OpenSpace/modules/globebrowsing/tile/tileprovider/tileprovider.cpp

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 * OpenSpace                                                                             *
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 * Copyright (c) 2014-2017                                                               *
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#include <modules/globebrowsing/tile/tileprovider/tileprovider.h>

#include <modules/globebrowsing/tile/tileselector.h>

#include <openspace/util/factorymanager.h>

#include <ghoul/misc/dictionary.h>
#include <ghoul/logging/logmanager.h>

#include <climits>

namespace {
    const char* KeyType = "Type";
}

namespace openspace {
namespace globebrowsing {
namespace tileprovider {

unsigned int TileProvider::_numTileProviders = 0;

std::unique_ptr<TileProvider> TileProvider::createFromDictionary(const ghoul::Dictionary& dictionary) {
    std::string type = "LRUCaching";
    dictionary.getValue(KeyType, type);
    auto factory = FactoryManager::ref().factory<TileProvider>();
    std::unique_ptr<TileProvider> result = factory->create(type, dictionary);
    return result;
}

TileProvider::TileProvider()
    : properties::PropertyOwner("tileProvider")
    , _initialized(false)
{
    initialize();
}

TileProvider::TileProvider(const ghoul::Dictionary&)
    : properties::PropertyOwner("tileProvider")
    , _initialized(false)
{
    initialize();
};

float TileProvider::noDataValueAsFloat() {
    ghoul_assert(_initialized, "TileProvider was not initialized.");
    return std::numeric_limits<float>::min();
}

ChunkTile TileProvider::getChunkTile(TileIndex tileIndex, int parents, int maxParents) {
    ghoul_assert(_initialized, "TileProvider was not initialized.");
    TileUvTransform uvTransform;
    uvTransform.uvOffset = glm::vec2(0, 0);
    uvTransform.uvScale = glm::vec2(1, 1);

    // Step 1. Traverse 0 or more parents up the chunkTree as requested by the caller
    for (int i = 0; i < parents && tileIndex.level > 1; i++) {
        tileselector::ascendToParent(tileIndex, uvTransform);
    }
    maxParents -= parents;

    // Step 2. Traverse 0 or more parents up the chunkTree to make sure we're inside 
    //         the range of defined data.
    int maximumLevel = maxLevel();
    while (tileIndex.level > maximumLevel){
        tileselector::ascendToParent(tileIndex, uvTransform);
        maxParents--;
    }
    if(maxParents < 0){
        return ChunkTile{ Tile::TileUnavailable, uvTransform, TileDepthTransform() };
    }
    
    // Step 3. Traverse 0 or more parents up the chunkTree until we find a chunk that 
    //         has a loaded tile ready to use. 
    while (tileIndex.level > 1) {
        Tile tile = getTile(tileIndex);
        if (tile.status() != Tile::Status::OK) {
            if (--maxParents < 0){
                return ChunkTile{ Tile::TileUnavailable, uvTransform, TileDepthTransform() };
            }
            tileselector::ascendToParent(tileIndex, uvTransform);
        }
        else {
            return ChunkTile{ tile, uvTransform, TileDepthTransform() };
        }
    }
    
    return ChunkTile{ Tile::TileUnavailable, uvTransform, TileDepthTransform() };
}

ChunkTilePile TileProvider::getChunkTilePile(TileIndex tileIndex, int pileSize) {
    ghoul_assert(_initialized, "TileProvider was not initialized.");
    ghoul_assert(pileSize >= 0, "pileSize must be positive");
    ChunkTilePile chunkTilePile;
    chunkTilePile.resize(pileSize);
    for (size_t i = 0; i < pileSize; ++i) {
        chunkTilePile[i] = getChunkTile(tileIndex, i);
        if (chunkTilePile[i].tile.status() == Tile::Status::Unavailable) {
            if (i>0) {
                chunkTilePile[i].tile = chunkTilePile[i-1].tile;
                chunkTilePile[i].uvTransform.uvOffset = chunkTilePile[i-1].uvTransform.uvOffset;
                chunkTilePile[i].uvTransform.uvScale = chunkTilePile[i-1].uvTransform.uvScale;
            }
            else {
                chunkTilePile[i].tile = getDefaultTile();
                chunkTilePile[i].uvTransform.uvOffset = { 0, 0 };
                chunkTilePile[i].uvTransform.uvScale = { 1, 1 };
            }
        }
    }
    return chunkTilePile;
}

bool TileProvider::initialize() {
    ghoul_assert(!_initialized, "TileProvider can only be initialized once.");
    _uniqueIdentifier = _numTileProviders;
    _numTileProviders++;
    if (_numTileProviders == UINT_MAX) {
        _numTileProviders--;
        return false;
    }
  
    _initialized = true;
    return true;
}

unsigned int TileProvider::uniqueIdentifier() const {
    ghoul_assert(_initialized, "TileProvider was not initialized.");
    return _uniqueIdentifier;
}

} // namespace tileprovider
} // namespace globebrowsing
} // namespace openspace