lib/ui/gfx/resources/host_image.cc

// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "garnet/lib/ui/gfx/resources/host_image.h"

#include <trace/event.h>

#include "garnet/lib/ui/gfx/engine/session.h"
#include "garnet/lib/ui/gfx/resources/memory.h"
#include "garnet/lib/ui/gfx/util/image_formats.h"
#include "lib/images/cpp/images.h"

namespace scenic_impl {
namespace gfx {

const ResourceTypeInfo HostImage::kTypeInfo = {
    ResourceType::kHostImage | ResourceType::kImage | ResourceType::kImageBase,
    "HostImage"};

HostImage::HostImage(Session* session, ResourceId id, MemoryPtr memory,
                     escher::ImagePtr image, uint64_t memory_offset,
                     fuchsia::images::ImageInfo image_format)
    : Image(session, id, HostImage::kTypeInfo),
      memory_(std::move(memory)),
      memory_offset_(memory_offset),
      image_format_(image_format) {
  image_ = std::move(image);
  image_conversion_function_ =
      image_formats::GetFunctionToConvertToBgra8(image_format);
}

ImagePtr HostImage::New(Session* session, ResourceId id, MemoryPtr memory,
                        const fuchsia::images::ImageInfo& image_info,
                        uint64_t memory_offset, ErrorReporter* error_reporter) {
  // No matter what the incoming format, the gpu format will be BGRA:
  vk::Format gpu_image_pixel_format = vk::Format::eB8G8R8A8Unorm;
  size_t pixel_alignment = images::MaxSampleAlignment(image_info.pixel_format);

  if (image_info.width <= 0) {
    error_reporter->ERROR()
        << "Image::CreateFromMemory(): width must be greater than 0.";
    return nullptr;
  }
  if (image_info.height <= 0) {
    error_reporter->ERROR()
        << "Image::CreateFromMemory(): height must be greater than 0.";
    return nullptr;
  }

  auto& caps = session->resource_context().vk_device_queues_capabilities;
  if (image_info.width > caps.max_image_width) {
    error_reporter->ERROR()
        << "Image::CreateFromMemory(): image width exceeds maximum ("
        << image_info.width << " vs. " << caps.max_image_width << ").";
    return nullptr;
  }
  if (image_info.height > caps.max_image_height) {
    error_reporter->ERROR()
        << "Image::CreateFromMemory(): image height exceeds maximum ("
        << image_info.height << " vs. " << caps.max_image_height << ").";
    return nullptr;
  }

  uint64_t width_bytes = image_info.width * images::StrideBytesPerWidthPixel(
                                                image_info.pixel_format);
  if (image_info.stride < width_bytes) {
    error_reporter->ERROR()
        << "Image::CreateFromMemory(): stride too small for width";
    return nullptr;
  }
  if (image_info.stride % pixel_alignment != 0) {
    error_reporter->ERROR()
        << "Image::CreateFromMemory(): stride must preserve pixel alignment.";
    return nullptr;
  }
  if (image_info.tiling != fuchsia::images::Tiling::LINEAR) {
    error_reporter->ERROR()
        << "Image::CreateFromMemory(): tiling must be LINEAR for images "
        << "created using host memory.";
    return nullptr;
  }

  size_t image_size = images::ImageSize(image_info);
  if (memory_offset >= memory->size()) {
    error_reporter->ERROR()
        << "Image::CreateFromMemory(): the offset of the Image must be "
        << "within the range of the Memory";
    return nullptr;
  }
  if (memory_offset + image_size > memory->size()) {
    error_reporter->ERROR()
        << "Image::CreateFromMemory(): the Image must fit within the size "
        << "of the Memory";
    return nullptr;
  }

  // TODO(SCN-141): Support non-minimal strides for all formats.  For now, NV12
  // is ok because it will have image_conversion_function_ and for formats with
  // image_conversion_function_, the stride is really only the input data stride
  // not the output data stride (which ends up being minimal thanks to the
  // image_conversion_function_).
  if (image_info.pixel_format != fuchsia::images::PixelFormat::NV12 &&
      image_info.stride != width_bytes) {
    error_reporter->ERROR()
        << "Image::CreateFromMemory(): the stride must be minimal (SCN-141)";
    return nullptr;
  }

  auto escher_image = escher::image_utils::NewImage(
      session->resource_context().escher_image_factory, gpu_image_pixel_format,
      image_info.width, image_info.height);

  auto host_image = fxl::AdoptRef(new HostImage(session, id, std::move(memory),
                                                std::move(escher_image),
                                                memory_offset, image_info));
  return host_image;
}

bool HostImage::UpdatePixels(escher::BatchGpuUploader* gpu_uploader) {
  if (!gpu_uploader) {
    FXL_LOG(WARNING) << "No BatchGpuUploader, cannot UpdatePixels.";
    return true;
  }

  TRACE_DURATION("gfx", "UpdatePixels");
  escher::image_utils::WritePixelsToImage(
      gpu_uploader, static_cast<uint8_t*>(memory_->host_ptr()) + memory_offset_,
      image_, image_conversion_function_);
  // Pixels have been updated, dirty state is now false.
  return false;
}

}  // namespace gfx
}  // namespace scenic_impl