Map create time in hue

1 files changed, 15 insertions, 40 deletions

diff --git a/ascii-town-heatmap.rs b/ascii-town-heatmap.rs
index 8243046..fa818cf 100644
--- a/ascii-town-heatmap.rs
+++ b/ascii-town-heatmap.rs
@@ -36,33 +36,17 @@ const TORUS_SZ: u32 = 512;
 const TILE_W: u32 = 8;
 const TILE_H: u32 = 5;
 
+// ~2017-07-30.
+const CREATE_ONE: u64 = 1501439553;
+
 fn main() {
-    // Read the `torus.csv` into a 2D array of `(access, modify)`.
-    // Also track the values we see in `BTreeSet` (for ordering).
-    let mut tiles = [[(0, 0); TORUS_SZ as usize]; TORUS_SZ as usize];
-    let mut ord_a = BTreeSet::new();
-    let mut ord_m = BTreeSet::new();
+    let mut tiles = [[0; TORUS_SZ as usize]; TORUS_SZ as usize];
+    let mut ord_c = BTreeSet::new();
     for result in csv::Reader::from_reader(io::stdin()).deserialize() {
-        let Tile {
-            create_time,
-            modify_time,
-            access_count: mut a,
-            modify_count: mut m,
-            tile_x: x,
-            tile_y: y,
-            ..
-        } = result.unwrap();
-
-        // Handle old migrated values.
-        if modify_time == create_time && m > 0 {
-            a += 1;
-            m = 0;
-        }
-
-        ord_a.insert(a);
-        ord_m.insert(m);
-
-        tiles[y][x] = (a, m);
+        let Tile { tile_x: x, tile_y: y, mut create_time, .. } = result.unwrap();
+        if create_time == 1 { create_time = CREATE_ONE }
+        ord_c.insert(create_time);
+        tiles[y][x] = create_time;
     }
 
     // Normalize all values by mapping them to equally spaced values in [0, 1].
@@ -71,28 +55,19 @@ fn main() {
             (x, i as f64 / (ord.len() - 1) as f64)
         }).collect()
     };
-    let normal_a = normal_map(ord_a);
-    let normal_m = normal_map(ord_m);
+    let normal_c = normal_map(ord_c);
 
     // Compose the heatmap image in-memory from the 2D array.
     let mut heatmap = image::ImageBuffer::new(TORUS_SZ * TILE_W, TORUS_SZ * TILE_H);
-    let red = hsl::HSL::from_rgb(&[255, 0, 0]).h;
-    // let green = hsl::HSL::from_rgb(&[0, 255, 0]).h;
-    // let blue = hsl::HSL::from_rgb(&[0, 0, 255]).h;
-    let yellow = hsl::HSL::from_rgb(&[255, 255, 0]).h;
     for y in 0..TORUS_SZ {
         for x in 0..TORUS_SZ {
             // Get and normalize the values.
-            let (a, m) = tiles[y as usize][x as usize];
-            let a = normal_a[&a].powf(1.0 / 2.0);
-            let m = normal_m[&m].powf(1.0 / 3.0);
+            let c = tiles[y as usize][x as usize];
+            let c = normal_c[&c];
 
-            // access => luminosity
-            let l = ((a + m) * 0.5).min(0.7);
-            // modify => saturation + hue (grey -> red -> yellow)
-            let interp = |a, b, x| a * (1.0 - x) + b * x;
-            let h = interp(red, yellow, m.powf(4.0));
-            let s = m;
+            let h = (1.0 - c) * 240.0;
+            let s = c * 0.5 + 0.5;
+            let l = if c > 0.0 { c * 0.5 } else { 0.0 };
 
             let (r, g, b) = hsl::HSL { h, s, l }.to_rgb();
             let rgb = image::Rgb([r, g, b]);