From 5fc4a74860671041808c4ea76e422995f0cb82a5 Mon Sep 17 00:00:00 2001
From: Jozufozu <jozsefaug@gmail.com>
Date: Fri, 26 Jan 2024 16:40:15 -0800
Subject: [PATCH] Get some bounding spheres at home

- Compute bounding spheres with the AABB method. Should be pretty well
  suited for funny block game.
- Remove Miniball from dependencies.
---
 build.gradle                                  | 18 -----
 .../flywheel/lib/model/ModelUtil.java         | 66 +++++++++++--------
 2 files changed, 40 insertions(+), 44 deletions(-)

diff --git a/build.gradle b/build.gradle
index 9446108f3..0018618a2 100644
--- a/build.gradle
+++ b/build.gradle
@@ -74,21 +74,6 @@ repositories {
     mavenCentral()
 }
 
-// Fix for loading non-mod libraries in dev-env, used for Miniball.
-// https://gist.github.com/SizableShrimp/66b22f1b24c255e1491c8d98d3f11f83
-// v--------------------------------------------------------------------v
-configurations {
-    library
-    implementation.extendsFrom library
-}
-
-minecraft.runs.configureEach {
-    lazyToken('minecraft_classpath') {
-        configurations.library.copyRecursive().resolve().collect { it.absolutePath }.join(File.pathSeparator)
-    }
-}
-// ^--------------------------------------------------------------------^
-
 dependencies {
     testImplementation 'org.junit.jupiter:junit-jupiter:5.8.1'
     minecraft "net.minecraftforge:forge:${minecraft_version}-${forge_version}"
@@ -96,9 +81,6 @@ dependencies {
     compileOnly fg.deobf("maven.modrinth:embeddium:0.2.10+mc1.20.1")
     compileOnly fg.deobf("maven.modrinth:oculus:1.20.1-1.6.9")
 
-    jarJar(group: 'com.dreizak', name: 'miniball', version: '[1.0.3,2.0.0)')
-    library 'com.dreizak:miniball:1.0.3'
-
     // https://discord.com/channels/313125603924639766/725850371834118214/910619168821354497
     // Prevent Mixin annotation processor from getting into IntelliJ's annotation processor settings
     // This allows 'Settings > Build, Execution, and Deployment > Build Tools > Gradle > Build and run using' set to IntelliJ to work correctly
diff --git a/src/main/java/com/jozufozu/flywheel/lib/model/ModelUtil.java b/src/main/java/com/jozufozu/flywheel/lib/model/ModelUtil.java
index b3d0dcfb9..76b23fd00 100644
--- a/src/main/java/com/jozufozu/flywheel/lib/model/ModelUtil.java
+++ b/src/main/java/com/jozufozu/flywheel/lib/model/ModelUtil.java
@@ -4,12 +4,11 @@ import java.lang.reflect.Field;
 import java.nio.ByteBuffer;
 
 import org.jetbrains.annotations.Nullable;
+import org.joml.Vector3f;
 import org.joml.Vector4f;
 import org.lwjgl.system.MemoryUtil;
 import org.slf4j.Logger;
 
-import com.dreizak.miniball.highdim.Miniball;
-import com.dreizak.miniball.model.PointSet;
 import com.jozufozu.flywheel.api.material.Material;
 import com.jozufozu.flywheel.api.model.Mesh;
 import com.jozufozu.flywheel.api.vertex.VertexList;
@@ -37,6 +36,7 @@ public final class ModelUtil {
 	 * Meant to be used for virtual rendering.
 	 */
 	public static final BlockRenderDispatcher VANILLA_RENDERER = createVanillaRenderer();
+	private static final float BOUNDING_SPHERE_EPSILON = 1e-4f;
 
 	private ModelUtil() {
 	}
@@ -128,33 +128,47 @@ public final class ModelUtil {
 	}
 
 	public static Vector4f computeBoundingSphere(VertexList vertexList) {
-		return computeBoundingSphere(new PointSet() {
-			@Override
-			public int size() {
-				return vertexList.vertexCount();
-			}
+		var center = computeCenterOfAABBContaining(vertexList);
 
-			@Override
-			public int dimension() {
-				return 3;
-			}
+		var radius = computeMaxDistanceTo(vertexList, center) + BOUNDING_SPHERE_EPSILON;
 
-			@Override
-			public double coord(int i, int dim) {
-				return switch (dim) {
-					case 0 -> vertexList.x(i);
-					case 1 -> vertexList.y(i);
-					case 2 -> vertexList.z(i);
-					default -> throw new IllegalArgumentException("Invalid dimension: " + dim);
-				};
-			}
-		});
+		return new Vector4f(center, radius);
 	}
 
-	public static Vector4f computeBoundingSphere(PointSet points) {
-		var miniball = new Miniball(points);
-		double[] center = miniball.center();
-		double radius = miniball.radius();
-		return new Vector4f((float) center[0], (float) center[1], (float) center[2], (float) radius);
+	private static float computeMaxDistanceTo(VertexList vertexList, Vector3f pos) {
+		float farthestDistanceSquared = -1;
+
+		for (int i = 0; i < vertexList.vertexCount(); i++) {
+			var distanceSquared = pos.distanceSquared(vertexList.x(i), vertexList.y(i), vertexList.z(i));
+
+			if (distanceSquared > farthestDistanceSquared) {
+				farthestDistanceSquared = distanceSquared;
+			}
+		}
+
+		return (float) Math.sqrt(farthestDistanceSquared);
+	}
+
+	private static Vector3f computeCenterOfAABBContaining(VertexList vertexList) {
+		var min = new Vector3f(Float.MAX_VALUE);
+		var max = new Vector3f(Float.MIN_VALUE);
+
+		for (int i = 0; i < vertexList.vertexCount(); i++) {
+			float x = vertexList.x(i);
+			float y = vertexList.y(i);
+			float z = vertexList.z(i);
+
+			// JOML's min/max methods don't accept floats :whywheel:
+			min.x = Math.min(min.x, x);
+			min.y = Math.min(min.y, y);
+			min.z = Math.min(min.z, z);
+
+			max.x = Math.max(max.x, x);
+			max.y = Math.max(max.y, y);
+			max.z = Math.max(max.z, z);
+		}
+
+		return min.add(max)
+				.mul(0.5f);
 	}
 }