Quadtrees are up and running! Let's render them!

4 files changed, 90 insertions, 33 deletions

diff --git a/src/ctx.rs b/src/ctx.rs
index 90d6c15..29161f2 100644
--- a/src/ctx.rs
+++ b/src/ctx.rs
@@ -1,32 +1,74 @@
 use std::marker::PhantomData;
 use crate::quad::{Quad, Node, Embed};
 
+pub trait Approx<A: Embed, B: Embed, S>: Default {
+    fn color_base(state: &mut S, base: A) -> [u8; 4];
+
+    fn compress_node(state: &mut S, compr: [B; 4]) -> B;
+    fn   expand_node(state: &mut S, compr: B) -> [B; 4];
+
+    fn compress_base(state: &mut S, embed: A) -> B;
+    fn   expand_base(state: &mut S, compr: B) -> A;
+}
+
+#[derive(Default)]
+pub struct Basic;
+
+impl Approx<u8, u8, ()> for Basic {
+    fn color_base(state: &mut (), base: u8) -> [u8; 4] {
+        [base;4]
+    }
+
+    fn compress_node(state: &mut (), c: [u8; 4]) -> u8 {
+        c[0]/4 + c[1]/4 + c[2]/4 + c[3]/4
+    }
+
+    fn expand_node(state: &mut (), compr: u8) -> [u8; 4] {
+        [compr;4]
+    }
+
+    fn compress_base(state: &mut (), embed: u8) -> u8 {
+        embed
+    }
+
+    fn expand_base(state: &mut (), compr: u8) -> u8 {
+        compr
+    }
+}
+
 /// Represents a context with shared state.
-#[derive(Default, Debug)]
-pub struct Ctx<A: Embed, B: Embed> {
+#[derive(Debug)]
+pub struct Ctx<A: Embed, B: Embed, S, N: Approx<A, B, S>> {
     _phantom_a: PhantomData<A>,
     _phantom_b: PhantomData<B>,
+    state:    S,
+    networks: N,
 }
 
-impl<A: Embed, B: Embed> Ctx<A, B> {
+impl<A: Embed, B: Embed, S, N: Approx<A, B, S>> Ctx<A, B, S, N> {
     /// Creates a new uninitialized context.
-    pub fn new_empty() -> Self {
-        Default::default()
+    pub fn new(state: S, networks: N) -> Self {
+        Ctx {
+            _phantom_a: PhantomData,
+            _phantom_b: PhantomData,
+            state,
+            networks,
+        }
     }
 
-    /// Combines 4 child node representations into a single representation
-    /// Using a neural network.
-    pub fn combine(&mut self, compr: [B; 4]) -> B {
-        todo!("Build new B from 4 child B");
+    pub fn color_base(&mut self, base: A) -> [u8; 4] {
+        N::color_base(&mut self.state, base)
     }
 
     /// Compresses a base-level cell into a vector.
     pub fn compress_base(&mut self, base: A) -> B {
-        todo!("Turn Base Cell into a vector B");
+        N::compress_base(&mut self.state, base)
     }
 
-    pub fn color_base(&mut self, base: &A) -> [u8; 4] {
-        todo!();
+    /// Combines 4 child node representations into a single representation
+    /// Using a neural network.
+    pub fn compress_node(&mut self, compr: [B; 4]) -> B {
+        N::compress_node(&mut self.state, compr)
     }
 
     /// Compresses a single node into a vector representation.
@@ -36,7 +78,7 @@ impl<A: Embed, B: Embed> Ctx<A, B> {
         match quad {
             Quad::Base(b) => Some(self.compress_base(*b)),
             Quad::Node(n) => Some(
-                self.combine([
+                self.compress_node([
                     n[0].compr,
                     n[1].compr,
                     n[2].compr,
@@ -48,12 +90,12 @@ impl<A: Embed, B: Embed> Ctx<A, B> {
     }
 
     /// Compresses a base-level cell into a vector.
-    fn expand_base(&mut self, compr: B) -> A {
-        todo!("Turn compressed B into the A that made it");
+    pub fn expand_base(&mut self, compr: B) -> A {
+        N::expand_base(&mut self.state, compr)
     }
 
-    fn expand_node(&mut self, compr: B) -> [B; 4] {
-        todo!("Turn compressed B into 4 child B that made it");
+    pub fn expand_node(&mut self, compr: B) -> [B; 4] {
+        N::expand_node(&mut self.state, compr)
     }
 
     /// Expands the compressed representation of a node into a node with 4 children.
diff --git a/src/main.rs b/src/main.rs
index 3078f49..6134893 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -6,9 +6,15 @@ mod render;
 fn main() {
     println!("Warming up...");
 
-    let mut ctx = ctx::Ctx::new_empty();
+    let mut ctx = ctx::Ctx::new((), ctx::Basic);
+
+    let mut base = vec![];
+    for i in 0..16 {
+        base.push(i);
+    }
+
     let quad: quad::Node<u8, u8> = quad::Node::new_from_square(
-        &mut ctx, vec![0xFF;64],
+        &mut ctx, base,
     );
 
     // render::graphics();
diff --git a/src/quad.rs b/src/quad.rs
index 2eb23b1..0ce8b58 100644
--- a/src/quad.rs
+++ b/src/quad.rs
@@ -1,7 +1,7 @@
-use crate::ctx::Ctx;
+use crate::ctx::{Ctx, Approx};
 
 pub trait Embed: Default + Copy + Sized + std::fmt::Debug {
-    
+
 }
 
 /// Represents the data present in a quad-tree node.
@@ -32,7 +32,12 @@ pub struct Node<A: Embed, B: Embed> {
 }
 
 impl<A: Embed, B: Embed> Node<A, B> {
-    pub fn sample_color(self, ctx: &mut Ctx<A, B>, x: isize, y: isize) -> (Self, [u8; 4]) {
+    pub fn sample_color<S, N: Approx<A, B, S>>(
+        self,
+        ctx: &mut Ctx<A, B, S, N>,
+        x: isize,
+        y: isize,
+    ) -> (Self, [u8; 4]) {
         // self = ctx.expand(self);
         // if let Quad::Base(b) = self.data {
         //     return (self, ctx.color_base(&b));
@@ -54,12 +59,12 @@ impl<A: Embed, B: Embed> Node<A, B> {
     }
 
     /// Creates a new tree with a single empty base node
-    pub fn new_empty(ctx: &mut Ctx<A, B>) -> Self {
+    pub fn new_empty<S, N: Approx<A, B, S>>(ctx: &mut Ctx<A, B, S, N>) -> Self {
         Self::new_base(ctx, Default::default())
     }
 
     /// Creates a new tree from a single base node
-    pub fn new_base(ctx: &mut Ctx<A, B>, base: A) -> Self {
+    pub fn new_base<S, N: Approx<A, B, S>>(ctx: &mut Ctx<A, B, S, N>, base: A) -> Self {
         Node {
             depth: 0,
             compr: ctx.compress_base(base),
@@ -67,7 +72,7 @@ impl<A: Embed, B: Embed> Node<A, B> {
         }
     }
 
-    pub fn new_node(ctx: &mut Ctx<A, B>, children: [Node<A, B>;4]) -> Self {
+    pub fn new_node<S, N: Approx<A, B, S>>(ctx: &mut Ctx<A, B, S, N>, children: [Node<A, B>;4]) -> Self {
         // Make sure the depths check out
         assert_eq!(children[0].depth, children[1].depth);
         assert_eq!(children[1].depth, children[2].depth);
@@ -88,8 +93,8 @@ impl<A: Embed, B: Embed> Node<A, B> {
         }
     }
 
-    fn build_square(
-        ctx: &mut Ctx<A, B>,
+    fn build_square<S, N: Approx<A, B, S>>(
+        ctx: &mut Ctx<A, B, S, N>,
         square: &[A],
         abs_size: usize,
         depth: usize,
@@ -106,16 +111,17 @@ impl<A: Embed, B: Embed> Node<A, B> {
             let half = size / 2;
             // in a z-like pattern
             let children = [
-                Self::build_square(ctx, square, abs_size, depth - 1, x + half, y       ),
                 Self::build_square(ctx, square, abs_size, depth - 1, x       , y       ),
-                Self::build_square(ctx, square, abs_size, depth - 1, x + half, y + half),
+                Self::build_square(ctx, square, abs_size, depth - 1, x + half, y       ),
                 Self::build_square(ctx, square, abs_size, depth - 1, x       , y + half),
+                Self::build_square(ctx, square, abs_size, depth - 1, x + half, y + half),
+
             ];
             Self::new_node(ctx, children)
         }
     }
 
-    pub fn new_from_square(ctx: &mut Ctx<A, B>, square: Vec<A>) -> Self {
+    pub fn new_from_square<S, N: Approx<A, B, S>>(ctx: &mut Ctx<A, B, S, N>, square: Vec<A>) -> Self {
         // get the side length, ensure this is a pow2 square
         let area = square.len();
         let size = ((area as f64).sqrt() + 0.5) as usize;
@@ -135,7 +141,7 @@ impl<A: Embed, B: Embed> Node<A, B> {
 
     /// Creates a new node double the size by centering the current node
     /// on a node double the size.
-    pub fn pad_empty(self, ctx: &mut Ctx<A, B>) -> Self {
+    pub fn pad_empty<S, N: Approx<A, B, S>>(self, ctx: &mut Ctx<A, B, S, N>) -> Self {
         todo!()
     }
 }
diff --git a/src/step.rs b/src/step.rs
index 7010bd9..35d4328 100644
--- a/src/step.rs
+++ b/src/step.rs
@@ -1,7 +1,10 @@
-use crate::ctx::Ctx;
+use crate::ctx::{Ctx, Approx};
 use crate::quad::{Node, Embed};
 
-pub fn step<A: Embed, B: Embed>(ctx: &mut Ctx<A, B>, node: Node<A, B>) -> Node<A, B> {
+pub fn step<A: Embed, B: Embed, S, N: Approx<A, B, S>>(
+    ctx: &mut Ctx<A, B, S, N>,
+    node: Node<A, B>
+) -> Node<A, B> {
     // pad the graph if needed.
 
     // if we're at the base, run the cellular automation rule: