EntitiesSample_9. CrossQuery

该示例主要的内容：

1.URPMaterialPropertyBaseColor：Unity.Rendering空间下的材质组件，该结构体拥有一个float4颜色的变量，赋值和其他的组件一样

2.EntityQuery转数组

boxQuery.ToComponentDataArray<LocalTransform>(Allocator.Temp);

3.IJobChunk的使用

  new CollisionJob
            {
                //获取LocalTransform组件的句柄
                LocalTransformTypeHandle = SystemAPI.GetComponentTypeHandle<LocalTransform>(true),
                //获取DefaultColor组件的句柄
                DefaultColorTypeHandle = SystemAPI.GetComponentTypeHandle<DefaultColor>(true),
                //获取URPMaterialPropertyBaseColor组件的句柄
                BaseColorTypeHandle = SystemAPI.GetComponentTypeHandle<URPMaterialPropertyBaseColor>(),
                //获取实体类型的句柄
                EntityTypeHandle = SystemAPI.GetEntityTypeHandle(),
                //实体查询对象转化为数组句柄
                OtherChunks = boxQuery.ToArchetypeChunkArray(state.WorldUpdateAllocator)
                //作业调度，   Complete()：需要全部完成，然后执行下一次 
            }.ScheduleParallel(boxQuery, state.Dependency).Complete();

特别注意的是IJobChunk接口中的句柄变量，都需要 [ReadOnly]标签修饰，例如：

 [ReadOnly] public ComponentTypeHandle<LocalTransform> LocalTransformTypeHandle;

在Chunk作业中，需要使用ArchetypeChunk chunk获取当前要操作的变量值，示例代码是这样的没什么好解释的，就是双循环判断距离

[BurstCompile]
    public struct CollisionJob : IJobChunk
    {
        [ReadOnly] public ComponentTypeHandle<LocalTransform> LocalTransformTypeHandle;
        [ReadOnly] public ComponentTypeHandle<DefaultColor> DefaultColorTypeHandle;
        public ComponentTypeHandle<URPMaterialPropertyBaseColor> BaseColorTypeHandle;
        [ReadOnly] public EntityTypeHandle EntityTypeHandle;
 
        [ReadOnly] public NativeArray<ArchetypeChunk> OtherChunks;
 
        public void Execute(in ArchetypeChunk chunk, int unfilteredChunkIndex, bool useEnabledMask,
            in v128 chunkEnabledMask)
        {
            var transforms = chunk.GetNativeArray(ref LocalTransformTypeHandle);
            var defaultColors = chunk.GetNativeArray(ref DefaultColorTypeHandle);
            var baseColors = chunk.GetNativeArray(ref BaseColorTypeHandle);
            var entities = chunk.GetNativeArray(EntityTypeHandle);
 
            for (int i = 0; i < transforms.Length; i++)
            {
                var transform = transforms[i];
                var baseColor = baseColors[i];
                var entity = entities[i];
                // reset to default color
                baseColor.Value = defaultColors[i].Value;
                for (int j = 0; j < OtherChunks.Length; j++)
                {
                    var otherChunk = OtherChunks[j];
                    var otherTranslations = otherChunk.GetNativeArray(ref LocalTransformTypeHandle);
                    var otherEntities = otherChunk.GetNativeArray(EntityTypeHandle);
 
                    for (int k = 0; k < otherChunk.Count; k++)
                    {
                        var otherTranslation = otherTranslations[k];
                        var otherEntity = otherEntities[k];
 
                        if (entity != otherEntity && math.distancesq(transform.Position, otherTranslation.Position) < 1)
                        {
                            baseColor.Value.y = 0.5f; // set green channel
                            break;
                        }
                    }
                }
                baseColors[i] = baseColor;
            }
        }
    }