/*
batch version of point grouping, modified from the original implementation of official PointNet++ codes.
Written by Shaoshuai Shi
All Rights Reserved 2018.
*/


#include <torch/serialize/tensor.h>
#include <cuda.h>
#include <cuda_runtime_api.h>
#include <vector>
#include <THC/THC.h>
#include "group_points_gpu.h"

extern THCState *state;


int group_points_grad_wrapper_fast(int b, int c, int n, int npoints, int nsample, 
    at::Tensor grad_out_tensor, at::Tensor idx_tensor, at::Tensor grad_points_tensor) {

    float *grad_points = grad_points_tensor.data<float>();
    const int *idx = idx_tensor.data<int>();
    const float *grad_out = grad_out_tensor.data<float>();

    cudaStream_t stream = THCState_getCurrentStream(state);

    group_points_grad_kernel_launcher_fast(b, c, n, npoints, nsample, grad_out, idx, grad_points, stream);
    return 1;
}


int group_points_wrapper_fast(int b, int c, int n, int npoints, int nsample, 
    at::Tensor points_tensor, at::Tensor idx_tensor, at::Tensor out_tensor) {

    const float *points = points_tensor.data<float>();
    const int *idx = idx_tensor.data<int>();
    float *out = out_tensor.data<float>();

    cudaStream_t stream = THCState_getCurrentStream(state);

    group_points_kernel_launcher_fast(b, c, n, npoints, nsample, points, idx, out, stream);
    return 1;
}