first implementation of tile hunter mode

This is a very basic idea, the downside is that you basically cannot
"fix" the tilehunt overlay to a specific zoom level. It might be nice to
get a second renderer that renders the tile hunt for a fixed zoom, and
then adjusts the output tiles accordingly (then it also takes more space
again though).

3 files changed, 53 insertions, 0 deletions

diff --git a/src/renderer/mod.rs b/src/renderer/mod.rs
index 927c6ed..f109872 100644
--- a/src/renderer/mod.rs
+++ b/src/renderer/mod.rs
@@ -7,6 +7,7 @@ use crossbeam_channel::Sender;
 use super::gpx::Coordinates;
 
 pub mod heatmap;
+pub mod tilehunt;
 
 const CHANNEL_SIZE: usize = 30;
 
diff --git a/src/renderer/tile-marked.png b/src/renderer/tile-marked.png
new file mode 100644
index 0000000..0b05ce2
--- /dev/null
+++ b/src/renderer/tile-marked.png
diff --git a/src/renderer/tilehunt.rs b/src/renderer/tilehunt.rs
new file mode 100644
index 0000000..f44644b
--- /dev/null
+++ b/src/renderer/tilehunt.rs
@@ -0,0 +1,52 @@
+//! Actual rendering functions for tile hunts.
+use color_eyre::eyre::Result;
+use crossbeam_channel::Sender;
+use fnv::FnvHashSet;
+
+use super::{
+    super::{
+        gpx::Coordinates,
+        layer::{TILE_HEIGHT, TILE_WIDTH},
+    },
+    RenderedTile,
+};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Renderer;
+
+impl super::Renderer for Renderer {
+    type Prepared = FnvHashSet<(u64, u64)>;
+
+    fn prepare(zoom: u32, tracks: &[Vec<Coordinates>], tick: Sender<()>) -> Result<Self::Prepared> {
+        let mut marked = FnvHashSet::default();
+
+        for track in tracks {
+            for point in track {
+                let merc = point.web_mercator(zoom);
+                let tile_x = merc.0 / TILE_WIDTH;
+                let tile_y = merc.1 / TILE_HEIGHT;
+                marked.insert((tile_x, tile_y));
+            }
+
+            tick.send(()).unwrap();
+        }
+
+        Ok(marked)
+    }
+
+    fn colorize(layer: Self::Prepared, tx: Sender<RenderedTile>) -> Result<()> {
+        static IMAGE_DATA: &[u8] = include_bytes!("tile-marked.png");
+        for (tile_x, tile_y) in layer {
+            tx.send(RenderedTile {
+                x: tile_x,
+                y: tile_y,
+                data: IMAGE_DATA.to_vec(),
+            })?;
+        }
+        Ok(())
+    }
+
+    fn tile_count(layer: &Self::Prepared) -> Result<u64> {
+        Ok(layer.len().try_into().unwrap())
+    }
+}