N维网格顶点计算

Question

问题：给定单元格索引（红色）计算单元格索引周围的数组索引（黑色）。

bool CalculateCellVerticesFromIndex(size_t index, size_t* vertices)
{
    size_t gridSize[2] = {6, 5};
    return true;  // if the index was valid
    return false; // if the index was invalid
}

计算已知大小的N维网格中单元格周围的顶点（m X n X ...）。

示例图：

说int vertices[4] = {0, 0, 0, 0}

在上图中，CalculateCellVerticesFromIndex（12，vertices）;应该用{14,15,20,21}填充顶点;

Answer 1

Width = 6
Row = Index div (Width - 1)
if Row > 5 - 2 then OutOfGrid
Column = Index mod (Width - 1)
LeftBottom = Row * Width + Column
LeftTop = LeftBottom + Width
RightBottom and RightTop - elaborate