void VCoronaManager::RenderCorona (VCoronaCandidate& coronaCandidate, VTextureObject*& pTexture)
{
#ifdef SUPPORTS_CORONAS
  VCoronaComponent *pCorona = coronaCandidate.m_pCorona;
  VisRenderContext_cl* pContext = VisRenderContext_cl::GetCurrentContext();
  VisLightSource_cl* pLight = (VisLightSource_cl*)pCorona->GetOwner();

  hkvVec3 vLightPos(hkvNoInitialization);
  pLight->GetVirtualPosition(vLightPos, pContext);
  hkvVec3 vEyePos(hkvNoInitialization);
  pContext->GetCamera()->GetPosition(vEyePos);
  hkvVec3 vDir = pContext->GetCamera()->GetDirection();

  // Corona texture
  VTextureObject *pTex = pCorona->GetCoronaTexture();
  if (pTex == NULL)
    return;

  if (pTexture != pTex)
  {
    pTexture = pTex;
    Vision::RenderLoopHelper.BindMeshTexture(pTexture,0);
  }

  // Get light color
  VColorRef color = pLight->GetColor();
  hkvVec3 vDist = vLightPos - vEyePos;
  float fEyeDist = vDir.dot(vDist);

  //determine if camera is in light cone if the light is directional
  float fDirectionalDampening = 1.0f;
  if ( pLight->GetType() == VIS_LIGHT_SPOTLIGHT && pCorona->GetOnlyVisibleInSpotLight() )
  {
    fDirectionalDampening = 0.0f;
    float fConeAngle = pLight->GetProjectionAngle();
    float fConeLength = pLight->GetRadius();
    hkvVec3 fConeDirection = pLight->GetDirection();
    fConeDirection.normalize();

    hkvVec3 vLightEyeDist = vEyePos - vLightPos;

    //#2 check if the camera is inside the angle of the cone
    float cosinusAngle = (vLightEyeDist/vLightEyeDist.getLength()).dot(fConeDirection);
    float fDegree = hkvMath::acosDeg(cosinusAngle);
    float normRadius = fDegree / (fConeAngle/2.0f);

    if (normRadius < 1.0f)
    {
      //hardcoded falloff. For better performance, we avoid sampling the projection texture here.
      const float fEpsilon = 64.0f/256.0f;
      const float fQuadFactor = 1.0f/fEpsilon - 1.0f;
      fDirectionalDampening = 1.0f / (1.0f + fQuadFactor*normRadius*normRadius);

      // scale the function so that the value is exactly 0.0 at the edge and 1.0 in the center
      fDirectionalDampening = (fDirectionalDampening - fEpsilon) / (1.0f - fEpsilon);  
    }
  }
  // Fog params
  float fFogDampening = 1.0f;
  if (pLight->GetType() != VIS_LIGHT_DIRECTED && Vision::World.IsLinearDepthFogEnabled())
  {  
    const VFogParameters &fog = Vision::World.GetFogParameters();
    float fFogStart = fog.fDepthStart;
    float fFogEnd = fog.fDepthEnd;

    float fFogFactor = (fFogEnd > fFogStart) ? ((fEyeDist - fFogStart) / (fFogEnd - fFogStart)) : 0.f;
    fFogDampening = 1.0f - hkvMath::clamp(fFogFactor, 0.0f, 1.0f);
  }

  // Get corona rotation
  float fRotation = 0.0f;
  hkvVec4 vRotation(1.0f, 0.0f, 0.0f, 1.0f);
  if (pCorona->CoronaFlags & VIS_CORONASCALE_ROTATING)
  { 
    fRotation = hkvMath::mod (fEyeDist * 0.5f, 360.f);

    vRotation.x = hkvMath::cosDeg (fRotation);
    vRotation.y = -hkvMath::sinDeg (fRotation);
    vRotation.z = -vRotation.y;
    vRotation.w = vRotation.x;
  }

  // Texture dimensions
  int iSizeX, iSizeY, depth;
  pTex->GetTextureDimensions(iSizeX, iSizeY, depth);

  hkvVec4 vScale(0.0f, 0.0f, 0.0f, 0.0f);

  int iMainWidth, iMainHeight, iWidth, iHeight;
  pContext->GetSize(iWidth, iHeight);
  VisRenderContext_cl::GetMainRenderContext()->GetSize(iMainWidth, iMainHeight);

  // Preserve texture aspect ratio
  int iTexHeight = pTex->GetTextureHeight();
  int iTexWidth = pTex->GetTextureWidth();

  // Perspective scaling
  // This scaling ensures roughly the same size on 720p as the old implementation.
  vScale.z = iTexWidth * pCorona->CoronaScaling * 0.25f;
  vScale.w = iTexHeight * pCorona->CoronaScaling * 0.25f;

  // Screen-space scaling
  // This scaling ensures roughly the same size on 720p as the old implementation.
  const float fScaleFactor = pCorona->CoronaScaling * iMainHeight / 11.0f;
  vScale.x = ((float)iTexWidth / 128.0f) * fScaleFactor * (float(iWidth) / float(iMainWidth));
  vScale.y = ((float)iTexHeight / 128.0f) * fScaleFactor * (float(iHeight) / float(iMainHeight));
  vScale.x *= 2.0f / iWidth;
  vScale.y *= 2.0f / iHeight;
  
  // Scale by visibility
  if (pCorona->CoronaFlags & VIS_CORONASCALE_VISIBLEAREA)
  {
    vScale.x *= coronaCandidate.m_fCurrentVisibility;
    vScale.y *= coronaCandidate.m_fCurrentVisibility;
    vScale.z *= coronaCandidate.m_fCurrentVisibility;
    vScale.w *= coronaCandidate.m_fCurrentVisibility;
  }

  VCompiledShaderPass* pShader = m_spCoronaTechnique->GetShader(0);
  VShaderConstantBuffer *pVertexConstBuffer = pShader->GetConstantBuffer(VSS_VertexShader);
  // xyz = worldspace position, w = 1.0 if VIS_CORONASCALE_DISTANCE is true, otherwise zero.
  pVertexConstBuffer->SetSingleParameterF("coronaPosition", vLightPos.x, vLightPos.y, vLightPos.z, (pCorona->CoronaFlags & VIS_CORONASCALE_DISTANCE) ? 1.0f : 0.0f);
  // xyz = light color, w = corona visibility.
  pVertexConstBuffer->SetSingleParameterF("coronaColor", color.r/255.0f, color.g/255.0f, color.b/255.0f, coronaCandidate.m_fCurrentVisibility * fFogDampening * fDirectionalDampening);
  // xyzw = 2x2 rotation matrix. float2x2 is not supported in shader model 2, so a float4 is used and multiplication is done manually in the shader.
  pVertexConstBuffer->SetSingleParameterF("coronaRotation", vRotation.x, vRotation.y, vRotation.z, vRotation.w);
  // xy = screen-space scaling. zw = view-space scaling.
  pVertexConstBuffer->SetSingleParameterF("coronaScale", vScale.x, vScale.y, vScale.z, vScale.w);
    
  Vision::RenderLoopHelper.RenderMeshes(pShader, VisMeshBuffer_cl::MB_PRIMTYPE_TRILIST, 0, 2, 6);
#endif
}
void VFakeSpecularGenerator::OnDoRenderLoop(void *pUserData)
{
  VFrustumMeshHelper::UpdateMeshBuffer(m_spMeshBuffer, Vision::Contexts.GetCurrentContext(), VFrustumMeshHelper::IN_WORLD_SPACE);

  Vision::RenderLoopHelper.ClearScreen(VisRenderLoopHelper_cl::VCTF_All, VColorRef(0, 0, 0, 0));

  VisRenderContext_cl* pContext = Vision::Contexts.GetCurrentContext();

  const VisLightSrcCollection_cl* pLights = pContext->GetVisibilityCollector()->GetVisibleLights();

  Vision::RenderLoopHelper.BeginMeshRendering();
  Vision::RenderLoopHelper.ResetMeshStreams();
  Vision::RenderLoopHelper.AddMeshStreams(m_spMeshBuffer, m_spShader->GetStreamMask () | VERTEX_STREAM_INDEXBUFFER);
  for(unsigned int iLightIndex = 0; iLightIndex < pLights->GetNumEntries(); iLightIndex++)
  {
    VisLightSource_cl* pLight = pLights->GetEntry(iLightIndex);

    if((pLight->GetVisibleBitmask() & pContext->GetRenderFilterMask()) == 0)
      continue;

    if(!pLight->GetUseSpecular())
      continue;

    hkvVec4 vDirection;

    hkvVec3 vLightPositionRel = pLight->GetPosition() - pContext->GetCamera()->GetPosition();
    hkvVec3 vLightDirection = pLight->GetDirection();

    float fAttenuation = 1;
    switch(pLight->GetType())
    {
    case VIS_LIGHT_DIRECTED:
      vDirection = vLightDirection.getAsVec4(1.0f);
      break;

    case VIS_LIGHT_SPOTLIGHT:
      {
        vDirection = vLightDirection.getAsVec4(1.0f);

        float fAngle = vLightPositionRel.getAngleBetween(-vLightDirection);
        float fConeAngle = pLight->GetProjectionAngle();
        fAttenuation = hkvMath::clamp((fConeAngle - fAngle) / fConeAngle, 0.0f, 1.0f);

        float fDistance = vLightPositionRel.getLength();
        float fRadius = pLight->GetRadius();
        fAttenuation *= hkvMath::clamp((fRadius - fDistance) / fRadius, 0.0f, 1.0f);
      }
      break;

    case VIS_LIGHT_POINT:
      vDirection = (-vLightPositionRel).getNormalized().getAsVec4(1.0f);
      float fDistance = vLightPositionRel.getLength();
      float fRadius = pLight->GetRadius();
      fAttenuation = hkvMath::clamp((fRadius - fDistance) / fRadius, 0.0f, 1.0f);
      break;
    }

    hkvVec4 vColor = pLight->GetColor().getAsVec4() * pLight->GetMultiplier() * fAttenuation;

    hkvVec4 vParams(m_fSpecularPower, 0, 0, 0);

    m_spShader->GetConstantBuffer(VSS_PixelShader)->SetSingleParameterF("fLightDirection", vDirection.data);
    m_spShader->GetConstantBuffer(VSS_PixelShader)->SetSingleParameterF("fLightColor", vColor.data);
    m_spShader->GetConstantBuffer(VSS_PixelShader)->SetSingleParameterF("fParams", vParams.data);

    Vision::RenderLoopHelper.RenderMeshes(m_spShader, VisMeshBuffer_cl::MB_PRIMTYPE_INDEXED_TRILIST, 0, 2, 6);
  }
  Vision::RenderLoopHelper.EndMeshRendering();

  // Trigger pre-screenmask render hook to make the attached cubemap handle flip and blur the cubemap target
  VisRenderHookDataObject_cl data(&Vision::Callbacks.OnRenderHook, VRH_PRE_SCREENMASKS);
  Vision::Callbacks.OnRenderHook.TriggerCallbacks(&data);
}