KIND OF ARBITRARY ZOOM (hangs at len 5 for some reason)

src/client/render/output/data.rs

@@ -0,0 +1,45 @@
+use nalgebra::Vector2;
+
+use crate::client::render::CHUNK_POW;
+
+use super::{Camera, CHUNK_WIDTH};
+
+#[repr(C, align(8))]
+#[derive(Clone, Copy, Default, PartialEq)]
+pub struct WindowView {
+    pub stretch: Vector2<f32>,
+    pub pos: Vector2<f32>,
+    pub rendered_chunks: Vector2<u32>,
+}
+
+unsafe impl bytemuck::Pod for WindowView {}
+unsafe impl bytemuck::Zeroable for WindowView {}
+
+impl WindowView {
+    pub fn from_camera_size(camera: &Camera, size: &Vector2<u32>) -> Self {
+        let visible_chunks = (size * 2 / CHUNK_WIDTH).add_scalar(1);
+        let rendered_chunks = Vector2::new(
+            visible_chunks.x.next_power_of_two(),
+            visible_chunks.y.next_power_of_two(),
+        );
+        let adj_zoom = camera.zoom.level() - CHUNK_POW as i32;
+        let pos = camera.pos.zip_map(&rendered_chunks, |pos, rc| {
+            let p = (pos << adj_zoom).with_lens(1, 1);
+            let (pw, pd) = p.split_whole_dec();
+            let mut chunk = (pw.parts().first().unwrap_or(&0) & (rc - 1)) as f32;
+            if pw.is_neg() {
+                chunk = rc as f32 - chunk;
+            }
+            let dec = f32::from(pd);
+            chunk + dec
+        });
+
+        let stretch = size.cast::<f32>() * camera.zoom.rel_zoom() / (CHUNK_WIDTH as f32);
+
+        Self {
+            pos,
+            stretch,
+            rendered_chunks,
+        }
+    }
+}