Method CalculateResidency

Source/Engine/Streaming/StreamingHandlers.cpp:36–67

}

int32 TexturesStreamingHandler::CalculateResidency(StreamableResource* resource, float quality)
{
    if (quality < ZeroTolerance)
        return 0;
    ASSERT(resource);
    auto& texture = *(StreamingTexture*)resource;
    ASSERT(texture.IsInitialized());
    const TextureHeader& header = *texture.GetHeader();

    const int32 totalMipLevels = texture.TotalMipLevels();
    int32 mipLevels = Math::CeilToInt(quality * (float)totalMipLevels);

    if (header.TextureGroup >= 0 && header.TextureGroup < Streaming::TextureGroups.Count())
    {
        const TextureGroup& group = Streaming::TextureGroups[header.TextureGroup];
        mipLevels = Math::Clamp(mipLevels + group.MipLevelsBias, group.MipLevelsMin, group.MipLevelsMax);
#if USE_EDITOR
        // Simulate per-platform limit in Editor
        int32 max;
        if (group.MipLevelsMaxPerPlatform.TryGet(PLATFORM_TYPE, max))
            mipLevels = Math::Min(mipLevels, max);
#endif
    }

    if (mipLevels > 0 && mipLevels < texture._minMipCountBlockCompressed && texture._isBlockCompressed)
    {
        // Block compressed textures require minimum size of block size (eg. 4 for BC formats)
        mipLevels = texture._minMipCountBlockCompressed;
    }

    return Math::Clamp(mipLevels, 0, totalMipLevels);
}

int32 TexturesStreamingHandler::CalculateRequestedResidency(StreamableResource* resource, int32 targetResidency)
{