Advanced Hands-on Rust: Mars mesh calculation wrong (B3 p248)

@herbert

Here’s a diff for the fix:

--- a/MarsBaseOneOptimize/mars_base_one/src/main.rs
+++ b/MarsBaseOneOptimize/mars_base_one/src/main.rs
@@ -377,7 +377,7 @@ impl World {
         if self.solid[self.mapidx(x, y)] {

           let left = (x as f32 * 24.0) - x_offset;//(7)
-          let right = x_offset;
+          let right = ((x as f32 + 1.0) * 24.0) - x_offset;
           let top = (y as f32 * 24.0) - y_offset;
           let bottom = ((y as f32 + 1.0) * 24.0) - y_offset;