Class VeinEdgeBitmask

plugins/changevein.cpp:38–98

static const df::coord2d DIAGONAL_OFFSETS[] = { df::coord2d(16, -16), df::coord2d(16, 16), df::coord2d(-16, -16), df::coord2d(-16, 16) };

struct VeinEdgeBitmask
{
    int32_t mat;
    // North: 0 | East: 1 | South: 2 | West: 3
    uint16_t edges[4];
    // NE: 0 | SE: 1 | SW: 2 | NW: 3
    bool corners[4];

    VeinEdgeBitmask(df::block_square_event_mineralst* event)
    {
        mat = event->inorganic_mat;

        // North & South
        edges[NORTH] = event->tile_bitmask.bits[0];
        edges[SOUTH] = event->tile_bitmask.bits[15];

        // East & West
        edges[EAST] = 0;
        edges[WEST] = 0;
        for (uint8_t i = 0; i < 16; i++)
        {
            // East-most tile is represented by the largest bit
            edges[EAST] |= (event->tile_bitmask.bits[i] & 0b1000000000000000) >> (15 - i);
            // West-most tile is represented by the smallest bit
            edges[WEST] |= (event->tile_bitmask.bits[i] & 0b0000000000000001) << i;
        }

        corners[NORTHEAST] = edges[NORTH] & 0b1000000000000000;
        corners[SOUTHEAST] = edges[SOUTH] & 0b1000000000000000;
        corners[SOUTHWEST] = edges[SOUTH] & 0b0000000000000001;
        corners[NORTHWEST] = edges[NORTH] & 0b0000000000000001;
    }

    void SmudgeBitmask()
    {
        for (uint8_t i = 0; i < 4; i++)
        {
            edges[i] |= (edges[i] << 1) | (edges[i] >> 1);
        }
    }

    bool Merge(VeinEdgeBitmask& other)
    {
        if (other.mat != this->mat)
            return false;

        for (uint8_t i = 0; i < 4; i++)
        {
            this->edges[i] |= other.edges[i];
            this->corners[i] |= other.corners[i];
        }

        return true;
    }

    bool Merge(df::block_square_event_mineralst* event)
    {
        VeinEdgeBitmask temp = VeinEdgeBitmask(event);