# Transformation

Translations: [简体中文](transformation_zh.md)

The decoded Bitmap can be converted through [Transformation]. Sketch has the following
built-in [Transformation]

* [CircleCropTransformation]: Crop the image into a circle
* [RotateTransformation]: Rotate the image by a specified angle
* [RoundedCornersTransformation]: Crop the image into a rounded rectangle
* [MaskTransformation]: Cover the image with a color mask, often used to darken the image when using
  it as the background of a window or module.
* [BlurTransformation]: Blur the image

> Notice:
> 1. [Transformation] does not support animated graphics. Please use the animatedTransformation()
     function for animated image.
> 2. When using RoundedCornersTransformation, please use it with 'resizePrecision(
     Precision.EXACTLY)', because if the original image size is the same as
     When the resize size is inconsistent, the final fillet will be scaled during display, resulting
     in the fillet size being inconsistent with expectations.

### Configure

Both [ImageRequest] and [ImageOptions] provide transformations methods for
configuring [Transformation]

```kotlin
imageView.displayImage("https://www.sample.com/image.jpg") {
    transformations(CircleCropTransformation(), RoundedCornersTransformation(20f))
}
```

### Customize

When customizing [Transformation], you need to pay attention to the implementation of the key
attribute

Because the key attribute is used to remove duplicate [Transformation] when building
the [Transformation] list, the uniqueness and certainty of the key attribute must be ensured:

* The same [Transformation] inputs the same parameters and outputs the same key
* The same [Transformation] inputs different parameters and outputs different keys.

> Note: For custom Transformation, do not perform recycle() on the input Bitmap of the transform
> method or put it into a BitmapPool. This will cause unpredictable errors.

[Transformation]: ../../sketch-core/src/main/kotlin/com/github/panpf/sketch/transform/Transformation.kt

[CircleCropTransformation]: ../../sketch-core/src/main/kotlin/com/github/panpf/sketch/transform/CircleCropTransformation.kt

[RotateTransformation]: ../../sketch-core/src/main/kotlin/com/github/panpf/sketch/transform/RotateTransformation.kt

[RoundedCornersTransformation]: ../../sketch-core/src/main/kotlin/com/github/panpf/sketch/transform/RoundedCornersTransformation.kt

[MaskTransformation]: ../../sketch-core/src/main/kotlin/com/github/panpf/sketch/transform/MaskTransformation.kt

[BlurTransformation]: ../../sketch-core/src/main/kotlin/com/github/panpf/sketch/transform/BlurTransformation.kt

[ImageRequest]: ../../sketch-core/src/main/kotlin/com/github/panpf/sketch/request/ImageRequest.kt

[ImageOptions]: ../../sketch-core/src/main/kotlin/com/github/panpf/sketch/request/ImageOptions.kt