fix iso grid scaling

1 files changed, 15 insertions, 17 deletions

diff --git a/src/grid.rs b/src/grid.rs
index 38efaba..029a196 100644
--- a/src/grid.rs
+++ b/src/grid.rs
@@ -3,10 +3,7 @@
 
 use sdl2::{pixels::Color, rect::Point, render::Canvas, video::Window};
 
-use crate::{
-    consts::{colors::*, ANGLE},
-    rect,
-};
+use crate::{consts::colors::*, rect};
 
 #[derive(Debug, Copy, Clone)]
 pub enum GridKind {
@@ -83,22 +80,23 @@ impl Grid {
                 canvas.draw_lines(&horizontals[..]).unwrap();
             }
             GridKind::Isometric => {
-                // tan 26.525 ~= 0.5
                 canvas.set_clip_rect(Some(rect!(x, y, width * cs, height * cs)));
                 for i in (0..2 * height + width).step_by(4) {
-                    let begin = Point::from(((i * cs) as i32, 0i32));
-                    let end = Point::from((0i32, ((i * cs) as f64 * 0.5).floor() as i32));
-                    canvas.draw_line(*start + begin, *start + end).unwrap();
-                }
-                for j in (0..height + width / 2).step_by(2) {
-                    let idx = (j as i32 - (width as i32 / 2)) * cs as i32;
-                    let begin = Point::from((-100i32, idx));
-                    let end = Point::from((
+                    let begin = ((i * cs) as i32, 0i32);
+                    let end = (0i32, (i * cs) as i32 / 2);
+                    canvas
+                        .draw_line(*start + begin.into(), *start + end.into())
+                        .unwrap();
+
+                    let begin_m = ((i as i32 - 2 * height as i32) * cs as i32, 0i32);
+                    let end_m = (
                         (width * cs) as i32,
-                        (idx as f64 + (width * cs) as f64 * ANGLE.to_radians().tan()).floor()
-                            as i32,
-                    ));
-                    canvas.draw_line(*start + begin, *start + end).unwrap();
+                        ((width + 2 * height - i) * cs) as i32 / 2,
+                    );
+
+                    canvas
+                        .draw_line(*start + begin_m.into(), *start + end_m.into())
+                        .unwrap();
                 }
                 canvas.set_clip_rect(None);
             }