Finally, working collision

Oliver-makes-code · Nov 18, 2023 · f9028bd · f9028bd
1 parent f5c3e47
commit f9028bd
Show file tree

Hide file tree

Showing 5 changed files with 105 additions and 35 deletions.
diff --git a/Client/Rendering/Camera.cs b/Client/Rendering/Camera.cs
@@ -1,4 +1,7 @@
+using System;
 using GlmSharp;
+using Voxel.Common.Collision;
+using Voxel.Common.World;
 
 namespace Voxel.Client.Rendering;
 
@@ -29,4 +32,35 @@ public class Camera {
     /// Far clip plane of camera.
     /// </summary>
     public float farClip = 500;
+
+    public void MoveAndSlide(VoxelWorld world, dvec3 delta) {
+        for (int i = 0; i < 3; i++) {
+            if (delta == dvec3.Zero)
+                break;
+            delta = MoveAndSlideSingle(world, delta);
+        }
+    }
+
+    private dvec3 MoveAndSlideSingle(VoxelWorld world, dvec3 delta) {
+        const double CollisionBackoff = 1/128d;
+
+        double minPercent = new AABB(
+            position - new dvec3(0.3, 1.6, 0.3),
+            position + new dvec3(0.3, 0.2, 0.3)
+        ).MoveAndSlide(world, delta, out var normal);
+
+        position += delta * minPercent;
+
+        if (minPercent < 1 && minPercent >= 0)
+            position += delta.NormalizedSafe * -CollisionBackoff;
+
+        double remaining = 1 - minPercent;
+        var project = new dvec3(0);
+
+        for (int i = 0; i < 3; i++)
+            if (Math.Abs(normal[i]) < 0.0000001)
+                project[i] = delta[i] * remaining;
+
+        return project;
+    }
 }
diff --git a/Client/Rendering/GameRenderer.cs b/Client/Rendering/GameRenderer.cs
@@ -62,11 +62,9 @@ public override void Render(double delta) {
             MainCamera.rotationVec.x = MathF.PI/2;
 
         inputDir = MainCamera.rotationY * (vec3)inputDir;
-
-        MainCamera.position += new AABB(
-            MainCamera.position - new dvec3(0.3, 1.6, 0.3),
-            MainCamera.position + new dvec3(0.3, 0.2, 0.3)
-        ).MoveAndSlide(VoxelClient.Instance.world!, inputDir / 4);
+        inputDir /= 4;
+
+        MainCamera.MoveAndSlide(VoxelClient.Instance.world!, inputDir);
 
         CameraStateManager.SetToCamera(MainCamera);
 

diff --git a/Common/Collision/AABB.cs b/Common/Collision/AABB.cs
@@ -21,27 +21,26 @@ public AABB(dvec3 a, dvec3 b) {
             Math.Max(a.z, b.z)
         );
     }
-
-    [Pure]
-    public bool CollidesWith(BlockView world) {
-        var min = (ivec3)dvec3.Floor(Min);
-        var max = (ivec3)dvec3.Ceiling(Max);
-        foreach (var pos in Iteration.Cubic(min, max))
-            if (world.GetBlock(pos).IsSolidBlock)
-                return true;
-        return false;
-    }
 
     [Pure]
-    public dvec3 MoveAndSlide(BlockView world, dvec3 delta) {
+    public double MoveAndSlide(BlockView world, dvec3 delta, out dvec3 normal) {
+        normal = new();
+
         var min = (ivec3)dvec3.Floor(Min) - new ivec3(1,1,1);
         var max = (ivec3)dvec3.Ceiling(Max) + new ivec3(1,1,1);
 
+        double minPercent = 1;
+
         foreach (var pos in Iteration.Cubic(min, max))
-            if (world.GetBlock(pos).IsSolidBlock)
-                delta = GetMinimumDistance(new(pos, pos + new ivec3(1, 1, 1)), delta);
+            if (world.GetBlock(pos).IsSolidBlock) {
+                double slide = SlideWith(new(pos, pos + new ivec3(1)), delta, out var locNormal);
+                if (slide >= minPercent)
+                    continue;
+                normal = locNormal;
+                minPercent = slide;
+            }
 
-        return delta;
+        return minPercent;
     }
 
     private bool CollidesWith(AABB other) 
@@ -52,21 +51,17 @@ private bool CollidesWith(AABB other)
             Min.z < other.Max.z &&
             Max.z > other.Min.z;
 
-    private dvec3 GetMinimumDistance(AABB other, dvec3 delta) {
+    private bool CollidesWithOnAxis(AABB other, int axis)
+        => Min[axis] < other.Max[axis] &&
+            Max[axis] > other.Min[axis];
+
+    public double SlideWith(AABB other, dvec3 delta, out dvec3 normal) {
+        normal = new();
         if (!new AABB(Min + delta, Max + delta).CollidesWith(other))
-            return delta;
-
-        double d = GetMinimumDistanceForAxis(other, delta);
+            return 1;
 
-        if (d != 0)
-            Console.WriteLine(d);
-
-        return delta;
-    }
-
-    // TODO: fix method name
-    private double GetMinimumDistanceForAxis(AABB other, dvec3 delta) {
         double length = delta.Length;
+
         if (length == 0)
             return 0;
 
@@ -79,8 +74,14 @@ private double GetMinimumDistanceForAxis(AABB other, dvec3 delta) {
                 enter[i] = other.Min[i] - Max[i];
                 exit[i] = other.Max[i] - Min[i];
             } else if (delta[i] < 0) {
-                exit[i] = other.Min[i] - Max[i];
-                enter[i] = other.Max[i] - Min[i];
+                enter[i] = Min[i] - other.Max[i];
+                exit[i] = Max[i] - other.Min[i];
+            } else if (CollidesWithOnAxis(other, i)) {
+                enter[i] = 0;
+                exit[i] = double.MaxValue;
+            } else {
+                enter[i] = double.MaxValue;
+                exit[i] = -1;
             }
         }
 
@@ -89,12 +90,23 @@ private double GetMinimumDistanceForAxis(AABB other, dvec3 delta) {
             exitDiv = exit / length;
 
         double
-            enterDivMax = enterDiv.Max(),
+            enterDivMax = double.MinValue,
             exitDivMin = exitDiv.Min();
 
+        int maxDir = 0;
+
+        for (int i = 0; i < 3; i++) {
+            if (enterDivMax >= enterDiv[i])
+                continue;
+            enterDivMax = enterDiv[i];
+            maxDir = i;
+        }
+
+        normal[maxDir] = -Math.Sign(delta[maxDir]);
+
         if (enterDivMax > exitDivMin)
             return 0;
-        if (enterDivMax > 1 || exitDivMin > 1)
+        if (enterDivMax > 1)
             return 0;
         if (enterDivMax < 0 || exitDivMin < 0)
             return 0;

diff --git a/Test/TestRegistry.cs b/Test/TestRegistry.cs
@@ -11,6 +11,7 @@ public static class TestRegistry {
     private static List<TestSuite> testSuites = new();
     public static void RegisterTests() {
         testSuites.Add(new BlockViewSuite());
+        testSuites.Add(new AABBSuite());
     }
 
     public static void Main() {

diff --git a/Test/Tests/AABBSuite.cs b/Test/Tests/AABBSuite.cs
@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using GlmSharp;
+using Voxel.Common.Collision;
+
+namespace Voxel.Test.Tests; 
+
+public class AABBSuite : TestSuite {
+
+    protected override Dictionary<string, Test> DefineTests()
+        => new() {
+            ["K.K. Slider"] = () => {
+                var boxA = new AABB(
+                    new(0),
+                    new(1)
+                );
+                var boxB = new AABB(
+                    new(2, 0, 0),
+                    new(3, 1, 1)
+                );
+
+                Assert(boxA.SlideWith(boxB, new(2, 0, 0), out _) == 0.5, "Sliding 1x1x1 cubes on one axis");
+            }
+        };
+}