From 4ebb90f7d152dd51fafb7853583d6c55d3656a91 Mon Sep 17 00:00:00 2001
From: "Lukas Rieger (Blue)" <TBlueF@users.noreply.github.com>
Date: Wed, 9 Nov 2022 16:56:53 +0100
Subject: [PATCH] Finalize shader changes, improve shading for lower lods and
 make flat-view rotatable

---
 src/controls/map/MapControls.js        | 11 ++++---
 src/map/LowresTileLoader.js            | 10 ++++--
 src/map/lowres/LowresFragmentShader.js | 42 ++++++++++++++------------
 3 files changed, 37 insertions(+), 26 deletions(-)

diff --git a/src/controls/map/MapControls.js b/src/controls/map/MapControls.js
index ef2b727..beb9afc 100644
--- a/src/controls/map/MapControls.js
+++ b/src/controls/map/MapControls.js
@@ -173,10 +173,13 @@ export class MapControls {
         let maxAngleForZoom = this.getMaxPerspectiveAngleForDistance(this.manager.distance);
 
         // rotation
-        if (this.manager.ortho === 0) {
-            this.mouseRotate.update(delta, map);
-            this.keyRotate.update(delta, map);
-            this.touchRotate.update(delta, map);
+        this.mouseRotate.update(delta, map);
+        this.keyRotate.update(delta, map);
+        this.touchRotate.update(delta, map);
+
+        // snap rotation to north on orthographic view
+        if (this.manager.ortho !== 0 && Math.abs(this.manager.rotation) < 0.3) {
+            this.manager.rotation = softClamp(this.manager.rotation, 0, 0, 0.05);
         }
 
         // tilt
diff --git a/src/map/LowresTileLoader.js b/src/map/LowresTileLoader.js
index a4a1933..15017a3 100644
--- a/src/map/LowresTileLoader.js
+++ b/src/map/LowresTileLoader.js
@@ -85,6 +85,8 @@ export class LowresTileLoader {
                         return;
                     }
 
+                    const scale = Math.pow(this.tileSettings.lodFactor, this.lod - 1);
+
                     let material = new ShaderMaterial({
                         uniforms: {
                             ...this.uniforms,
@@ -98,7 +100,12 @@ export class LowresTileLoader {
                                 type: 't',
                                 value: texture
                             },
-                            lod: {value: this.lod}
+                            lod: {
+                                value: this.lod
+                            },
+                            lodScale: {
+                                value: scale
+                            }
                         },
                         vertexShader: this.vertexShader,
                         fragmentShader: this.fragmentShader,
@@ -112,7 +119,6 @@ export class LowresTileLoader {
 
                     let object = new Mesh(this.geometry, material);
 
-                    const scale = Math.pow(this.tileSettings.lodFactor, this.lod - 1);
                     object.position.set(tileX * this.tileSettings.tileSize.x * scale, 0, tileZ * this.tileSettings.tileSize.z * scale);
                     object.scale.set(scale, 1, scale);
 
diff --git a/src/map/lowres/LowresFragmentShader.js b/src/map/lowres/LowresFragmentShader.js
index 36532bc..cc7b731 100644
--- a/src/map/lowres/LowresFragmentShader.js
+++ b/src/map/lowres/LowresFragmentShader.js
@@ -28,8 +28,6 @@ export const LOWRES_FRAGMENT_SHADER = `
 ${ShaderChunk.logdepthbuf_pars_fragment}
 
 #define PI 3.1415926535897932
-#define PI_D10 0.3141592653589793
-#define PI_D5 0.6283185307179586
 
 #ifndef texture
 	#define texture texture2D
@@ -49,7 +47,8 @@ uniform TileMap hiresTileMap;
 uniform sampler2D textureImage;
 uniform vec2 tileSize;
 uniform vec2 textureSize;
-uniform int lod;
+uniform float lod;
+uniform float lodScale;
 
 varying vec3 vPosition;
 varying vec3 vWorldPosition;
@@ -88,29 +87,32 @@ void main() {
 	
 	float heightX = metaToHeight(texture(textureImage, posToMetaUV(vPosition.xz + vec2(1.0, 0.0))));
 	float heightZ = metaToHeight(texture(textureImage, posToMetaUV(vPosition.xz + vec2(0.0, 1.0))));
-	float diff = (height - heightX) + (height - heightZ);
-	vec3 defaultRGB = color.rgb + clamp(diff * 0.04, -0.2, 0.04);
+	float heightDiff = ((height - heightX) + (height - heightZ)) / lodScale;
+	float shade = clamp(heightDiff * 0.06, -0.2, 0.04);
 	
-	if(lod == 1) {
-		vec3 occRGB = color.rgb + clamp(diff * 0.02, -0.1, 0.04);
+	float ao = 0.0;
+	float aoStrength = 0.0;
+	if(lod == 1.0) {
+		aoStrength = smoothstep(PI - 0.8, PI - 0.2, acos(-clamp(viewMatrix[1][2], 0.0, 1.0)));
+		aoStrength *= 1.0 - smoothstep(200.0, 500.0, vDistance);
 		
-		float ao = 0.0;
-		const float r = 3.0;
-		const float step = 0.2;
-		for (float vx = -r; vx <= r; vx++) {
-			for (float vz = -r; vz <= r; vz++) {
-				diff = height - metaToHeight(texture(textureImage, posToMetaUV(vPosition.xz + vec2(vx * step, vz * step))));
-				if (diff < 0.0) {
-					ao -= step / r;            
+		if (aoStrength > 0.0) { 
+			const float r = 3.0;
+			const float step = 0.2;
+			const float o = step / r * 0.1;
+			for (float vx = -r; vx <= r; vx++) {
+				for (float vz = -r; vz <= r; vz++) {
+					heightDiff = height - metaToHeight(texture(textureImage, posToMetaUV(vPosition.xz + vec2(vx * step, vz * step))));
+					if (heightDiff < 0.0) {
+						ao -= o;            
+					}
 				}
 			}
 		}
-		occRGB += ao * 0.1;
-		
-		color.rgb = mix(defaultRGB, occRGB, smoothstep(PI - PI_D5, PI - PI_D10, acos(-clamp(viewMatrix[1][2], 0.0, 1.0))));
-	} else {
-		color.rgb = defaultRGB;
 	}
+	
+	color.rgb += mix(shade, shade * 0.3 + ao, aoStrength);
+	
 	float blockLight = metaToLight(meta);
 	float light = mix(blockLight, 15.0, sunlightStrength);
 	color.rgb *= mix(ambientLight, 1.0, light / 15.0);