feat: ao init

Author: syntaxerror-9

src/utils.rs

@@ -164,6 +164,14 @@ pub(crate) mod threadpool {
     }
 }
 
+// https://0fps.net/2013/07/03/ambient-occlusion-for-minecraft-like-worlds/
+fn calc_vertex_ao(side1: bool, side2: bool, up: bool) -> u8 {
+    if side1 && side2 {
+        return 0;
+    }
+    return 3 - (side1 as u8 + side2 as u8 + up as u8);
+}
+
 /* Utility traits */
 pub trait ChunkFromPosition {
     fn get_chunk_from_position_absolute(&self) -> (i32, i32);
@@ -193,7 +201,52 @@ impl ChunkFromPosition for glam::Vec3 {
 }
 
 mod tests {
-    use crate::utils::{ChunkFromPosition, RelativeFromAbsolute};
+    use crate::utils::{calc_vertex_ao, ChunkFromPosition, RelativeFromAbsolute};
+    use glam::vec3;
+    #[test]
+    fn should_calculate_the_correct_ao() {
+        let vertex_position = vec3(0.5, 0.5, 0.5); // Belongs to voxel 0,0,0
+        let neighbour_voxels = [vec3(1.0, 1.0, 0.0), vec3(1.0, 1.0, 1.0)];
+
+        let has_side1 = neighbour_voxels.contains(&vec3(
+            f32::floor(vertex_position.x + 1.0),
+            f32::floor(vertex_position.y + 1.0),
+            f32::floor(vertex_position.z + 0.0),
+        ));
+        let has_side2 = neighbour_voxels.contains(&vec3(
+            f32::floor(vertex_position.x + 0.0),
+            f32::floor(vertex_position.y + 1.0),
+            f32::floor(vertex_position.z + 1.0),
+        ));
+        let has_corner = neighbour_voxels.contains(&vec3(
+            f32::floor(vertex_position.x + 1.0),
+            f32::floor(vertex_position.y + 1.0),
+            f32::floor(vertex_position.z + 1.0),
+        ));
+        let vao = calc_vertex_ao(has_side1, has_side2, has_corner);
+
+        assert_eq!(vao, 1);
+
+        let vertex_position = vec3(0.5, 0.5, -0.5); // Belongs to voxel 0,0,0
+
+        let has_side1 = neighbour_voxels.contains(&vec3(
+            f32::floor(vertex_position.x + 1.0),
+            f32::floor(vertex_position.y + 1.0),
+            f32::floor(vertex_position.z + 0.0),
+        ));
+        let has_side2 = neighbour_voxels.contains(&vec3(
+            f32::floor(vertex_position.x + 0.0),
+            f32::floor(vertex_position.y + 1.0),
+            f32::floor(vertex_position.z + 1.0),
+        ));
+        let has_corner = neighbour_voxels.contains(&vec3(
+            f32::floor(vertex_position.x + 1.0),
+            f32::floor(vertex_position.y + 1.0),
+            f32::floor(vertex_position.z + 1.0),
+        ));
+        let vao = calc_vertex_ao(has_side1, has_side2, has_corner);
+        assert_eq!(vao, 2)
+    }
 
     #[test]
     fn should_get_the_correct_chunk_from_position_absolute() {