// Copyright 2019 Tencent
// SPDX-License-Identifier: BSD-3-Clause

#version 450

layout (constant_id = 0) const int stride = 0;
layout (constant_id = 1) const int mode = 0;

#define shape_constant_id_offset 2
layout (constant_id = shape_constant_id_offset + 0) const int dims = 0;
layout (constant_id = shape_constant_id_offset + 1) const int w = 0;
layout (constant_id = shape_constant_id_offset + 2) const int h = 0;
layout (constant_id = shape_constant_id_offset + 3) const int c = 0;
layout (constant_id = shape_constant_id_offset + 4) const int cstep = 0;

layout (constant_id = shape_constant_id_offset + 5) const int outdims = 0;
layout (constant_id = shape_constant_id_offset + 6) const int outw = 0;
layout (constant_id = shape_constant_id_offset + 7) const int outh = 0;
layout (constant_id = shape_constant_id_offset + 8) const int outc = 0;
layout (constant_id = shape_constant_id_offset + 9) const int outcstep = 0;

#if NCNN_fp16_packed
layout (binding = 0) readonly buffer bottom_blob { sfpvec2 bottom_blob_data[]; };
#else
layout (binding = 0) readonly buffer bottom_blob { sfp bottom_blob_data[]; };
#endif
layout (binding = 1) writeonly buffer top_blob { sfpvec4 top_blob_data[]; };

layout (push_constant) uniform parameter
{
    int dims;
    int w;
    int h;
    int c;
    int cstep;

    int outdims;
    int outw;
    int outh;
    int outc;
    int outcstep;
} p;

void main()
{
    int gx = int(gl_GlobalInvocationID.x);
    int gy = int(gl_GlobalInvocationID.y);
    int gz = int(gl_GlobalInvocationID.z);

    if (gx >= psc(outw) || gy >= psc(outh) || gz >= psc(outc))
        return;

    ivec4 gz4 = gz * 4 + ivec4(0, 1, 2, 3);

    ivec4 z4;
    ivec4 zi4;
    if (mode == 0)
    {
        z4 = gz4 / (stride * stride);
        zi4 = gz4 % (stride * stride);
    }
    else // if (mode == 1)
    {
        z4 = gz4 % (psc(c) * 4);
        zi4 = gz4 / (psc(c) * 4);
    }
    ivec4 y4 = gy * stride + zi4 / stride;
    ivec4 x4 = gx * stride + zi4 % stride;

    int gi = gz * psc(outcstep) + gy * psc(outw) + gx;

#if NCNN_fp16_packed
    ivec4 v_offset = ((z4 / 4) * psc(cstep) + y4 * psc(w) + x4) * 2 + (z4 % 4) / 2;
    ivec4 lane2 = z4 % 2;

    afpvec2 vr = buffer_ld2(bottom_blob_data, v_offset.r);
    afpvec2 vg = buffer_ld2(bottom_blob_data, v_offset.g);
    afpvec2 vb = buffer_ld2(bottom_blob_data, v_offset.b);
    afpvec2 va = buffer_ld2(bottom_blob_data, v_offset.a);

    afpvec4 v = afpvec4(vr[lane2.r], vg[lane2.g], vb[lane2.b], va[lane2.a]);

    buffer_st4(top_blob_data, gi, v);
#else
    ivec4 v_offset = ((z4 / 4) * psc(cstep) + y4 * psc(w) + x4) * 4 + z4 % 4;

    buffer_cp1to4(top_blob_data, gi, bottom_blob_data, v_offset);
#endif
}
