some basic operations

.gitignore

@@ -1,2 +1,3 @@
 /target
 /.direnv
+*.png

Cargo.lock

@@ -2,6 +2,84 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "adler2"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
+
+[[package]]
+name = "bitflags"
+version = "2.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "812e12b5285cc515a9c72a5c1d3b6d46a19dac5acfef5265968c166106e31dd3"
+
+[[package]]
+name = "cfg-if"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
+
+[[package]]
+name = "crc32fast"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9481c1c90cbf2ac953f07c8d4a58aa3945c425b7185c9154d67a65e4230da511"
+dependencies = [
+ "cfg-if",
+]
+
+[[package]]
+name = "fdeflate"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e6853b52649d4ac5c0bd02320cddc5ba956bdb407c4b75a2c6b75bf51500f8c"
+dependencies = [
+ "simd-adler32",
+]
+
+[[package]]
+name = "flate2"
+version = "1.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "843fba2746e448b37e26a819579957415c8cef339bf08564fe8b7ddbd959573c"
+dependencies = [
+ "crc32fast",
+ "miniz_oxide",
+]
+
 [[package]]
 name = "imgsyn"
 version = "0.1.0"
+dependencies = [
+ "png",
+]
+
+[[package]]
+name = "miniz_oxide"
+version = "0.8.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fa76a2c86f704bdb222d66965fb3d63269ce38518b83cb0575fca855ebb6316"
+dependencies = [
+ "adler2",
+ "simd-adler32",
+]
+
+[[package]]
+name = "png"
+version = "0.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97baced388464909d42d89643fe4361939af9b7ce7a31ee32a168f832a70f2a0"
+dependencies = [
+ "bitflags",
+ "crc32fast",
+ "fdeflate",
+ "flate2",
+ "miniz_oxide",
+]
+
+[[package]]
+name = "simd-adler32"
+version = "0.3.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e320a6c5ad31d271ad523dcf3ad13e2767ad8b1cb8f047f75a8aeaf8da139da2"

Cargo.toml

@@ -4,3 +4,4 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+png = "0.18.0"

shell.nix

@@ -8,5 +8,6 @@ pkgs.mkShell {
     ffmpeg
     imagemagick
     rust-analyzer
+    cargo-watch
   ];
 }

src/assist.rs

@@ -0,0 +1,25 @@
+use std::f32::consts::*;
+
+use crate::Canvas;
+
+pub fn polar(x: f32, y: f32, meta: Canvas) -> (f32, f32) {
+    let x = x - 0.5;
+    let y = y - 0.5;
+    let r = (x * x + y * y).sqrt();
+    let mut phi = f32::atan2(y, x) + PI / 2.;
+    phi = phi.rem_euclid(TAU);
+    (r * 2. / corner_distance(meta), phi / TAU)
+}
+
+pub fn axial(r: f32, phi: f32, meta: Canvas) -> (f32, f32) {
+    let phi = phi * TAU - PI / 2.;
+    let r = r / 2. * corner_distance(meta);
+    let x = r * phi.cos();
+    let y = r * phi.sin();
+    (x + 0.5, y + 0.5)
+}
+
+fn corner_distance(meta: Canvas) -> f32 {
+    let corner_distance = (meta.width * meta.width + meta.height * meta.height).sqrt();
+    corner_distance / meta.width.max(meta.height)
+}

src/canvas.rs

@@ -2,19 +2,18 @@ use crate::{ImgSyn, pixel::Pixel};
 
 #[derive(Clone, Copy, PartialEq)]
 pub struct Canvas {
-    pub width: u32,
-    pub height: u32,
+    pub width: f32,
+    pub height: f32,
     pub default_px: Pixel,
 }
 
 #[derive(Clone, PartialEq)]
 pub struct PaintedCanvas {
-    pub meta: Canvas,
     pub array: Vec<Vec<Pixel>>,
 }
 
 impl Canvas {
-    pub fn new(width: u32, height: u32, default_px: Pixel) -> Self {
+    pub fn new(width: f32, height: f32, default_px: Pixel) -> Self {
         Self {
             width,
             height,
@@ -32,25 +31,34 @@ impl ImgSyn for Canvas {
 impl PaintedCanvas {
     pub fn new(meta @ Canvas { width, height, .. }: Canvas, function: impl ImgSyn) -> Self {
         Self {
-            meta,
-            array: (0..width)
-                .map(|x| x as f32 / width as f32)
-                .map(|x| {
-                    (0..height)
-                        .map(|y| y as f32 / height as f32)
-                        .map(|y| function.getpx(meta, x, y))
+            array: (0..height as u32)
+                .map(|y| y as f32 / height)
+                .map(|y| {
+                    (0..width as u32)
+                        .map(|x| x as f32 / width)
+                        .map(|x| function.getpx(meta, x, y))
                         .collect()
                 })
                 .collect(),
         }
     }
+
+    pub fn rgba255(&self) -> Vec<u8> {
+        self.array
+            .iter()
+            .flat_map(|row| row.iter().flat_map(|pix| pix.rgba255()))
+            .collect()
+    }
 }
 
 impl ImgSyn for PaintedCanvas {
     fn getpx(&self, meta: Canvas, x: f32, y: f32) -> Pixel {
         // float coords -> int coords
-        let x = (x * meta.width as f32).round() as usize;
-        let y = (y * meta.height as f32).round() as usize;
-        self.array[x][y]
+        let x = (x * meta.width).round() as usize;
+        let y = (y * meta.height).round() as usize;
+        self.array[y][x]
+    }
+    fn paint(self, _meta: Canvas) -> PaintedCanvas {
+        self
     }
 }

src/lib.rs

@@ -1,5 +1,6 @@
+pub mod assist;
 mod canvas;
-pub mod ops;
+mod ops;
 mod pixel;
 mod pixfn;
 
@@ -7,30 +8,171 @@ pub use canvas::*;
 pub use pixel::*;
 pub use pixfn::*;
 
-use crate::ops::ImgSynMap;
+use crate::ops::{
+    ImgSynArea, ImgSynAxial, ImgSynMap, ImgSynMapArea, ImgSynPolar, ImgSynRect, ImgSynStretched,
+    ImgSynUnmapRect,
+};
 
-pub trait ImgSynPixFn: Clone {
-    fn run(&self, meta: Canvas, x: f32, y: f32, pixel: Pixel) -> Pixel;
+pub trait ImgSynPixFn<T>: Clone {
+    fn run(&self, meta: Canvas, x: f32, y: f32, pixel: Pixel) -> T;
 }
 
 pub trait ImgSyn: Clone {
     fn getpx(&self, meta: Canvas, x: f32, y: f32) -> Pixel;
-    fn map<F: ImgSynPixFn>(self, f: F) -> ImgSynMap<Self, F> {
+    fn map<F: ImgSynPixFn<Pixel>>(self, f: F) -> ImgSynMap<Self, F> {
         ImgSynMap(self, f)
     }
+    fn area<C: ImgSynPixFn<bool>, ImgB: ImgSyn, F: FnOnce(Self) -> ImgB>(
+        self,
+        condition: C,
+        f: F,
+    ) -> ImgSynArea<Self, ImgB, C> {
+        ImgSynArea(self.clone(), f(self), condition)
+    }
+    fn mapped_rect<ImgB: ImgSyn, F: FnOnce(ImgSynUnmapRect<Self>) -> ImgB>(
+        self,
+        begin_x: f32,
+        begin_y: f32,
+        size_x: f32,
+        size_y: f32,
+        f: F,
+    ) -> ImgSynRect<Self, ImgB> {
+        let rect = (begin_x, begin_y, size_x, size_y);
+        ImgSynRect(self.clone(), f(ImgSynUnmapRect(self, rect)), rect)
+    }
+    fn add_image<ImgB: ImgSyn>(
+        self,
+        begin_x: f32,
+        begin_y: f32,
+        size_x: f32,
+        size_y: f32,
+        img: ImgB,
+    ) -> ImgSynRect<Self, ImgB> {
+        let rect = (begin_x, begin_y, size_x, size_y);
+        ImgSynRect(self, img, rect)
+    }
+    fn map_area<C: ImgSynPixFn<bool>, F: ImgSynPixFn<Pixel>>(
+        self,
+        condition: C,
+        f: F,
+    ) -> ImgSynMapArea<Self, C, F> {
+        ImgSynMapArea(self, condition, f)
+    }
+    /// Makes future operations work on polar coordinates when terminated by .axial()
+    ///
+    /// **MUST** be used before a subsequent .axial()
+    fn polar(self) -> ImgSynAxial<Self> {
+        ImgSynAxial(self)
+    }
+    /// Makes future operations work on axial coordinates when .polar() was used previously
+    ///
+    /// **MUST** be used after .polar()
+    fn axial(self) -> ImgSynPolar<Self> {
+        ImgSynPolar(self)
+    }
+    fn stretched_by(self, x: f32, y: f32) -> ImgSynStretched<Self> {
+        ImgSynStretched(self, (x, y))
+    }
     fn paint(self, meta: Canvas) -> PaintedCanvas {
         PaintedCanvas::new(meta, self)
     }
+    fn rgba255(self, meta: Canvas) -> Vec<u8> {
+        let painted = self.paint(meta);
+        PaintedCanvas::rgba255(&painted)
+    }
+    fn png(self, meta: Canvas) -> Vec<u8> {
+        let painted = self.paint(meta);
+        let mut data = Vec::new();
+        {
+            let mut encoder = png::Encoder::new(&mut data, meta.width as u32, meta.height as u32);
+            encoder.set_color(png::ColorType::Rgba);
+            encoder.set_depth(png::BitDepth::Eight);
+            let mut writer = encoder.write_header().unwrap();
+            writer.write_image_data(&painted.rgba255(meta)).unwrap();
+            writer.finish().unwrap();
+        }
+        data
+    }
 }
 
 #[cfg(test)]
 mod test {
+    use std::fs;
+
     use crate::{Canvas, ImgSyn, PixFnFloat, Pixel};
 
     #[test]
     fn test() {
-        Canvas::new(100, 100, Pixel::new_black())
-            .map(PixFnFloat(|_, x, y, pix| pix.with_r(x).with_g(y)))
-            .map(PixFnFloat(|_, _, _, pix| pix.with_b(1.0)));
+        let canvas = Canvas::new(1000., 1000., Pixel::new_black());
+        fs::write(
+            "test.png",
+            canvas
+                .polar()
+                .map(|_, y: f32, pix: Pixel| pix.with_r((y - 0.5).abs() * 2.))
+                .map(|_, y, pix: Pixel| pix.with_b(y))
+                .axial()
+                .map(PixFnFloat(|_, _, y, pix| pix.with_g(y)))
+                .map_area(
+                    PixFnFloat(|_, x, y, _| x < 0.2 && y < 0.2),
+                    PixFnFloat(|_, _, _, pix| pix.with_g(1.0)),
+                )
+                .area(PixFnFloat(|_, _, _, px| px.g > 0.8 && px.r < 0.3), |img| {
+                    img.polar()
+                        .map(PixFnFloat(|_, x, y, pix| pix.with_r(x).with_b(1. - y)))
+                        .axial()
+                })
+                .mapped_rect(0.3, 0.3, 0.4, 0.4, |img| {
+                    img.map(PixFnFloat(|_, x, y, px| {
+                        let thickness = 0.01;
+                        if !(thickness..=1. - thickness).contains(&x)
+                            || !(thickness..=1. - thickness).contains(&y)
+                        {
+                            return Pixel::new_white();
+                        }
+                        px
+                    }))
+                })
+                .paint(canvas)
+                .png(canvas),
+        )
+        .unwrap();
+    }
+
+    #[test]
+    fn graph() {
+        let canvas = Canvas::new(1000., 1000., Pixel::new_white());
+        fs::write(
+            "graph.png",
+            canvas
+                .add_image(
+                    0.1,
+                    0.0,
+                    0.9,
+                    0.9,
+                    Canvas::new(900., 900., Pixel::new_black()).map_area(
+                        |x, y, _| x < 0.7 || y > 0.3,
+                        |x, y, px: Pixel| px.with_r(x).with_g(1. - y),
+                    ),
+                )
+                .map_area(
+                    |x, y, _| {
+                        let t = 0.004;
+                        (0.1 - t..0.1 + t).contains(&x) || (0.9 - t..0.9 + t).contains(&y)
+                    },
+                    |_, _, px: Pixel| px.with_rgb(1.0, 0.0, 0.0),
+                )
+                .mapped_rect(0.05, 0.90, 0.05, 0.05, |img| {
+                    img.polar()
+                        .map_area(
+                            |r: f32, phi, _| (r - 0.3).abs() < 0.04,
+                            |_, _, px: Pixel| px.with_rgb_of(0.0),
+                        )
+                        .axial()
+                        .stretched_by(1.0, 1.5)
+                })
+                .paint(canvas)
+                .png(canvas),
+        )
+        .unwrap();
     }
 }

src/ops/area.rs

@@ -0,0 +1,91 @@
+use crate::{Canvas, ImgSyn, ImgSynPixFn, Pixel};
+
+#[derive(Clone, Copy)]
+pub struct ImgSynMapArea<Prev: ImgSyn, C: ImgSynPixFn<bool>, F: ImgSynPixFn<Pixel>>(
+    pub(crate) Prev,
+    pub(crate) C,
+    pub(crate) F,
+);
+
+impl<Prev, C, F> ImgSyn for ImgSynMapArea<Prev, C, F>
+where
+    Prev: ImgSyn,
+    C: ImgSynPixFn<bool>,
+    F: ImgSynPixFn<Pixel>,
+{
+    fn getpx(&self, meta: Canvas, x: f32, y: f32) -> crate::Pixel {
+        let px = self.0.getpx(meta, x, y);
+        if !self.1.run(meta, x, y, px) {
+            return px;
+        }
+        self.2.run(meta, x, y, px)
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct ImgSynArea<Prev: ImgSyn, ImgB: ImgSyn, C: ImgSynPixFn<bool>>(
+    pub(crate) Prev,
+    pub(crate) ImgB,
+    pub(crate) C,
+);
+
+impl<Prev, ImgB, C> ImgSyn for ImgSynArea<Prev, ImgB, C>
+where
+    Prev: ImgSyn,
+    ImgB: ImgSyn,
+    C: ImgSynPixFn<bool>,
+{
+    fn getpx(&self, meta: Canvas, x: f32, y: f32) -> crate::Pixel {
+        let px = self.0.getpx(meta, x, y);
+        if !self.2.run(meta, x, y, px) {
+            return px;
+        }
+        self.1.getpx(meta, x, y)
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct ImgSynRect<Prev: ImgSyn, ImgB: ImgSyn>(
+    pub(crate) Prev,
+    pub(crate) ImgB,
+    pub(crate) (f32, f32, f32, f32),
+);
+
+impl<Prev, ImgB> ImgSyn for ImgSynRect<Prev, ImgB>
+where
+    Prev: ImgSyn,
+    ImgB: ImgSyn,
+{
+    fn getpx(&self, meta: Canvas, x: f32, y: f32) -> crate::Pixel {
+        let px = self.0.getpx(meta, x, y);
+        let (startx, starty, sizex, sizey) = self.2;
+        if x < startx || y < starty {
+            return px;
+        }
+        if x - startx >= sizex || y - starty >= sizey {
+            return px;
+        }
+        self.1.getpx(
+            Canvas::new(sizex * meta.width, sizey * meta.height, meta.default_px),
+            (x - startx) / sizex,
+            (y - starty) / sizey,
+        )
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct ImgSynUnmapRect<Prev: ImgSyn>(pub(crate) Prev, pub(crate) (f32, f32, f32, f32));
+
+impl<Prev> ImgSyn for ImgSynUnmapRect<Prev>
+where
+    Prev: ImgSyn,
+{
+    fn getpx(&self, meta: Canvas, x: f32, y: f32) -> crate::Pixel {
+        let (startx, starty, sizex, sizey) = self.1;
+        self.0.getpx(
+            Canvas::new(meta.width / sizex, meta.height / sizey, meta.default_px),
+            x * sizex + startx,
+            y * sizey + starty,
+        )
+    }
+}

src/ops/axial.rs

@@ -0,0 +1,29 @@
+use crate::{
+    Canvas, ImgSyn,
+    assist::{axial, polar},
+};
+
+#[derive(Clone, Copy)]
+pub struct ImgSynAxial<Prev: ImgSyn>(pub(crate) Prev);
+
+impl<Prev> ImgSyn for ImgSynAxial<Prev>
+where
+    Prev: ImgSyn,
+{
+    fn getpx(&self, meta: Canvas, x: f32, y: f32) -> crate::Pixel {
+        let (x, y) = axial(x, y, meta);
+        self.0.getpx(meta, x, y)
+    }
+}
+#[derive(Clone, Copy)]
+pub struct ImgSynPolar<Prev: ImgSyn>(pub(crate) Prev);
+
+impl<Prev> ImgSyn for ImgSynPolar<Prev>
+where
+    Prev: ImgSyn,
+{
+    fn getpx(&self, meta: Canvas, x: f32, y: f32) -> crate::Pixel {
+        let (x, y) = polar(x, y, meta);
+        self.0.getpx(meta, x, y)
+    }
+}

src/ops/map.rs

@@ -1,9 +1,9 @@
-use crate::{ImgSyn, ImgSynPixFn};
+use crate::{ImgSyn, ImgSynPixFn, Pixel};
 
 #[derive(Clone, Copy)]
-pub struct ImgSynMap<Prev: ImgSyn, F: ImgSynPixFn>(pub(crate) Prev, pub(crate) F);
+pub struct ImgSynMap<Prev: ImgSyn, F: ImgSynPixFn<Pixel>>(pub(crate) Prev, pub(crate) F);
 
-impl<Prev: ImgSyn, F: ImgSynPixFn> ImgSyn for ImgSynMap<Prev, F> {
+impl<Prev: ImgSyn, F: ImgSynPixFn<Pixel>> ImgSyn for ImgSynMap<Prev, F> {
     fn getpx(&self, meta: crate::Canvas, x: f32, y: f32) -> crate::Pixel {
         self.1.run(meta, x, y, self.0.getpx(meta, x, y))
     }

src/ops/mod.rs

@@ -1,2 +1,8 @@
 mod map;
 pub use map::*;
+mod area;
+pub use area::*;
+mod axial;
+pub use axial::*;
+mod stretch;
+pub use stretch::*;

src/ops/stretch.rs

@@ -0,0 +1,14 @@
+use crate::ImgSyn;
+
+#[derive(Clone, Copy)]
+pub struct ImgSynStretched<Prev: ImgSyn>(pub(crate) Prev, pub(crate) (f32, f32));
+
+impl<Prev: ImgSyn> ImgSyn for ImgSynStretched<Prev> {
+    fn getpx(&self, meta: crate::Canvas, x: f32, y: f32) -> crate::Pixel {
+        self.0.getpx(
+            meta,
+            x / self.1.0 - 0.5 / self.1.0 + 0.5,
+            y / self.1.1 - 0.5 / self.1.1 + 0.5,
+        )
+    }
+}

src/pixel.rs

@@ -1,9 +1,9 @@
 #[derive(Clone, Copy, PartialEq)]
 pub struct Pixel {
-    r: f32,
-    g: f32,
-    b: f32,
-    a: f32,
+    pub r: f32,
+    pub g: f32,
+    pub b: f32,
+    pub a: f32,
 }
 
 impl Pixel {
@@ -33,6 +33,10 @@ impl Pixel {
         }
     }
 
+    pub fn of(r: f32, g: f32, b: f32, a: f32) -> Pixel {
+        Self { r, g, b, a }
+    }
+
     pub fn with_r(self, x: f32) -> Pixel {
         Self { r: x, ..self }
     }
@@ -45,6 +49,17 @@ impl Pixel {
     pub fn with_a(self, x: f32) -> Pixel {
         Self { a: x, ..self }
     }
+    pub fn with_rgb(self, r: f32, g: f32, b: f32) -> Pixel {
+        Self { r, g, b, ..self }
+    }
+    pub fn with_rgb_of(self, x: f32) -> Pixel {
+        Self {
+            r: x,
+            g: x,
+            b: x,
+            ..self
+        }
+    }
 
     pub fn map(self, f: impl FnOnce(Self) -> Pixel) -> Pixel {
         f(self)
@@ -66,4 +81,13 @@ impl Pixel {
         self.r = f(self.r);
         self
     }
+
+    pub fn rgba255(self) -> [u8; 4] {
+        [
+            (self.r.clamp(0.0, 1.0) * 255.) as u8,
+            (self.g.clamp(0.0, 1.0) * 255.) as u8,
+            (self.b.clamp(0.0, 1.0) * 255.) as u8,
+            (self.a.clamp(0.0, 1.0) * 255.) as u8,
+        ]
+    }
 }

src/pixfn.rs

@@ -1,28 +1,37 @@
 use crate::{Canvas, ImgSynPixFn, Pixel};
 
 #[derive(Clone, Copy)]
-pub struct PixFnInt<T: (Fn(Canvas, u32, u32, Pixel) -> Pixel) + Copy>(pub T);
-impl<T> ImgSynPixFn for PixFnInt<T>
+pub struct PixFnInt<T: Clone + Copy, F: (Fn(Canvas, u32, u32, Pixel) -> T) + Copy>(pub F);
+impl<T: Clone + Copy, F> ImgSynPixFn<T> for PixFnInt<T, F>
 where
-    T: (Fn(Canvas, u32, u32, Pixel) -> Pixel) + Copy,
+    F: (Fn(Canvas, u32, u32, Pixel) -> T) + Copy,
 {
-    fn run(&self, meta: Canvas, x: f32, y: f32, pixel: Pixel) -> Pixel {
+    fn run(&self, meta: Canvas, x: f32, y: f32, pixel: Pixel) -> T {
         self.0(
             meta,
-            (x * meta.width as f32).round() as u32,
-            (y * meta.height as f32).round() as u32,
+            (x * meta.width).round() as u32,
+            (y * meta.height).round() as u32,
             pixel,
         )
     }
 }
 
 #[derive(Clone, Copy)]
-pub struct PixFnFloat<T: (Fn(Canvas, f32, f32, Pixel) -> Pixel) + Copy>(pub T);
-impl<T> ImgSynPixFn for PixFnFloat<T>
+pub struct PixFnFloat<T: Clone + Copy, F: (Fn(Canvas, f32, f32, Pixel) -> T) + Copy>(pub F);
+impl<T: Clone + Copy, F> ImgSynPixFn<T> for PixFnFloat<T, F>
 where
-    T: (Fn(Canvas, f32, f32, Pixel) -> Pixel) + Copy,
+    F: (Fn(Canvas, f32, f32, Pixel) -> T) + Copy,
 {
-    fn run(&self, meta: Canvas, x: f32, y: f32, pixel: Pixel) -> Pixel {
+    fn run(&self, meta: Canvas, x: f32, y: f32, pixel: Pixel) -> T {
         self.0(meta, x, y, pixel)
     }
 }
+
+impl<T: Clone + Copy, F> ImgSynPixFn<T> for F
+where
+    F: (Fn(f32, f32, Pixel) -> T) + Copy,
+{
+    fn run(&self, _meta: Canvas, x: f32, y: f32, px: Pixel) -> T {
+        self(x, y, px)
+    }
+}