kraken/kraken/KRContext.cpp

//
//  KRContext.cpp
//  Kraken Engine
//
//  Copyright 2022 Kearwood Gilbert. All rights reserved.
//
//  Redistribution and use in source and binary forms, with or without modification, are
//  permitted provided that the following conditions are met:
//
//  1. Redistributions of source code must retain the above copyright notice, this list of
//  conditions and the following disclaimer.
//
//  2. Redistributions in binary form must reproduce the above copyright notice, this list
//  of conditions and the following disclaimer in the documentation and/or other materials
//  provided with the distribution.
//
//  THIS SOFTWARE IS PROVIDED BY KEARWOOD GILBERT ''AS IS'' AND ANY EXPRESS OR IMPLIED
//  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
//  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL KEARWOOD GILBERT OR
//  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
//  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
//  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
//  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
//  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
//  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
//  The views and conclusions contained in the software and documentation are those of the
//  authors and should not be interpreted as representing official policies, either expressed
//  or implied, of Kearwood Gilbert.
//

#include "KREngine-common.h"

#include "KRContext.h"
#include "KRCamera.h"
#include "KRAudioManager.h"
#include "KRAudioSample.h"
#include "KRBundle.h"
#include "KRPresentationThread.h"
#include "KRStreamerThread.h"

#if defined(ANDROID)
#include <chrono>
#include <unistd.h>
#endif

#if defined(_WIN32) || defined(_WIN64)
#include <windows.h>
#endif

 // TODO - Make values dynamic after Vulkan conversion:
int KRContext::KRENGINE_MAX_PIPELINE_HANDLES = 4000;
int KRContext::KRENGINE_GPU_MEM_MAX = 256000000;
int KRContext::KRENGINE_GPU_MEM_TARGET = 192000000;
int KRContext::KRENGINE_MAX_TEXTURE_DIM = 8192;
int KRContext::KRENGINE_MIN_TEXTURE_DIM = 64;

// TODO - This should be configured per-scene?  Or auto/dynamic?
int KRContext::KRENGINE_PRESTREAM_DISTANCE = 1000.0f;

int KRContext::KRENGINE_SYS_ALLOCATION_GRANULARITY;
int KRContext::KRENGINE_SYS_PAGE_SIZE;

#if TARGET_OS_IPHONE


#elif TARGET_OS_MAC

#elif defined(_WIN32) || defined(_WIN64)

#elif defined(ANDROID)

#else

#error Unsupported Platform

#endif

std::mutex KRContext::g_SurfaceInfoMutex;
std::mutex KRContext::g_DeviceInfoMutex;

KRContext::log_callback* KRContext::s_log_callback = NULL;
void* KRContext::s_log_callback_user_data = NULL;

KRContext::KRContext(const KrInitializeInfo* initializeInfo)
  : m_resourceMapSize(initializeInfo->resourceMapSize)
{
  m_presentationThread = std::make_unique<KRPresentationThread>(*this);
  m_streamerThread = std::make_unique<KRStreamerThread>(*this);
  m_resourceMap = (KRResource**)malloc(sizeof(KRResource*) * m_resourceMapSize);
  memset(m_resourceMap, 0, m_resourceMapSize * sizeof(KRResource*));
  m_streamingEnabled = false;
#ifdef __APPLE__
  mach_timebase_info(&m_timebase_info);
#endif

  m_current_frame = 0;
  m_last_memory_warning_frame = 0;
  m_last_fully_streamed_frame = 0;
  m_absolute_time = 0.0f;

  m_pBundleManager = std::make_unique<KRBundleManager>(*this);
  m_deviceManager = std::make_unique<KRDeviceManager>(*this);
  m_deviceManager->initialize();
  m_uniformBufferManager = std::make_unique<KRUniformBufferManager>(*this);
  m_uniformBufferManager->init();
  m_surfaceManager = std::make_unique<KRSurfaceManager>(*this);
  m_pPipelineManager = std::make_unique<KRPipelineManager>(*this);
  m_pSamplerManager = std::make_unique<KRSamplerManager>(*this);
  m_pSamplerManager->init();
  m_pTextureManager = std::make_unique<KRTextureManager>(*this);
  m_pMaterialManager = std::make_unique<KRMaterialManager>(*this, m_pTextureManager.get(), m_pPipelineManager.get());
  m_pMeshManager = std::make_unique<KRMeshManager>(*this);
  m_pMeshManager->init();
  m_pSceneManager = std::make_unique<KRSceneManager>(*this);
  m_pAnimationManager = std::make_unique<KRAnimationManager>(*this);
  m_pAnimationCurveManager = std::make_unique<KRAnimationCurveManager>(*this);
  m_pSoundManager = std::make_unique<KRAudioManager>(*this);
  m_pUnknownManager = std::make_unique<KRUnknownManager>(*this);
  m_pShaderManager = std::make_unique<KRShaderManager>(*this);
  m_pSourceManager = std::make_unique<KRSourceManager>(*this);
  m_streamingEnabled = true;

#if defined(_WIN32) || defined(_WIN64)

  SYSTEM_INFO winSysInfo;
  GetSystemInfo(&winSysInfo);
  KRENGINE_SYS_ALLOCATION_GRANULARITY = winSysInfo.dwAllocationGranularity;
  KRENGINE_SYS_PAGE_SIZE = winSysInfo.dwPageSize;

#elif defined(__APPLE__) || defined(ANDROID)

  KRENGINE_SYS_PAGE_SIZE = getpagesize();
  KRENGINE_SYS_ALLOCATION_GRANULARITY = KRENGINE_SYS_PAGE_SIZE;

#else
#error Unsupported
#endif

  m_presentationThread->start();
  m_streamerThread->start();
}

KRContext::~KRContext()
{
  m_presentationThread->stop();
  m_streamerThread->stop();
  m_pSceneManager.reset();
  m_pMeshManager.reset();
  m_pMaterialManager.reset();
  m_pTextureManager->destroy();
  m_pTextureManager.reset();
  m_pPipelineManager.reset();
  if (m_pSamplerManager) {
    m_pSamplerManager->destroy();
  }
  m_pSamplerManager.reset();
  m_pAnimationManager.reset();
  m_pAnimationCurveManager.reset();
  m_pSoundManager->destroy();
  m_pSoundManager.reset();
  m_pSourceManager.reset();
  m_pUnknownManager.reset();
  m_pShaderManager.reset();
  m_surfaceManager.reset();
  m_deviceManager.reset();
  m_uniformBufferManager.reset();

  // The bundles must be destroyed last, as the other objects may be using mmap'ed data from bundles
  m_pBundleManager.reset();


  if (m_resourceMap) {
    delete m_resourceMap;
    m_resourceMap = NULL;
  }
}

void KRContext::SetLogCallback(log_callback* log_callback, void* user_data)
{
  s_log_callback = log_callback;
  s_log_callback_user_data = user_data;
}

void KRContext::Log(log_level level, const std::string message_format, ...)
{
  va_list args;
  va_start(args, message_format);

  if (s_log_callback) {
    const int LOG_BUFFER_SIZE = 32768;
    char log_buffer[LOG_BUFFER_SIZE];
    vsnprintf(log_buffer, LOG_BUFFER_SIZE, message_format.c_str(), args);
    s_log_callback(s_log_callback_user_data, std::string(log_buffer), level);
  } else {
    FILE* out_file = level == LOG_LEVEL_INFORMATION ? stdout : stderr;
    fprintf(out_file, "Kraken - INFO: ");
    vfprintf(out_file, message_format.c_str(), args);
    fprintf(out_file, "\n");
  }

  va_end(args);
}

KRBundleManager* KRContext::getBundleManager()
{
  return m_pBundleManager.get();
}
KRSceneManager* KRContext::getSceneManager()
{
  return m_pSceneManager.get();
}
KRTextureManager* KRContext::getTextureManager()
{
  return m_pTextureManager.get();
}
KRMaterialManager* KRContext::getMaterialManager()
{
  return m_pMaterialManager.get();
}
KRPipelineManager* KRContext::getPipelineManager()
{
  return m_pPipelineManager.get();
}
KRSamplerManager* KRContext::getSamplerManager()
{
  return m_pSamplerManager.get();
}
KRMeshManager* KRContext::getMeshManager()
{
  return m_pMeshManager.get();
}
KRAnimationManager* KRContext::getAnimationManager()
{
  return m_pAnimationManager.get();
}
KRAnimationCurveManager* KRContext::getAnimationCurveManager()
{
  return m_pAnimationCurveManager.get();
}
KRAudioManager* KRContext::getAudioManager()
{
  return m_pSoundManager.get();
}
KRShaderManager* KRContext::getShaderManager()
{
  return m_pShaderManager.get();
}
KRSourceManager* KRContext::getSourceManager()
{
  return m_pSourceManager.get();
}
KRSurfaceManager* KRContext::getSurfaceManager()
{
  return m_surfaceManager.get();
}
KRDeviceManager* KRContext::getDeviceManager()
{
  return m_deviceManager.get();
}
KRUniformBufferManager* KRContext::getUniformBufferManager()
{
  return m_uniformBufferManager.get();
}
KRUnknownManager* KRContext::getUnknownManager()
{
  return m_pUnknownManager.get();
}
std::vector<KRResource*> KRContext::getResources()
{
  std::vector<KRResource*> resources;

  for (unordered_map<std::string, KRScene*>::iterator itr = m_pSceneManager->getScenes().begin(); itr != m_pSceneManager->getScenes().end(); itr++) {
    resources.push_back((*itr).second);
  }
  for (unordered_map<std::string, KRTexture*>::iterator itr = m_pTextureManager->getTextures().begin(); itr != m_pTextureManager->getTextures().end(); itr++) {
    resources.push_back((*itr).second);
  }
  for (unordered_map<std::string, KRMaterial*>::iterator itr = m_pMaterialManager->getMaterials().begin(); itr != m_pMaterialManager->getMaterials().end(); itr++) {
    resources.push_back((*itr).second);
  }
  for (unordered_multimap<std::string, KRMesh*>::iterator itr = m_pMeshManager->getModels().begin(); itr != m_pMeshManager->getModels().end(); itr++) {
    resources.push_back((*itr).second);
  }
  for (unordered_map<std::string, KRAnimation*>::iterator itr = m_pAnimationManager->getAnimations().begin(); itr != m_pAnimationManager->getAnimations().end(); itr++) {
    resources.push_back((*itr).second);
  }
  for (unordered_map<std::string, KRAnimationCurve*>::iterator itr = m_pAnimationCurveManager->getAnimationCurves().begin(); itr != m_pAnimationCurveManager->getAnimationCurves().end(); itr++) {
    resources.push_back((*itr).second);
  }
  for (unordered_map<std::string, KRAudioSample*>::iterator itr = m_pSoundManager->getSounds().begin(); itr != m_pSoundManager->getSounds().end(); itr++) {
    resources.push_back((*itr).second);
  }

  unordered_map<std::string, unordered_map<std::string, KRSource*> > sources = m_pSourceManager->getSources();
  for (unordered_map<std::string, unordered_map<std::string, KRSource*> >::iterator itr = sources.begin(); itr != sources.end(); itr++) {
    for (unordered_map<std::string, KRSource*>::iterator itr2 = (*itr).second.begin(); itr2 != (*itr).second.end(); itr2++) {
      resources.push_back((*itr2).second);
    }
  }

  unordered_map<std::string, unordered_map<std::string, KRShader*> > shaders = m_pShaderManager->getShaders();
  for (unordered_map<std::string, unordered_map<std::string, KRShader*> >::iterator itr = shaders.begin(); itr != shaders.end(); itr++) {
    for (unordered_map<std::string, KRShader*>::iterator itr2 = (*itr).second.begin(); itr2 != (*itr).second.end(); itr2++) {
      resources.push_back((*itr2).second);
    }
  }

  unordered_map<std::string, unordered_map<std::string, KRUnknown*> > unknowns = m_pUnknownManager->getUnknowns();
  for (unordered_map<std::string, unordered_map<std::string, KRUnknown*> >::iterator itr = unknowns.begin(); itr != unknowns.end(); itr++) {
    for (unordered_map<std::string, KRUnknown*>::iterator itr2 = (*itr).second.begin(); itr2 != (*itr).second.end(); itr2++) {
      resources.push_back((*itr2).second);
    }
  }

  return resources;
}

KRResource* KRContext::loadResource(const std::string& file_name, KRDataBlock* data)
{
  std::string name = KRResource::GetFileBase(file_name);
  std::string extension = KRResource::GetFileExtension(file_name);

  KRResource* resource = nullptr;

  //    fprintf(stderr, "KRContext::loadResource - Loading: %s\n", file_name.c_str());

  if (extension.compare("krbundle") == 0) {
    resource = m_pBundleManager->loadBundle(name.c_str(), data);
  } else if (extension.compare("krmesh") == 0) {
    resource = m_pMeshManager->loadModel(name.c_str(), data);
  } else if (extension.compare("krscene") == 0) {
    resource = m_pSceneManager->loadScene(name.c_str(), data);
  } else if (extension.compare("kranimation") == 0) {
    resource = m_pAnimationManager->loadAnimation(name.c_str(), data);
  } else if (extension.compare("kranimationcurve") == 0) {
    resource = m_pAnimationCurveManager->loadAnimationCurve(name.c_str(), data);
  } else if (extension.compare("pvr") == 0) {
    resource = m_pTextureManager->loadTexture(name.c_str(), extension.c_str(), data);
  } else if (extension.compare("ktx") == 0) {
    resource = m_pTextureManager->loadTexture(name.c_str(), extension.c_str(), data);
  } else if (extension.compare("tga") == 0) {
    resource = m_pTextureManager->loadTexture(name.c_str(), extension.c_str(), data);
  } else if (extension.compare("spv") == 0) {
    // SPIR-V shader binary
    resource = m_pShaderManager->load(name, extension, data);
  } else if (getShaderStageFromExtension(extension.c_str()) != ShaderStage::Invalid) {
    // Shader source
    resource = m_pSourceManager->load(name, extension, data);
  } else if (extension.compare("glsl") == 0) {
    // glsl included by other shaders
    resource = m_pSourceManager->load(name, extension, data);
  } else if (extension.compare("options") == 0) {
    // shader pre-processor options definition file
    resource = m_pSourceManager->load(name, extension, data);
  } else if (extension.compare("mtl") == 0) {
    resource = m_pMaterialManager->load(name.c_str(), data);
  } else if (extension.compare("mp3") == 0) {
    resource = m_pSoundManager->load(name.c_str(), extension, data);
  } else if (extension.compare("wav") == 0) {
    resource = m_pSoundManager->load(name.c_str(), extension, data);
  } else if (extension.compare("aac") == 0) {
    resource = m_pSoundManager->load(name.c_str(), extension, data);
  } else if (extension.compare("obj") == 0) {
    resource = KRResource::LoadObj(*this, file_name);
#if !TARGET_OS_IPHONE
    /*
      // FINDME, TODO, HACK! - Uncomment
        } else if(extension.compare("fbx") == 0) {
            resource = KRResource::LoadFbx(*this, file_name);
    */
  } else if (extension.compare("blend") == 0) {
    resource = KRResource::LoadBlenderScene(*this, file_name);
#endif
  } else {
    resource = m_pUnknownManager->load(name, extension, data);
  }
  return resource;
}

KrResult KRContext::loadResource(const KrLoadResourceInfo* loadResourceInfo)
{
  if (loadResourceInfo->resourceHandle < 0 || loadResourceInfo->resourceHandle >= m_resourceMapSize) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }
  KRDataBlock* data = new KRDataBlock();
  if (!data->load(loadResourceInfo->pResourcePath)) {
    KRContext::Log(KRContext::LOG_LEVEL_ERROR, "KRContext::loadResource - Failed to open file: %s", loadResourceInfo->pResourcePath);
    delete data;
    return KR_ERROR_UNEXPECTED;
  }

  KRResource* resource = loadResource(loadResourceInfo->pResourcePath, data);
  m_resourceMap[loadResourceInfo->resourceHandle] = resource;
  return KR_SUCCESS;
}

KrResult KRContext::unloadResource(const KrUnloadResourceInfo* unloadResourceInfo)
{
  if (unloadResourceInfo->resourceHandle < 0 || unloadResourceInfo->resourceHandle >= m_resourceMapSize) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }
  KRResource* resource = m_resourceMap[unloadResourceInfo->resourceHandle];
  if (resource == nullptr) {
    return KR_ERROR_NOT_MAPPED;
  }
  // TODO - Need to implement unloading logic
  return KR_ERROR_NOT_IMPLEMENTED;
}

KrResult KRContext::mapResource(const KrMapResourceInfo* mapResourceInfo)
{
  if (mapResourceInfo->resourceHandle < 0 || mapResourceInfo->resourceHandle >= m_resourceMapSize) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }

  std::string lowerName = mapResourceInfo->pResourceName;
  std::transform(lowerName.begin(), lowerName.end(),
    lowerName.begin(), ::tolower);

  KRResource* resource = nullptr;

  std::pair<unordered_multimap<std::string, KRResource*>::iterator, unordered_multimap<std::string, KRResource*>::iterator> range = m_resources.equal_range(lowerName);
  for (unordered_multimap<std::string, KRResource*>::iterator itr_match = range.first; itr_match != range.second; itr_match++) {
    if (resource != nullptr) {
      return KR_ERROR_AMBIGUOUS_MATCH;
    }
    resource = itr_match->second;
  }
  if (resource == nullptr) {
    return KR_ERROR_NOT_FOUND;
  }
  m_resourceMap[mapResourceInfo->resourceHandle] = resource;
  return KR_SUCCESS;
}

KrResult KRContext::unmapResource(const KrUnmapResourceInfo* unmapResourceInfo)
{
  if (unmapResourceInfo->resourceHandle < 0 || unmapResourceInfo->resourceHandle >= m_resourceMapSize) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }
  m_resourceMap[unmapResourceInfo->resourceHandle] = nullptr;
  // TODO - Delete objects after lass dereference
  return KR_SUCCESS;
}

KrResult KRContext::getResourceData(const KrGetResourceDataInfo* getResourceDataInfo, KrGetResourceDataCallback callback)
{
  if (getResourceDataInfo->resourceHandle < 0 || getResourceDataInfo->resourceHandle >= m_resourceMapSize) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }
  // TODO - This will be asynchronous...
  KRDataBlock data;
  KrGetResourceDataResult result = {};
  if (m_resourceMap[getResourceDataInfo->resourceHandle] == nullptr) {
    result.result = KR_ERROR_NOT_MAPPED;
    callback(result);
  } else if (m_resourceMap[getResourceDataInfo->resourceHandle]->save(data)) {
    data.lock();
    result.data = data.getStart();
    result.length = static_cast<size_t>(data.getSize());
    result.result = KR_SUCCESS;
    callback(result);
    data.unlock();
  } else {
    result.result = KR_ERROR_UNEXPECTED;
    callback(result);
  }

  return KR_SUCCESS;
}

KrResult KRContext::createScene(const KrCreateSceneInfo* createSceneInfo)
{
  if (createSceneInfo->resourceHandle < 0 || createSceneInfo->resourceHandle >= m_resourceMapSize) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }
  KRScene* scene = m_pSceneManager->createScene(createSceneInfo->pSceneName);
  m_resourceMap[createSceneInfo->resourceHandle] = scene;
  return KR_SUCCESS;
}

KrResult KRContext::createBundle(const KrCreateBundleInfo* createBundleInfo)
{
  if (createBundleInfo->resourceHandle < 0 || createBundleInfo->resourceHandle >= m_resourceMapSize) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }
  KRResource* bundle = m_pBundleManager->createBundle(createBundleInfo->pBundleName);
  m_resourceMap[createBundleInfo->resourceHandle] = bundle;

  return KR_SUCCESS;
}

KrResult KRContext::moveToBundle(const KrMoveToBundleInfo* moveToBundleInfo)
{
  if (moveToBundleInfo->bundleHandle < 0 || moveToBundleInfo->bundleHandle >= m_resourceMapSize) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }
  if (moveToBundleInfo->resourceHandle < 0 || moveToBundleInfo->resourceHandle >= m_resourceMapSize) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }
  KRResource* resource = m_resourceMap[moveToBundleInfo->resourceHandle];
  if (resource == nullptr) {
    return KR_ERROR_NOT_MAPPED;
  }
  KRResource* bundleResource = m_resourceMap[moveToBundleInfo->bundleHandle];
  if (bundleResource == nullptr) {
    return KR_ERROR_NOT_MAPPED;
  }
  KRBundle* bundle = dynamic_cast<KRBundle*>(bundleResource);
  if (bundle == nullptr) {
    return KR_ERROR_INCORRECT_TYPE;
  }
  return resource->moveToBundle(bundle);
}

KrResult KRContext::compileAllShaders(const KrCompileAllShadersInfo* pCompileAllShadersInfo)
{
  if (pCompileAllShadersInfo->bundleHandle < 0 || pCompileAllShadersInfo->bundleHandle >= m_resourceMapSize) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }
  KRResource* bundleResource = m_resourceMap[pCompileAllShadersInfo->bundleHandle];
  if (bundleResource == nullptr) {
    return KR_ERROR_NOT_MAPPED;
  }
  KRBundle* bundle = dynamic_cast<KRBundle*>(bundleResource);
  if (bundle == nullptr) {
    return KR_ERROR_INCORRECT_TYPE;
  }
  if (pCompileAllShadersInfo->logHandle < -1 || pCompileAllShadersInfo->logHandle >= m_resourceMapSize) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }

  KRResource* existing_log = m_pUnknownManager->getResource("shader_compile", "log");
  KRUnknown* logResource = nullptr;
  if (existing_log != nullptr) {
    logResource = dynamic_cast<KRUnknown*>(existing_log);
  }
  if (logResource == nullptr) {
    logResource = new KRUnknown(*this, "shader_compile", "log");
    m_pUnknownManager->add(logResource);
  }
  if (pCompileAllShadersInfo->logHandle != -1) {
    m_resourceMap[pCompileAllShadersInfo->logHandle] = logResource;
  }

  bool success = m_pShaderManager->compileAll(bundle, logResource);
  if (success) {
    return KR_SUCCESS;
  }
  return KR_ERROR_SHADER_COMPILE_FAILED;
}

KrResult KRContext::saveResource(const KrSaveResourceInfo* saveResourceInfo)
{
  if (saveResourceInfo->resourceHandle < 0 || saveResourceInfo->resourceHandle >= m_resourceMapSize) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }
  KRResource* resource = m_resourceMap[saveResourceInfo->resourceHandle];
  if (resource == nullptr) {
    return KR_ERROR_NOT_MAPPED;
  }
  if (resource->save(saveResourceInfo->pResourcePath)) {
    return KR_SUCCESS;
  }
  return KR_ERROR_UNEXPECTED;
}

void KRContext::startFrame(float deltaTime)
{
  m_pTextureManager->startFrame(deltaTime);
  m_pAnimationManager->startFrame(deltaTime);
  m_pSoundManager->startFrame(deltaTime);
  m_pMeshManager->startFrame(deltaTime);
}

void KRContext::endFrame(float deltaTime)
{
  m_pTextureManager->endFrame(deltaTime);
  m_pAnimationManager->endFrame(deltaTime);
  m_pMeshManager->endFrame(deltaTime);
  m_current_frame++;
  m_absolute_time += deltaTime;
}

long KRContext::getCurrentFrame() const
{
  return m_current_frame;
}

long KRContext::getLastFullyStreamedFrame() const
{
  return m_last_fully_streamed_frame;
}

float KRContext::getAbsoluteTime() const
{
  return m_absolute_time;
}


long KRContext::getAbsoluteTimeMilliseconds()
{
#if defined(ANDROID)
  return std::chrono::duration_cast<std::chrono::milliseconds>(
          std::chrono::system_clock::now().time_since_epoch()).count();
#elif defined(__APPLE__)
  return (long)(mach_absolute_time() / 1000 * m_timebase_info.numer / m_timebase_info.denom); // Division done first to avoid potential overflow
#else
  return (long)GetTickCount64();
#endif
}

#if TARGET_OS_IPHONE || TARGET_OS_MAC

void KRContext::getMemoryStats(long& free_memory)
{
  free_memory = 0;

  mach_port_t host_port = mach_host_self();
  mach_msg_type_number_t host_size = sizeof(vm_statistics_data_t) / sizeof(integer_t);
  vm_size_t pagesize = 0;
  vm_statistics_data_t vm_stat;
  // int total_ram = 256 * 1024 * 1024;
  if (host_page_size(host_port, &pagesize) != KERN_SUCCESS) {
    KRContext::Log(KRContext::LOG_LEVEL_ERROR, "Could not get VM page size.");
  } else if (host_statistics(host_port, HOST_VM_INFO, (host_info_t)&vm_stat, &host_size) != KERN_SUCCESS) {
    KRContext::Log(KRContext::LOG_LEVEL_ERROR, "Could not get VM stats.");
  } else {
    // total_ram = (vm_stat.wire_count + vm_stat.active_count + vm_stat.inactive_count + vm_stat.free_count) * pagesize;

    free_memory = (vm_stat.free_count + vm_stat.inactive_count) * pagesize;
  }
}

#endif

void KRContext::doStreaming()
{
  if (m_streamingEnabled) {
    /*
    long free_memory = KRENGINE_GPU_MEM_TARGET;
    long total_memory = KRENGINE_GPU_MEM_MAX;
    */
    /*
#if TARGET_OS_IPHONE
        // FINDME, TODO, HACK! - Experimental code, need to expose through engine parameters
        const long KRENGINE_RESERVE_MEMORY = 0x4000000; // 64MB

        getMemoryStats(free_memory);
        free_memory = KRCLAMP(free_memory - KRENGINE_RESERVE_MEMORY, 0, KRENGINE_GPU_MEM_TARGET);
        total_memory = KRMIN(KRENGINE_GPU_MEM_MAX, free_memory * 3 / 4 + m_pTextureManager->getMemUsed() + m_pMeshManager->getMemUsed());

#endif
        */
        /*
        // FINDME, TODO - Experimental code, need to expose through engine parameters
        const long MEMORY_WARNING_THROTTLE_FRAMES = 5;
        bool memory_warning_throttle = m_last_memory_warning_frame != 0 && m_current_frame - m_last_memory_warning_frame < MEMORY_WARNING_THROTTLE_FRAMES;
        if(memory_warning_throttle) {
            free_memory = 0;
        }
        */

        /*
        // FINDME, TODO - Experimental code, need to expose through engine parameters
        const long MEMORY_WARNING_THROTTLE2_FRAMES = 30;
        bool memory_warning_throttle2 = m_last_memory_warning_frame != 0 && m_current_frame - m_last_memory_warning_frame < MEMORY_WARNING_THROTTLE2_FRAMES;
        if(memory_warning_throttle2) {
            total_memory /= 2;
            free_memory /= 2;
        }
        */

        /*
        m_pMeshManager->doStreaming(total_memory, free_memory);
        m_pTextureManager->doStreaming(total_memory, free_memory);
        */

    KRDeviceManager* deviceManager = getDeviceManager();

    for (auto deviceItr = deviceManager->getDevices().begin(); deviceItr != deviceManager->getDevices().end(); deviceItr++) {
      KRDevice& device = *(*deviceItr).second;
      device.streamStart();
    }

    // TODO - Ensure that each iteration does not exhaust the currently fixed 256MB staging buffer

    long streaming_start_frame = m_current_frame;

    long memoryRemaining = KRENGINE_GPU_MEM_TARGET;
    long memoryRemainingThisFrame = KRENGINE_GPU_MEM_MAX - m_pTextureManager->getMemUsed() - m_pMeshManager->getMemUsed();
    long memoryRemainingThisFrameStart = memoryRemainingThisFrame;
    m_pMeshManager->doStreaming(memoryRemaining, memoryRemainingThisFrame);
    m_pTextureManager->doStreaming(memoryRemaining, memoryRemainingThisFrame);

    if (memoryRemainingThisFrame == memoryRemainingThisFrameStart && memoryRemainingThisFrame > 0) {
      m_last_fully_streamed_frame = streaming_start_frame;
    }

    bool fullyStreamed = false;
    for (auto deviceItr = deviceManager->getDevices().begin(); deviceItr != deviceManager->getDevices().end(); deviceItr++) {
      KRDevice& device = *(*deviceItr).second;
      device.streamEnd();
    }

  }
}

void KRContext::receivedMemoryWarning()
{
  m_last_memory_warning_frame = m_current_frame;
}

KrResult KRContext::findNodeByName(const KrFindNodeByNameInfo* pFindNodeByNameInfo)
{
  return KR_ERROR_NOT_IMPLEMENTED;
}

KrResult KRContext::findAdjacentNodes(const KrFindAdjacentNodesInfo* pFindAdjacentNodesInfo)
{
  return KR_ERROR_NOT_IMPLEMENTED;
}

KrResult KRContext::setNodeLocalTransform(const KrSetNodeLocalTransformInfo* pSetNodeLocalTransform)
{
  return KR_ERROR_NOT_IMPLEMENTED;
}

KrResult KRContext::setNodeWorldTransform(const KrSetNodeWorldTransformInfo* pSetNodeWorldTransform)
{
  return KR_ERROR_NOT_IMPLEMENTED;
}

KrResult KRContext::deleteNode(const KrDeleteNodeInfo* pDeleteNodeInfo)
{
  return KR_ERROR_NOT_IMPLEMENTED;
}

KrResult KRContext::deleteNodeChildren(const KrDeleteNodeChildrenInfo* pDeleteNodeChildrenInfo)
{
  return KR_ERROR_NOT_IMPLEMENTED;
}

KrResult KRContext::appendBeforeNode(const KrAppendBeforeNodeInfo* pAppendBeforeNodeInfo)
{
  return KR_ERROR_NOT_IMPLEMENTED;
}

KrResult KRContext::appendAfterNode(const KrAppendAfterNodeInfo* pAppendAfterNodeInfo)
{
  return KR_ERROR_NOT_IMPLEMENTED;
}

KrResult KRContext::appendFirstChildNode(const KrAppendFirstChildNodeInfo* pAppendFirstChildNodeInfo)
{
  return KR_ERROR_NOT_IMPLEMENTED;
}

KrResult KRContext::appendLastChildNode(const KrAppendLastChildNodeInfo* pAppendLastChildNodeInfo)
{
  return KR_ERROR_NOT_IMPLEMENTED;
}

KrResult KRContext::updateNode(const KrUpdateNodeInfo* pUpdateNodeInfo)
{
  return KR_ERROR_NOT_IMPLEMENTED;
}

void KRContext::addResource(KRResource* resource, const std::string& name)
{
  std::string lowerName = name;
  std::transform(lowerName.begin(), lowerName.end(),
    lowerName.begin(), ::tolower);

  m_resources.insert(std::pair<std::string, KRResource*>(lowerName, resource));
}

void KRContext::removeResource(KRResource* resource)
{
  std::string lowerName = resource->getName();
  std::transform(lowerName.begin(), lowerName.end(),
    lowerName.begin(), ::tolower);

  std::pair<unordered_multimap<std::string, KRResource*>::iterator, unordered_multimap<std::string, KRResource*>::iterator> range = m_resources.equal_range(lowerName);
  for (unordered_multimap<std::string, KRResource*>::iterator itr_match = range.first; itr_match != range.second; itr_match++) {
    if (itr_match->second == resource) {
      m_resources.erase(itr_match);
      return;
    }
  }
}

KrResult KRContext::createWindowSurface(const KrCreateWindowSurfaceInfo* createWindowSurfaceInfo)
{
  if (createWindowSurfaceInfo->surfaceHandle < 0) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }
  if (!m_deviceManager->haveVulkan()) {
    return KR_ERROR_VULKAN_REQUIRED;
  }
  if (m_surfaceHandleMap.count(createWindowSurfaceInfo->surfaceHandle)) {
    return KR_ERROR_DUPLICATE_HANDLE;
  }

  if (!m_deviceManager->haveDevice()) {
    return KR_ERROR_NO_DEVICE;
  }

  const std::lock_guard<std::mutex> surfaceLock(KRContext::g_SurfaceInfoMutex);
  const std::lock_guard<std::mutex> deviceLock(KRContext::g_DeviceInfoMutex);

#ifdef WIN32
  HWND hWnd = static_cast<HWND>(createWindowSurfaceInfo->hWnd);
  KrSurfaceHandle surfaceHandle = 0;
  KrResult result = m_surfaceManager->create(hWnd, surfaceHandle);
  if (result != KR_SUCCESS) {
    return result;
  }

  m_surfaceHandleMap.insert(std::pair<KrSurfaceMapIndex, KrSurfaceHandle>(createWindowSurfaceInfo->surfaceHandle, surfaceHandle));

  return KR_SUCCESS;
#else
  // Not implemented for this platform
  return KR_ERROR_NOT_IMPLEMENTED;
#endif
}

KrResult KRContext::deleteWindowSurface(const KrDeleteWindowSurfaceInfo* deleteWindowSurfaceInfo)
{
  if (deleteWindowSurfaceInfo->surfaceHandle < 0) {
    return KR_ERROR_OUT_OF_BOUNDS;
  }
  if (!m_deviceManager->haveVulkan()) {
    return KR_ERROR_VULKAN_REQUIRED;
  }

  auto handleItr = m_surfaceHandleMap.find(deleteWindowSurfaceInfo->surfaceHandle);
  if (handleItr == m_surfaceHandleMap.end()) {
    return KR_ERROR_NOT_FOUND;
  }
  KrSurfaceHandle surfaceHandle = (*handleItr).second;
  m_surfaceHandleMap.erase(handleItr);

  return m_surfaceManager->destroy(surfaceHandle);
}