74 lines
2.7 KiB
C#

using UnityEngine;
using Unity.Burst;
using Unity.Collections;
using Unity.Jobs;
using Unity.Mathematics;
namespace Pathfinding.Graphs.Grid.Jobs {
/// <summary>Calculates for each grid node if it should be walkable or not</summary>
[BurstCompile(FloatMode = FloatMode.Fast)]
public struct JobNodeWalkability : IJob {
/// <summary>
/// If true, use the normal of the raycast hit to check if the ground is flat enough to stand on.
///
/// Any nodes with a steeper slope than <see cref="maxSlope"/> will be made unwalkable.
/// </summary>
public bool useRaycastNormal;
/// <summary>Max slope in degrees</summary>
public float maxSlope;
/// <summary>Normalized up direction of the graph</summary>
public Vector3 up;
/// <summary>If true, nodes will be made unwalkable if no ground was found under them</summary>
public bool unwalkableWhenNoGround;
/// <summary>For layered grid graphs, if there's a node above another node closer than this distance, the lower node will be made unwalkable</summary>
public float characterHeight;
/// <summary>Number of nodes in each layer</summary>
public int layerStride;
[ReadOnly]
public NativeArray<float3> nodePositions;
public NativeArray<float4> nodeNormals;
[WriteOnly]
public NativeArray<bool> nodeWalkable;
public void Execute () {
// Cosinus of the max slope
float cosMaxSlopeAngle = math.cos(math.radians(maxSlope));
float4 upNative = new float4(up.x, up.y, up.z, 0);
float3 upNative3 = upNative.xyz;
for (int i = 0; i < nodeNormals.Length; i++) {
// walkable will be set to false if no ground was found (unless that setting has been disabled)
// The normal will only be non-zero if something was hit.
bool didHit = math.any(nodeNormals[i]);
var walkable = didHit;
if (!didHit && !unwalkableWhenNoGround && i < layerStride) {
walkable = true;
// If there was no hit, but we still want to make the node walkable, then we set the normal to the up direction
nodeNormals[i] = upNative;
}
// Check if the node is on a slope steeper than permitted
if (walkable && useRaycastNormal && didHit) {
// Take the dot product to find out the cosine of the angle it has (faster than Vector3.Angle)
float angle = math.dot(nodeNormals[i], upNative);
// Check if the ground is flat enough to stand on
if (angle < cosMaxSlopeAngle) {
walkable = false;
}
}
// Check if there is a node above this one (layered grid graph only)
if (walkable && i + layerStride < nodeNormals.Length && math.any(nodeNormals[i + layerStride])) {
walkable = math.dot(upNative3, nodePositions[i + layerStride] - nodePositions[i]) >= characterHeight;
}
nodeWalkable[i] = walkable;
}
}
}
}