// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license. 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, thiserror::Error)] pub enum CanvasError { #[error("Color type '{0:?}' not supported")] UnsupportedColorType(ColorType), #[error(transparent)] Image(#[from] image::ImageError), } #[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, ) -> ToJsBuffer { 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 }) } } } 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, CanvasError> { 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(CanvasError::UnsupportedColorType(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") }