ReadbackTask.cpp

#include "ReadbackTask.h"
 
#include "Rendering/IGraphicsDevice.h"
#include "Rendering/IContext.h"
 
#include "Foundation/Logging/Logger.h"
 
#include "Services/Time.h"
 
#include "Renderer/RenderBuffer.h"
#include "Renderer/RenderList.h"
#include "Renderer/RenderTarget.h"
 
#include "Context.h"
 
namespace
{
  Cogs::Logging::Log logger = Cogs::Logging::getLogger("ReadbackTask");
}
 
void Cogs::Core::ReadbackTask::apply(RenderTaskContext * renderContext)
{
  RenderInstrumentationScope(renderContext->device->getImmediateContext(), SCOPE_RENDERING, "ReadbackTask::apply");
 
  auto device = renderContext->device;
  auto deviceContext = device->getImmediateContext();
 
  if (size > std::numeric_limits<uint32_t>::max()) {
    LOG_ERROR(logger, "Invalid readback size %zd.", size.getValue());
    return;
  }
 
  auto source = input.get(RenderResourceType::RenderBuffer);
 
  if (!source) {
    LOG_ERROR(logger, "No input resource bound for readback.");
    return;
  }
 
  auto inputBuffer = source->renderBuffer;
 
  if (size > inputBuffer->size) {
    LOG_ERROR(logger, "Readback size (%zd) larger than buffer size %zd.", size.getValue(), inputBuffer->size);
    return;
  }
 
  if (size % inputBuffer->elementSize != 0) {
    LOG_WARNING(logger, "Readback size %zd not multiple of input element size %zd.", size.getValue(), inputBuffer->elementSize.getValue());
  }
 
  auto bufferHandle = inputBuffer->getHandle(bufferIndex);
 
  if (!HandleIsValid(bufferHandle)) {
    LOG_ERROR(logger, "Invalid buffer handle for buffer: %.*s, index: %zd.", StringViewFormat(inputBuffer->getName()), bufferIndex.getValue());
    return;
  }
 
  auto mappedData = deviceContext->map(bufferHandle, MapMode::Read);
 
  if (!mappedData) {
    LOG_ERROR(logger, "Could not map resource for readback.");
    return;
  }
 
  hostBuffer.resize(size, false);
  std::memcpy(hostBuffer.data(), mappedData, size);
  deviceContext->unmap(bufferHandle);
  uint32_t frame = inputBuffer->getFrame(bufferIndex);
 
  bool published = false;
  const auto * list = input.get(RenderResourceType::RenderList);
  for (auto it : renderContext->context->callbacks.readbackCallbackInternal) {
    (*it)(renderContext->context, list ? list->renderList->viewportData : nullptr, frame, key.data(), hostBuffer.data(), (int)hostBuffer.size());
    published = true;
  }
 
  if (renderContext->context->callbacks.readbackCallback) {
    renderContext->context->callbacks.readbackCallback(renderContext->context, key.data(), hostBuffer.data(), (int)hostBuffer.size());
    published = true;
  }
 
  if (published) {
    errorState = false;
  }
  else if (!errorState) {
    LOG_WARNING(logger, "Performed readback of %.*s without callback.", StringViewFormat(inputBuffer->getName()));
    errorState = true;
  }
}