From 9ffb800e93c7f52b55f256dc6412e333f48b113c Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Fri, 28 Mar 2025 14:35:19 +0000
Subject: [PATCH] [idd] driver: use the frameSize instead of the resource size

As the resource size can be larger then the actual frame data, we
need to track this seperately so that we don't waste cycles copying
data the client will never use.
---
 idd/LGIdd/CFrameBufferResource.cpp | 10 +++++++---
 idd/LGIdd/CFrameBufferResource.h   | 10 ++++++----
 idd/LGIdd/CSwapChainProcessor.cpp  |  3 ++-
 3 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/idd/LGIdd/CFrameBufferResource.cpp b/idd/LGIdd/CFrameBufferResource.cpp
index cebf65af..41c30d90 100644
--- a/idd/LGIdd/CFrameBufferResource.cpp
+++ b/idd/LGIdd/CFrameBufferResource.cpp
@@ -12,7 +12,10 @@ bool CFrameBufferResource::Init(CSwapChainProcessor * swapChain, uint8_t * base,
 
   // nothing to do if the resource already exists and is large enough
   if (m_base == base && m_size >= size)
+  {
+    m_frameSize = size;
     return true;
+  }
 
   Reset();
 
@@ -87,9 +90,10 @@ bool CFrameBufferResource::Init(CSwapChainProcessor * swapChain, uint8_t * base,
 
   m_res->SetName(resName);
 
-  m_base  = base;
-  m_size  = size;
-  m_valid = true;
+  m_base      = base;
+  m_size      = size;
+  m_frameSize = size;
+  m_valid     = true;
   return true;
 }
 
diff --git a/idd/LGIdd/CFrameBufferResource.h b/idd/LGIdd/CFrameBufferResource.h
index 1ec6a2f4..ba8377d9 100644
--- a/idd/LGIdd/CFrameBufferResource.h
+++ b/idd/LGIdd/CFrameBufferResource.h
@@ -16,6 +16,7 @@ class CFrameBufferResource
     bool                   m_valid;
     uint8_t              * m_base;
     size_t                 m_size;
+    size_t                 m_frameSize;
     ComPtr<ID3D12Resource> m_res;
     void                 * m_map;
 
@@ -23,10 +24,11 @@ class CFrameBufferResource
     bool Init(CSwapChainProcessor * swapChain, uint8_t * base, size_t size);
     void Reset();
 
-    bool      IsValid() { return m_valid; }
-    uint8_t * GetBase() { return m_base;  }
-    size_t    GetSize() { return m_size;  }
-    void *    GetMap()  { return m_map;   }
+    bool      IsValid()      { return m_valid;     }
+    uint8_t * GetBase()      { return m_base;      }
+    size_t    GetSize()      { return m_size;      }
+    size_t    GetFrameSize() { return m_frameSize; }
+    void *    GetMap()       { return m_map;       }
 
     ComPtr<ID3D12Resource> Get() { return m_res; }
 };
diff --git a/idd/LGIdd/CSwapChainProcessor.cpp b/idd/LGIdd/CSwapChainProcessor.cpp
index 56d58833..eec3afde 100644
--- a/idd/LGIdd/CSwapChainProcessor.cpp
+++ b/idd/LGIdd/CSwapChainProcessor.cpp
@@ -217,7 +217,8 @@ void CSwapChainProcessor::SwapChainNewFrame(ComPtr<IDXGIResource> acquiredBuffer
   m_dx12Device->GetCopyQueue().Reset();
 
   if (m_dx12Device->IsIndirectCopy())
-    m_devContext->WriteFrameBuffer(fbRes->GetMap(), 0, fbRes->GetSize(), true);
+    m_devContext->WriteFrameBuffer(
+      fbRes->GetMap(), 0, fbRes->GetFrameSize(), true);
   else
     m_devContext->FinalizeFrameBuffer();
 }
\ No newline at end of file