From ff0fc6cdee36c0147a7109c020cbfa20f3e330f0 Mon Sep 17 00:00:00 2001
From: Vijfhoek <me@vijf.life>
Date: Sat, 29 May 2021 19:26:55 +0200
Subject: [PATCH] Clean up DDA a bit

---
 src/chunk.rs | 36 ++++++++++++++++--------------------
 src/state.rs |  6 ++----
 2 files changed, 18 insertions(+), 24 deletions(-)

diff --git a/src/chunk.rs b/src/chunk.rs
index 8a71c68..23341ce 100644
--- a/src/chunk.rs
+++ b/src/chunk.rs
@@ -70,30 +70,26 @@ impl Chunk {
     pub fn dda(&self, position: Vector3<f32>, direction: Vector3<f32>) -> Option<Vector3<usize>> {
         assert!(f32::abs(direction.magnitude() - 1.0) < f32::EPSILON);
 
-        let scale_x = Self::calc_scale(direction, direction.x);
-        let scale_y = Self::calc_scale(direction, direction.y);
-        let scale_z = Self::calc_scale(direction, direction.z);
-        dbg!(direction, scale_x, scale_y, scale_z);
+        let scale = Vector3::new(
+            Self::calc_scale(direction, direction.x),
+            Self::calc_scale(direction, direction.y),
+            Self::calc_scale(direction, direction.z),
+        );
 
         let mut new_position = position;
-
-        let mut x_length = 0.0;
-        let mut y_length = 0.0;
-        let mut z_length = 0.0;
+        let mut lengths = Vector3::new(0.0, 0.0, 0.0);
         loop {
-            let new_x_length = x_length + scale_x;
-            let new_y_length = y_length + scale_y;
-            let new_z_length = z_length + scale_z;
+            let new_lengths = lengths + scale;
 
-            if new_x_length < f32::min(new_y_length, new_z_length) {
-                x_length = new_x_length;
-                new_position += direction * scale_x;
-            } else if new_y_length < f32::min(new_x_length, new_z_length) {
-                y_length = new_y_length;
-                new_position += direction * scale_y;
-            } else if new_z_length < f32::min(new_x_length, new_y_length) {
-                z_length = new_z_length;
-                new_position += direction * scale_z;
+            if new_lengths.x < f32::min(new_lengths.y, new_lengths.z) {
+                lengths.x = new_lengths.x;
+                new_position += direction * scale.x;
+            } else if new_lengths.y < f32::min(new_lengths.x, new_lengths.z) {
+                lengths.y = new_lengths.y;
+                new_position += direction * scale.y;
+            } else if new_lengths.z < f32::min(new_lengths.x, new_lengths.y) {
+                lengths.z = new_lengths.z;
+                new_position += direction * scale.z;
             }
 
             let pos_usize = new_position.map(|field| field.round() as usize);
diff --git a/src/state.rs b/src/state.rs
index c712351..2bc0e8c 100644
--- a/src/state.rs
+++ b/src/state.rs
@@ -428,13 +428,11 @@ impl State {
 
         let (camera, projection) = Self::create_camera(&swap_chain_descriptor);
 
-        let dda_start = Instant::now();
-        let coll_pos = chunk
+        let pointy_at = chunk
             .dda(camera.position.to_vec(), camera.direction())
             .unwrap();
-        dbg!(dda_start.elapsed());
 
-        chunk.blocks[coll_pos.y][coll_pos.z][coll_pos.x] = Some(Block {
+        chunk.blocks[pointy_at.y][pointy_at.z][pointy_at.x] = Some(Block {
             block_type: BlockType::Cobblestone,
         });