[idd] capture: define immutable texture products

idd/LGIdd/capture/CFrameGraph.cpp

@@ -20,6 +20,8 @@
 
 #include "capture/CFrameGraph.h"
 
+#include <cstring>
+
 bool Frame::Same(const GraphCfg& left, const GraphCfg& right)
 {
   return
@@ -311,13 +313,35 @@ bool CFrameGraph::Want(FrameSignal signal) const
   return false;
 }
 
-bool CFrameGraph::Desc(unsigned leaf, const FrameDesc& frame,
+bool CFrameGraph::Desc(unsigned leaf, const FrameContentRef& content,
   LeafDesc& desc) const
 {
-  if (!m_sealed || leaf >= m_leafCount || !frame.serial ||
-      frame.format.width != m_cfg.srcWidth ||
-      frame.format.height != m_cfg.srcHeight ||
-      !Frame::Valid(frame.damage, frame.rects, frame.count,
+  if (!content)
+    return false;
+
+  const D12FrameFormat& source = content->format;
+  FrameProfile sourceProfile;
+  const bool validProfile = D12::Profile(source,
+    FrameStorage::D3D12_TEXTURE, sourceProfile);
+  if (!validProfile || !Frame::Same(sourceProfile, m_cfg.src))
+    return false;
+
+  if (!m_sealed                                             ||
+      leaf                         >= m_leafCount           ||
+      !content->serial                                      ||
+      source.width                 != m_cfg.srcWidth        ||
+      source.height                != m_cfg.srcHeight       ||
+      source.dataWidth             != m_cfg.srcWidth        ||
+      source.dataHeight            != m_cfg.srcHeight       ||
+      source.pitch                 != 0                     ||
+      source.desc.Dimension        !=
+        D3D12_RESOURCE_DIMENSION_TEXTURE2D                  ||
+      source.desc.Width            != m_cfg.srcWidth        ||
+      source.desc.Height           != m_cfg.srcHeight       ||
+      source.desc.DepthOrArraySize != 1                     ||
+      source.desc.MipLevels        != 1                     ||
+      source.desc.SampleDesc.Count != 1                     ||
+      !Frame::Valid(content->damage, content->rects, content->count,
         m_cfg.srcWidth, m_cfg.srcHeight))
     return false;
 
@@ -327,10 +351,32 @@ bool CFrameGraph::Desc(unsigned leaf, const FrameDesc& frame,
   desc.epoch   = route.epoch;
   desc.node    = route.node;
   desc.profile = route.cfg.profile;
-  desc.frame   = frame;
+
+  desc.frame         = FrameDesc {};
+  desc.frame.content = content;
+  desc.frame.damage  = content->damage;
+  desc.frame.count   = content->count;
+  if (content->count)
+    memcpy(desc.frame.rects, content->rects,
+      content->count * sizeof(*content->rects));
+  desc.frame.format  = content->format;
+
+  // A scaled checkpoint has a different damage coordinate space. Until the
+  // executor owns exact edge transforms, preserve correctness by making any
+  // partial source damage a full node update.
+  if (desc.frame.damage == FrameDamage::RECTS &&
+      (node.width != m_cfg.srcWidth || node.height != m_cfg.srcHeight))
+  {
+    desc.frame.damage = FrameDamage::FULL;
+    desc.frame.count  = 0;
+  }
 
   D12FrameFormat& format = desc.frame.format;
-  return D12::Set(format, node.profile, node.width, node.height);
+  if (!D12::Set(format, node.profile, node.width, node.height))
+    return false;
+  // Calibration/LUT nodes have already consumed this transform.
+  format.colorTransform.reset();
+  return true;
 }
 
 const GraphNode * CFrameGraph::Nodes(unsigned& count) const

idd/LGIdd/capture/CFrameGraph.h

@@ -91,9 +91,9 @@ struct GraphLeaf
   FrameCfg  cfg;
 };
 
-// FrameDesc is resource-free. It can cross graph nodes without retaining the
-// acquired IddCx texture and is paired with owned texture storage separately.
-struct FrameDesc
+// All products derived from one capture retain the same immutable content.
+// It contains no acquired IddCx or Direct3D resource.
+struct FrameContent
 {
   uint64_t       serial                  = 0;
   uint64_t       captureTime             = 0;
@@ -103,6 +103,19 @@ struct FrameDesc
   D12FrameFormat format                  = {};
 };
 
+using FrameContentRef = std::shared_ptr<const FrameContent>;
+
+// FrameDesc adds one graph node's representation and damage to the shared
+// content identity. It remains resource-free.
+struct FrameDesc
+{
+  FrameContentRef content;
+  FrameDamage     damage                  = FrameDamage::NONE;
+  RECT            rects[FRAME_DAMAGE_MAX] = {};
+  unsigned        count                   = 0;
+  D12FrameFormat  format                  = {};
+};
+
 struct LeafDesc
 {
   BackendId    id     = 0;
@@ -140,7 +153,8 @@ public:
   bool Same(const GraphCfg& cfg) const;
   bool Want(FrameSignal signal) const;
   bool Need(FrameOp op) const;
-  bool Desc(unsigned leaf, const FrameDesc& frame, LeafDesc& desc) const;
+  bool Desc(unsigned leaf, const FrameContentRef& content,
+    LeafDesc& desc) const;
 
   const GraphCfg& Cfg() const { return m_cfg; }
   const GraphNode * Nodes(unsigned& count) const;

idd/LGIdd/capture/CFrameTex.cpp

@@ -0,0 +1,537 @@
+/**
+ * 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 "capture/CFrameTex.h"
+
+#include "Atomic.h"
+#include "CDebug.h"
+#include "CSRWLock.h"
+#include "Seq.h"
+
+#include <new>
+
+enum class TexState : uint8_t
+{
+  FREE,
+  WRITE,
+  LEASED,
+  WAIT,
+  DEAD,
+};
+
+static void WaitSync(const D12Sync& sync)
+{
+  while (sync.State() == D12SyncState::PENDING)
+    Sleep(1);
+}
+
+static uint64_t NextPool()
+{
+  static std::atomic<uint64_t> next { 0 };
+  return Atomic::Next(next);
+}
+
+static bool ValidFrame(const FrameProfile& profile,
+  const D3D12_RESOURCE_DESC& resource, const FrameDesc& frame)
+{
+  const D12FrameFormat& format = frame.format;
+  FrameProfile formatProfile;
+  const bool validProfile = D12::Profile(format,
+    FrameStorage::D3D12_TEXTURE, formatProfile);
+  if (!validProfile || !Frame::Same(formatProfile, profile))
+    return false;
+
+  const bool validDamage = Frame::Valid(frame.damage, frame.rects,
+    frame.count, format.width, format.height);
+  return
+    frame.content                                                   &&
+    frame.content->serial                                           &&
+    validDamage                                                     &&
+    resource.Dimension        == D3D12_RESOURCE_DIMENSION_TEXTURE2D &&
+    resource.Width            == format.width                       &&
+    resource.Height           == format.height                      &&
+    resource.DepthOrArraySize == 1                                  &&
+    resource.MipLevels        == 1                                  &&
+    resource.SampleDesc.Count == 1                                  &&
+    D12::Same(resource, format.desc, D12::DescCmp::NO_FLAGS)        &&
+    format.pitch              == 0                                  &&
+    format.dataWidth          == resource.Width                     &&
+    format.dataHeight         == resource.Height;
+}
+
+struct CTexCore
+{
+  struct Slot
+  {
+    ComPtr<ID3D12Resource> res;
+    D12Sync                sync;
+    TexState               state = TexState::FREE;
+    uint64_t               gen   = 0;
+  };
+
+  mutable CSRWLock       lock;
+  bool                   open    = true;
+  bool                   closed  = false;
+  bool                   failed  = false;
+  uint64_t               graph   = 0;
+  uint64_t               id      = 0;
+  unsigned               node    = 0;
+  unsigned               count   = 0;
+  FrameProfile           profile;
+  D3D12_RESOURCE_DESC    desc    = {};
+  D3D12_RESOURCE_STATES  read    = D3D12_RESOURCE_STATE_COMMON;
+  Slot                   slots[CTexPool::MAX_SLOTS];
+
+  TexResult Acquire(unsigned& index, uint64_t& generation)
+  {
+    CSRWExclusiveLock guard(lock);
+    if (!open || failed)
+      return TexResult::FAILED;
+
+    for (unsigned i = 0; i < count; ++i)
+      if (slots[i].state == TexState::WAIT)
+      {
+        const D12SyncState state = slots[i].sync.State();
+        if (state == D12SyncState::FAILED)
+        {
+          slots[i].state = TexState::DEAD;
+          failed         = true;
+          return TexResult::FAILED;
+        }
+        else if (state == D12SyncState::READY)
+        {
+          slots[i].sync  = D12Sync {};
+          slots[i].state = TexState::FREE;
+        }
+      }
+
+    for (unsigned i = 0; i < count; ++i)
+      if (slots[i].state == TexState::FREE)
+      {
+        Seq::Inc(slots[i].gen);
+        slots[i].state = TexState::WRITE;
+        index          = i;
+        generation     = slots[i].gen;
+        return TexResult::OK;
+      }
+
+    for (unsigned i = 0; i < count; ++i)
+      if (slots[i].state != TexState::DEAD)
+        return TexResult::BUSY;
+    return TexResult::FAILED;
+  }
+
+  bool Info(unsigned index, uint64_t generation,
+    ComPtr<ID3D12Resource>& resource) const
+  {
+    CSRWSharedLock guard(lock);
+    if (!open || failed || index >= count ||
+        slots[index].gen != generation ||
+        slots[index].state != TexState::WRITE)
+      return false;
+    resource = slots[index].res;
+    return true;
+  }
+
+  bool Seal(unsigned index, uint64_t generation, const D12Sync& sync)
+  {
+    CSRWExclusiveLock guard(lock);
+    if (!open || failed || index >= count ||
+        slots[index].gen != generation ||
+        slots[index].state != TexState::WRITE || !sync.Valid())
+      return false;
+    slots[index].sync  = sync;
+    slots[index].state = TexState::LEASED;
+    return true;
+  }
+
+  void Fail(unsigned index, uint64_t generation, const D12Sync& sync)
+  {
+    D12Sync retired;
+    {
+      CSRWExclusiveLock guard(lock);
+      if (index >= count || slots[index].gen != generation ||
+          slots[index].state != TexState::WRITE)
+        return;
+      slots[index].sync = sync;
+      if (open)
+        slots[index].state = TexState::WAIT;
+      else
+      {
+        retired = sync;
+        slots[index].state = TexState::DEAD;
+      }
+    }
+    if (retired.Valid())
+      WaitSync(retired);
+  }
+
+  void Drop(unsigned index, uint64_t generation)
+  {
+    D12Sync retired;
+    {
+      CSRWExclusiveLock guard(lock);
+      if (index >= count || slots[index].gen != generation)
+        return;
+
+      Slot& slot = slots[index];
+      if (slot.state == TexState::WRITE)
+      {
+        slot.state = TexState::DEAD;
+        return;
+      }
+      if (slot.state != TexState::LEASED)
+        return;
+
+      const D12SyncState state = slot.sync.State();
+      if (!open)
+      {
+        retired    = slot.sync;
+        slot.state = TexState::DEAD;
+      }
+      else if (state == D12SyncState::FAILED)
+      {
+        slot.state = TexState::DEAD;
+        failed     = true;
+      }
+      else if (state == D12SyncState::READY)
+      {
+        slot.sync  = D12Sync {};
+        slot.state = TexState::FREE;
+      }
+      else
+        slot.state = TexState::WAIT;
+    }
+    if (retired.Valid())
+      WaitSync(retired);
+  }
+
+  void Cancel(unsigned index, uint64_t generation)
+  {
+    CSRWExclusiveLock guard(lock);
+    if (index >= count || slots[index].gen != generation ||
+        slots[index].state != TexState::WRITE)
+      return;
+    slots[index].state = open ? TexState::FREE : TexState::DEAD;
+  }
+
+  void Retire(unsigned index, uint64_t generation)
+  {
+    CSRWExclusiveLock guard(lock);
+    if (index < count && slots[index].gen == generation &&
+        slots[index].state == TexState::WRITE)
+      slots[index].state = TexState::DEAD;
+  }
+
+  void Close()
+  {
+    D12Sync waits[CTexPool::MAX_SLOTS];
+    unsigned waitCount = 0;
+    {
+      CSRWExclusiveLock guard(lock);
+      if (closed)
+        return;
+      open   = false;
+      closed = true;
+      for (unsigned i = 0; i < count; ++i)
+      {
+        if ((slots[i].state == TexState::LEASED ||
+             slots[i].state == TexState::WAIT) &&
+            slots[i].sync.Valid())
+          waits[waitCount++] = slots[i].sync;
+        if (slots[i].state != TexState::LEASED &&
+            slots[i].state != TexState::WRITE)
+          slots[i].state = TexState::DEAD;
+      }
+    }
+
+    // Reset is infrequent and cannot release a texture still referenced by
+    // producer commands. Outstanding consumers keep their own core alive.
+    for (unsigned i = 0; i < waitCount; ++i)
+      WaitSync(waits[i]);
+  }
+
+  void Stop()
+  {
+    CSRWExclusiveLock guard(lock);
+    open = false;
+  }
+};
+
+CFrameTex::CFrameTex(uint64_t graphValue, uint64_t poolValue,
+  unsigned nodeValue, unsigned slotValue, uint64_t versionValue,
+  const FrameProfile& profileValue,
+  const FrameDesc& frameValue, const ComPtr<ID3D12Resource>& res,
+  const D12Sync& sync, D3D12_RESOURCE_STATES state) :
+  m_res(res),
+  m_sync(sync),
+  m_state(state),
+  graph(graphValue),
+  pool(poolValue),
+  node(nodeValue),
+  slot(slotValue),
+  version(versionValue),
+  profile(profileValue),
+  frame(frameValue)
+{
+}
+
+bool CFrameTex::Wait(CD3D12CommandSlot& cmd) const
+{
+  if (!m_sync.Valid())
+    return false;
+  const UINT64 completed = m_sync.fence->GetCompletedValue();
+  if (completed == UINT64_MAX)
+    return false;
+  if (completed >= m_sync.value)
+    return true;
+  return cmd.WaitFor(m_sync.fence.Get(), m_sync.value);
+}
+
+TexWrite::TexWrite(const std::shared_ptr<CTexCore>& core,
+  unsigned index, uint64_t version) :
+  m_core(core), m_index(index), m_version(version)
+{
+}
+
+TexWrite::TexWrite(TexWrite&& other) noexcept :
+  m_core(std::move(other.m_core)),
+  m_index(other.m_index),
+  m_version(other.m_version)
+{
+  other.Clear();
+}
+
+TexWrite& TexWrite::operator=(TexWrite&& other) noexcept
+{
+  if (this == &other)
+    return *this;
+  Retire();
+  m_core    = std::move(other.m_core);
+  m_index   = other.m_index;
+  m_version = other.m_version;
+  other.Clear();
+  return *this;
+}
+
+TexWrite::~TexWrite()
+{
+  Retire();
+}
+
+void TexWrite::Retire()
+{
+  if (m_core)
+    m_core->Retire(m_index, m_version);
+  Clear();
+}
+
+void TexWrite::Clear()
+{
+  m_core.reset();
+  m_index   = 0;
+  m_version = 0;
+}
+
+ID3D12Resource * TexWrite::Get() const
+{
+  ComPtr<ID3D12Resource> resource;
+  return m_core && m_core->Info(m_index, m_version, resource) ?
+    resource.Get() : nullptr;
+}
+
+bool TexWrite::Seal(const FrameDesc& frame, const D12Sync& sync,
+  TexLease& lease)
+{
+  if (!m_core || !sync.Valid())
+    return false;
+
+  const std::shared_ptr<CTexCore> core = m_core;
+  ComPtr<ID3D12Resource> resource;
+  FrameDesc desc = frame;
+  if (!core->Info(m_index, m_version, resource) ||
+      !ValidFrame(core->profile, resource->GetDesc(), desc))
+  {
+    core->Fail(m_index, m_version, sync);
+    Clear();
+    return false;
+  }
+
+  // The graph descriptor is resource-free and canonical. Publish the exact
+  // pool descriptor, including producer-only UAV creation capability.
+  desc.format.desc = resource->GetDesc();
+
+  const unsigned index = m_index;
+  const uint64_t generation = m_version;
+  if (!core->Seal(index, generation, sync))
+  {
+    core->Fail(index, generation, sync);
+    Clear();
+    return false;
+  }
+
+  CFrameTex * raw = new (std::nothrow) CFrameTex(core->graph, core->id,
+    core->node, m_index, m_version, core->profile, desc, resource, sync,
+    core->read);
+  if (!raw)
+  {
+    core->Drop(index, generation);
+    Clear();
+    return false;
+  }
+
+  std::shared_ptr<const CFrameTex> product;
+  try
+  {
+    product = std::shared_ptr<const CFrameTex>(raw,
+      [core, index, generation](const CFrameTex * texture)
+      {
+        delete texture;
+        core->Drop(index, generation);
+      });
+  }
+  catch (const std::bad_alloc&)
+  {
+    // The shared_ptr constructor invokes the supplied deleter on failure.
+    Clear();
+    return false;
+  }
+
+  Clear();
+  lease = TexLease(product);
+  return true;
+}
+
+void TexWrite::Cancel()
+{
+  if (m_core)
+    m_core->Cancel(m_index, m_version);
+  Clear();
+}
+
+TexResult CTexPool::Init(ID3D12Device3 * device, uint64_t graph,
+  unsigned node, const FrameProfile& profile,
+  const D3D12_RESOURCE_DESC& desc, D3D12_RESOURCE_STATES state,
+  unsigned slots)
+{
+  if (!device || !graph || !node || !slots || slots > MAX_SLOTS     ||
+      profile.storage         != FrameStorage::D3D12_TEXTURE        ||
+      !Frame::Valid(profile)                                        ||
+      desc.Dimension          != D3D12_RESOURCE_DIMENSION_TEXTURE2D ||
+      !desc.Width || !desc.Height || desc.Width > UINT_MAX          ||
+      desc.Format             != D12::Dxgi(profile.pixel)           ||
+      desc.DepthOrArraySize   != 1                                  ||
+      desc.MipLevels          != 1                                  ||
+      desc.SampleDesc.Count   != 1                                  ||
+      desc.SampleDesc.Quality != 0                                  ||
+      desc.Alignment          != 0                                  ||
+      desc.Layout             != D3D12_TEXTURE_LAYOUT_UNKNOWN       ||
+      (static_cast<UINT>(desc.Flags) &
+       ~static_cast<UINT>(D3D12_RESOURCE_FLAG_ALLOW_UNORDERED_ACCESS |
+         D3D12_RESOURCE_FLAG_ALLOW_SIMULTANEOUS_ACCESS)) != 0       ||
+      node                    >= FRAME_GRAPH_MAX_NODES              ||
+      state                   != D3D12_RESOURCE_STATE_COMMON)
+    return TexResult::REJECTED;
+
+  std::shared_ptr<CTexCore> core;
+  try
+  {
+    core = std::shared_ptr<CTexCore>(new (std::nothrow) CTexCore);
+  }
+  catch (const std::bad_alloc&)
+  {
+    return TexResult::FAILED;
+  }
+  if (!core)
+    return TexResult::FAILED;
+  core->graph   = graph;
+  core->id      = NextPool();
+  core->node    = node;
+  core->count   = slots;
+  core->profile = profile;
+  core->desc    = desc;
+  core->read    = state;
+
+  D3D12_HEAP_PROPERTIES heap = {};
+  heap.Type                 = D3D12_HEAP_TYPE_DEFAULT;
+  heap.CPUPageProperty      = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
+  heap.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
+  heap.CreationNodeMask     = 1;
+  heap.VisibleNodeMask      = 1;
+
+  for (unsigned i = 0; i < slots; ++i)
+  {
+    const HRESULT hr = device->CreateCommittedResource(&heap,
+      D3D12_HEAP_FLAG_CREATE_NOT_ZEROED, &desc, state, nullptr,
+      IID_PPV_ARGS(&core->slots[i].res));
+    if (FAILED(hr))
+    {
+      DEBUG_ERROR_HR(hr, "Failed to create frame texture");
+      core->Close();
+      return TexResult::FAILED;
+    }
+    core->slots[i].res->SetName(L"Frame Texture");
+  }
+
+  std::shared_ptr<CTexCore> old;
+  {
+    CSRWExclusiveLock guard(m_lock);
+    old = std::move(m_core);
+    if (old)
+      old->Stop();
+    m_core = core;
+  }
+  if (old)
+    old->Close();
+  return TexResult::OK;
+}
+
+void CTexPool::Reset()
+{
+  std::shared_ptr<CTexCore> core;
+  {
+    CSRWExclusiveLock guard(m_lock);
+    core = std::move(m_core);
+    if (core)
+      core->Stop();
+  }
+  if (core)
+    core->Close();
+}
+
+TexResult CTexPool::Try(TexWrite& write)
+{
+  if (write)
+    return TexResult::REJECTED;
+
+  std::shared_ptr<CTexCore> core;
+  {
+    CSRWSharedLock guard(m_lock);
+    core = m_core;
+  }
+  if (!core)
+    return TexResult::FAILED;
+  unsigned index;
+  uint64_t generation;
+  const TexResult result = core->Acquire(index, generation);
+  if (result == TexResult::OK)
+    write = TexWrite(core, index, generation);
+  return result;
+}

idd/LGIdd/capture/CFrameTex.h

@@ -0,0 +1,158 @@
+/**
+ * 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
+ */
+
+#pragma once
+
+#include "CSRWLock.h"
+#include "capture/CFrameGraph.h"
+#include "d3d/CD3D12CommandQueue.h"
+
+#include <memory>
+
+struct CTexCore;
+class TexWrite;
+
+enum class TexResult : uint8_t
+{
+  OK,
+  BUSY,
+  REJECTED,
+  FAILED,
+};
+
+// An immutable, pool-owned D3D12 graph product. Node zero is deliberately
+// excluded because it aliases the acquired IddCx surface.
+class CFrameTex final
+{
+  friend class TexWrite;
+
+private:
+  ComPtr<ID3D12Resource>  m_res;
+  D12Sync                 m_sync;
+  D3D12_RESOURCE_STATES   m_state;
+
+  CFrameTex(uint64_t graph, uint64_t pool, unsigned node, unsigned slot,
+    uint64_t version, const FrameProfile& profile, const FrameDesc& frame,
+    const ComPtr<ID3D12Resource>& res, const D12Sync& sync,
+    D3D12_RESOURCE_STATES state);
+
+public:
+  CFrameTex(const CFrameTex&) = delete;
+  CFrameTex& operator=(const CFrameTex&) = delete;
+
+  const uint64_t     graph;
+  const uint64_t     pool;
+  const unsigned     node;
+  const unsigned     slot;
+  const uint64_t     version;
+  const FrameProfile profile;
+  const FrameDesc    frame;
+
+  ID3D12Resource * Get() const { return m_res.Get(); }
+  const D12Sync& Sync() const { return m_sync; }
+  D3D12_RESOURCE_STATES State() const { return m_state; }
+  bool Wait(CD3D12CommandSlot& cmd) const;
+  D12SyncState Status() const { return m_sync.State(); }
+  bool Ready() const { return m_sync.Done(); }
+};
+
+// Consumers retain a lease until their own GPU use of the texture has
+// completed. Dropping the CPU call's local copy is not sufficient.
+class TexLease
+{
+  friend class TexWrite;
+
+private:
+  std::shared_ptr<const CFrameTex> m_tex;
+  explicit TexLease(std::shared_ptr<const CFrameTex> tex) : m_tex(tex) {}
+
+public:
+  TexLease() = default;
+  TexLease(const TexLease&) = default;
+  TexLease& operator=(const TexLease&) = default;
+  TexLease(TexLease&&) noexcept = default;
+  TexLease& operator=(TexLease&&) noexcept = default;
+
+  explicit operator bool() const { return !!m_tex; }
+  const CFrameTex * Get() const { return m_tex.get(); }
+  const CFrameTex * operator->() const { return m_tex.get(); }
+  void Reset() { m_tex.reset(); }
+};
+
+// A move-only producer reservation. Abandoning a writer retires its slot;
+// Cancel may be used only before any command referencing the texture submits.
+class TexWrite
+{
+  friend class CTexPool;
+
+private:
+  std::shared_ptr<CTexCore> m_core;
+  unsigned                  m_index   = 0;
+  uint64_t                  m_version = 0;
+
+  TexWrite(const std::shared_ptr<CTexCore>& core,
+    unsigned index, uint64_t version);
+  void Clear();
+  void Retire();
+
+public:
+  TexWrite() = default;
+  TexWrite(const TexWrite&) = delete;
+  TexWrite& operator=(const TexWrite&) = delete;
+  TexWrite(TexWrite&& other) noexcept;
+  TexWrite& operator=(TexWrite&& other) noexcept;
+  ~TexWrite();
+
+  explicit operator bool() const { return !!m_core; }
+  ID3D12Resource * Get() const;
+  // Seal only after producer commands restore the texture to the pool's
+  // configured immutable state and Execute returns this exact sync point.
+  bool Seal(const FrameDesc& frame, const D12Sync& sync, TexLease& lease);
+  void Cancel();
+};
+
+// One pool owns interchangeable textures for a single graph node. Reset stops
+// acquisition and drains every sealed producer point. Existing writers and
+// leases keep the retired core alive. Reset invalidates writers; a writer
+// which already submitted must still Seal so its point is safely drained,
+// but it will not publish a product from the retired generation.
+// The configured state is the promised state presented to every consumer;
+// it is not queried from D3D12. Consumers may read but never transition or
+// write a shared product.
+class CTexPool
+{
+private:
+  mutable CSRWLock          m_lock;
+  std::shared_ptr<CTexCore> m_core;
+
+public:
+  static const unsigned MAX_SLOTS = 4;
+
+  CTexPool() = default;
+  CTexPool(const CTexPool&) = delete;
+  CTexPool& operator=(const CTexPool&) = delete;
+  ~CTexPool() { Reset(); }
+
+  TexResult Init(ID3D12Device3 * device, uint64_t graph, unsigned node,
+    const FrameProfile& profile, const D3D12_RESOURCE_DESC& desc,
+    D3D12_RESOURCE_STATES state, unsigned slots);
+  void Reset();
+  TexResult Try(TexWrite& write);
+};