From 2c23e462b377b110faf5bffed75035ac8f4cb176 Mon Sep 17 00:00:00 2001
From: WinterSnowfall <WinterSnowfall@users.noreply.github.com>
Date: Sat, 31 Aug 2024 21:10:01 +0300
Subject: [PATCH] [d3d8] Clamp BaseVertexIndex to INT_MAX during use

---
 src/d3d8/d3d8_device.cpp | 7 +++++--
 src/d3d8/d3d8_device.h   | 2 +-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/d3d8/d3d8_device.cpp b/src/d3d8/d3d8_device.cpp
index 86ca46bbf..ec224298d 100644
--- a/src/d3d8/d3d8_device.cpp
+++ b/src/d3d8/d3d8_device.cpp
@@ -1168,7 +1168,7 @@ namespace dxvk {
           UINT             PrimitiveCount) {
     return GetD3D9()->DrawIndexedPrimitive(
       d3d9::D3DPRIMITIVETYPE(PrimitiveType),
-      m_baseVertexIndex, // set by SetIndices
+      static_cast<INT>(std::min(m_baseVertexIndex, static_cast<UINT>(INT_MAX))), // set by SetIndices
       MinVertexIndex,
       NumVertices,
       StartIndex,
@@ -1292,8 +1292,11 @@ namespace dxvk {
     if (unlikely(ShouldRecord()))
       return m_recorder->SetIndices(pIndexData, BaseVertexIndex);
 
+    if (unlikely(BaseVertexIndex > INT_MAX))
+      Logger::warn("BaseVertexIndex exceeds INT_MAX and will be clamped on use.");
+
     // used by DrawIndexedPrimitive
-    m_baseVertexIndex = static_cast<INT>(BaseVertexIndex);
+    m_baseVertexIndex = BaseVertexIndex;
 
     D3D8IndexBuffer* buffer = static_cast<D3D8IndexBuffer*>(pIndexData);
 
diff --git a/src/d3d8/d3d8_device.h b/src/d3d8/d3d8_device.h
index eb46b8dfc..437989728 100644
--- a/src/d3d8/d3d8_device.h
+++ b/src/d3d8/d3d8_device.h
@@ -432,7 +432,7 @@ namespace dxvk {
     std::array<D3D8VBO, d8caps::MAX_STREAMS>                           m_streams;
 
     Com<D3D8IndexBuffer, false>        m_indices;
-    INT                                m_baseVertexIndex = 0;
+    UINT                               m_baseVertexIndex = 0;
 
     // TODO: Which of these should be a private ref
     std::vector<Com<D3D8Surface, false>> m_backBuffers;