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denoland-deno/ext/canvas/lib.rs

154 lines
3.7 KiB
Rust

// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
use deno_core::error::type_error;
use deno_core::error::AnyError;
use deno_core::op2;
use deno_core::ToJsBuffer;
use image::imageops::FilterType;
use image::ColorType;
use image::ImageDecoder;
use image::Pixel;
use image::RgbaImage;
use serde::Deserialize;
use serde::Serialize;
use std::path::PathBuf;
#[derive(Debug, Deserialize)]
#[serde(rename_all = "snake_case")]
enum ImageResizeQuality {
Pixelated,
Low,
Medium,
High,
}
#[derive(Debug, Deserialize)]
#[serde(rename_all = "camelCase")]
struct ImageProcessArgs {
width: u32,
height: u32,
surface_width: u32,
surface_height: u32,
input_x: i64,
input_y: i64,
output_width: u32,
output_height: u32,
resize_quality: ImageResizeQuality,
flip_y: bool,
premultiply: Option<bool>,
}
#[op2]
#[serde]
fn op_image_process(
#[buffer] buf: &[u8],
#[serde] args: ImageProcessArgs,
) -> Result<ToJsBuffer, AnyError> {
let view =
RgbaImage::from_vec(args.width, args.height, buf.to_vec()).unwrap();
let surface = if !(args.width == args.surface_width
&& args.height == args.surface_height
&& args.input_x == 0
&& args.input_y == 0)
{
let mut surface = RgbaImage::new(args.surface_width, args.surface_height);
image::imageops::overlay(&mut surface, &view, args.input_x, args.input_y);
surface
} else {
view
};
let filter_type = match args.resize_quality {
ImageResizeQuality::Pixelated => FilterType::Nearest,
ImageResizeQuality::Low => FilterType::Triangle,
ImageResizeQuality::Medium => FilterType::CatmullRom,
ImageResizeQuality::High => FilterType::Lanczos3,
};
let mut image_out = image::imageops::resize(
&surface,
args.output_width,
args.output_height,
filter_type,
);
if args.flip_y {
image::imageops::flip_vertical_in_place(&mut image_out);
}
// ignore 9.
if let Some(premultiply) = args.premultiply {
let is_not_premultiplied = image_out.pixels().any(|pixel| {
(pixel.0[0].max(pixel.0[1]).max(pixel.0[2])) > (255 * pixel.0[3])
});
if premultiply {
if is_not_premultiplied {
for pixel in image_out.pixels_mut() {
let alpha = pixel.0[3];
pixel.apply_without_alpha(|channel| {
(channel as f32 * (alpha as f32 / 255.0)) as u8
})
}
}
} else if !is_not_premultiplied {
for pixel in image_out.pixels_mut() {
let alpha = pixel.0[3];
pixel.apply_without_alpha(|channel| {
(channel as f32 / (alpha as f32 / 255.0)) as u8
})
}
}
}
Ok(image_out.to_vec().into())
}
#[derive(Debug, Serialize)]
struct DecodedPng {
data: ToJsBuffer,
width: u32,
height: u32,
}
#[op2]
#[serde]
fn op_image_decode_png(#[buffer] buf: &[u8]) -> Result<DecodedPng, AnyError> {
let png = image::codecs::png::PngDecoder::new(buf)?;
let (width, height) = png.dimensions();
// TODO(@crowlKats): maybe use DynamicImage https://docs.rs/image/0.24.7/image/enum.DynamicImage.html ?
if png.color_type() != ColorType::Rgba8 {
return Err(type_error(format!(
"Color type '{:?}' not supported",
png.color_type()
)));
}
// read_image will assert that the buffer is the correct size, so we need to fill it with zeros
let mut png_data = vec![0_u8; png.total_bytes() as usize];
png.read_image(&mut png_data)?;
Ok(DecodedPng {
data: png_data.into(),
width,
height,
})
}
deno_core::extension!(
deno_canvas,
deps = [deno_webidl, deno_web, deno_webgpu],
ops = [op_image_process, op_image_decode_png],
lazy_loaded_esm = ["01_image.js"],
);
pub fn get_declaration() -> PathBuf {
PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("lib.deno_canvas.d.ts")
}