)
 	}
 	parallel(len(images), move)