Graphite/node-graph/gstd/src/raster.rs

629 lines
24 KiB
Rust

use dyn_any::DynAny;
use fastnoise_lite;
use glam::{DAffine2, DVec2, Vec2};
use graphene_core::raster::bbox::Bbox;
use graphene_core::raster::image::{Image, ImageFrameTable};
use graphene_core::raster::{
Alpha, AlphaMut, Bitmap, BitmapMut, CellularDistanceFunction, CellularReturnType, DomainWarpType, FractalType, LinearChannel, Luminance, NoiseType, Pixel, RGBMut, Sample,
};
use graphene_core::transform::{Transform, TransformMut};
use graphene_core::{AlphaBlending, Color, Ctx, ExtractFootprint, GraphicElement, Node};
use rand::prelude::*;
use rand_chacha::ChaCha8Rng;
use std::fmt::Debug;
use std::hash::Hash;
#[derive(Debug, DynAny)]
pub enum Error {
IO(std::io::Error),
Image(::image::ImageError),
}
impl From<std::io::Error> for Error {
fn from(e: std::io::Error) -> Self {
Error::IO(e)
}
}
#[node_macro::node(category("Debug: Raster"))]
fn sample_image(ctx: impl ExtractFootprint + Clone + Send, image_frame: ImageFrameTable<Color>) -> ImageFrameTable<Color> {
let image_frame_transform = image_frame.transform();
let image_frame_alpha_blending = image_frame.one_instance_ref().alpha_blending;
let image = image_frame.one_instance_ref().instance;
// Resize the image using the image crate
let data = bytemuck::cast_vec(image.data.clone());
let footprint = ctx.footprint();
let viewport_bounds = footprint.viewport_bounds_in_local_space();
let image_bounds = Bbox::from_transform(image_frame_transform).to_axis_aligned_bbox();
let intersection = viewport_bounds.intersect(&image_bounds);
let image_size = DAffine2::from_scale(DVec2::new(image.width as f64, image.height as f64));
let size = intersection.size();
let size_px = image_size.transform_vector2(size).as_uvec2();
// If the image would not be visible, return an empty image
if size.x <= 0. || size.y <= 0. {
return ImageFrameTable::one_empty_image();
}
let image_buffer = ::image::Rgba32FImage::from_raw(image.width, image.height, data).expect("Failed to convert internal image format into image-rs data type.");
let dynamic_image: ::image::DynamicImage = image_buffer.into();
let offset = (intersection.start - image_bounds.start).max(DVec2::ZERO);
let offset_px = image_size.transform_vector2(offset).as_uvec2();
let cropped = dynamic_image.crop_imm(offset_px.x, offset_px.y, size_px.x, size_px.y);
let viewport_resolution_x = footprint.transform.transform_vector2(DVec2::X * size.x).length();
let viewport_resolution_y = footprint.transform.transform_vector2(DVec2::Y * size.y).length();
let mut new_width = size_px.x;
let mut new_height = size_px.y;
// Only downscale the image for now
let resized = if new_width < image.width || new_height < image.height {
new_width = viewport_resolution_x as u32;
new_height = viewport_resolution_y as u32;
// TODO: choose filter based on quality requirements
cropped.resize_exact(new_width, new_height, ::image::imageops::Triangle)
} else {
cropped
};
let buffer = resized.to_rgba32f();
let buffer = buffer.into_raw();
let vec = bytemuck::cast_vec(buffer);
let image = Image {
width: new_width,
height: new_height,
data: vec,
base64_string: None,
};
// we need to adjust the offset if we truncate the offset calculation
let new_transform = image_frame_transform * DAffine2::from_translation(offset) * DAffine2::from_scale(size);
let mut result = ImageFrameTable::new(image);
*result.transform_mut() = new_transform;
*result.one_instance_mut().alpha_blending = *image_frame_alpha_blending;
result
}
#[node_macro::node(category("Raster"))]
fn combine_channels<_I, Red, Green, Blue, Alpha>(
_: impl Ctx,
_primary: (),
#[implementations(ImageFrameTable<Color>)] red: Red,
#[implementations(ImageFrameTable<Color>)] green: Green,
#[implementations(ImageFrameTable<Color>)] blue: Blue,
#[implementations(ImageFrameTable<Color>)] alpha: Alpha,
) -> ImageFrameTable<Color>
where
_I: Pixel + Luminance,
Red: Bitmap<Pixel = _I>,
Green: Bitmap<Pixel = _I>,
Blue: Bitmap<Pixel = _I>,
Alpha: Bitmap<Pixel = _I>,
{
let dimensions = [red.dim(), green.dim(), blue.dim(), alpha.dim()];
if dimensions.iter().any(|&(x, y)| x == 0 || y == 0) || dimensions.iter().any(|&(x, y)| dimensions.iter().any(|&(other_x, other_y)| x != other_x || y != other_y)) {
return ImageFrameTable::one_empty_image();
}
let mut image = Image::new(red.width(), red.height(), Color::TRANSPARENT);
for y in 0..image.height() {
for x in 0..image.width() {
let image_pixel = image.get_pixel_mut(x, y).unwrap();
if let Some(r) = red.get_pixel(x, y) {
image_pixel.set_red(r.l().cast_linear_channel());
}
if let Some(g) = green.get_pixel(x, y) {
image_pixel.set_green(g.l().cast_linear_channel());
}
if let Some(b) = blue.get_pixel(x, y) {
image_pixel.set_blue(b.l().cast_linear_channel());
}
if let Some(a) = alpha.get_pixel(x, y) {
image_pixel.set_alpha(a.l().cast_linear_channel());
}
}
}
ImageFrameTable::new(image)
}
#[node_macro::node(category("Raster"))]
fn mask<_P, _S, Input, Stencil>(
_: impl Ctx,
/// The image to be masked.
#[implementations(ImageFrameTable<Color>)]
mut image: Input,
/// The stencil to be used for masking.
#[implementations(ImageFrameTable<Color>)]
#[expose]
stencil: Stencil,
) -> Input
where
// _P is the color of the input image. It must have an alpha channel because that is going to be modified by the mask.
_P: Alpha,
// _S is the color of the stencil. It must have a luminance channel because that is used to mask the input image.
_S: Luminance,
// Input image
Input: Transform + BitmapMut<Pixel = _P>,
// Stencil
Stencil: Transform + Sample<Pixel = _S>,
{
let image_size = DVec2::new(image.width() as f64, image.height() as f64);
let mask_size = stencil.transform().decompose_scale();
if mask_size == DVec2::ZERO {
return image;
}
// Transforms a point from the background image to the foreground image
let bg_to_fg = image.transform() * DAffine2::from_scale(1. / image_size);
let stencil_transform_inverse = stencil.transform().inverse();
let area = bg_to_fg.transform_vector2(DVec2::ONE);
for y in 0..image.height() {
for x in 0..image.width() {
let image_point = DVec2::new(x as f64, y as f64);
let mut mask_point = bg_to_fg.transform_point2(image_point);
let local_mask_point = stencil_transform_inverse.transform_point2(mask_point);
mask_point = stencil.transform().transform_point2(local_mask_point.clamp(DVec2::ZERO, DVec2::ONE));
let image_pixel = image.get_pixel_mut(x, y).unwrap();
if let Some(mask_pixel) = stencil.sample(mask_point, area) {
*image_pixel = image_pixel.multiplied_alpha(mask_pixel.l().cast_linear_channel());
}
}
}
image
}
// #[derive(Debug, Clone, Copy)]
// pub struct BlendImageTupleNode<P, Fg, MapFn> {
// map_fn: MapFn,
// _p: PhantomData<P>,
// _fg: PhantomData<Fg>,
// }
#[node_macro::node(skip_impl)]
async fn blend_image_tuple<_P, MapFn, _Fg>(images: (ImageFrameTable<_P>, _Fg), map_fn: &'n MapFn) -> ImageFrameTable<_P>
where
_P: Alpha + Pixel + Debug + Send,
MapFn: for<'any_input> Node<'any_input, (_P, _P), Output = _P> + 'n + Clone,
_Fg: Sample<Pixel = _P> + Transform + Clone + Send + 'n,
GraphicElement: From<Image<_P>>,
{
let (background, foreground) = images;
blend_image(foreground, background, map_fn)
}
fn blend_image<'input, _P, MapFn, Frame, Background>(foreground: Frame, background: Background, map_fn: &'input MapFn) -> Background
where
MapFn: Node<'input, (_P, _P), Output = _P>,
_P: Pixel + Alpha + Debug,
Frame: Sample<Pixel = _P> + Transform,
Background: BitmapMut<Pixel = _P> + Sample<Pixel = _P> + Transform,
{
blend_image_closure(foreground, background, |a, b| map_fn.eval((a, b)))
}
pub fn blend_image_closure<_P, MapFn, Frame, Background>(foreground: Frame, mut background: Background, map_fn: MapFn) -> Background
where
MapFn: Fn(_P, _P) -> _P,
_P: Pixel + Alpha + Debug,
Frame: Sample<Pixel = _P> + Transform,
Background: BitmapMut<Pixel = _P> + Sample<Pixel = _P> + Transform,
{
let background_size = DVec2::new(background.width() as f64, background.height() as f64);
// Transforms a point from the background image to the foreground image
let bg_to_fg = background.transform() * DAffine2::from_scale(1. / background_size);
// Footprint of the foreground image (0,0) (1, 1) in the background image space
let bg_aabb = Bbox::unit().affine_transform(background.transform().inverse() * foreground.transform()).to_axis_aligned_bbox();
// Clamp the foreground image to the background image
let start = (bg_aabb.start * background_size).max(DVec2::ZERO).as_uvec2();
let end = (bg_aabb.end * background_size).min(background_size).as_uvec2();
let area = bg_to_fg.transform_point2(DVec2::new(1., 1.)) - bg_to_fg.transform_point2(DVec2::ZERO);
for y in start.y..end.y {
for x in start.x..end.x {
let bg_point = DVec2::new(x as f64, y as f64);
let fg_point = bg_to_fg.transform_point2(bg_point);
if let Some(src_pixel) = foreground.sample(fg_point, area) {
if let Some(dst_pixel) = background.get_pixel_mut(x, y) {
*dst_pixel = map_fn(src_pixel, *dst_pixel);
}
}
}
}
background
}
#[node_macro::node(category(""))]
fn extend_image_to_bounds(_: impl Ctx, image: ImageFrameTable<Color>, bounds: DAffine2) -> ImageFrameTable<Color> {
let image_aabb = Bbox::unit().affine_transform(image.transform()).to_axis_aligned_bbox();
let bounds_aabb = Bbox::unit().affine_transform(bounds.transform()).to_axis_aligned_bbox();
if image_aabb.contains(bounds_aabb.start) && image_aabb.contains(bounds_aabb.end) {
return image;
}
let image_instance = image.one_instance_ref().instance;
if image_instance.width == 0 || image_instance.height == 0 {
return empty_image((), bounds, Color::TRANSPARENT);
}
let orig_image_scale = DVec2::new(image_instance.width as f64, image_instance.height as f64);
let layer_to_image_space = DAffine2::from_scale(orig_image_scale) * image.transform().inverse();
let bounds_in_image_space = Bbox::unit().affine_transform(layer_to_image_space * bounds).to_axis_aligned_bbox();
let new_start = bounds_in_image_space.start.floor().min(DVec2::ZERO);
let new_end = bounds_in_image_space.end.ceil().max(orig_image_scale);
let new_scale = new_end - new_start;
// Copy over original image into enlarged image.
let mut new_img = Image::new(new_scale.x as u32, new_scale.y as u32, Color::TRANSPARENT);
let offset_in_new_image = (-new_start).as_uvec2();
for y in 0..image_instance.height {
let old_start = y * image_instance.width;
let new_start = (y + offset_in_new_image.y) * new_img.width + offset_in_new_image.x;
let old_row = &image_instance.data[old_start as usize..(old_start + image_instance.width) as usize];
let new_row = &mut new_img.data[new_start as usize..(new_start + image_instance.width) as usize];
new_row.copy_from_slice(old_row);
}
// Compute new transform.
// let layer_to_new_texture_space = (DAffine2::from_scale(1. / new_scale) * DAffine2::from_translation(new_start) * layer_to_image_space).inverse();
let new_texture_to_layer_space = image.transform() * DAffine2::from_scale(1. / orig_image_scale) * DAffine2::from_translation(new_start) * DAffine2::from_scale(new_scale);
let mut result = ImageFrameTable::new(new_img);
*result.transform_mut() = new_texture_to_layer_space;
*result.one_instance_mut().alpha_blending = *image.one_instance_ref().alpha_blending;
result
}
#[node_macro::node(category("Debug: Raster"))]
fn empty_image(_: impl Ctx, transform: DAffine2, color: Color) -> ImageFrameTable<Color> {
let width = transform.transform_vector2(DVec2::new(1., 0.)).length() as u32;
let height = transform.transform_vector2(DVec2::new(0., 1.)).length() as u32;
let image = Image::new(width, height, color);
let mut result = ImageFrameTable::new(image);
*result.transform_mut() = transform;
*result.one_instance_mut().alpha_blending = AlphaBlending::default();
result
}
/// Constructs a raster image.
#[node_macro::node(category(""))]
fn image(_: impl Ctx, _primary: (), image: ImageFrameTable<Color>) -> ImageFrameTable<Color> {
image
}
// #[cfg(feature = "serde")]
// macro_rules! generate_imaginate_node {
// ($($val:ident: $t:ident: $o:ty,)*) => {
// pub struct ImaginateNode<P: Pixel, E, C, G, $($t,)*> {
// editor_api: E,
// controller: C,
// generation_id: G,
// $($val: $t,)*
// cache: std::sync::Arc<std::sync::Mutex<HashMap<u64, Image<P>>>>,
// last_generation: std::sync::atomic::AtomicU64,
// }
// impl<'e, P: Pixel, E, C, G, $($t,)*> ImaginateNode<P, E, C, G, $($t,)*>
// where $($t: for<'any_input> Node<'any_input, (), Output = DynFuture<'any_input, $o>>,)*
// E: for<'any_input> Node<'any_input, (), Output = DynFuture<'any_input, &'e WasmEditorApi>>,
// C: for<'any_input> Node<'any_input, (), Output = DynFuture<'any_input, ImaginateController>>,
// G: for<'any_input> Node<'any_input, (), Output = DynFuture<'any_input, u64>>,
// {
// #[allow(clippy::too_many_arguments)]
// pub fn new(editor_api: E, controller: C, $($val: $t,)* generation_id: G ) -> Self {
// Self { editor_api, controller, generation_id, $($val,)* cache: Default::default(), last_generation: std::sync::atomic::AtomicU64::new(u64::MAX) }
// }
// }
// impl<'i, 'e: 'i, P: Pixel + 'i + Hash + Default + Send, E: 'i, C: 'i, G: 'i, $($t: 'i,)*> Node<'i, ImageFrame<P>> for ImaginateNode<P, E, C, G, $($t,)*>
// where $($t: for<'any_input> Node<'any_input, (), Output = DynFuture<'any_input, $o>>,)*
// E: for<'any_input> Node<'any_input, (), Output = DynFuture<'any_input, &'e WasmEditorApi>>,
// C: for<'any_input> Node<'any_input, (), Output = DynFuture<'any_input, ImaginateController>>,
// G: for<'any_input> Node<'any_input, (), Output = DynFuture<'any_input, u64>>,
// {
// type Output = DynFuture<'i, ImageFrame<P>>;
// fn eval(&'i self, frame: ImageFrame<P>) -> Self::Output {
// let controller = self.controller.eval(());
// $(let $val = self.$val.eval(());)*
// use std::hash::Hasher;
// let mut hasher = rustc_hash::FxHasher::default();
// frame.image.hash(&mut hasher);
// let hash = hasher.finish();
// let editor_api = self.editor_api.eval(());
// let cache = self.cache.clone();
// let generation_future = self.generation_id.eval(());
// let last_generation = &self.last_generation;
// Box::pin(async move {
// let controller: ImaginateController = controller.await;
// let generation_id = generation_future.await;
// if generation_id != last_generation.swap(generation_id, std::sync::atomic::Ordering::SeqCst) {
// let image = super::imaginate::imaginate(frame.image, editor_api, controller, $($val,)*).await;
// cache.lock().unwrap().insert(hash, image.clone());
// return wrap_image_frame(image, frame.transform);
// }
// let image = cache.lock().unwrap().get(&hash).cloned().unwrap_or_default();
// return wrap_image_frame(image, frame.transform);
// })
// }
// }
// }
// }
// fn wrap_image_frame<P: Pixel>(image: Image<P>, transform: DAffine2) -> ImageFrame<P> {
// if !transform.decompose_scale().abs_diff_eq(DVec2::ZERO, 0.00001) {
// ImageFrame {
// image,
// transform,
// alpha_blending: AlphaBlending::default(),
// }
// } else {
// let resolution = DVec2::new(image.height as f64, image.width as f64);
// ImageFrame {
// image,
// transform: DAffine2::from_scale_angle_translation(resolution, 0., transform.translation),
// alpha_blending: AlphaBlending::default(),
// }
// }
// }
// #[cfg(feature = "serde")]
// generate_imaginate_node! {
// seed: Seed: f64,
// res: Res: Option<DVec2>,
// samples: Samples: u32,
// sampling_method: SamplingMethod: ImaginateSamplingMethod,
// prompt_guidance: PromptGuidance: f64,
// prompt: Prompt: String,
// negative_prompt: NegativePrompt: String,
// adapt_input_image: AdaptInputImage: bool,
// image_creativity: ImageCreativity: f64,
// inpaint: Inpaint: bool,
// mask_blur: MaskBlur: f64,
// mask_starting_fill: MaskStartingFill: ImaginateMaskStartingFill,
// improve_faces: ImproveFaces: bool,
// tiling: Tiling: bool,
// }
#[node_macro::node(category("Raster"))]
#[allow(clippy::too_many_arguments)]
fn noise_pattern(
ctx: impl ExtractFootprint + Ctx,
_primary: (),
clip: bool,
seed: u32,
scale: f64,
noise_type: NoiseType,
domain_warp_type: DomainWarpType,
domain_warp_amplitude: f64,
fractal_type: FractalType,
fractal_octaves: u32,
fractal_lacunarity: f64,
fractal_gain: f64,
fractal_weighted_strength: f64,
fractal_ping_pong_strength: f64,
cellular_distance_function: CellularDistanceFunction,
cellular_return_type: CellularReturnType,
cellular_jitter: f64,
) -> ImageFrameTable<Color> {
let footprint = ctx.footprint();
let viewport_bounds = footprint.viewport_bounds_in_local_space();
let mut size = viewport_bounds.size();
let mut offset = viewport_bounds.start;
if clip {
// TODO: Remove "clip" entirely (and its arbitrary 100x100 clipping square) once we have proper resolution-aware layer clipping
const CLIPPING_SQUARE_SIZE: f64 = 100.;
let image_bounds = Bbox::from_transform(DAffine2::from_scale(DVec2::splat(CLIPPING_SQUARE_SIZE))).to_axis_aligned_bbox();
let intersection = viewport_bounds.intersect(&image_bounds);
offset = (intersection.start - image_bounds.start).max(DVec2::ZERO);
size = intersection.size();
}
// If the image would not be visible, return an empty image
if size.x <= 0. || size.y <= 0. {
return ImageFrameTable::one_empty_image();
}
let footprint_scale = footprint.scale();
let width = (size.x * footprint_scale.x) as u32;
let height = (size.y * footprint_scale.y) as u32;
// All
let mut image = Image::new(width, height, Color::from_luminance(0.5));
let mut noise = fastnoise_lite::FastNoiseLite::with_seed(seed as i32);
noise.set_frequency(Some(1. / (scale as f32).max(f32::EPSILON)));
// Domain Warp
let domain_warp_type = match domain_warp_type {
DomainWarpType::None => None,
DomainWarpType::OpenSimplex2 => Some(fastnoise_lite::DomainWarpType::OpenSimplex2),
DomainWarpType::OpenSimplex2Reduced => Some(fastnoise_lite::DomainWarpType::OpenSimplex2Reduced),
DomainWarpType::BasicGrid => Some(fastnoise_lite::DomainWarpType::BasicGrid),
};
let domain_warp_active = domain_warp_type.is_some();
noise.set_domain_warp_type(domain_warp_type);
noise.set_domain_warp_amp(Some(domain_warp_amplitude as f32));
// Fractal
let noise_type = match noise_type {
NoiseType::Perlin => fastnoise_lite::NoiseType::Perlin,
NoiseType::OpenSimplex2 => fastnoise_lite::NoiseType::OpenSimplex2,
NoiseType::OpenSimplex2S => fastnoise_lite::NoiseType::OpenSimplex2S,
NoiseType::Cellular => fastnoise_lite::NoiseType::Cellular,
NoiseType::ValueCubic => fastnoise_lite::NoiseType::ValueCubic,
NoiseType::Value => fastnoise_lite::NoiseType::Value,
NoiseType::WhiteNoise => {
// TODO: Generate in layer space, not viewport space
let mut rng = ChaCha8Rng::seed_from_u64(seed as u64);
for y in 0..height {
for x in 0..width {
let pixel = image.get_pixel_mut(x, y).unwrap();
let luminance = rng.random_range(0.0..1.) as f32;
*pixel = Color::from_luminance(luminance);
}
}
let mut result = ImageFrameTable::new(image);
*result.transform_mut() = DAffine2::from_translation(offset) * DAffine2::from_scale(size);
*result.one_instance_mut().alpha_blending = AlphaBlending::default();
return result;
}
};
noise.set_noise_type(Some(noise_type));
let fractal_type = match fractal_type {
FractalType::None => fastnoise_lite::FractalType::None,
FractalType::FBm => fastnoise_lite::FractalType::FBm,
FractalType::Ridged => fastnoise_lite::FractalType::Ridged,
FractalType::PingPong => fastnoise_lite::FractalType::PingPong,
FractalType::DomainWarpProgressive => fastnoise_lite::FractalType::DomainWarpProgressive,
FractalType::DomainWarpIndependent => fastnoise_lite::FractalType::DomainWarpIndependent,
};
noise.set_fractal_type(Some(fractal_type));
noise.set_fractal_octaves(Some(fractal_octaves as i32));
noise.set_fractal_lacunarity(Some(fractal_lacunarity as f32));
noise.set_fractal_gain(Some(fractal_gain as f32));
noise.set_fractal_weighted_strength(Some(fractal_weighted_strength as f32));
noise.set_fractal_ping_pong_strength(Some(fractal_ping_pong_strength as f32));
// Cellular
let cellular_distance_function = match cellular_distance_function {
CellularDistanceFunction::Euclidean => fastnoise_lite::CellularDistanceFunction::Euclidean,
CellularDistanceFunction::EuclideanSq => fastnoise_lite::CellularDistanceFunction::EuclideanSq,
CellularDistanceFunction::Manhattan => fastnoise_lite::CellularDistanceFunction::Manhattan,
CellularDistanceFunction::Hybrid => fastnoise_lite::CellularDistanceFunction::Hybrid,
};
let cellular_return_type = match cellular_return_type {
CellularReturnType::CellValue => fastnoise_lite::CellularReturnType::CellValue,
CellularReturnType::Nearest => fastnoise_lite::CellularReturnType::Distance,
CellularReturnType::NextNearest => fastnoise_lite::CellularReturnType::Distance2,
CellularReturnType::Average => fastnoise_lite::CellularReturnType::Distance2Add,
CellularReturnType::Difference => fastnoise_lite::CellularReturnType::Distance2Sub,
CellularReturnType::Product => fastnoise_lite::CellularReturnType::Distance2Mul,
CellularReturnType::Division => fastnoise_lite::CellularReturnType::Distance2Div,
};
noise.set_cellular_distance_function(Some(cellular_distance_function));
noise.set_cellular_return_type(Some(cellular_return_type));
noise.set_cellular_jitter(Some(cellular_jitter as f32));
let coordinate_offset = offset.as_vec2();
let scale = size.as_vec2() / Vec2::new(width as f32, height as f32);
// Calculate the noise for every pixel
for y in 0..height {
for x in 0..width {
let pixel = image.get_pixel_mut(x, y).unwrap();
let pos = Vec2::new(x as f32, y as f32);
let vec = pos * scale + coordinate_offset;
let (mut x, mut y) = (vec.x, vec.y);
if domain_warp_active && domain_warp_amplitude > 0. {
(x, y) = noise.domain_warp_2d(x, y);
}
let luminance = (noise.get_noise_2d(x, y) + 1.) * 0.5;
*pixel = Color::from_luminance(luminance);
}
}
let mut result = ImageFrameTable::new(image);
*result.transform_mut() = DAffine2::from_translation(offset) * DAffine2::from_scale(size);
*result.one_instance_mut().alpha_blending = AlphaBlending::default();
result
}
#[node_macro::node(category("Raster"))]
fn mandelbrot(ctx: impl ExtractFootprint + Send) -> ImageFrameTable<Color> {
let footprint = ctx.footprint();
let viewport_bounds = footprint.viewport_bounds_in_local_space();
let image_bounds = Bbox::from_transform(DAffine2::IDENTITY).to_axis_aligned_bbox();
let intersection = viewport_bounds.intersect(&image_bounds);
let size = intersection.size();
let offset = (intersection.start - image_bounds.start).max(DVec2::ZERO);
// If the image would not be visible, return an empty image
if size.x <= 0. || size.y <= 0. {
return ImageFrameTable::one_empty_image();
}
let scale = footprint.scale();
let width = (size.x * scale.x) as u32;
let height = (size.y * scale.y) as u32;
let mut data = Vec::with_capacity(width as usize * height as usize);
let max_iter = 255;
let scale = 3. * size.as_vec2() / Vec2::new(width as f32, height as f32);
let coordinate_offset = offset.as_vec2() * 3. - Vec2::new(2., 1.5);
for y in 0..height {
for x in 0..width {
let pos = Vec2::new(x as f32, y as f32);
let c = pos * scale + coordinate_offset;
let iter = mandelbrot_impl(c, max_iter);
data.push(map_color(iter, max_iter));
}
}
let image = Image {
width,
height,
data,
..Default::default()
};
let mut result = ImageFrameTable::new(image);
*result.transform_mut() = DAffine2::from_translation(offset) * DAffine2::from_scale(size);
*result.one_instance_mut().alpha_blending = Default::default();
result
}
#[inline(always)]
fn mandelbrot_impl(c: Vec2, max_iter: usize) -> usize {
let mut z = Vec2::new(0., 0.);
for i in 0..max_iter {
z = Vec2::new(z.x * z.x - z.y * z.y, 2. * z.x * z.y) + c;
if z.length_squared() > 4. {
return i;
}
}
max_iter
}
fn map_color(iter: usize, max_iter: usize) -> Color {
let v = iter as f32 / max_iter as f32;
Color::from_rgbaf32_unchecked(v, v, v, 1.)
}