OpenSpace/modules/multiresvolume/rendering/shenbrickselector.cpp

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 * OpenSpace                                                                             *
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 * Copyright (c) 2014-2017                                                               *
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#include <modules/multiresvolume/rendering/shenbrickselector.h>

namespace {
    const std::string _loggerCat = "ShenBrickSelector";
}

namespace openspace {

ShenBrickSelector::ShenBrickSelector(TSP* tsp, float spatialTolerance, float temporalTolerance)
    : _tsp(tsp)
    , _spatialTolerance(spatialTolerance)
    , _temporalTolerance(temporalTolerance) {}

ShenBrickSelector::~ShenBrickSelector() {

}

void ShenBrickSelector::setSpatialTolerance(float spatialTolerance) {
    _spatialTolerance = spatialTolerance;
}

void ShenBrickSelector::setTemporalTolerance(float temporalTolerance) {
    _temporalTolerance = temporalTolerance;
}

void ShenBrickSelector::selectBricks(int timestep, std::vector<int>& bricks) {
    int numTimeSteps = _tsp->header().numTimesteps_;
    BrickCover coveredBricks(_tsp->header().xNumBricks_);
    selectBricks(timestep, 0, 0, 0, numTimeSteps, coveredBricks, bricks);
}

/**
 * Traverse the Octree in the BST root
 */
void ShenBrickSelector::traverseOT(int timestep, unsigned int brickIndex, BrickCover coveredBricks, std::vector<int>& bricks) {
    unsigned int firstChild = _tsp->getFirstOctreeChild(brickIndex);
    int numTimeSteps = _tsp->header().numTimesteps_;
    for (unsigned int i = 0; i < 8; i++) {
        unsigned int child = firstChild + i;
        BrickCover cover = coveredBricks.split(i % 2, (i/2) % 2, (i/4));
        selectBricks(timestep, child, child, 0, numTimeSteps, cover, bricks);
    }
}

void ShenBrickSelector::traverseBST(int timestep,
                                unsigned int brickIndex,
                                unsigned int bstRootBrickIndex,
                                int timeSpanStart,
                                int timeSpanEnd,
                                BrickCover coveredBricks,
                                std::vector<int>& bricks) {


    int timeSpanCenter = timeSpanStart + (timeSpanEnd - timeSpanStart) / 2;
    unsigned int bstChild;
    if (timestep <= timeSpanCenter) {
        bstChild = _tsp->getBstLeft(brickIndex);
        timeSpanEnd = timeSpanCenter;
    } else {
        bstChild = _tsp->getBstRight(brickIndex);
        timeSpanStart = timeSpanCenter;
    }
    selectBricks(timestep, bstChild, bstRootBrickIndex, timeSpanStart, timeSpanEnd, coveredBricks, bricks);
}

void ShenBrickSelector::selectBricks(int timestep,
                                 unsigned int brickIndex,
                                 unsigned int bstRootBrickIndex,
                                 int timeSpanStart,
                                 int timeSpanEnd,
                                 BrickCover coveredBricks,
                                 std::vector<int>& bricks) {

    if (_tsp->getTemporalError(brickIndex) <= _temporalTolerance) {
        if (_tsp->isOctreeLeaf(bstRootBrickIndex)) {
            selectCover(coveredBricks, brickIndex, bricks);
        } else if (_tsp->getSpatialError(brickIndex) <= _spatialTolerance) {
            selectCover(coveredBricks, brickIndex, bricks);
        } else if (_tsp->isBstLeaf(brickIndex)) {
            traverseOT(timestep, bstRootBrickIndex, coveredBricks, bricks);
        } else {
            traverseBST(timestep, brickIndex, bstRootBrickIndex, timeSpanStart, timeSpanEnd, coveredBricks, bricks);
        }
    } else if (_tsp->isBstLeaf(brickIndex)) {
        if (_tsp->isOctreeLeaf(bstRootBrickIndex)) {
            selectCover(coveredBricks, brickIndex, bricks);
        } else {
            traverseOT(timestep, bstRootBrickIndex, coveredBricks, bricks);
        }
    } else {
        traverseBST(timestep, brickIndex, bstRootBrickIndex, timeSpanStart, timeSpanEnd, coveredBricks, bricks);
    }
}

int ShenBrickSelector::linearCoords(int x, int y, int z) {
    const TSP::Header &header = _tsp->header();
    return x + (header.xNumBricks_ * y) + (header.xNumBricks_ * header.yNumBricks_ * z);
}

void ShenBrickSelector::selectCover(BrickCover coveredBricks, unsigned int brickIndex, std::vector<int>& bricks) {
    for (int z = coveredBricks.lowZ; z < coveredBricks.highZ; z++) {
        for (int y = coveredBricks.lowY; y < coveredBricks.highY; y++) {
            for (int x = coveredBricks.lowX; x < coveredBricks.highX; x++) {
                bricks[linearCoords(x, y, z)] = brickIndex;
            }
        }
    }
}

} // namespace openspace