LookingGlass/idd/LGIdd/CPostProcessor.cpp

/**
 * Looking Glass
 * Copyright © 2017-2026 The Looking Glass Authors
 * https://looking-glass.io
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc., 59
 * Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "CPostProcessor.h"

#include "CD3D12Device.h"
#include "CDebug.h"
#include "effect/CColorTransformEffect.h"
#include "effect/CDownsampleEffect.h"
#include "effect/CHDR16to10Effect.h"
#include "effect/CRGB24Effect.h"

#include <cstring>
#include <utility>

namespace
{
  bool NearlyEqual(float a, float b, float tolerance)
  {
    const float delta = a - b;
    return delta >= -tolerance && delta <= tolerance;
  }
}

bool IsIdentityColorTransform(const D12ColorTransform& transform)
{
  static const float matrixTolerance = 1.0f / 1048576.0f;
  static const float lutTolerance    = 1.0f / 65535.0f;

  if (transform.matrixEnabled)
  {
    for (unsigned row = 0; row < 3; ++row)
      for (unsigned column = 0; column < 4; ++column)
      {
        const float expected = row == column ? 1.0f : 0.0f;
        const float effective =
          transform.matrix[row][column] * transform.scalar;
        if (!NearlyEqual(effective, expected, matrixTolerance))
          return false;
      }
  }

  if (transform.lutEnabled)
    for (unsigned i = 0; i < 4096; ++i)
    {
      const float expected = (float)i / 4095.0f;
      if (!NearlyEqual(transform.lut[i][0], expected, lutTolerance) ||
          !NearlyEqual(transform.lut[i][1], expected, lutTolerance) ||
          !NearlyEqual(transform.lut[i][2], expected, lutTolerance))
        return false;
    }

  return true;
}

static void CopyHDRMetadata(D12FrameFormat& dst, const D12FrameFormat& src)
{
  dst.hdrMetadata   = src.hdrMetadata;
  dst.sdrWhiteLevel = src.sdrWhiteLevel;
  std::memcpy(dst.displayPrimary, src.displayPrimary, sizeof(dst.displayPrimary));
  std::memcpy(dst.whitePoint, src.whitePoint, sizeof(dst.whitePoint));
  dst.maxDisplayLuminance       = src.maxDisplayLuminance;
  dst.minDisplayLuminance       = src.minDisplayLuminance;
  dst.maxContentLightLevel      = src.maxContentLightLevel;
  dst.maxFrameAverageLightLevel = src.maxFrameAverageLightLevel;
}

bool CPostProcessor::Init(std::shared_ptr<CD3D12Device> dx12Device)
{
  m_dx12Device = dx12Device;
  m_device = dx12Device->GetDevice();
  m_effects.clear();

  std::unique_ptr<CColorTransformEffect> colorTransform(new CColorTransformEffect());
  if (colorTransform->Init(m_device))
  {
    DEBUG_INFO("Created post-processing effect: %s", colorTransform->GetName());
    m_effects.push_back(std::move(colorTransform));
  }
  else
    return false;

  std::unique_ptr<CDownsampleEffect> downsample(new CDownsampleEffect());
  if (downsample->Init(m_device))
  {
    DEBUG_INFO("Created post-processing effect: %s", downsample->GetName());
    m_effects.push_back(std::move(downsample));
  }

  std::unique_ptr<CHDR16to10Effect> hdr16to10(new CHDR16to10Effect());
  if (hdr16to10->Init(m_device))
  {
    DEBUG_INFO("Created post-processing effect: %s", hdr16to10->GetName());
    m_effects.push_back(std::move(hdr16to10));
  }
  else
    return false;

  std::unique_ptr<CRGB24Effect> rgb24(new CRGB24Effect());
  if (rgb24->Init(m_device))
  {
    DEBUG_INFO("Created post-processing effect: %s", rgb24->GetName());
    m_effects.push_back(std::move(rgb24));
  }

  return true;
}

void CPostProcessor::Reset()
{
  m_effects.clear();
  m_dx12Device.reset();
  m_device.Reset();
  m_srcFormat     = {};
  m_dstFormat     = {};
  m_effectsActive = false;
  m_configured    = false;
}

bool CPostProcessor::HasSameEffectChain(const CPostProcessor& other) const
{
  if (m_effects.size() != other.m_effects.size())
    return false;

  for (size_t i = 0; i < m_effects.size(); ++i)
    if (std::strcmp(m_effects[i]->GetName(),
                    other.m_effects[i]->GetName()) != 0)
      return false;

  return true;
}

bool CPostProcessor::NeedsReconfigure(const D12FrameFormat& srcFormat) const
{
  return !m_configured ||
    srcFormat.desc.Width     != m_srcFormat.desc.Width  ||
    srcFormat.desc.Height    != m_srcFormat.desc.Height ||
    srcFormat.desc.Format    != m_srcFormat.desc.Format ||
    srcFormat.format         != m_srcFormat.format      ||
    srcFormat.width          != m_srcFormat.width       ||
    srcFormat.height         != m_srcFormat.height      ||
    srcFormat.hdr            != m_srcFormat.hdr         ||
    srcFormat.hdrPQ          != m_srcFormat.hdrPQ       ||
    srcFormat.colorTransform != m_srcFormat.colorTransform;
}

bool CPostProcessor::Configure(const D12FrameFormat& srcFormat,
  bool * formatChanged)
{
  if (formatChanged)
    *formatChanged = false;

  if (!NeedsReconfigure(srcFormat))
  {
    // Static HDR metadata may change independently of the resource format.
    // Propagate it without recreating textures or post-processing state.
    CopyHDRMetadata(m_srcFormat, srcFormat);
    CopyHDRMetadata(m_dstFormat, srcFormat);
    return true;
  }

  D12FrameFormat oldDst        = m_dstFormat;
  D12FrameFormat cur           = srcFormat;
  bool           effectsActive = false;

  for (const auto& effect : m_effects)
  {
    D12FrameFormat dst = cur;
    switch (effect->SetFormat(m_device, cur, dst))
    {
    case PostProcessStatus::SUCCESS:
      effect->Enabled = true;
      effectsActive   = true;
      cur             = dst;
      DEBUG_INFO("Post-processing effect active: %s", effect->GetName());
      break;

    case PostProcessStatus::BYPASS_EFFECT:
      effect->Enabled = false;
      break;

    case PostProcessStatus::FAILED:
      DEBUG_ERROR("Failed to configure post-processing effect: %s", effect->GetName());
      return false;
    }
  }

  m_srcFormat     = srcFormat;
  m_dstFormat     = cur;
  m_effectsActive = effectsActive;
  m_configured    = true;
  if (formatChanged)
    *formatChanged =
      oldDst.desc.Width     != m_dstFormat.desc.Width     ||
      oldDst.desc.Height    != m_dstFormat.desc.Height    ||
      oldDst.desc.Format    != m_dstFormat.desc.Format    ||
      oldDst.format         != m_dstFormat.format         ||
      oldDst.width          != m_dstFormat.width          ||
      oldDst.height         != m_dstFormat.height         ||
      oldDst.hdr            != m_dstFormat.hdr            ||
      oldDst.hdrPQ          != m_dstFormat.hdrPQ          ||
      oldDst.sdrWhiteLevel  != m_dstFormat.sdrWhiteLevel  ||
      oldDst.colorTransform != m_dstFormat.colorTransform;
  return true;
}

void CPostProcessor::AdjustFrameDamage(RECT dirtyRects[], unsigned * nbDirtyRects)
{
  for (const auto& effect : m_effects)
    if (effect->Enabled)
      effect->AdjustDamage(dirtyRects, nbDirtyRects);
}

ComPtr<ID3D12Resource> CPostProcessor::Run(
  const ComPtr<ID3D12GraphicsCommandList>& commandList,
  const ComPtr<ID3D12Resource>& src, RECT dirtyRects[],
  unsigned * nbDirtyRects)
{
  ComPtr<ID3D12Resource> next = src;
  for (const auto& effect : m_effects)
  {
    if (!effect->Enabled)
      continue;

    //DEBUG_TRACE("Run post-processing effect: %s", effect->GetName());
    effect->AdjustDamage(dirtyRects, nbDirtyRects);
    next = effect->Run(m_device, commandList, next, dirtyRects, nbDirtyRects);
  }

  return next;
}