Rustfmt

I was hoping to implement the image filter/reduction step as well, but that seems to be meaningfully more complex

Cargo.toml

@@ -1,8 +1,7 @@
 [workspace]
 members = [
     "enkou-shaders",
-    "examples/image-runner",
-    "examples/image-binary",
+    "enkou-shaders-tests",
 ]
 resolver = "3"
 
@@ -14,7 +13,6 @@ license = "MIT"
 repository = ""
 
 [workspace.lints.rust]
-missing_docs = { level = "warn" }
 unexpected_cfgs = { level = "allow", check-cfg = ['cfg(target_arch, values("spirv"))'] }
 
 [workspace.dependencies]
@@ -23,7 +21,6 @@ spirv-std = { git = "https://github.com/Rust-GPU/rust-gpu.git", rev = "67f1ff2"
 
 anyhow = "1.0.102"
 bytemuck = { version = "1.25.0", features = ["derive"] }
-futures = "0.3.32"
 glam = { version = "0.33.1", default-features = false, features = ["bytemuck", "scalar-math"] }
 image = { version = "0.25.10", default-features = false, features = ["default-formats"]}
 libm = "0.2.16"
@@ -31,6 +28,3 @@ rand = { version = "0.10.1", default-features = false }
 rand_xoshiro = "0.8.1"
 rspirv = "0.13.0"
 tempfile = "3.27.0"
-thiserror = "2.0.19"
-wgpu = { version = "30.0.0", features = ["spirv"] }
-xflags = "0.3.2"

enkou-shaders-tests/Cargo.toml

@@ -1,16 +1,18 @@
 [package]
-name = "image-binary"
+name = "enkou-shaders-tests"
+publish = false
 version.workspace = true
 authors.workspace = true
 edition.workspace = true
 license.workspace = true
 repository.workspace = true
 
-[dependencies]
-enkou-shaders = { path = "../../enkou-shaders" }
-glam.workspace = true
-spirv-std.workspace = true
-wgpu = { workspace = true, optional = true }
-
 [lints]
 workspace = true
+
+[dependencies]
+rspirv.workspace = true
+
+[build-dependencies]
+anyhow.workspace = true
+cargo-gpu-install.workspace = true

enkou-shaders-tests/build.rs

@@ -4,7 +4,7 @@ use std::path::PathBuf;
 
 pub fn main() -> anyhow::Result<()> {
     let manifest_dir = env!("CARGO_MANIFEST_DIR");
-    let crate_path = [manifest_dir, "..", "image-binary"]
+    let crate_path = [manifest_dir, "..", "enkou-shaders"]
         .iter()
         .copied()
         .collect::<PathBuf>();
@@ -20,9 +20,6 @@ pub fn main() -> anyhow::Result<()> {
 
     let compile_result = builder.build()?;
     let spv_path = compile_result.module.unwrap_single();
-    println!(
-        "cargo::rustc-env=SHADER_SPV_PATH_IMAGE_BINARY={}",
-        spv_path.display()
-    );
+    println!("cargo::rustc-env=SHADER_SPV_PATH={}", spv_path.display());
     Ok(())
 }

enkou-shaders-tests/src/lib.rs

@@ -0,0 +1,62 @@
+#[cfg(test)]
+mod test {
+    use rspirv::binary::parse_bytes;
+    use rspirv::dr::{Module, Operand};
+    use rspirv::spirv::ExecutionModel;
+    use std::sync::OnceLock;
+
+    static SHADER_MODULE: OnceLock<Module> = OnceLock::new();
+
+    fn shader() -> &'static Module {
+        SHADER_MODULE.get_or_init(|| {
+            let shader_bytes = include_bytes!(env!("SHADER_SPV_PATH"));
+
+            let mut loader = rspirv::dr::Loader::new();
+            parse_bytes(shader_bytes, &mut loader).expect("Unable to parse shader");
+
+            loader.module()
+        })
+    }
+
+    fn has_entry_point(execution_model: ExecutionModel, name: &str) -> bool {
+        for entry_point in shader().entry_points.iter() {
+            let operands: Vec<Operand> = entry_point
+                .operands
+                .iter()
+                .filter(|op| matches!(op, Operand::ExecutionModel(_) | Operand::LiteralString(_)))
+                .cloned()
+                .collect();
+
+            assert_eq!(operands.len(), 2);
+            match &operands[0] {
+                Operand::ExecutionModel(actual) => {
+                    if execution_model != *actual {
+                        continue;
+                    }
+                }
+                op => panic!("Unexpected operand; {}", op),
+            }
+
+            match &operands[1] {
+                Operand::LiteralString(actual) => {
+                    if name != actual {
+                        continue;
+                    }
+                }
+                op => panic!("Unexpected operand; {}", op),
+            }
+
+            return true;
+        }
+
+        false
+    }
+
+    #[test]
+    fn has_entry_main_camera() {
+        assert!(has_entry_point(
+            ExecutionModel::GLCompute,
+            "main_image_accumulate"
+        ))
+    }
+}

enkou-shaders/Cargo.toml

@@ -16,3 +16,8 @@ libm.workspace = true
 rand.workspace = true
 rand_xoshiro.workspace = true
 spirv-std.workspace = true
+
+[dev-dependencies]
+anyhow.workspace = true
+image.workspace = true
+tempfile.workspace = true

enkou-shaders/examples/gasket.rs

@@ -0,0 +1,85 @@
+use anyhow::{Context, Result};
+use enkou_shaders::Coefficients2;
+use enkou_shaders::camera::Camera;
+use enkou_shaders::chaos_game::ChaosGame;
+use enkou_shaders::image::{BlendMode, ImageSettings};
+use enkou_shaders::transform::Transform;
+use enkou_shaders::variation::Variation;
+use glam::{Affine2, UVec2, Vec2, uvec2, vec2};
+use image::{GrayImage, Luma};
+use rand::SeedableRng;
+use rand_xoshiro::Xoshiro256StarStar;
+use std::mem;
+use std::process::Command;
+use tempfile::NamedTempFile;
+
+const ITERATIONS_DISCARD: usize = 20;
+const ITERATIONS: usize = 50_000;
+const IMAGE_DIMENSION: UVec2 = uvec2(600, 600);
+
+pub fn main() -> Result<()> {
+    let mut rng = Xoshiro256StarStar::from_seed([4u8; 32]);
+
+    let transforms = [
+        {
+            // F_0: (x / 2, y / 2)
+            let coefficients = Affine2::from_coefficients(0.5, 0.0, 0.0, 0.0, 0.5, 0.0);
+            Transform::new(coefficients, Affine2::IDENTITY, uvec2(0, 1), vec2(0.0, 1.0))
+        },
+        {
+            // F_1: ((x + 1) / 2, y / 2)
+            let coefficients = Affine2::from_coefficients(0.5, 0.0, 0.5, 0.0, 0.5, 0.0);
+            Transform::new(coefficients, Affine2::IDENTITY, uvec2(0, 1), vec2(0.0, 1.0))
+        },
+        {
+            // F_2: (x / 2, (y + 1) / 2)
+            let coefficients = Affine2::from_coefficients(0.5, 0.0, 0.0, 0.0, 0.5, 0.5);
+            Transform::new(coefficients, Affine2::IDENTITY, uvec2(0, 1), vec2(0.0, 1.0))
+        },
+    ];
+
+    let weights = [1.0 / 3.0, 1.0 / 3.0, 1.0 / 3.0];
+
+    let variations = [Variation::IDENTITY];
+
+    // The gasket is defined on the range [0, 1] for both X and Y
+    let camera = Camera::new(
+        IMAGE_DIMENSION,
+        Vec2::ONE * 0.5,
+        0.0,
+        Vec2::ZERO,
+        IMAGE_DIMENSION.as_vec2(),
+    );
+
+    let image_settings = ImageSettings::new(BlendMode::Linear, IMAGE_DIMENSION);
+
+    let mut image = GrayImage::new(IMAGE_DIMENSION.x, IMAGE_DIMENSION.y);
+
+    let chaos_game = ChaosGame::new(&mut rng, &transforms, &weights, &variations);
+
+    chaos_game
+        .skip(ITERATIONS_DISCARD)
+        .take(ITERATIONS)
+        .map(|(point_ifs, _)| camera.transform_point(point_ifs))
+        .filter_map(|point_pixel| image_settings.transform_point_to_image(point_pixel))
+        .for_each(|point_pixel| image.put_pixel(point_pixel.x, point_pixel.y, Luma([255])));
+
+    let temp = NamedTempFile::with_suffix(".png").context("Unable to create file for image")?;
+    image.save(temp.path()).context("Unable to save image")?;
+
+    let open_program: &str = cfg_select! {
+        unix => "xdg-open",
+        _ => panic!("No available program to open images")
+    };
+
+    Command::new(open_program)
+        .arg(temp.path())
+        .spawn()?
+        .wait()?;
+
+    // In case the image viewer forks and gives control back prior to reading the file,
+    // drop it and don't run the destructor
+    mem::forget(temp);
+
+    Ok(())
+}

enkou-shaders/src/camera.rs

@@ -12,7 +12,6 @@ use libm::powf;
 #[derive(Copy, Clone, Pod, Zeroable)]
 #[repr(C)]
 pub struct Camera {
-    dimensions: UVec2,
     transform: Affine2,
 }
 
@@ -23,7 +22,7 @@ impl Camera {
     /// to express the transform steps individually.
     ///
     /// # Arguments
-    ///
+    /// * `blend_mode` - Color blending mode for the output image
     /// * `dimensions` - Width and height of the output image (in pixels).
     /// * `center` - Location of the origin in IFS coordinates. Positive `x` shifts the image
     ///   left, and positive `y` position shifts the image up.
@@ -47,10 +46,7 @@ impl Camera {
             * zoom_transform
             * ifs_center_transform;
 
-        Camera {
-            dimensions,
-            transform,
-        }
+        Camera { transform }
     }
 
     /// Map a point from IFS coordinates to pixel coordinates.
@@ -73,40 +69,6 @@ impl Camera {
     pub fn transform_point(&self, point: Vec2) -> IVec2 {
         self.transform.transform_point2(point).as_ivec2()
     }
-
-    /// Map a point from IFS coordinates to pixel coordinates (like [`transform_point`](Camera::transform_point)),
-    /// and check that the result is within the provided image dimensions.
-    pub fn transform_point_to_image(&self, point: Vec2) -> Option<UVec2> {
-        let pixel_coordinates = self.transform_point(point);
-        if pixel_coordinates.x < 0
-            || pixel_coordinates.y < 0
-            || (pixel_coordinates.x as u32) >= self.dimensions.x
-            || (pixel_coordinates.y as u32) >= self.dimensions.y
-        {
-            None
-        } else {
-            Some(pixel_coordinates.as_uvec2())
-        }
-    }
-}
-
-/// Shader entry point for running the camera transformation over a list of IFS coordinates
-pub mod entry {
-    use crate::camera::Camera;
-    use spirv_std::glam::{IVec2, Vec2};
-    use spirv_std::spirv;
-
-    /// Transform IFS coordinates to pixel coordinates
-    #[spirv(compute(entry_point_name = "main_camera", threads(1)))]
-    pub fn main_camera(
-        #[spirv(storage_buffer, descriptor_set = 0, binding = 0)] camera: &Camera,
-        #[spirv(storage_buffer, descriptor_set = 0, binding = 1)] coordinates_ifs: &[Vec2],
-        #[spirv(storage_buffer, descriptor_set = 1, binding = 0)] coordinates_pixel: &mut [IVec2],
-    ) {
-        for i in 0..coordinates_ifs.len() {
-            coordinates_pixel[i] = camera.transform_point(coordinates_ifs[i])
-        }
-    }
 }
 
 #[cfg(test)]
@@ -116,7 +78,7 @@ mod test {
     use libm::powf;
 
     #[test]
-    pub fn manual_camera() {
+    fn manual_camera() {
         let starting_point = vec2(1.0, 1.0);
 
         // Move the origin; points move right and up by one unit, giving us (2.0, 2.0)
@@ -148,13 +110,14 @@ mod test {
 
         // The camera is implemented by composing affine transforms,
         // which ends up with a slightly different result because of rounding.
-        let error = camera.transform_point(starting_point) - point;
-        assert!(error.x.abs() <= 1);
-        assert!(error.y.abs() <= 1);
+        let error = (camera.transform_point(starting_point) - point)
+            .abs()
+            .as_uvec2();
+        assert!(error.x <= 1 && error.y <= 1);
     }
 
     #[test]
-    pub fn point_outside_camera() {
+    fn point_outside_camera() {
         // Scale 250 for an image 1000 x 1000 gives an effective range of [-2, 2]
         let camera = Camera::new(
             uvec2(1000, 1000),
@@ -169,7 +132,7 @@ mod test {
     }
 
     #[test]
-    pub fn point_outside_camera_negative() {
+    fn point_outside_camera_negative() {
         // Scale 250 for an image 1000 x 1000 gives an effective range of [-2, 2]
         let camera = Camera::new(
             uvec2(1000, 1000),
@@ -184,7 +147,7 @@ mod test {
     }
 
     #[test]
-    pub fn aspect_ratio() {
+    fn aspect_ratio() {
         // Scale 100 for an image 1600 x 900 gives an effective X range of [-8, 8],
         // and effective Y range of [-4.5, 4.5]
         let camera = Camera::new(

enkou-shaders/src/chaos_game.rs

@@ -12,7 +12,6 @@
 //!
 //! This algorithm is also known as the ["chaos game"](https://en.wikipedia.org/wiki/Chaos_game),
 //! and it forms the basic system for producing images.
-
 use crate::transform::Transform;
 use crate::variation::Variation;
 use rand::distr::{Distribution, StandardUniform};
@@ -36,11 +35,12 @@ impl Distribution<f32> for BiUnit {
 /// * `weights` - Weights are assumed to be normalized; adding all elements together should return the value 1
 pub fn step_chaos_game<R: Rng>(
     point: Vec2,
+    color: f32,
     rng: &mut R,
     transforms: &[Transform],
     weights: &[f32],
     variations: &[Variation],
-) -> (Vec2, u32) {
+) -> (Vec2, f32, u32) {
     let mut choice_weight = rng.sample::<f32, _>(StandardUniform);
     let mut transform_index: u32 = 0;
 
@@ -53,8 +53,11 @@ pub fn step_chaos_game<R: Rng>(
         transform_index += 1;
     }
 
+    let transform = transforms[transform_index as usize];
+
     (
-        transforms[transform_index as usize].transform_point(rng, variations, point),
+        transform.transform_point(rng, variations, point),
+        transform.transform_color(color),
         transform_index,
     )
 }
@@ -65,6 +68,7 @@ pub fn step_chaos_game<R: Rng>(
 /// New points in the chaos game are produced by iterating on the chaos game.
 pub struct ChaosGame<'a, R: Rng> {
     current_point: Vec2,
+    current_color: f32,
     rng: &'a mut R,
     transforms: &'a [Transform],
     weights: &'a [f32],
@@ -80,8 +84,10 @@ impl<'a, R: Rng> ChaosGame<'a, R> {
         variations: &'a [Variation],
     ) -> Self {
         let current_point = vec2(rng.sample(BiUnit), rng.sample(BiUnit));
+        let current_color = rng.sample(StandardUniform);
         ChaosGame {
             current_point,
+            current_color,
             rng,
             transforms,
             weights,
@@ -91,18 +97,20 @@ impl<'a, R: Rng> ChaosGame<'a, R> {
 }
 
 impl<'a, R: Rng> Iterator for ChaosGame<'a, R> {
-    type Item = Vec2;
+    type Item = (Vec2, f32);
 
     fn next(&mut self) -> Option<Self::Item> {
-        let (next_point, _) = step_chaos_game(
+        let (next_point, next_color, _) = step_chaos_game(
             self.current_point,
+            self.current_color,
             self.rng,
             self.transforms,
             self.weights,
             self.variations,
         );
         self.current_point = next_point;
+        self.current_color = next_color;
 
-        Some(next_point)
+        Some((next_point, next_color))
     }
 }

enkou-shaders/src/entry/image_accumulate.rs

@@ -0,0 +1,63 @@
+//! Image Accumulate
+
+use crate::camera::Camera;
+use crate::chaos_game::ChaosGame;
+use crate::image::ImageSettings;
+use crate::rng::xoshiro256starstar_from_seed;
+use crate::transform::Transform;
+use crate::variation::Variation;
+use glam::{UVec2, Vec4};
+use spirv_std::spirv;
+
+/// Run the chaos game and accumulate points into the output image buffer
+///
+/// # Arguments
+/// * `iterations` - Controls the iteration count; the first `x` iterations are discarded,
+///   the next `y` iterations are accumulated into the output image
+/// * `rng_seed`
+/// * `transforms`
+/// * `weights`
+/// * `variations`
+/// * `camera` - Camera transformation to map IFS coordinates to pixel coordinates
+/// * `image_settings` - Settings to use for image accumulation
+/// * `palette` - List of colors to use for the image palette; assumed to be RGB values scaled to `[0-255]`, with an alpha of 255
+/// * `image` - Output image buffer
+#[spirv(compute(entry_point_name = "main_image_accumulate", threads(1)))]
+pub fn main_image_accumulate(
+    #[spirv(storage_buffer, descriptor_set = 0, binding = 0)] iterations: &UVec2,
+    #[spirv(storage_buffer, descriptor_set = 0, binding = 1)] rng_seed: &[u8],
+    #[spirv(storage_buffer, descriptor_set = 0, binding = 2)] transforms: &[Transform],
+    #[spirv(storage_buffer, descriptor_set = 0, binding = 3)] weights: &[f32],
+    #[spirv(storage_buffer, descriptor_set = 0, binding = 4)] variations: &[Variation],
+    #[spirv(storage_buffer, descriptor_set = 0, binding = 5)] camera: &Camera,
+    #[spirv(storage_buffer, descriptor_set = 0, binding = 6)] image_settings: &ImageSettings,
+    #[spirv(storage_buffer, descriptor_set = 0, binding = 7)] palette: &[Vec4],
+    #[spirv(storage_buffer, descriptor_set = 1, binding = 0)] image: &mut [Vec4],
+) {
+    let mut rng_seed_actual = [0u8; 32];
+    for i in 0..rng_seed_actual.len() {
+        rng_seed_actual[i] = rng_seed[i];
+    }
+
+    let mut rng = xoshiro256starstar_from_seed(rng_seed_actual);
+
+    let chaos_game = ChaosGame::new(&mut rng, transforms, weights, variations);
+    let (iterations_fuse, iterations_accumulate) = (iterations.x, iterations.y);
+
+    let ifs_to_image = |(ifs_point, ifs_color)| {
+        let pixel_coordinates = camera.transform_point(ifs_point);
+        let pixel_color = image_settings.transform_color(ifs_color, palette);
+        image_settings
+            .transform_point_to_index(pixel_coordinates)
+            .map(|pixel_index| (pixel_index, pixel_color))
+    };
+
+    for ifs_point in chaos_game
+        .skip(iterations_fuse as usize)
+        .take(iterations_accumulate as usize)
+    {
+        if let Some((pixel_index, pixel_color)) = ifs_to_image(ifs_point) {
+            image[pixel_index as usize] = pixel_color;
+        }
+    }
+}

enkou-shaders/src/entry/mod.rs

@@ -0,0 +1,4 @@
+//! # Entry
+//!
+//! Entry points for Enkou shaders
+pub mod image_accumulate;

enkou-shaders/src/image.rs

@@ -0,0 +1,155 @@
+//! Image
+
+use bytemuck::{Pod, Zeroable};
+use glam::{IVec2, UVec2, Vec4};
+use libm::floorf;
+
+/// Blending modes for mapping IFS color values (which are on a scale `[0, 1]`)
+/// to RGBA colors.
+#[derive(Copy, Clone, Default)]
+#[repr(u32)]
+pub enum BlendMode {
+    /// Map IFS color values to a linear blend of the nearest two palette colors
+    #[default]
+    Linear = 0,
+
+    /// Map IFS color values to the nearest single palette color
+    Step = 1,
+}
+
+impl BlendMode {
+    /// Map an IFS color value to RGBA color from the provided palette.
+    pub fn ifs_to_rgb(&self, color: f32, palette: &[Vec4]) -> Vec4 {
+        let colors_m_one = palette.len() - 1;
+        let period = 1.0 / colors_m_one as f32;
+        let index_lower = floorf(color / period) as usize;
+        let index_upper = (index_lower + 1).clamp(0, colors_m_one);
+        let rem = color % period / period;
+
+        match self {
+            BlendMode::Linear => palette[index_lower].lerp(palette[index_upper], rem),
+            BlendMode::Step => palette[index_lower],
+        }
+    }
+}
+
+// UNSAFE: Sound because enum has guaranteed layout (u32) and defined zero-value
+unsafe impl bytemuck::Zeroable for BlendMode {}
+// UNSAFE: Sound because enum has guaranteed layout (u32) and defined zero-value
+unsafe impl bytemuck::Pod for BlendMode {}
+
+/// Settings to use for mapping the IFS coordinates to an output image
+#[derive(Copy, Clone, Pod, Zeroable)]
+#[repr(C)]
+pub struct ImageSettings {
+    blend_mode: BlendMode,
+    dimensions: UVec2,
+}
+
+impl ImageSettings {
+    /// Create a new settings object
+    pub fn new(blend_mode: BlendMode, dimensions: UVec2) -> Self {
+        ImageSettings {
+            blend_mode,
+            dimensions,
+        }
+    }
+
+    /// Map a point from camera coordinates to pixel coordinates,
+    /// and check that the result is within the provided image dimensions.
+    pub fn transform_point_to_image(&self, point: IVec2) -> Option<UVec2> {
+        if 0 <= point.x
+            && (point.x as u32) < self.dimensions.x
+            && 0 <= point.y
+            && (point.y as u32) < self.dimensions.y
+        {
+            Some(point.as_uvec2())
+        } else {
+            None
+        }
+    }
+
+    /// Map a point from camera coordinates to a final pixel index
+    pub fn transform_point_to_index(&self, point: IVec2) -> Option<u32> {
+        self.transform_point_to_image(point)
+            .map(|pixel| self.dimensions.with_x(1).dot(pixel))
+    }
+
+    /// Map an IFS color coordinate to the palette RGB value
+    pub fn transform_color(&self, color: f32, palette: &[Vec4]) -> Vec4 {
+        self.blend_mode.ifs_to_rgb(color, palette)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::image::{BlendMode, ImageSettings};
+    use glam::{Vec4, ivec2, uvec2};
+
+    #[test]
+    fn blend_linear() {
+        let ifs_to_rgb = |color, palette| BlendMode::Linear.ifs_to_rgb(color, palette);
+
+        let palette = &[Vec4::splat(0.0), Vec4::splat(1.0)];
+        assert_eq!(ifs_to_rgb(0.0, palette), Vec4::splat(0.0));
+        assert_eq!(ifs_to_rgb(0.5, palette), Vec4::splat(0.5));
+        assert_eq!(ifs_to_rgb(1.0, palette), Vec4::splat(1.0));
+
+        let palette = &[Vec4::splat(1.0), Vec4::splat(2.0), Vec4::splat(3.0)];
+        assert_eq!(ifs_to_rgb(0.0, palette), Vec4::splat(1.0));
+        assert_eq!(ifs_to_rgb(0.5, palette), Vec4::splat(2.0));
+        assert_eq!(ifs_to_rgb(1.0, palette), Vec4::splat(3.0));
+
+        let palette = &[
+            Vec4::splat(1.0),
+            Vec4::splat(2.0),
+            Vec4::splat(3.0),
+            Vec4::splat(4.0),
+        ];
+        assert_eq!(ifs_to_rgb(0.0, palette), Vec4::splat(1.0));
+        assert_eq!(ifs_to_rgb(0.5, palette), Vec4::splat(2.5));
+        assert_eq!(ifs_to_rgb(1.0, palette), Vec4::splat(4.0));
+    }
+
+    #[test]
+    fn blend_step() {
+        let ifs_to_rgb = |color, palette| BlendMode::Step.ifs_to_rgb(color, palette);
+
+        let palette = &[Vec4::splat(0.0), Vec4::splat(1.0)];
+        assert_eq!(ifs_to_rgb(0.5, palette), Vec4::splat(0.0));
+
+        let palette = &[Vec4::splat(1.0), Vec4::splat(2.0), Vec4::splat(3.0)];
+        assert_eq!(ifs_to_rgb(0.0, palette), palette[0]);
+        assert_eq!(ifs_to_rgb(0.25, palette), palette[0]);
+        assert_eq!(ifs_to_rgb(0.4, palette), palette[0]);
+        assert_eq!(ifs_to_rgb(0.5, palette), palette[1]);
+        assert_eq!(ifs_to_rgb(0.7, palette), palette[1]);
+        assert_eq!(ifs_to_rgb(1.0, palette), palette[2]);
+    }
+
+    #[test]
+    fn image_bounds() {
+        let image_settings = ImageSettings::new(BlendMode::Linear, uvec2(100, 100));
+
+        assert!(
+            image_settings
+                .transform_point_to_image(ivec2(-1, -1))
+                .is_none()
+        );
+        assert!(
+            image_settings
+                .transform_point_to_image(ivec2(0, 0))
+                .is_some()
+        );
+        assert!(
+            image_settings
+                .transform_point_to_image(ivec2(99, 99))
+                .is_some()
+        );
+        assert!(
+            image_settings
+                .transform_point_to_image(ivec2(100, 100))
+                .is_none()
+        );
+    }
+}

enkou-shaders/src/lib.rs

@@ -1,12 +1,17 @@
 //! # Enkou
-#![cfg_attr(target_arch = "spirv", no_std)]
-
-// SPIR-V backend is unable to compile iteration over items
+#![no_std]
+#![warn(missing_docs)]
+// SPIR-V backend has issues with iteration over items:
 #![allow(clippy::needless_range_loop)]
+#![allow(clippy::manual_memcpy)]
+// Shader entry points are expected to have a lot of arguments:
+#![allow(clippy::too_many_arguments)]
 
 pub mod camera;
 pub mod chaos_game;
-pub mod rng;
+pub mod entry;
+pub mod image;
+mod rng;
 pub mod transform;
 pub mod variation;
 

enkou-shaders/src/rng.rs

@@ -1,6 +1,3 @@
-//! # RNG
-//!
-//! Random number generation utilities for shaders
 use rand::SeedableRng;
 use rand_xoshiro::Xoshiro256StarStar;
 
@@ -17,7 +14,9 @@ use rand_xoshiro::Xoshiro256StarStar;
 /// This function assumes a properly-initialized state array;
 /// output may silently degenerate if the initial state is all zeros,
 /// so this module is private to the crate.
-pub fn xoshiro256starstar_from_seed(
+// Temporarily unused, will be required once the main image accumulation entry point is implemented
+#[allow(unused)]
+pub(crate) fn xoshiro256starstar_from_seed(
     rng_state: <Xoshiro256StarStar as SeedableRng>::Seed,
 ) -> Xoshiro256StarStar {
     let mut rng_state_actual = [0u64; 4];

enkou-shaders/src/transform.rs

@@ -5,7 +5,7 @@
 //! but produce more interesting images once we add variations.
 use crate::variation::Variation;
 use bytemuck::{Pod, Zeroable};
-use glam::{Affine2, UVec2, Vec2};
+use glam::{Affine2, FloatExt, UVec2, Vec2};
 use rand::Rng;
 
 /// Affine transform for use in the [`chaos_game`](crate::chaos_game).
@@ -15,15 +15,22 @@ pub struct Transform {
     coefficients: Affine2,
     coefficients_post: Affine2,
     variation_range: UVec2,
+    color: Vec2,
 }
 
 impl Transform {
     /// Create a new transform from an affine transformation matrix
-    pub fn new(coefficients: Affine2, coefficients_post: Affine2, variation_range: UVec2) -> Self {
+    pub fn new(
+        coefficients: Affine2,
+        coefficients_post: Affine2,
+        variation_range: UVec2,
+        color: Vec2,
+    ) -> Self {
         Transform {
             coefficients,
             coefficients_post,
             variation_range,
+            color,
         }
     }
 
@@ -47,6 +54,11 @@ impl Transform {
 
         self.coefficients_post.transform_point2(point)
     }
+
+    /// Apply this transform to a color
+    pub fn transform_color(&self, color: f32) -> f32 {
+        color.lerp(self.color.x, self.color.y)
+    }
 }
 
 #[cfg(test)]
@@ -54,7 +66,7 @@ mod test {
     use crate::rng::xoshiro256starstar_from_seed;
     use crate::transform::Transform;
     use crate::variation::{Variation, VariationKind};
-    use glam::{Affine2, uvec2, vec2};
+    use glam::{Affine2, Vec2, uvec2, vec2};
 
     #[test]
     fn transform_scaling() {
@@ -63,6 +75,7 @@ mod test {
             Affine2::from_scale(scale_coefficients),
             Affine2::IDENTITY,
             uvec2(0, 1),
+            Vec2::ZERO,
         );
 
         let mut rng = xoshiro256starstar_from_seed([0; 32]);
@@ -78,11 +91,17 @@ mod test {
     #[test]
     fn transform_scaling_post() {
         let scale_coefficients = vec2(2.0, 0.5);
-        let transform_pdj = Transform::new(Affine2::IDENTITY, Affine2::IDENTITY, uvec2(0, 1));
+        let transform_pdj = Transform::new(
+            Affine2::IDENTITY,
+            Affine2::IDENTITY,
+            uvec2(0, 1),
+            Vec2::ZERO,
+        );
         let transform_pdj_post = Transform::new(
             Affine2::IDENTITY,
             Affine2::from_scale(scale_coefficients),
             uvec2(0, 1),
+            Vec2::ZERO,
         );
 
         let mut rng = xoshiro256starstar_from_seed([0; 32]);
@@ -94,4 +113,23 @@ mod test {
 
         assert_eq!(point_pdj * scale_coefficients, point_pdj_post);
     }
+
+    #[test]
+    fn transform_color() {
+        // Color 0.5, color speed 1.0, so color value will always be 0.5 after transform
+        let color = vec2(0.5, 1.0);
+        let transform = Transform::new(Affine2::IDENTITY, Affine2::IDENTITY, uvec2(0, 1), color);
+
+        assert_eq!(transform.transform_color(0.0), 0.5);
+        assert_eq!(transform.transform_color(1.0), 0.5);
+        assert_eq!(transform.transform_color(2.0), 0.5);
+
+        // Color 1.0, color speed 0.5, so color value moves to halfway between current and 1.0
+        let color = vec2(1.0, 0.5);
+        let transform = Transform::new(Affine2::IDENTITY, Affine2::IDENTITY, uvec2(0, 1), color);
+
+        assert_eq!(transform.transform_color(0.0), 0.5);
+        assert_eq!(transform.transform_color(1.0), 1.0);
+        assert_eq!(transform.transform_color(2.0), 1.5);
+    }
 }

enkou-shaders/src/variation.rs

@@ -68,7 +68,7 @@ impl Variation {
     };
 
     /// Create a new variation by providing the variation kind, weight, and parameters.
-    pub const fn new(kind: VariationKind, weight: f32, params: VariationParams) -> Variation {
+    pub fn new(kind: VariationKind, weight: f32, params: VariationParams) -> Variation {
         Variation {
             kind,
             weight,

examples/image-binary/src/lib.rs

@@ -1,82 +0,0 @@
-//! # Binary image
-#![cfg_attr(target_arch = "spirv", no_std)]
-use enkou_shaders::camera::Camera;
-use enkou_shaders::chaos_game::ChaosGame;
-use enkou_shaders::rng::xoshiro256starstar_from_seed;
-use enkou_shaders::transform::Transform;
-use enkou_shaders::variation::Variation;
-use glam::{UVec2, UVec4};
-use spirv_std::spirv;
-
-#[cfg(feature = "wgpu")]
-pub use wgpu::*;
-
-const IMAGE_QUALITY: f32 = 1.0;
-const ITERATIONS_FUSE: u32 = 20;
-
-/// Sierpinski Gasket
-#[spirv(compute(entry_point_name = "main_image_binary", threads(1)))]
-pub fn main_image_binary(
-    #[spirv(storage_buffer, descriptor_set = 0, binding = 0)] image_dimensions: &UVec2,
-    #[spirv(storage_buffer, descriptor_set = 0, binding = 1)] transforms: &[Transform],
-    #[spirv(storage_buffer, descriptor_set = 0, binding = 2)] weights: &[f32],
-    #[spirv(storage_buffer, descriptor_set = 0, binding = 3)] variations: &[Variation],
-    #[spirv(storage_buffer, descriptor_set = 0, binding = 4)] camera: &Camera,
-    #[spirv(storage_buffer, descriptor_set = 0, binding = 5)] image_buffer: &mut [UVec4],
-) {
-    // Initialize RNG and run the chaos game
-    let mut rng = xoshiro256starstar_from_seed([4; 32]);
-    let mut chaos_game = ChaosGame::new(&mut rng, transforms, weights, variations);
-
-    // Discard the first few iterations
-    for _ in 0..ITERATIONS_FUSE {
-        chaos_game.next().unwrap();
-    }
-
-    // Plot the remaining points generated by the chaos game
-    let iterations = (image_dimensions.as_vec2().element_product() * IMAGE_QUALITY) as u32;
-    for _ in 0..iterations {
-        let ifs_point = chaos_game.next().unwrap();
-        let pixel_point = camera.transform_point_to_image(ifs_point);
-
-        if let Some(pixel_point) = pixel_point {
-            let pixel_index = pixel_point.y * image_dimensions.x + pixel_point.x;
-            image_buffer[pixel_index as usize] = UVec4::splat(255);
-        }
-    }
-}
-
-#[cfg(feature = "wgpu")]
-pub mod wgpu {
-    const fn bgle(binding: u32, read_only: bool) -> wgpu::BindGroupLayoutEntry {
-        wgpu::BindGroupLayoutEntry {
-            binding,
-            visibility: wgpu::ShaderStages::COMPUTE,
-            ty: wgpu::BindingType::Buffer {
-                ty: wgpu::BufferBindingType::Storage { read_only },
-                has_dynamic_offset: false,
-                min_binding_size: None,
-            },
-            count: None,
-        }
-    }
-
-    pub const BGLE_IMAGE_DIMENSIONS: wgpu::BindGroupLayoutEntry = bgle(0, true);
-    pub const BGLE_TRANSFORMS: wgpu::BindGroupLayoutEntry = bgle(1, true);
-    pub const BGLE_WEIGHTS: wgpu::BindGroupLayoutEntry = bgle(2, true);
-    pub const BGLE_VARIATIONS: wgpu::BindGroupLayoutEntry = bgle(3, true);
-    pub const BGLE_CAMERA: wgpu::BindGroupLayoutEntry = bgle(4, true);
-    pub const BGLE_IMAGE_BUFFER: wgpu::BindGroupLayoutEntry = bgle(5, false);
-
-    pub const BIND_GROUP_IMAGE_BINARY: wgpu::BindGroupLayoutDescriptor = wgpu::BindGroupLayoutDescriptor {
-        label: Some("main_image_binary"),
-        entries: &[
-            BGLE_IMAGE_DIMENSIONS,
-            BGLE_TRANSFORMS,
-            BGLE_WEIGHTS,
-            BGLE_VARIATIONS,
-            BGLE_CAMERA,
-            BGLE_IMAGE_BUFFER,
-        ],
-    };
-}

examples/image-runner/Cargo.toml

@@ -1,27 +0,0 @@
-[package]
-name = "image-runner"
-version.workspace = true
-authors.workspace = true
-edition.workspace = true
-license.workspace = true
-repository.workspace = true
-
-[dependencies]
-enkou-shaders = { path = "../../enkou-shaders" }
-image-binary = { path = "../image-binary", features = ["wgpu"] }
-
-anyhow.workspace = true
-bytemuck.workspace = true
-futures.workspace = true
-glam = { workspace = true, features = ["u8"] }
-image.workspace = true
-tempfile.workspace = true
-wgpu.workspace = true
-xflags.workspace = true
-
-[build-dependencies]
-anyhow.workspace = true
-cargo-gpu-install.workspace = true
-
-[lints]
-workspace = true

examples/image-runner/src/image_binary.rs

@@ -1,210 +0,0 @@
-use enkou_shaders::Coefficients2;
-use enkou_shaders::transform::Transform;
-use enkou_shaders::variation::Variation;
-use futures::channel::oneshot;
-use futures::executor::block_on;
-use glam::{uvec2, Affine2, UVec2, UVec4, Vec2};
-use image::{Rgba, RgbaImage};
-use image_binary::{main_image_binary, BIND_GROUP_IMAGE_BINARY, BGLE_IMAGE_DIMENSIONS, BGLE_TRANSFORMS, BGLE_WEIGHTS, BGLE_CAMERA, BGLE_IMAGE_BUFFER, BGLE_VARIATIONS};
-use std::path::Path;
-use wgpu::util::DeviceExt;
-use enkou_shaders::camera::Camera;
-
-fn transforms() -> [Transform; 3] {
-    [
-        {
-            // F_0: (x / 2, y / 2)
-            let coefficients = Affine2::from_coefficients(0.5, 0.0, 0.0, 0.0, 0.5, 0.0);
-            Transform::new(coefficients, Affine2::IDENTITY, uvec2(0, 1))
-        },
-        {
-            // F_1: ((x + 1) / 2, y / 2)
-            let coefficients = Affine2::from_coefficients(0.5, 0.0, 0.5, 0.0, 0.5, 0.0);
-            Transform::new(coefficients, Affine2::IDENTITY, uvec2(0, 1))
-        },
-        {
-            // F_2: (x / 2, (y + 1) / 2)
-            let coefficients = Affine2::from_coefficients(0.5, 0.0, 0.0, 0.0, 0.5, 0.5);
-            Transform::new(coefficients, Affine2::IDENTITY, uvec2(0, 1))
-        },
-    ]
-}
-
-fn weights() -> [f32; 3] {
-    [1.0 / 3.0; 3]
-}
-
-fn variations() -> [Variation; 1] {
-    [Variation::IDENTITY]
-}
-
-fn camera(image_dimensions: UVec2) -> Camera {
-    Camera::new(
-        image_dimensions,
-        Vec2::ONE * 0.5,
-        0.0,
-        Vec2::ZERO,
-        Vec2::splat(image_dimensions.min_element() as f32),
-    )
-}
-
-pub(crate) fn main_cpu(image_dimensions: UVec2, output_path: &Path) -> Result<(), anyhow::Error> {
-    let mut image_buffer = Vec::<UVec4>::new();
-    image_buffer.resize(image_dimensions.element_product() as usize, UVec4::ZERO);
-
-    main_image_binary(
-        &image_dimensions,
-        &transforms(),
-        &weights(),
-        &variations(),
-        &camera(image_dimensions),
-        &mut image_buffer,
-    );
-
-    let mut image = RgbaImage::new(image_dimensions.x, image_dimensions.y);
-    for (i, color) in image_buffer.into_iter().enumerate() {
-        let image_x = i as u32 % image_dimensions.x;
-        let image_y = i as u32 / image_dimensions.x;
-
-        image.put_pixel(image_x, image_y, color.as_u8vec4().to_array().into());
-    }
-
-    image.save(output_path)?;
-    Ok(())
-}
-
-const SHADER_MODULE: wgpu::ShaderModuleDescriptor = wgpu::include_spirv!(env!("SHADER_SPV_PATH_IMAGE_BINARY"));
-
-fn bge<'a>(entry: &'a wgpu::BindGroupLayoutEntry, buffer: &'a wgpu::Buffer) -> wgpu::BindGroupEntry<'a> {
-    wgpu::BindGroupEntry {
-        binding: entry.binding,
-        resource: buffer.as_entire_binding(),
-    }
-}
-
-pub(crate) fn main_gpu(device: &wgpu::Device, queue: &wgpu::Queue, image_dimensions: UVec2, output_path: &Path) -> Result<(), anyhow::Error> {
-
-    let bind_group_layout = device.create_bind_group_layout(&BIND_GROUP_IMAGE_BINARY);
-
-    let image_dimensions_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
-        label: Some("image_dimensions"),
-        contents: bytemuck::bytes_of(&image_dimensions),
-        usage: wgpu::BufferUsages::COPY_DST | wgpu::BufferUsages::STORAGE,
-    });
-
-    let transforms_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
-        label: Some("transforms"),
-        contents: bytemuck::cast_slice(&transforms()),
-        usage: wgpu::BufferUsages::COPY_DST | wgpu::BufferUsages::STORAGE,
-    });
-
-    let weights_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
-        label: Some("weights"),
-        contents: bytemuck::cast_slice(&weights()),
-        usage: wgpu::BufferUsages::COPY_DST | wgpu::BufferUsages::STORAGE,
-    });
-
-    let variations_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
-        label: Some("variations"),
-        contents: bytemuck::cast_slice(&variations()),
-        usage: wgpu::BufferUsages::COPY_DST | wgpu::BufferUsages::STORAGE,
-    });
-
-    let camera_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
-        label: Some("camera"),
-        contents: bytemuck::bytes_of(&camera(image_dimensions)),
-        usage: wgpu::BufferUsages::COPY_DST | wgpu::BufferUsages::STORAGE,
-    });
-
-    let image_buffer_elements = image_dimensions.element_product() as u64;
-    let image_buffer_size = image_buffer_elements * size_of::<UVec4>() as u64;
-    let image_buffer = device.create_buffer(&wgpu::BufferDescriptor {
-        label: Some("image_buffer"),
-        size: image_buffer_size,
-        usage: wgpu::BufferUsages::COPY_SRC | wgpu::BufferUsages::STORAGE,
-        mapped_at_creation: false,
-    });
-
-    let image_staging = device.create_buffer(&wgpu::BufferDescriptor {
-        label: Some("image_buffer_staging"),
-        size: image_buffer_size,
-        usage: wgpu::BufferUsages::MAP_READ | wgpu::BufferUsages::COPY_DST,
-        mapped_at_creation: false,
-    });
-
-    let bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
-        label: Some("main_image_binary"),
-        layout: &bind_group_layout,
-        entries: &[
-            bge(&BGLE_IMAGE_DIMENSIONS, &image_dimensions_buffer),
-            bge(&BGLE_TRANSFORMS, &transforms_buffer),
-            bge(&BGLE_WEIGHTS, &weights_buffer),
-            bge(&BGLE_VARIATIONS, &variations_buffer),
-            bge(&BGLE_CAMERA, &camera_buffer),
-            bge(&BGLE_IMAGE_BUFFER, &image_buffer),
-        ],
-    });
-
-    let layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
-        label: Some("main_image_binary"),
-        bind_group_layouts: &[Some(&bind_group_layout)],
-        immediate_size: 0,
-    });
-
-    let module = device.create_shader_module(SHADER_MODULE);
-
-    let compute_pipeline = device.create_compute_pipeline(&wgpu::ComputePipelineDescriptor {
-        label: Some("main_image_binary"),
-        layout: Some(&layout),
-        module: &module,
-        entry_point: Some("main_image_binary"),
-        compilation_options: Default::default(),
-        cache: None,
-    });
-
-    let mut encoder = device.create_command_encoder(&wgpu::CommandEncoderDescriptor {
-        label: Some("main_image_binary"),
-    });
-
-    {
-        let mut compute_pass = encoder.begin_compute_pass(&wgpu::ComputePassDescriptor {
-            label: Some("main_image_binary"),
-            timestamp_writes: None,
-        });
-
-        compute_pass.set_pipeline(&compute_pipeline);
-        compute_pass.set_bind_group(0, &bind_group, &[]);
-    }
-
-    encoder.copy_buffer_to_buffer(&image_buffer, 0, &image_staging, 0, Some(image_buffer_size));
-
-    let (sender, receiver) = oneshot::channel();
-    let image_staging_capturable = image_staging.clone();
-    encoder.map_buffer_on_submit(&image_buffer, wgpu::MapMode::Read, .., move |result| {
-        result.expect("unable to map buffer");
-
-        let staging_buffer_view = image_staging_capturable.get_mapped_range(..).expect("Unable to map staging buffer");
-
-        let mut image = RgbaImage::new(image_dimensions.x, image_dimensions.y);
-        let image_buffer_elements = bytemuck::cast_slice::<u8, UVec4>(staging_buffer_view.as_ref());
-        for (i, element) in image_buffer_elements.iter().enumerate() {
-            let image_x = i as u32 % image_dimensions.x;
-            let image_y = i as u32 / image_dimensions.x;
-
-            let pixel_colors = element.as_u8vec4();
-            image.put_pixel(image_x, image_y, Rgba(*pixel_colors.as_ref()))
-        }
-
-        sender.send(image).expect("Unable to send image");
-    });
-
-    queue.submit(Some(encoder.finish()));
-    device.poll(wgpu::PollType::wait_indefinitely())?;
-    let image = block_on(receiver)?;
-
-    image_staging.unmap();
-
-    image.save(output_path)?;
-
-    Ok(())
-}

examples/image-runner/src/main.rs

@@ -1,77 +0,0 @@
-use glam::{uvec2};
-use std::mem;
-use std::process::Command;
-use std::path::PathBuf;
-use futures::executor::block_on;
-use tempfile::NamedTempFile;
-
-mod image_binary;
-
-fn main() -> Result<(), anyhow::Error> {
-    let instance_future = wgpu::util::new_instance_with_webgpu_detection(wgpu::InstanceDescriptor {
-        backends: Default::default(),
-        flags: Default::default(),
-        memory_budget_thresholds: Default::default(),
-        backend_options: Default::default(),
-        display: None,
-    });
-    let instance = block_on(instance_future);
-
-    let adapter_future = instance.request_adapter(&wgpu::RequestAdapterOptions {
-        power_preference: Default::default(),
-        force_fallback_adapter: false,
-        compatible_surface: None,
-        apply_limit_buckets: false,
-    });
-    let adapter = block_on(adapter_future)?;
-
-    let device_future = adapter.request_device(&wgpu::DeviceDescriptor {
-        label: Some("image-runner"),
-        required_features: Default::default(),
-        required_limits: Default::default(),
-        experimental_features: Default::default(),
-        memory_hints: Default::default(),
-        trace: Default::default(),
-    });
-    let (device, queue) = block_on(device_future)?;
-
-    let flags = xflags::parse_or_exit! {
-        /// Image dimensions to output, as `width,height`
-        optional -d, --dimensions dimensions: String
-
-        /// Output pathname to use
-        optional -o, --output output: PathBuf
-
-        /// Image type to generate
-        required image: String
-    };
-
-    let dimensions = if let Some(dimensions) = flags.dimensions {
-        let (width_str, height_str) = dimensions.split_once(",").ok_or(anyhow::anyhow!("Invalid format for image dimensions"))?;
-        uvec2(width_str.parse()?, height_str.parse()?)
-    } else {
-        uvec2(1600, 900)
-    };
-
-    let output = if let Some(output) = flags.output { output } else {
-        let path = NamedTempFile::with_suffix(".png")?;
-        let pathbuf: PathBuf = path.path().into();
-        mem::forget(path);
-        pathbuf
-    };
-
-    match flags.image.as_ref() {
-        "binary_cpu" => image_binary::main_cpu(dimensions, output.as_ref()),
-        "binary_gpu" => image_binary::main_gpu(&device, &queue, dimensions, output.as_ref()),
-        _ => Err(anyhow::anyhow!("Unrecognized image type"))
-    }?;
-
-    let mut command = cfg_select! {
-        unix => Command::new("xdg-open").arg(temp.path()).spawn(),
-        windows => Command::new("PowerShell").arg("-Command").arg(format!("start {}", output.display())).spawn(),
-        _ => Err(anyhow::anyhow!("No available program to open images"))?
-    }?;
-    command.wait()?;
-
-    Ok(())
-}