Merge pull request #90 from sosiska/patch-1

rewrite if-else to switch statement

adjust.go

@@ -91,11 +91,12 @@ func AdjustContrast(img image.Image, percentage float64) *image.NRGBA {
 
 	v := (100.0 + percentage) / 100.0
 	for i := 0; i < 256; i++ {
-		if 0 <= v && v <= 1 {
+		switch {
+		case 0 <= v && v <= 1:
 			lut[i] = clamp((0.5 + (float64(i)/255.0-0.5)*v) * 255.0)
-		} else if 1 < v && v < 2 {
+		case 1 < v && v < 2:
 			lut[i] = clamp((0.5 + (float64(i)/255.0-0.5)*(1/(2.0-v))) * 255.0)
-		} else {
+		default:
 			lut[i] = uint8(float64(i)/255.0+0.5) * 255
 		}
 	}