[英]How do I convert Clamped<Vec<u8>> to Clamped<&mut [u8]> with Rust and web-sys?
I am manipulating pixel data using Rust and WebAssembly, and am struggling to create new ImageData with the manipulated pixels.我正在使用 Rust 和 WebAssembly 操作像素数据,并且正在努力使用操作的像素创建新的 ImageData。
When I get my ImageData
's data, it returns a Clamped<Vec<u8>>
当我获得
ImageData
的数据时,它返回一个Clamped<Vec<u8>>
fn get_buffer_image_data(&self) -> Clamped<Vec<u8>> {
let image_data = match self.buffer_ctx.get_image_data(0.0, 0.0, 640.0, 480.0) {
Ok(d) => d,
Err(_err) => panic!("failed to fetch buffer image data")
};
image_data.data()
}
I manipulate the pixel data in another function, and then attempt to create new ImageData with these manipulated pixels.我在另一个 function 中操作像素数据,然后尝试使用这些操作像素创建新的 ImageData。 The problem is that I can only create new ImageData with Clamped<&mut [u8]>
问题是我只能用Clamped<&mut [u8]>创建新的 ImageData
fn create_image_data(&self, data: Clamped<Vec<u8>>) {
let imageData = ImageData::new_with_u8_clamped_array_and_sh(data, 640, 480);
}
However, the error I receive is:但是,我收到的错误是:
mismatched types
expected `&mut [u8]`, found struct `std::vec::Vec`
note: expected struct `wasm_bindgen::Clamped<&mut [u8]>`
found struct `wasm_bindgen::Clamped<std::vec::Vec<u8>>`
I think I need to convert one type to another.我想我需要将一种类型转换为另一种。 How do I convert efficiently?
如何高效转换? I have been trying this for a while and I am stuck.
我已经尝试了一段时间,但我被卡住了。 The only solution I have is to send the entire Uint8ClampedArray to wasm from my JS.
我唯一的解决方案是将整个 Uint8ClampedArray 从我的 JS 发送到 wasm。 Here is a code example you can use.
这是您可以使用的代码示例。 Note, if you clone this repo please checkout the branch
problem
https://github.com/Fallenstedt/rotated-pixels/blob/problem/src/pixel_rotator.rs#L42-L44注意,如果你克隆这个 repo,请检查分支
problem
https://github.com/Fallenstedt/rotated-pixels/blob/problem/src/pixel_rotator.rs#L42-L44
If you look at the source code for Clamped
, you'll see that it is just a wrapper around T
.如果您查看
Clamped
的源代码,您会发现它只是T
的包装器。
pub struct Clamped<T>(pub T);
Because the inner T
is public, you can perform any operations on it, such as converting a Vec
to a slice:因为内部
T
是公共的,所以可以对其执行任何操作,例如将Vec
转换为切片:
let slice_data: &mut [u8] = &mut data.0[..];
You can then wrap slice_data
in a new instance of Clamped
, and pass it to ImageData
:然后,您可以将
slice_data
包装在Clamped
的新实例中,并将其传递给ImageData
:
fn create_image_data(&self, data: Clamped<Vec<u8>>) {
let slice_data = Clamped(&mut data.0[..]);
let imageData = ImageData::new_with_u8_clamped_array_and_sh(slice_data, 640, 480);
}
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