// SPDX-License-Identifier: GPL-3.0-or-later

#version 450
layout(local_size_x = 128) in;
layout(std430, set = 0, binding = 0) readonly buffer Source { uint source_words[]; };
layout(std430, set = 0, binding = 1) writeonly buffer Destination { uint dest_words[]; };
layout(push_constant) uniform Parameters { uint source_bias; uint source_size; uint total_words; };

// Diagnostic conversion of the captured 69-byte layout: insert three bytes before offset 65.
void main() {
    uint word = gl_GlobalInvocationID.x;
    if (word >= total_words) return;
    uint vertex = word / 18;
    uint offset = (word % 18) * 4;
    uint value = 0;
    for (uint i = 0; i < 4; ++i) {
        uint dest_byte = offset + i;
        if (dest_byte >= 65 && dest_byte < 68) continue;
        uint src_byte = vertex * 69 + dest_byte - (dest_byte >= 68 ? 3 : 0);
        if (src_byte >= source_size) continue;
        uint address = source_bias + src_byte;
        uint byte_value = (source_words[address / 4] >> ((address % 4) * 8)) & 255;
        value |= byte_value << (i * 8);
    }
    dest_words[word] = value;
}