Method ModifySplatMap

Source/Engine/Terrain/TerrainPatch.cpp:1554–1751

}

bool TerrainPatch::ModifySplatMap(int32 index, const Color32* samples, const Int2& modifiedOffset, const Int2& modifiedSize)
{
    ASSERT(index >= 0 && index < TERRAIN_MAX_SPLATMAPS_COUNT);

    // Ensure that terrain has a valid heightmap
    if (Heightmap == nullptr)
    {
        if (InitializeHeightMap() || Heightmap == nullptr)
        {
            LOG(Warning, "Cannot modify splatmap without valid heightmap loaded.");
            return true;
        }
    }

    // Validate input samples range
    TerrainDataUpdateInfo info(this, _yOffset, _yHeight);
    if (samples == nullptr)
    {
        LOG(Warning, "Missing splatmap samples data.");
        return true;
    }
    if (modifiedOffset.X < 0 || modifiedOffset.Y < 0 ||
        modifiedSize.X <= 0 || modifiedSize.Y <= 0 ||
        modifiedOffset.X + modifiedSize.X > info.HeightmapSize ||
        modifiedOffset.Y + modifiedSize.Y > info.HeightmapSize)
    {
        LOG(Warning, "Invalid heightmap samples range.");
        return true;
    }
    PROFILE_CPU_NAMED("Terrain.ModifySplatMap");
    PROFILE_MEM(LevelTerrain);

    // Get the current data to modify it
    Color32* splatMap = GetSplatMapData(index);
    if (samples == splatMap)
    {
        LOG(Warning, "Updating terrain with its own data. Oh god xD");
    }

    // Modify splat map data
    {
        PROFILE_CPU_NAMED("Terrain.WrtieCache");
        for (int32 z = 0; z < modifiedSize.Y; z++)
        {
            // TODO: use batches row mem copy

            for (int32 x = 0; x < modifiedSize.X; x++)
            {
                splatMap[(z + modifiedOffset.Y) * info.HeightmapSize + (x + modifiedOffset.X)] = samples[z * modifiedSize.X + x];
            }
        }
    }

    // Initialize data container if need to
    auto& splatmap = Splatmap[index];
    auto& dataSplatmap = _dataSplatmap[index];
    if (dataSplatmap == nullptr)
    {