From 09197049cb0d95b9923b1e3430aec47344b8201f Mon Sep 17 00:00:00 2001
From: Joshua Barretto <joshua.s.barretto@gmail.com>
Date: Fri, 27 Sep 2019 11:06:32 +0100
Subject: [PATCH] Made meshing considerably faster

---
 voxygen/src/mesh/segment.rs |  8 ++-----
 voxygen/src/mesh/terrain.rs |  5 ++--
 voxygen/src/mesh/vol.rs     | 47 +++++++++++++++++++++++++++----------
 3 files changed, 39 insertions(+), 21 deletions(-)

diff --git a/voxygen/src/mesh/segment.rs b/voxygen/src/mesh/segment.rs
index 3d8657f4eb..659cb6c926 100644
--- a/voxygen/src/mesh/segment.rs
+++ b/voxygen/src/mesh/segment.rs
@@ -25,14 +25,12 @@ impl Meshable<FigurePipeline, FigurePipeline> for Segment {
 
         for (pos, vox) in self.full_vol_iter() {
             if let Some(col) = vox.get_color() {
-                let col = col.map(|e| e as f32 / 255.0);
-
                 vol::push_vox_verts(
                     &mut mesh,
                     self,
                     pos,
                     offs + pos.map(|e| e as f32),
-                    &[[[Some(col); 3]; 3]; 3],
+                    &[[[Rgba::from_opaque(col); 3]; 3]; 3],
                     |origin, norm, col, ao, light| {
                         FigureVertex::new(
                             origin,
@@ -84,14 +82,12 @@ impl Meshable<SpritePipeline, SpritePipeline> for Segment {
 
         for (pos, vox) in self.full_vol_iter() {
             if let Some(col) = vox.get_color() {
-                let col = col.map(|e| e as f32 / 255.0);
-
                 vol::push_vox_verts(
                     &mut mesh,
                     self,
                     pos,
                     offs + pos.map(|e| e as f32),
-                    &[[[Some(col); 3]; 3]; 3],
+                    &[[[Rgba::from_opaque(col); 3]; 3]; 3],
                     |origin, norm, col, ao, light| {
                         SpriteVertex::new(
                             origin,
diff --git a/voxygen/src/mesh/terrain.rs b/voxygen/src/mesh/terrain.rs
index bb38183b15..b0a8a8755d 100644
--- a/voxygen/src/mesh/terrain.rs
+++ b/voxygen/src/mesh/terrain.rs
@@ -160,10 +160,11 @@ impl<V: RectRasterableVol<Vox = Block> + ReadVol + Debug> Meshable<TerrainPipeli
                         .ok()
                         .filter(|vox| vox.is_opaque())
                         .and_then(|vox| vox.get_color())
-                        .map(|col| col.map(|e| e as f32 / 255.0))
+                        .map(|col| Rgba::from_opaque(col))
+                        .unwrap_or(Rgba::zero())
                 };
 
-                let mut colors = [[[None; 3]; 3]; 3];
+                let mut colors = [[[Rgba::zero(); 3]; 3]; 3];
                 for i in 0..3 {
                     for j in 0..3 {
                         for k in 0..3 {
diff --git a/voxygen/src/mesh/vol.rs b/voxygen/src/mesh/vol.rs
index 1aca68ad81..f3da805ffa 100644
--- a/voxygen/src/mesh/vol.rs
+++ b/voxygen/src/mesh/vol.rs
@@ -10,8 +10,9 @@ use crate::render::{
 /// Given volume, position, and cardinal directions, compute each vertex's AO value.
 /// `dirs` should be a slice of length 5 so that the sliding window of size 2 over the slice
 /// yields each vertex' adjacent positions.
+#[allow(unsafe_code)]
 fn get_ao_quad<V: ReadVol>(
-    vol: &V,
+    _vol: &V,
     pos: Vec3<i32>,
     shift: Vec3<i32>,
     dirs: &[Vec3<i32>],
@@ -20,22 +21,40 @@ fn get_ao_quad<V: ReadVol>(
 ) -> Vec4<(f32, f32)> {
     dirs.windows(2)
         .map(|offs| {
+            let vox_opaque = |pos: Vec3<i32>| {
+                let pos = (pos + 1).map(|e| e as usize);
+                unsafe {
+                    darknesses
+                        .get_unchecked(pos.z)
+                        .get_unchecked(pos.y)
+                        .get_unchecked(pos.x)
+                        <= &0.0
+                }
+            };
+
             let (s1, s2) = (
+                vox_opaque(shift + offs[0]),
+                vox_opaque(shift + offs[1]),
+                /*
                 vol.get(pos + shift + offs[0])
                     .map(&is_opaque)
                     .unwrap_or(false),
                 vol.get(pos + shift + offs[1])
                     .map(&is_opaque)
                     .unwrap_or(false),
+                */
             );
 
             let mut darkness = 0.0;
             for x in 0..2 {
                 for y in 0..2 {
                     let dark_pos = shift + offs[0] * x + offs[1] * y + 1;
-                    darkness += darknesses[dark_pos.z as usize][dark_pos.y as usize]
-                        [dark_pos.x as usize]
-                        / 4.0;
+                    darkness += unsafe {
+                        darknesses
+                            .get_unchecked(dark_pos.z as usize)
+                            .get_unchecked(dark_pos.y as usize)
+                            .get_unchecked(dark_pos.x as usize)
+                    } / 4.0;
                 }
             }
 
@@ -66,27 +85,29 @@ fn get_col_quad<V: ReadVol>(
     _pos: Vec3<i32>,
     _shift: Vec3<i32>,
     dirs: &[Vec3<i32>],
-    cols: &[[[Option<Rgb<f32>>; 3]; 3]; 3],
+    cols: &[[[Rgba<u8>; 3]; 3]; 3],
     _is_opaque: impl Fn(&V::Vox) -> bool,
 ) -> Vec4<Rgb<f32>> {
     dirs.windows(2)
         .map(|offs| {
-            let primary_col = cols[1][1][1].unwrap_or(Rgb::zero());
+            let primary_col = Rgb::from(cols[1][1][1]).map(|e: u8| e as f32);
             let mut color = Rgb::zero();
             let mut total = 0.0;
             for x in 0..2 {
                 for y in 0..2 {
                     let col_pos = offs[0] * x + offs[1] * y + 1;
-                    if let Some(col) = unsafe {
+                    let col = unsafe {
                         cols.get_unchecked(col_pos.z as usize)
                             .get_unchecked(col_pos.y as usize)
                             .get_unchecked(col_pos.x as usize)
-                    } {
-                        if Vec3::<f32>::from(primary_col).distance_squared(Vec3::from(*col))
-                            < 0.25 * 0.25
+                    };
+                    if col.a > 0 {
+                        let col = Rgb::new(col.r, col.g, col.b).map(|e| e as f32);
+                        if Vec3::<f32>::from(primary_col).distance_squared(Vec3::from(col))
+                            < (0.25f32 * 256.0).powf(2.0)
                         {
-                            color += *col;
-                            total += 1.0;
+                            color += col;
+                            total += 256.0;
                         }
                     }
                 }
@@ -148,7 +169,7 @@ pub fn push_vox_verts<V: ReadVol, P: Pipeline>(
     vol: &V,
     pos: Vec3<i32>,
     offs: Vec3<f32>,
-    cols: &[[[Option<Rgb<f32>>; 3]; 3]; 3],
+    cols: &[[[Rgba<u8>; 3]; 3]; 3],
     vcons: impl Fn(Vec3<f32>, Vec3<f32>, Rgb<f32>, f32, f32) -> P::Vertex,
     error_makes_face: bool,
     darknesses: &[[[f32; 3]; 3]; 3],