High-res tiles also in 128x128 for close views

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/render3d.rs

@@ -1587,9 +1587,31 @@ impl R3d {
         self.lit.set_uniform("LightCount", count);
         // wrapped so the shader keeps its precision (the flow speeds are whole tiles per period)
         self.lit.set_uniform("Time", (time % 1000.0) as f32);
+        // high-res: the 128x128 tiles where a tile gets nearly that many pixels, else the 64x64
+        // ones (same layout: the chunks keep their uvs, only the texture changes)
         let hd_tiles = self.chunks_hd;
-        self.lit.set_uniform("AtlasSize", if hd_tiles { vec2(crate::gfx::ATLAS_HD_W, crate::gfx::ATLAS_HD_H) } else { vec2(ATLAS_W, ATLAS_H) });
-        self.lit.set_uniform("CellSize", if hd_tiles { crate::gfx::HD_TILE as f32 } else { 16.0 });
+        let rows = pix.map_or(screen_height() * screen_dpi_scale(), |(_, th, _)| th as f32);
+        let tile = if !hd_tiles {
+            16
+        } else if rows / cam.view_h().max(0.1) >= crate::gfx::HD_TILE2 as f32 * 0.85 {
+            crate::gfx::HD_TILE2
+        } else {
+            crate::gfx::HD_TILE
+        };
+        let atlas = match tile {
+            16 => &gfx.atlas,
+            crate::gfx::HD_TILE => &gfx.atlas_hd,
+            _ => &gfx.atlas_hd2,
+        };
+        for ch in self.chunks.iter_mut() {
+            for mesh in [&mut ch.mesh, &mut ch.overlay].into_iter().flatten() {
+                if mesh.texture.as_ref() != Some(atlas) {
+                    mesh.texture = Some(atlas.clone());
+                }
+            }
+        }
+        self.lit.set_uniform("AtlasSize", vec2((crate::gfx::ATLAS_COLS * tile) as f32, (crate::gfx::ATLAS_ROWS * tile) as f32));
+        self.lit.set_uniform("CellSize", tile as f32);
         self.lit.set_uniform("HdLiquid", if hd_tiles { 1.0f32 } else { 0.0 });
         gl_use_material(&self.lit);
         for cz in 0..self.ncz {