Method ModifyHeightMap

Source/Engine/Terrain/TerrainPatch.cpp:1393–1486

}

bool TerrainPatch::ModifyHeightMap(const float* samples, const Int2& modifiedOffset, const Int2& modifiedSize)
{
    // Validate input samples range
    TerrainDataUpdateInfo info(this);
    if (samples == nullptr)
    {
        LOG(Warning, "Missing heightmap 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.ModifyHeightMap");
    PROFILE_MEM(LevelTerrain);

    // Check if has no heightmap
    if (Heightmap == nullptr)
    {
        // Initialize with flat heightmap data
        if (InitializeHeightMap())
        {
            LOG(Error, "Failed to initialize patch heightmap for modification.");
            return true;
        }
    }

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

    // Modify heightmap 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++)
            {
                heightMap[(z + modifiedOffset.Y) * info.HeightmapSize + (x + modifiedOffset.X)] = samples[z * modifiedSize.X + x];
            }
        }
    }

    // Process heightmap to get per-patch height normalization values
    float chunkOffsets[Terrain::ChunksCount];
    float chunkHeights[Terrain::ChunksCount];
    CalculateHeightmapRange(_terrain, info, heightMap, chunkOffsets, chunkHeights);
    // TODO: maybe calculate chunk ranges for only modified chunks
    const bool wasHeightRangeChanged = Math::NotNearEqual(_yOffset, info.PatchOffset) || Math::NotNearEqual(_yHeight, info.PatchHeight);