From 77a3b47bdace578849715649fdb18984de40704e Mon Sep 17 00:00:00 2001
From: Joshua Barretto <joshua.s.barretto@gmail.com>
Date: Thu, 6 Jun 2019 08:13:58 +0100
Subject: [PATCH] Only draw chunks outside of fog boundary, reduce fog strength

---
 voxygen/shaders/include/sky.glsl |  2 +-
 voxygen/src/scene/mod.rs         |  7 ++++++-
 voxygen/src/scene/terrain.rs     | 31 +++++++++++++++++++++++++++----
 3 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/voxygen/shaders/include/sky.glsl b/voxygen/shaders/include/sky.glsl
index b7fe28d4ca..6ee29fb132 100644
--- a/voxygen/shaders/include/sky.glsl
+++ b/voxygen/shaders/include/sky.glsl
@@ -21,7 +21,7 @@ vec3 get_sky_color(vec3 dir, float time_of_day) {
 
 float fog(vec2 f_pos, vec2 focus_pos) {
 	float dist = distance(f_pos, focus_pos) / view_distance.x;
-	float min_fog = 0.5;
+	float min_fog = 0.75;
 	float max_fog = 1.0;
 
 	return clamp((dist - min_fog) / (max_fog - min_fog), 0.0, 1.0);
diff --git a/voxygen/src/scene/mod.rs b/voxygen/src/scene/mod.rs
index 305fbca348..4f74fae068 100644
--- a/voxygen/src/scene/mod.rs
+++ b/voxygen/src/scene/mod.rs
@@ -166,7 +166,12 @@ impl Scene {
         renderer.render_skybox(&self.skybox.model, &self.globals, &self.skybox.locals);
 
         // Render terrain and figures.
-        self.terrain.render(renderer, &self.globals);
+        self.terrain.render(
+            renderer,
+            &self.globals,
+            self.camera.get_focus_pos(),
+            self.loaded_distance,
+        );
         self.figure_mgr.render(renderer, client, &self.globals);
 
         renderer.render_post_process(
diff --git a/voxygen/src/scene/terrain.rs b/voxygen/src/scene/terrain.rs
index 8e1a39d57c..dfa13703a5 100644
--- a/voxygen/src/scene/terrain.rs
+++ b/voxygen/src/scene/terrain.rs
@@ -3,7 +3,11 @@ use crate::{
     render::{Consts, Globals, Mesh, Model, Renderer, TerrainLocals, TerrainPipeline},
 };
 use client::Client;
-use common::{terrain::TerrainMap, vol::SampleVol, volumes::vol_map_2d::VolMap2dErr};
+use common::{
+    terrain::{TerrainChunkSize, TerrainMap},
+    vol::{SampleVol, VolSize},
+    volumes::vol_map_2d::VolMap2dErr,
+};
 use std::{collections::HashMap, i32, sync::mpsc, time::Duration};
 use vek::*;
 
@@ -200,9 +204,28 @@ impl Terrain {
         }
     }
 
-    pub fn render(&self, renderer: &mut Renderer, globals: &Consts<Globals>) {
-        for (_, chunk) in &self.chunks {
-            renderer.render_terrain_chunk(&chunk.model, globals, &chunk.locals);
+    pub fn render(
+        &self,
+        renderer: &mut Renderer,
+        globals: &Consts<Globals>,
+        focus_pos: Vec3<f32>,
+        loaded_distance: f32,
+    ) {
+        for (pos, chunk) in &self.chunks {
+            // Limit focus_pos to chunk bounds
+            let chunk_pos = pos.map2(TerrainChunkSize::SIZE.into(), |e, sz: u32| {
+                e as f32 * sz as f32
+            });
+            let nearest_in_chunk = Vec2::from(focus_pos).clamped(
+                chunk_pos,
+                chunk_pos + Vec2::from(TerrainChunkSize::SIZE).map(|e: u32| e as f32),
+            );
+
+            if Vec2::<f32>::from(focus_pos).distance_squared(nearest_in_chunk)
+                < loaded_distance.powf(2.0)
+            {
+                renderer.render_terrain_chunk(&chunk.model, globals, &chunk.locals);
+            }
         }
     }
 }